Marine Drugs

17 pages, 376 KiB

Open AccessReview

Potential Beneficial Effects of Sargassum spp. in Skin Aging

by Min-Kyeong Lee, Heeyeon Ryu, Ji Yun Lee, Hyeon Hak Jeong, Jiwon Baek, Ji Yun Van, Myeong-Jin Kim, Won-Kyo Jung and Bonggi Lee

Mar. Drugs 2022, 20(8), 540; https://doi.org/10.3390/md20080540 - 22 Aug 2022

Cited by 16 | Viewed by 5413

Abstract

Seaweeds are receiving much attention as a rich source of bioactive compounds with cosmeceutical potential. Recent studies have revealed that Sargassum spp., a genus of brown algae in the family Sargassaceae, has multiple functions in preventing and improving skin aging. Sargassum spp. contains [...] Read more.

Seaweeds are receiving much attention as a rich source of bioactive compounds with cosmeceutical potential. Recent studies have revealed that Sargassum spp., a genus of brown algae in the family Sargassaceae, has multiple functions in preventing and improving skin aging. Sargassum spp. contains many bioactive compounds, such as fucoidan, fucoxanthin, terpenoids, flavonoids, and meroterpenoids. These Sargassum spp. extracts and derivative compounds have excellent potential for skincare, as they exhibit skin health-promoting properties, including antioxidants, anti-inflammation, whitening, skin barrier repair, and moisturizing. Therefore, searching for bioactive compounds in marine resources such as Sargassum spp. could be an attractive approach to preventing and improving skin aging. The current review focused on the various biological abilities of Sargassum extracts or derived compounds for anti-skin aging. Full article

(This article belongs to the Special Issue High-Value Products from Seaweeds: Medical, Cosmetic, and Biotechnological Applications)

12 pages, 690 KiB

Open AccessReview

An Insight into the Role of Marine Biopolymer Alginate in Endodontics: A Review

by Galvin Sim Siang Lin, Chia Yee Cher, Yong Hong Goh, Daryl Zhun Kit Chan, Mohmed Isaqali Karobari, Josephine Chang Hui Lai and Tahir Yusuf Noorani

Mar. Drugs 2022, 20(8), 539; https://doi.org/10.3390/md20080539 - 22 Aug 2022

Cited by 5 | Viewed by 2533

Abstract

Alginate is a natural marine biopolymer that has been widely used in biomedical applications, but research on its use as an endodontic material is still sparse in the literature. This pioneer review aims to summarize the emerging roles of alginate and to outline [...] Read more.

Alginate is a natural marine biopolymer that has been widely used in biomedical applications, but research on its use as an endodontic material is still sparse in the literature. This pioneer review aims to summarize the emerging roles of alginate and to outline its prospective applications as a core biomaterial in endodontics. Ten electronic databases and five textbooks were used to perform a search of English-language literature on the use of alginate in endodontics published between January 1980 and June 2022. The risk of bias (RoB) of each included study was assessed using the Office of Health Assessment and Translation (OHAT) tool. Subsequently, studies were categorized into three tiers to represent the overall risk. Qualitative analysis was performed, and the articles were sorted into different thematic categories. An initial search yielded a total of 1491 articles, but only 13 articles were chosen. For most domains, all the studies were rated with ‘probably low’ or ‘definitely low’ RoB, except for domains 2 and 6. All included studies fall in the Tier 1 category and were either in vitro, in vivo, or ex vivo. Four thematic categories were identified: endodontic regeneration, intracanal medicament, filing material, and chelating agent. Based on the available evidence, alginate has emerged as a cell carrier and scaffold in regenerative endodontics, a microcapsule delivery system for intracanal medicaments, a chelating agent reinforcing material, and a root canal sealer. More well-designed experiments and clinical trials are needed to warrant the promising advent of this hydrogel-based biomaterial. Full article

(This article belongs to the Special Issue Alginate-Based Biomaterials and Drug Delivery)

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15 pages, 40120 KiB

Open AccessArticle

Synaptamide Modulates Astroglial Activity in Mild Traumatic Brain Injury

by Arina Ponomarenko, Anna Tyrtyshnaia, Darya Ivashkevich, Ekaterina Ermolenko, Inessa Dyuizen and Igor Manzhulo

Mar. Drugs 2022, 20(8), 538; https://doi.org/10.3390/md20080538 - 21 Aug 2022

Cited by 8 | Viewed by 2580

Abstract

At present, the study of the neurotropic activity of polyunsaturated fatty acid ethanolamides (N-acylethanolamines) is becoming increasingly important. N-docosahexaenoylethanolamine (synaptamide, DHEA) is a highly active metabolite of docosahexaenoic acid (DHA) with neuroprotective, synaptogenic, neuritogenic, and anti-inflammatory properties in the nervous system. Synaptamide tested [...] Read more.

At present, the study of the neurotropic activity of polyunsaturated fatty acid ethanolamides (N-acylethanolamines) is becoming increasingly important. N-docosahexaenoylethanolamine (synaptamide, DHEA) is a highly active metabolite of docosahexaenoic acid (DHA) with neuroprotective, synaptogenic, neuritogenic, and anti-inflammatory properties in the nervous system. Synaptamide tested in the present study was obtained using a chemical modification of DHA isolated from squid Berryteuthis magister liver. The results of this study demonstrate the effects of synaptamide on the astroglial response to injury in the acute (1 day) and chronic (7 days) phases of mild traumatic brain injury (mTBI) development. HPLC-MS study revealed several times increase of synaptamide concentration in the cerebral cortex and serum of experimental animals after subcutaneous administration (10 mg/kg/day). Using immunohistochemistry, it was shown that synaptamide regulates the activation of GFAP- and S100β-positive astroglia, reduce nNOS-positive immunostaining, and stimulates the secretion of neurotrophin BDNF. Dynamics of superoxide dismutase production in synaptamide treatment confirm the antioxidant efficacy of the test compound. We found a decrease in TBI biomarkers such as GFAP, S100β, and IL-6 in the blood serum of synaptamide-treated experimental animals using Western blot analysis. The results indicate the high therapeutic potential of synaptamide in reducing the severity of the brain damage consequences. Full article

(This article belongs to the Special Issue Marine Drugs Research in Russia)

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9 pages, 1074 KiB

Open AccessArticle

Halo- and Thiocarbazomycins from Coral- and Coral Reef Sands-Derived Actinomycetes

by Qiaoling Wu, Hongjie Zhu, Changli Sun, Le Zhou, Huimin Wang, Songbiao Shi, Xinpeng Tian and Jianhua Ju

Mar. Drugs 2022, 20(8), 537; https://doi.org/10.3390/md20080537 - 21 Aug 2022

Cited by 6 | Viewed by 2412

Abstract

Four actinomycete strains isolated from the coral Acropora austera and coral sand samples from the South China Sea, were found to produce a series of halogenated compounds baring similar ultraviolet absorption based on the analysis of HPLC and LC-MS. The production titers of [...] Read more.

Four actinomycete strains isolated from the coral Acropora austera and coral sand samples from the South China Sea, were found to produce a series of halogenated compounds baring similar ultraviolet absorption based on the analysis of HPLC and LC-MS. The production titers of halogenated compounds from Streptomyces diacarni SCSIO 64983 exceeded those of other similar strains leading us to focus on SCSIO 64983. Four new thiocarbazomycins A–B (1–2), chlocarbazomycin E (3), and brocarbazomycin A (4), together with three known chlocarbazomycins A–C (5–7) containing a carbazole core were identified, and their structures were determined using a combination of spectroscopic analysis including HRESIMS, 1D and 2D NMR. Structurally speaking, compounds 1 and 2 have the rare sulfur-containing carbazole nuclei, and 3 and 4 contain Cl and Br atoms, respectively. Although these compounds have not yet been found to have obvious biological activity, their discovery highlights the role of molecular libraries in subsequent drug discovery campaigns. Full article

(This article belongs to the Section Marine Biotechnology Related to Drug Discovery or Production)

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36 pages, 5897 KiB

Open AccessReview

Progress in Research of Chitosan Chemical Modification Technologies and Their Applications

by Qizhou Chen, Yi Qi, Yuwei Jiang, Weiyan Quan, Hui Luo, Kefeng Wu, Sidong Li and Qianqian Ouyang

Mar. Drugs 2022, 20(8), 536; https://doi.org/10.3390/md20080536 - 21 Aug 2022

Cited by 80 | Viewed by 6920

Abstract

Chitosan, which is derived from chitin, is the only known natural alkaline cationic polymer. Chitosan is a biological material that can significantly improve the living standard of the country. It has excellent properties such as good biodegradability, biocompatibility, and cell affinity, and has [...] Read more.

Chitosan, which is derived from chitin, is the only known natural alkaline cationic polymer. Chitosan is a biological material that can significantly improve the living standard of the country. It has excellent properties such as good biodegradability, biocompatibility, and cell affinity, and has excellent biological activities such as antibacterial, antioxidant, and hemostasis. In recent years, the demand has increased significantly in many fields and has huge application potential. Due to the poor water solubility of chitosan, its wide application is limited. However, chemical modification of the chitosan matrix structure can improve its solubility and biological activity, thereby expanding its application range. The review covers the period from 1996 to 2022 and was elaborated by searching Google Scholar, PubMed, Elsevier, ACS publications, MDPI, Web of Science, Springer, and other databases. The various chemical modification methods of chitosan and its main activities and application research progress were reviewed. In general, the modification of chitosan and the application of its derivatives have had great progress, such as various reactions, optimization of conditions, new synthetic routes, and synthesis of various novel multifunctional chitosan derivatives. The chemical properties of modified chitosan are usually better than those of unmodified chitosan, so chitosan derivatives have been widely used and have more promising prospects. This paper aims to explore the latest progress in chitosan chemical modification technologies and analyze the application of chitosan and its derivatives in various fields, including pharmaceuticals and textiles, thus providing a basis for further development and utilization of chitosan. Full article

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35 pages, 14826 KiB

Open AccessReview

Unusual Secondary Metabolites from the Mangrove Ecosystems: Structures, Bioactivities, Chemical, and Bio-Syntheses

by Meng-Jun Wu, Baofu Xu and Yue-Wei Guo

Mar. Drugs 2022, 20(8), 535; https://doi.org/10.3390/md20080535 - 20 Aug 2022

Cited by 14 | Viewed by 4032

Abstract

Mangrove ecosystems are widely distributed in the intertidal zone of tropical and subtropical estuaries or coasts, containing abundant biological communities, for example, mangrove plants and diverse groups of microorganisms, featuring various bioactive secondary metabolites. We surveyed the literature from 2010 to 2022, resulting [...] Read more.

Mangrove ecosystems are widely distributed in the intertidal zone of tropical and subtropical estuaries or coasts, containing abundant biological communities, for example, mangrove plants and diverse groups of microorganisms, featuring various bioactive secondary metabolites. We surveyed the literature from 2010 to 2022, resulting in a collection of 134 secondary metabolites, and classified them into two major families in terms of the biological sources and 15 subfamilies according to the chemical structures. To highlight the structural diversity and bioactivities of the mangrove ecosystem-associated secondary metabolites, we presented the chemical structures, bioactivities, biosynthesis, and chemical syntheses. Full article

(This article belongs to the Special Issue Bio-Active Products from Mangrove Ecosystems)

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20 pages, 4039 KiB

Open AccessArticle

Carrageenophyte Kappaphycus malesianus Inhibits Microglia-Mediated Neuroinflammation via Suppression of AKT/NF-κB and ERK Signaling Pathways

by Nicole Jean-Yean Lai, Ee-Ling Ngu, Jun-Rui Pang, Kah-Hui Wong, Chrismawan Ardianto, Long Chiau Ming, Siew-Huah Lim, Shweta Gangasa Walvekar, Ayaz Anwar and Yoon-Yen Yow

Mar. Drugs 2022, 20(8), 534; https://doi.org/10.3390/md20080534 - 20 Aug 2022

Cited by 8 | Viewed by 3047

Abstract

Neuroinflammation is an inflammatory response in any part of the central nervous system triggered by the activation of microglia and astrocytes to produce proinflammatory cytokines in the brain. However, overproduction of proinflammatory cytokines further contributes to the development of neurodegenerative disorders. Red seaweed, [...] Read more.

Neuroinflammation is an inflammatory response in any part of the central nervous system triggered by the activation of microglia and astrocytes to produce proinflammatory cytokines in the brain. However, overproduction of proinflammatory cytokines further contributes to the development of neurodegenerative disorders. Red seaweed, Kappaphycus malesianus, is a predominant carrageenophyte commercially cultivated in Semporna, Sabah, Malaysia. It is an important source of raw material for kappa-carrageenan productions in the food, pharmaceutical and cosmetics industries. However, no studies have been conducted focusing on the antineuroinflammatory effects of K. malesianus. The aim of the present study was to investigate the effect of the antineuroinflammatory activity of K. malesianus extracts (ethyl acetate, ethanol and methanol) on lipopolysaccharide-stimulated BV2 microglia and the underlying mechanisms involved in the regulation of neuroinflammatory pathways. Extract with the most promising antineuroinflammatory activity was analyzed using liquid chromatography-mass spectrometry (LC-MS). Our results show that methanol extract has a convincing antineuroinflammatory effect by suppressing both AKT/NF-κB and ERK signaling pathways to inhibit the expression of all proinflammatory cytokines without causing a cytotoxicity effect. LC-MS analysis of methanol extract revealed two compounds: prosopinine and eplerenone. Our findings indicated that metabolites of K. malesianus are potent antineuroinflammatory agents with respect to prevention of neurological disorders. Full article

(This article belongs to the Special Issue Novel Applications and Technologies for the Industrial Exploitation of Algal Derived Marine Bioactives as Nutraceuticals or Pharmaceuticals 2.0)

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20 pages, 3600 KiB

Open AccessArticle

Structural and Biochemical Analysis Reveals Catalytic Mechanism of Fucoidan Lyase from Flavobacterium sp. SA-0082

by Juanjuan Wang, Zebin Liu, Xiaowei Pan, Ning Wang, Legong Li, Yuguang Du, Jianjun Li and Mei Li

Mar. Drugs 2022, 20(8), 533; https://doi.org/10.3390/md20080533 - 20 Aug 2022

Cited by 5 | Viewed by 2449

Abstract

Fucoidans represent a type of polyanionic fucose-containing sulfated polysaccharides (FCSPs) that are cleaved by fucoidan-degrading enzymes, producing low-molecular-weight fucoidans with multiple biological activities suitable for pharmacological use. Most of the reported fucoidan-degrading enzymes are glycoside hydrolases, which have been well studied for their [...] Read more.

Fucoidans represent a type of polyanionic fucose-containing sulfated polysaccharides (FCSPs) that are cleaved by fucoidan-degrading enzymes, producing low-molecular-weight fucoidans with multiple biological activities suitable for pharmacological use. Most of the reported fucoidan-degrading enzymes are glycoside hydrolases, which have been well studied for their structures and catalytic mechanisms. Little is known, however, about the rarer fucoidan lyases, primarily due to the lack of structural information. FdlA from Flavobacterium sp. SA-0082 is an endo-type fucoidan-degrading enzyme that cleaves the sulfated fuco-glucuronomannan (SFGM) through a lytic mechanism. Here, we report nine crystal structures of the catalytic N-terminal domain of FdlA (FdlA-NTD), in both its wild type (WT) and mutant forms, at resolutions ranging from 1.30 to 2.25 Å. We show that the FdlA-NTD adopts a right-handed parallel β-helix fold, and possesses a substrate binding site composed of a long groove and a unique alkaline pocket. Our structural, biochemical, and enzymological analyses strongly suggest that FdlA-NTD utilizes catalytic residues different from other β-helix polysaccharide lyases, potentially representing a novel polysaccharide lyase family. Full article

(This article belongs to the Special Issue Advances in Oligosaccharides and Polysaccharide Modifications in Marine Bioresources)

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19 pages, 2356 KiB

Open AccessArticle

Discovery of Ircinianin Lactones B and C—Two New Cyclic Sesterterpenes from the Marine Sponge Ircinia wistarii

by Thomas Majer, Keshab Bhattarai, Jan Straetener, Justus Pohlmann, Patrick Cahill, Markus O. Zimmermann, Marc P. Hübner, Marcel Kaiser, Johan Svenson, Michael Schindler, Heike Brötz-Oesterhelt, Frank M. Boeckler and Harald Gross

Mar. Drugs 2022, 20(8), 532; https://doi.org/10.3390/md20080532 - 19 Aug 2022

Cited by 5 | Viewed by 3006

Abstract

Two new ircinianin-type sesterterpenoids, ircinianin lactone B and ircinianin lactone C (7 and 8), together with five known entities from the ircinianin compound family (1, 3–6) were isolated from the marine sponge Ircinia wistarii. Ircinianin [...] Read more.

Two new ircinianin-type sesterterpenoids, ircinianin lactone B and ircinianin lactone C (7 and 8), together with five known entities from the ircinianin compound family (1, 3–6) were isolated from the marine sponge Ircinia wistarii. Ircinianin lactones B and C (7 and 8) represent new ircinianin terpenoids with a modified oxidation pattern. Despite their labile nature, the structures could be established using a combination of spectroscopic data, including HRESIMS and 1D/2D NMR techniques, as well as computational chemistry and quantum-mechanical calculations. In a broad screening approach for biological activity, the class-defining compound ircinianin (1) showed moderate antiprotozoal activity against Plasmodium falciparum (IC₅₀ 25.4 μM) and Leishmania donovani (IC₅₀ 16.6 μM). Full article

(This article belongs to the Section Structural Studies on Marine Natural Products)

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20 pages, 7849 KiB

Open AccessReview

Conotoxin Patenting Trends in Academia and Industry

by Noemi Sanchez-Campos, Johanna Bernaldez-Sarabia and Alexei F. Licea-Navarro

Mar. Drugs 2022, 20(8), 531; https://doi.org/10.3390/md20080531 - 19 Aug 2022

Cited by 5 | Viewed by 3386

Abstract

Sea snails of the genus Conus produce toxins that have been the subjects of numerous studies, projects, publications, and patents over the years. Since Conus toxins were discovered in the 1960s, their biological activity has been thought to have high pharmaceutical potential that [...] Read more.

Sea snails of the genus Conus produce toxins that have been the subjects of numerous studies, projects, publications, and patents over the years. Since Conus toxins were discovered in the 1960s, their biological activity has been thought to have high pharmaceutical potential that could be explored beyond the limits of academic laboratories. We reviewed 224 patent documents related to conotoxins and conopeptides globally to determine the course that innovation and development has taken over the years, their primary applications, the technological trends over the last six years, and the leaders in the field, since the only previous patent review was performed in 2015 and focused in USA valid patents. In addition, we explored which countries/territories protect their inventions and patents and the most relevant collaborations among assignees. We also evaluated whether academia or pharmaceutical companies are the future of conotoxin research. We concluded that the 224 conotoxin patents reviewed in this study have more academic value than industrial value, which was noted by the number of active patents that have not yet been licensed and the contributions to medical research, especially as tools to study neuropathic pain, inflammation, immunology, drug design, receptor binding sites, cancer, neurotransmission, epilepsy, peptide biosynthesis, and depression. The aim of this review is to provide an overview of the current state of conotoxin patents, their main applications, and success based on the number of licensing and products in the market. Full article

(This article belongs to the Special Issue Conotoxins II)

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19 pages, 5609 KiB

Open AccessArticle

Application of Green Chiral Chromatography in Enantioseparation of Newly Synthesized Racemic Marinoepoxides

by Anđela Buljan and Marin Roje

Mar. Drugs 2022, 20(8), 530; https://doi.org/10.3390/md20080530 - 19 Aug 2022

Cited by 4 | Viewed by 1972

Abstract

Enantioseparation of the newly synthesized series of novel quinoline-2(1H)-one epoxide structures rac-6a–c and rac-8a–c, named marinoepoxides, is described. Marinoepoxide rac-6a, the key intermediate in the total synthesis of natural [...] Read more.

Enantioseparation of the newly synthesized series of novel quinoline-2(1H)-one epoxide structures rac-6a–c and rac-8a–c, named marinoepoxides, is described. Marinoepoxide rac-6a, the key intermediate in the total synthesis of natural products marinoaziridines A and B, as well as their structural analogues, was synthesized by addition of the achiral ylide generated in situ from the sulfonium salt 5 or 7, to the carbon-oxygen double bond of the corresponding quinoline-2(1H)-one-4-carbaldehyde 4a–c in good yield. Separation of enantiomers of (±)-2,3,3-trisubstituted marinoepoxides rac-6a–c and (±)-trans-2,3-disubstituted marinoepoxides rac-8a–c was studied using two immobilized polysaccharide type chiral stationary phases (CSPs); tris-(3,5-dichlorophenylcarbamoyl)cellulose stationary phase (CHIRAL ART Cellulose-SC) and tris-(3,5-dimethylphenylcarbamoyl)amylose stationary phase (CHIRAL ART Amylose-SA). Enantioseparation conditions were explored by high-performance liquid chromatography (HPLC) using dimethyl carbonate/alcohol mixtures and n-hexane/ethanol (80/20, v/v) as mobile phase, and by supercritical fluid chromatography (SFC) using CO₂/alcohol mixtures as mobile phase. In all examined racemates, enantioseparation was successfully achieved, but its efficiency largely depended on the structure of chiral selector and type/composition of the mobile phase. Full article

(This article belongs to the Special Issue Green Chemistry in Marine Natural Product Research)

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9 pages, 1587 KiB

Open AccessArticle

Aromatic Polyketides from the Deep-Sea Cold-Seep Mussel Associated Endozoic Fungus Talaromyces minioluteus CS-138

by Qi Song, Sui-Qun Yang, Xiao-Ming Li, Xue-Yi Hu, Xin Li and Bin-Gui Wang

Mar. Drugs 2022, 20(8), 529; https://doi.org/10.3390/md20080529 - 18 Aug 2022

Cited by 17 | Viewed by 2361

Abstract

Five new aromatic polyketides, including a unique benzofuran derivative, talarominine A (1), and four chromone analogs talamins A–D (2–5), along with one known related metabolite, 5-hydroxy-7-methoxy-2,3-dimethylchromone (6), were isolated and identified from the Talaromyces minioluteus [...] Read more.

Five new aromatic polyketides, including a unique benzofuran derivative, talarominine A (1), and four chromone analogs talamins A–D (2–5), along with one known related metabolite, 5-hydroxy-7-methoxy-2,3-dimethylchromone (6), were isolated and identified from the Talaromyces minioluteus CS-138, an endozoic fungus obtained from the deep-sea cold seep mussel Gigantidas platifrons. Their chemical structures were elucidated by detailed analysis of their NMR spectra, HRESIMS and X-ray crystallographic data, and by comparison with literature data as well. The antibacterial and DPPH scavenging activities of compounds 1–6 were evaluated. Compounds 1–3 showed inhibitory activity against some of the tested bacteria whereas compounds 2 and 5 showed potent DPPH radical scavenging activities, which were better than that of the positive control butylated hydroxytoluene (BHT). This work is likely the first report on marine natural products of mussel-derived fungus living in cold seep environments. Full article

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40 pages, 8288 KiB

Open AccessReview

Marine Natural Products in Clinical Use

by Neshatul Haque, Sana Parveen, Tingting Tang, Jiaen Wei and Zunnan Huang

Mar. Drugs 2022, 20(8), 528; https://doi.org/10.3390/md20080528 - 18 Aug 2022

Cited by 66 | Viewed by 7848 | Correction

Abstract

Marine natural products are potent and promising sources of drugs among other natural products of plant, animal, and microbial origin. To date, 20 drugs from marine sources are in clinical use. Most approved marine compounds are antineoplastic, but some are also used for [...] Read more.

Marine natural products are potent and promising sources of drugs among other natural products of plant, animal, and microbial origin. To date, 20 drugs from marine sources are in clinical use. Most approved marine compounds are antineoplastic, but some are also used for chronic neuropathic pain, for heparin overdosage, as haptens and vaccine carriers, and for omega-3 fatty-acid supplementation in the diet. Marine drugs have diverse structural characteristics and mechanisms of action. A considerable increase in the number of marine drugs approved for clinical use has occurred in the past few decades, which may be attributed to increasing research on marine compounds in laboratories across the world. In the present manuscript, we comprehensively studied all marine drugs that have been successfully used in the clinic. Researchers and clinicians are hopeful to discover many more drugs, as a large number of marine natural compounds are being investigated in preclinical and clinical studies. Full article

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30 pages, 1813 KiB

Open AccessReview

Marine-Bioinspired Nanoparticles as Potential Drugs for Multiple Biological Roles

by Geum-Jae Jeong, Sohail Khan, Nazia Tabassum, Fazlurrahman Khan and Young-Mog Kim

Mar. Drugs 2022, 20(8), 527; https://doi.org/10.3390/md20080527 - 18 Aug 2022

Cited by 20 | Viewed by 4626

Abstract

The increased interest in nanomedicine and its applicability for a wide range of biological functions demands the search for raw materials to create nanomaterials. Recent trends have focused on the use of green chemistry to synthesize metal and metal-oxide nanoparticles. Bioactive chemicals have [...] Read more.

The increased interest in nanomedicine and its applicability for a wide range of biological functions demands the search for raw materials to create nanomaterials. Recent trends have focused on the use of green chemistry to synthesize metal and metal-oxide nanoparticles. Bioactive chemicals have been found in a variety of marine organisms, including invertebrates, marine mammals, fish, algae, plankton, fungi, and bacteria. These marine-derived active chemicals have been widely used for various biological properties. Marine-derived materials, either whole extracts or pure components, are employed in the synthesis of nanoparticles due to their ease of availability, low cost of production, biocompatibility, and low cytotoxicity toward eukaryotic cells. These marine-derived nanomaterials have been employed to treat infectious diseases caused by bacteria, fungi, and viruses as well as treat non-infectious diseases, such as tumors, cancer, inflammatory responses, and diabetes, and support wound healing. Furthermore, several polymeric materials derived from the marine, such as chitosan and alginate, are exploited as nanocarriers in drug delivery. Moreover, a variety of pure bioactive compounds have been loaded onto polymeric nanocarriers and employed to treat infectious and non-infectious diseases. The current review is focused on a thorough overview of nanoparticle synthesis and its biological applications made from their entire extracts or pure chemicals derived from marine sources. Full article

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14 pages, 3171 KiB

Open AccessArticle

Immunosuppressive Cytochalasins from the Mangrove Endophytic Fungus Phomopsis asparagi DHS-48

by Zhao Feng, Xuexia Zhang, Jingwan Wu, Chengwen Wei, Ting Feng, Dongdong Zhou, Zhenchang Wen and Jing Xu

Mar. Drugs 2022, 20(8), 526; https://doi.org/10.3390/md20080526 - 18 Aug 2022

Cited by 12 | Viewed by 2270

Abstract

Three new cytochalasins, phomoparagins A-C (1–3), along with five known analogs (4–8), were isolated from Phomopsis asparagi DHS-48, a mangrove-derived endophytic fungus. Their structures, including their absolute configurations, were elucidated using a combination of detailed [...] Read more.

Three new cytochalasins, phomoparagins A-C (1–3), along with five known analogs (4–8), were isolated from Phomopsis asparagi DHS-48, a mangrove-derived endophytic fungus. Their structures, including their absolute configurations, were elucidated using a combination of detailed HRESIMS, NMR, and ECD techniques. Notably, 1 possessed an unprecedented 5/6/5/8/5-fused pentacyclic skeleton. These compounds were tested for their inhibitory activity against concanavalin A (ConA)/lipopolysaccharide (LPS)-induced spleen lymphocyte proliferation and calcineurin (CN) enzyme. Several metabolites (2 and 4–6) exhibited fascinating inhibitory activities with a relatively low toxicity. Furthermore, 2 was demonstrated to inhibit ConA-stimulated activation of NFAT1 dephosphorylation and block NFAT1 translocation in vitro, subsequently inhibiting the transcription of interleukin-2 (IL-2). Our results provide evidence that 2 may, at least partially, suppress the activation of spleen lymphocytes via the CN/NFAT signaling pathway, highlighting that it could serve as an effective immunosuppressant that is noncytotoxic and natural. Full article

(This article belongs to the Special Issue Bio-Active Products from Mangrove Ecosystems)

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15 pages, 2915 KiB

Open AccessArticle

Utilizing Fish Skin of Ikan Belida (Notopterus lopis) as a Source of Collagen: Production and Rheology Properties

by Tzen T. Heng, Jing Y. Tey, Kean S. Soon and Kwan K. Woo

Mar. Drugs 2022, 20(8), 525; https://doi.org/10.3390/md20080525 - 18 Aug 2022

Cited by 1 | Viewed by 2474

Abstract

Collagen hydrogels have been extensively applied in biomedical applications. However, their mechanical properties are insufficient for such applications. Our previous study showed improved mechanical properties when collagen was blended with alginate. The current study aims to analyze the physico-chemical properties of collagen-alginate (CA) [...] Read more.

Collagen hydrogels have been extensively applied in biomedical applications. However, their mechanical properties are insufficient for such applications. Our previous study showed improved mechanical properties when collagen was blended with alginate. The current study aims to analyze the physico-chemical properties of collagen-alginate (CA) films such as swelling, porosity, denaturation temperature (T_d), and rheology properties. Collagen was prepared from discarded fish skin of Ikan Belida (Notopterus lopis) that was derived from fish ball manufacturing industries and cross-linked with alginate from brown seaweed (Sargasum polycystum) of a local species as a means to benefit the downstream production of marine industries. CA hydrogels were fabricated with ratios (v/v) of 1:1, 1:4, 3:7, 4:1, and 7:3 respectively. FTIR spectrums of CA film showed an Amide I shift of 1636.12 cm⁻¹ to 1634.64 cm⁻¹, indicating collagen-alginate interactions. SEM images of CA films show a porous structure that varied from pure collagen. DSC analysis shows T_d was improved from 61.26 °C (collagen) to 83.11 °C (CA 3:7). CA 4:1 swelled nearly 800% after 48 h, correlated with the of hydrogels porosity. Most CA demonstrated visco-elastic solid characteristics with greater storage modulus (G′) than lost modulus (G″). Shear thinning and non-Newtonian behavior was observed in CA with 0.4% to 1.0% (w/v) CaCl₂. CA hydrogels that were derived from discarded materials shows promising potential to serve as a wound dressing or ink for bio printing in the future. Full article

(This article belongs to the Section Biomaterials of Marine Origin)

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31 pages, 11939 KiB

Open AccessReview

Archaea Carotenoids: Natural Pigments with Unexplored Innovative Potential

by Antoine Grivard, Isabelle Goubet, Luiz Miranda de Souza Duarte Filho, Valérie Thiéry, Sylvie Chevalier, Raimundo Gonçalves de Oliveira-Junior, Noureddine El Aouad, Jackson Roberto Guedes da Silva Almeida, Przemysław Sitarek, Lucindo José Quintans-Junior, Raphaël Grougnet, Hélène Agogué and Laurent Picot

Mar. Drugs 2022, 20(8), 524; https://doi.org/10.3390/md20080524 - 17 Aug 2022

Cited by 27 | Viewed by 4323

Abstract

For more than 40 years, marine microorganisms have raised great interest because of their major ecological function and their numerous applications for biotechnology and pharmacology. Particularly, Archaea represent a resource of great potential for the identification of new metabolites because of their adaptation [...] Read more.

For more than 40 years, marine microorganisms have raised great interest because of their major ecological function and their numerous applications for biotechnology and pharmacology. Particularly, Archaea represent a resource of great potential for the identification of new metabolites because of their adaptation to extreme environmental conditions and their original metabolic pathways, allowing the synthesis of unique biomolecules. Studies on archaeal carotenoids are still relatively scarce and only a few works have focused on their industrial scale production and their biotechnological and pharmacological properties, while the societal demand for these bioactive pigments is growing. This article aims to provide a comprehensive review of the current knowledge on carotenoid metabolism in Archaea and the potential applications of these pigments in biotechnology and medicine. After reviewing the ecology and classification of these microorganisms, as well as their unique cellular and biochemical characteristics, this paper highlights the most recent data concerning carotenoid metabolism in Archaea, the biological properties of these pigments, and biotechnological considerations for their production at industrial scale. Full article

(This article belongs to the Special Issue Marine Pigments)

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12 pages, 2721 KiB

Open AccessArticle

Identification of PKS-NRPS Hybrid Metabolites in Marine-Derived Penicillium oxalicum

by Hongcheng Li, Wei Zhang, Xuan Zhang, Shen Tang, Ping Men, Mengyi Xiong, Zhimin Li, Yongyu Zhang, Xuenian Huang and Xuefeng Lu

Mar. Drugs 2022, 20(8), 523; https://doi.org/10.3390/md20080523 - 16 Aug 2022

Cited by 2 | Viewed by 2898

Abstract

Filamentous fungi are abundant resources of bioactive natural products. Here, 151 marine-derived fungi were collected from the north Yellow Sea and identified by an internal transcribed spacer (ITS) sequence. The crude extracts of all strains were evaluated for their antimicrobial activities and analyzed [...] Read more.

Filamentous fungi are abundant resources of bioactive natural products. Here, 151 marine-derived fungi were collected from the north Yellow Sea and identified by an internal transcribed spacer (ITS) sequence. The crude extracts of all strains were evaluated for their antimicrobial activities and analyzed by HPLC fingerprint. Based on these, strain Penicillium oxalicum MEFC104 was selected for further investigation. Two new polyketide–amino acid hybrid compounds with feature structures of tetramic acid, oxopyrrolidine A and B, were isolated. Their planner structures were assigned by HRESIMS and 1D/2D NMR experiments. The absolute configurations were determined by modified Mosher’s method, J-based configuration analysis, and ECD calculations. Furthermore, the biosynthetic pathway was identified by bioinformatic analysis and gene-deletion experiments. This study established a link between oxopyrrolidines and the corresponding biosynthesis genes in P. oxalicum. Full article

(This article belongs to the Special Issue Bioactive Substances from Marine Sediments, Invertebrates and Algae Derived Fungi)

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25 pages, 2310 KiB

Open AccessReview

Mucoadhesive Marine Polysaccharides

by Irina M. Yermak, Viktoriya N. Davydova and Aleksandra V. Volod’ko

Mar. Drugs 2022, 20(8), 522; https://doi.org/10.3390/md20080522 - 15 Aug 2022

Cited by 36 | Viewed by 6033

Abstract

Mucoadhesive polymers are of growing interest in the field of drug delivery due to their ability to interact with the body’s mucosa and increase the effectiveness of the drug. Excellent mucoadhesive performance is typically observed for polymers possessing charged groups or non-ionic functional [...] Read more.

Mucoadhesive polymers are of growing interest in the field of drug delivery due to their ability to interact with the body’s mucosa and increase the effectiveness of the drug. Excellent mucoadhesive performance is typically observed for polymers possessing charged groups or non-ionic functional groups capable of forming hydrogen bonds and electrostatic interactions with mucosal surfaces. Among mucoadhesive polymers, marine carbohydrate biopolymers have been attracting attention due to their biocompatibility and biodegradability, sample functional groups, strong water absorption and favorable physiochemical properties. Despite the large number of works devoted to mucoadhesive polymers, there are very few systematic studies on the influence of structural features of marine polysaccharides on mucoadhesive interactions. The purpose of this review is to characterize the mucoadhesive properties of marine carbohydrates with a focus on chitosan, carrageenan, alginate and their use in designing drug delivery systems. A wide variety of methods which have been used to characterize mucoadhesive properties of marine polysaccharides are presented in this review. Mucoadhesive drug delivery systems based on such polysaccharides are characterized by simplicity and ease of use in the form of tablets, gels and films through oral, buccal, transbuccal and local routes of administration. Full article

(This article belongs to the Special Issue Marine Carbohydrate-Based Compounds with Medicinal Properties II)

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22 pages, 2374 KiB

Open AccessReview

Antioxidant Potential of Sea Cucumbers and Their Beneficial Effects on Human Health

by Abul Hossain, Deepika Dave and Fereidoon Shahidi

Mar. Drugs 2022, 20(8), 521; https://doi.org/10.3390/md20080521 - 15 Aug 2022

Cited by 39 | Viewed by 6026

Abstract

Sea cucumbers are considered a luxury food item and used locally in traditional medication due to their impressive nutritional profile and curative effects. Sea cucumbers contain a wide range of bioactive compounds, namely phenolics, polysaccharides, proteins (collagen and peptides), carotenoids, and saponins, demonstrating [...] Read more.

Sea cucumbers are considered a luxury food item and used locally in traditional medication due to their impressive nutritional profile and curative effects. Sea cucumbers contain a wide range of bioactive compounds, namely phenolics, polysaccharides, proteins (collagen and peptides), carotenoids, and saponins, demonstrating strong antioxidant and other activities. In particular, phenolic compounds, mainly phenolic acids and flavonoids, are abundant in this marine invertebrate and exhibit antioxidant activity. Protein hydrolysates and peptides obtained from sea cucumbers exhibit antioxidant potential, mainly dependent on the amino acid compositions and sequences as well as molecular weight, displayed for those of ≤20 kDa. Moreover, the antioxidant activity of sea cucumber polysaccharides, including fucosylated chondroitin sulfate and fucan, is a combination of numerous factors and is mostly associated with molecular weight, degree of sulfation, and type of major sugars. However, the activity of these bioactive compounds typically depends on the sea cucumber species, harvesting location, food habit, body part, and processing methods employed. This review summarizes the antioxidant activity of bioactive compounds obtained from sea cucumbers and their by-products for the first time. The mechanism of actions, chemical structures, and factors affecting the antioxidant activity are also discussed, along with the associated health benefits. Full article

(This article belongs to the Special Issue Bioactive Compounds from Sea Cucumbers)

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18 pages, 1355 KiB

Open AccessArticle

The Discovery, Enzymatic Characterization and Functional Analysis of a Newly Isolated Chitinase from Marine-Derived Fungus Aspergillus fumigatus df347

by Ya-Li Wu, Sheng Wang, Deng-Feng Yang, Li-Yan Yang, Qing-Yan Wang, Jun Yu, Nan Li and Li-Xia Pan

Mar. Drugs 2022, 20(8), 520; https://doi.org/10.3390/md20080520 - 15 Aug 2022

Cited by 15 | Viewed by 2508

Abstract

In order to discover a broad-specificity and high stability chitinase, a marine fungus, Aspergillus fumigatus df347, was identified in the sediments of mangrove wetlands in Qinzhou Bay, China. The chitinase gene (AfChi28) from A. fumigatus df347 was cloned and heterologously expressed [...] Read more.

In order to discover a broad-specificity and high stability chitinase, a marine fungus, Aspergillus fumigatus df347, was identified in the sediments of mangrove wetlands in Qinzhou Bay, China. The chitinase gene (AfChi28) from A. fumigatus df347 was cloned and heterologously expressed in Escherichia coli, and the recombinant enzyme AfChi28 was purified and characterized. AfChi28 is an acido-halotolerant- and temperature-resistant bifunctional enzyme with both endo- and exo-cleavage functions. Its enzymatic products are mainly GlcNAc, (GlcNAc)₂, (GlcNAc)₃ and (GlcNAc)₄. Na⁺, Mg²⁺, K⁺, Ca²⁺ and Tris at a concentration of 50 mM had a strong stimulatory effect on AfChi28. The crude enzyme and pure enzyme exhibited the highest specific activity of 0.737 mU/mg and 52.414 mU/mg towards colloidal chitin. The DxDxE motif at the end of strand β5 and with Glu154 as the catalytic residue was verified by the AlphaFold2 prediction and sequence alignment of homologous proteins. Moreover, the results of molecular docking showed that molecular modeling of chitohexaose was shown to bind to AfChi28 in subsites −4 to +2 in the deep groove substrate-binding pocket. This study demonstrates that AfChi28 is a promising chitinase for the preparation of desirable chitin oligosaccharides, and provides a foundation for elucidating the catalytic mechanism of chitinases from marine fungi. Full article

(This article belongs to the Special Issue Application of Marine Chitin and Chitosan II)

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18 pages, 3355 KiB

Open AccessArticle

Antibacterial and Anticancer Activities of Pleurocidin-Amide, a Potent Marine Antimicrobial Peptide Derived from Winter Flounder, Pleuronectes americanus

by Hui-Chen Hsu, Ming-Hsin Chen, Ming-Lung Yeh and Wei-Jung Chen

Mar. Drugs 2022, 20(8), 519; https://doi.org/10.3390/md20080519 - 14 Aug 2022

Cited by 8 | Viewed by 2522

Abstract

The extensive use of conventional antibiotics has led to the growing emergence of many resistant strains of pathogenic bacteria. Evidence suggests that cationic antimicrobial peptides (AMPs) have the greatest potential to serve as traditional antibiotic substitutes. Recent studies have also reported that certain [...] Read more.

The extensive use of conventional antibiotics has led to the growing emergence of many resistant strains of pathogenic bacteria. Evidence suggests that cationic antimicrobial peptides (AMPs) have the greatest potential to serve as traditional antibiotic substitutes. Recent studies have also reported that certain AMPs have selective toxicity toward various types of cancer cells. The electrostatic attraction between the negatively charged membrane components and AMPs is believed to play a crucial role in the disruption of bacterial and cancer cell membranes. In the current study, we used a potent AMP called Pleurocidin (Ple) derived from winter flounder Pleuronectes americanus and its C-terminal-amidated derivative Pleurocidin-amide (Ple-a), and evaluated their antibacterial and anticancer activities. Our results indicated that both Ple and Ple-a exhibited significant antibacterial activity against a broad spectrum of Gram-positive and Gram-negative bacteria, especially marine pathogens, with MIC values ranging from 0.25 to 32 μg/mL. These peptides are also potent against several multidrug-resistant (MDR) bacterial strains, with MIC values ranging from 2 to 256 μg/mL. When used in combination with certain antibiotics, they exhibited a synergistic effect against MDR E. coli. Ple and Ple-a also showed notable cytotoxicity toward various cancer cell lines, with IC₅₀ values ranging from 11 to 340 μM, while normal mouse fibroblast 3T3 cells were less susceptible to these peptides. Ple-a was then selected to study its anticancer mechanism toward A549 human lung adenocarcinoma cells. Western blot analysis and confocal microscopy showed that Ple-a could inhibit autophagy of A549 cells, and induce apoptosis 48 h after treatment. Our findings provided support for the future application of Ple-a as potential therapeutic agent for bacterial infections and cancer treatment. Full article

(This article belongs to the Special Issue Marine Bioactive Peptides: Structure, Function, and Therapeutic Potential - III)

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13 pages, 2852 KiB

Open AccessArticle

Mixotrophic Cultivation Optimization of Microalga Euglena pisciformis AEW501 for Paramylon Production

by Panpan Fan, Yanhua Li, Rui Deng, Feixia Zhu, Fengfeng Cheng, Gaofei Song, Wujuan Mi and Yonghong Bi

Mar. Drugs 2022, 20(8), 518; https://doi.org/10.3390/md20080518 - 14 Aug 2022

Cited by 6 | Viewed by 2863

Abstract

Euglena, a flagellated unicellular protist, has recently received widespread attention for various high-value metabolites, especially paramylon, which was only found in Euglenophyta. The limited species and low biomass of Euglena has impeded paramylon exploitation and utilization. This study established an optimal cultivation [...] Read more.

Euglena, a flagellated unicellular protist, has recently received widespread attention for various high-value metabolites, especially paramylon, which was only found in Euglenophyta. The limited species and low biomass of Euglena has impeded paramylon exploitation and utilization. This study established an optimal cultivation method of Euglena pisciformis AEW501 for paramylon production under mixotrophic cultivation. The results showed that the optimum mixotrophic conditions were 20 °C, pH 7.0, and 63 μmol photons m⁻²∙s⁻¹, and the concentrations of sodium acetate and diammonium hydrogen phosphate were 0.98 g L⁻¹ and 0.79 g L⁻¹, respectively. The maximal biomass and paramylon content were 0.72 g L⁻¹ and 71.39% of dry weight. The algal powder contained more than 16 amino acids, 6 vitamins, and 10 unsaturated fatty acids under the optimal cultivation. E. pisciformis paramylon was pure β-1,3-glucan-type polysaccharide (the purity was up to 99.13 ± 0.61%) composed of linear glucose chains linked together by β-1,3-glycosidic bonds. These findings present a valuable basis for the industrial exploitation of paramylon with E. pisciformis AEW501. Full article

(This article belongs to the Special Issue Marine Microalgal Functional Foods)

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19 pages, 2429 KiB

Open AccessArticle

Novel β-Hairpin Peptide from Marine Polychaeta with a High Efficacy against Gram-Negative Pathogens

by Victoria N. Safronova, Ilia A. Bolosov, Roman N. Kruglikov, Olga V. Korobova, Eugenia S. Pereskokova, Alexander I. Borzilov, Pavel V. Panteleev and Tatiana V. Ovchinnikova

Mar. Drugs 2022, 20(8), 517; https://doi.org/10.3390/md20080517 - 13 Aug 2022

Cited by 11 | Viewed by 2378

Abstract

In recent years, new antibiotics targeting multidrug resistant Gram-negative bacteria have become urgently needed. Therefore, antimicrobial peptides are considered to be a novel perspective class of antibacterial agents. In this study, a panel of novel BRICHOS-related β-hairpin antimicrobial peptides were identified in transcriptomes [...] Read more.

In recent years, new antibiotics targeting multidrug resistant Gram-negative bacteria have become urgently needed. Therefore, antimicrobial peptides are considered to be a novel perspective class of antibacterial agents. In this study, a panel of novel BRICHOS-related β-hairpin antimicrobial peptides were identified in transcriptomes of marine polychaeta species. Two of them—abarenicin from Abarenicola pacifica and UuBRI-21 from Urechis unicinctus—possess strong antibacterial potential in vitro against a wide panel of Gram-negative bacteria including drug-resistant strains. Mechanism of action assays demonstrate that peptides disrupt bacterial and mammalian membrane integrity. Considering the stronger antibacterial potential and a low ability of abarenicin to be bound by components of serum, this peptide was selected for further modification. We conducted an alanine and arginine scanning of abarenicin by replacing individual amino acids and modulating hydrophobicity so as to improve its antibacterial potency and membrane selectivity. This design approach allowed us to obtain the Ap9 analog displaying a high efficacy in vivo in the mice septicemia and neutropenic mice peritonitis models. We demonstrated that abarenicin analogs did not significantly induce bacterial resistance after a four-week selection experiment and acted on different steps of the biofilm formation: (a) killing bacteria at their planktonic stage and preventing biofilm formation and (b) degrading pre-formed biofilm and killing embedded bacteria. The potent antibacterial and antibiofilm activity of the abarenicin analog Ap9 with its high efficacy in vivo against Gram-negative infection in mice models makes this peptide an attractive candidate for further preclinical investigation. Full article

(This article belongs to the Special Issue Marine Bioactive Peptides: Structure, Function, and Therapeutic Potential - III)

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13 pages, 2366 KiB

Open AccessArticle

In Vitro Antioxidant and Antiaging Activities of Collagen and Its Hydrolysate from Mackerel Scad Skin (Decapterus macarellus)

by Elisa Herawati, Yochidamai Akhsanitaqwim, Pipin Agnesia, Shanti Listyawati, Artini Pangastuti and Adi Ratriyanto

Mar. Drugs 2022, 20(8), 516; https://doi.org/10.3390/md20080516 - 13 Aug 2022

Cited by 15 | Viewed by 3862

Abstract

The skin of mackerel scad fish (Decapterus macarellus) is a new source for pepsin-soluble collagen and its hydrolysate, both of which have never been explored. This study aims to characterize and determine the in vitro antioxidant, antiglycation, and antityrosinase activity of [...] Read more.

The skin of mackerel scad fish (Decapterus macarellus) is a new source for pepsin-soluble collagen and its hydrolysate, both of which have never been explored. This study aims to characterize and determine the in vitro antioxidant, antiglycation, and antityrosinase activity of pepsin-soluble collagen (PSC) and hydrolyzed collagen (HC) from mackerel scad skin. PSC was extracted using 0.5 M acetic acid containing 0.1% pepsin for 48 h at 4 °C. The obtained PSC was then hydrolyzed with collagenase type II (6250 U/g) to produce HC. The PSC yield obtained was 6.39 ± 0.97%, with a pH of 6.76 ± 0.18, while the HC yield was 96% from PSC. SDS-PAGE and Fourier Transform Infrared (FTIR) analysis showed the typical features of type I collagen. HC demonstrated high solubility (66.75–100%) throughout the entire pH range (1–10). The PSC and HC from mackerel scad skin showed antioxidant activity against 2,2-diphenyl-1-picrylhydrazyl (DPPH), with IC50 values of 148.55 ± 3.14 ppm and 34.966 ± 0.518 ppm, respectively. In the antiglycation test, PSC had an IC50 value of 239.29 ± 15.67 ppm, while HC had an IC50 of 68.43 ± 0.44 ppm. PSC also exhibited antityrosinase activity, with IC50 values of 234.66 ± 0.185 ppm (on the L-DOPA substrate), while HC had an IC50 value of 79.35 ± 0.5 ppm. Taken together, these results suggest that the skin of mackerel scad fish has potential antiaging properties and can be further developed for pharmaceutical and cosmetic purposes. Full article

(This article belongs to the Section Biomaterials of Marine Origin)

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22 pages, 4793 KiB

Open AccessArticle

Novel Labdane Diterpenes-Based Synthetic Derivatives: Identification of a Bifunctional Vasodilator That Inhibits Ca_V1.2 and Stimulates K_Ca1.1 Channels

by Gabriele Carullo, Simona Saponara, Amer Ahmed, Beatrice Gorelli, Sarah Mazzotta, Alfonso Trezza, Beatrice Gianibbi, Giuseppe Campiani, Fabio Fusi and Francesca Aiello

Mar. Drugs 2022, 20(8), 515; https://doi.org/10.3390/md20080515 - 13 Aug 2022

Cited by 12 | Viewed by 2374

Abstract

Sesquiterpenes such as leucodin and the labdane-type diterpene manool are natural compounds endowed with remarkably in vitro vasorelaxant and in vivo hypotensive activities. Given their structural similarity with the sesquiterpene lactone (+)-sclareolide, this molecule was selected as a scaffold to develop novel vasoactive [...] Read more.

Sesquiterpenes such as leucodin and the labdane-type diterpene manool are natural compounds endowed with remarkably in vitro vasorelaxant and in vivo hypotensive activities. Given their structural similarity with the sesquiterpene lactone (+)-sclareolide, this molecule was selected as a scaffold to develop novel vasoactive agents. Functional, electrophysiology, and molecular dynamics studies were performed. The opening of the five-member lactone ring in the (+)-sclareolide provided a series of labdane-based small molecules, promoting a significant in vitro vasorelaxant effect. Electrophysiology data identified 7 as a Ca_V1.2 channel blocker and a K_Ca1.1 channel stimulator. These activities were also confirmed in the intact vascular tissue. The significant antagonism caused by the Ca_V1.2 channel agonist Bay K 8644 suggested that 7 might interact with the dihydropyridine binding site. Docking and molecular dynamic simulations provided the molecular basis of the Ca_V1.2 channel blockade and K_Ca1.1 channel stimulation produced by 7. Finally, 7 reduced coronary perfusion pressure and heart rate, while prolonging conduction and refractoriness of the atrioventricular node, likely because of its Ca²⁺ antagonism. Taken together, these data indicate that the labdane scaffold represents a valuable starting point for the development of new vasorelaxant agents endowed with negative chronotropic properties and targeting key pathways involved in the pathophysiology of hypertension and ischemic cardiomyopathy. Full article

(This article belongs to the Special Issue Marine-Derived Compounds Applied in Cardiovascular Disease)

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10 pages, 1524 KiB

Open AccessArticle

Hemiacetalmeroterpenoids A–C and Astellolide Q with Antimicrobial Activity from the Marine-Derived Fungus Penicillium sp. N-5

by Tao Chen, Wencong Yang, Taobo Li, Yihao Yin, Yufeng Liu, Bo Wang and Zhigang She

Mar. Drugs 2022, 20(8), 514; https://doi.org/10.3390/md20080514 - 13 Aug 2022

Cited by 11 | Viewed by 2222

Abstract

Four new compounds including three andrastin-type meroterpenoids hemiacetalmeroterpenoids A-C (1–3), and a drimane sesquiterpenoid astellolide Q (15), together with eleven known compounds (4–14) were isolated from the cultures of the marine-derived fungus Penicillium [...] Read more.

Four new compounds including three andrastin-type meroterpenoids hemiacetalmeroterpenoids A-C (1–3), and a drimane sesquiterpenoid astellolide Q (15), together with eleven known compounds (4–14) were isolated from the cultures of the marine-derived fungus Penicillium sp. N-5, while compound 14 was first isolated from a natural source. The structures of the new compounds were determined by analysis of detailed spectroscopic data, and the absolute configurations were further decided by a comparison of the experimental and calculated ECD spectra. Hemiacetalmeroterpenoid A (1) possesses a unique and highly congested 6,6,6,6,5,5-hexa-cyclic skeleton. Moreover, the absolute configuration of compound 14 was also reported for the first time. Compounds 1, 5 and 10 exhibited significant antimicrobial activities against Penicillium italicum and Colletrichum gloeosporioides with MIC values ranging from 1.56 to 6.25 μg/mL. Full article

(This article belongs to the Special Issue Diversity of Marine Fungi as a Source of Bioactive Natural Products)

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17 pages, 3226 KiB

Open AccessArticle

An Alkaloid from a Highly Invasive Seaweed Increases the Voracity and Reproductive Output of a Model Fish Species

by Valentina Schiano, Adele Cutignano, Daniela Maiello, Marianna Carbone, Maria Letizia Ciavatta, Gianluca Polese, Federica Fioretto, Chiara Attanasio, Antonio Palladino, Serena Felline, Antonio Terlizzi, Livia D’Angelo, Paolo de Girolamo, Mimmo Turano, Carla Lucini and Ernesto Mollo

Mar. Drugs 2022, 20(8), 513; https://doi.org/10.3390/md20080513 - 12 Aug 2022

Cited by 7 | Viewed by 2600

Abstract

The invasive macroalga Caulerpa cylindracea has spread widely in the Mediterranean Sea, becoming a favorite food item for native fish for reasons yet unknown. By using a combination of behavioral, morphological, and molecular approaches, herein we provide evidence that the bisindole alkaloid caulerpin, [...] Read more.

The invasive macroalga Caulerpa cylindracea has spread widely in the Mediterranean Sea, becoming a favorite food item for native fish for reasons yet unknown. By using a combination of behavioral, morphological, and molecular approaches, herein we provide evidence that the bisindole alkaloid caulerpin, a major secondary metabolite of C. cylindracea, significantly increases food intake in the model fish Danio rerio, influencing the regulation of genes involved in the orexigenic pathway. In addition, we found that the compound improves fish reproductive performance by affecting the hypothalamus–pituitary–gonadal axis. The obtained results pave the way for the possible valorization of C. cylindracea as a sustainable source of a functional feed additive of interest to face critical challenges both in aquaculture and in human nutrition. Full article

(This article belongs to the Section Marine Chemoecology for Drug Discovery)

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21 pages, 1218 KiB

Open AccessReview

Exopolysaccharides from Marine Microbes: Source, Structure and Application

by Mingxing Qi, Caijuan Zheng, Wenhui Wu, Guangli Yu and Peipei Wang

Mar. Drugs 2022, 20(8), 512; https://doi.org/10.3390/md20080512 - 12 Aug 2022

Cited by 32 | Viewed by 4451

Abstract

The unique living environment of marine microorganisms endows them with the potential to produce novel chemical compounds with various biological activities. Among them, the exopolysaccharides produced by marine microbes are an important factor for them to survive in these extreme environments. Up to [...] Read more.

The unique living environment of marine microorganisms endows them with the potential to produce novel chemical compounds with various biological activities. Among them, the exopolysaccharides produced by marine microbes are an important factor for them to survive in these extreme environments. Up to now, exopolysaccharides from marine microbes, especially from extremophiles, have attracted more and more attention due to their structural complexity, biodegradability, biological activities, and biocompatibility. With the development of culture and separation methods, an increasing number of novel exopolysaccharides are being found and investigated. Here, the source, structure and biological activities of exopolysaccharides, as well as their potential applications in environmental restoration fields of the last decade are summarized, indicating the commercial potential of these versatile EPS in different areas, such as food, cosmetic, and biomedical industries, and also in environmental remediation. Full article

(This article belongs to the Topic Advances on the Extraction, Functionalities and Applications of Polysaccharides)

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13 pages, 2053 KiB

Open AccessArticle

Fluorescently Labeled α-Conotoxin TxID, a New Probe for α3β4 Neuronal Nicotinic Acetylcholine Receptors

by Meiling Huang, Xiaopeng Zhu, Yishuai Yang, Yao Tan, Sulan Luo and Dongting Zhangsun

Mar. Drugs 2022, 20(8), 511; https://doi.org/10.3390/md20080511 - 12 Aug 2022

Cited by 3 | Viewed by 2212

Abstract

Neuronal nicotinic acetylcholine receptors (nAChRs) are important ion channel membrane proteins that are widely distributed in the central nervous system (CNS) and peripheral nervous system (PNS). As an important member, α3β4 nAChRs are related to pain sensation in PNS and nicotine addiction in [...] Read more.

Neuronal nicotinic acetylcholine receptors (nAChRs) are important ion channel membrane proteins that are widely distributed in the central nervous system (CNS) and peripheral nervous system (PNS). As an important member, α3β4 nAChRs are related to pain sensation in PNS and nicotine addiction in CNS. However, research related to the α3β4 nAChRs is greatly limited by the lack of subtype-selective pharmacological tools. The α-conotoxin (α-CTx) TxID from the marine cone snail, Conus textile, is a selective α3β4 nAChR antagonist with relatively high potency. In this study, a fluorescent dye (5-TAMRA SE) was used to label TxID on the N-terminus of α-CTx TxID, and pure TxID-F (fluorescent analogue of TxID) was obtained by HPLC. At the same time, the potency and selectivity of TxID-F were detected by high-performance liquid chromatography (HPLC). Additionally, the potency and selectivity of TxID-F were determined by using a two-electrode voltage-clamp technique on various nAChRs expressed in the Xenopus oocyte expression system. The results obtained by electrophysiology showed that TxID-F maintained the same order of potency (IC₅₀ 73 nM) as the native toxin (IC₅₀ 25 nM) for the α3β4 nAChR subtype. In addition, the results of fluorescent spectroscopy and circular dichroism showed TxID-F has the same fluorescence as 5-TAMRA SE, as well as similar profiles as TxID. The results of flow cytometry showed that the histogram shifted significantly to the right for the RAW264.7 cells expressing α3β4-containing nAChRs stained with TxID-F and confirmed by live cell imaging. The study of fluorescent-labeled α-CTx TxID provides a rich pharmacological tool to explore the structure–function relationship, distribution, and ligand-binding domain of α3β4 nAChR subtype in the future. Full article

(This article belongs to the Section Marine Toxins)

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