Molecules

22 pages, 6078 KiB

Open AccessReview

Advances in the Synthesis of Lignan Natural Products

by Xianhe Fang and Xiangdong Hu

Molecules 2018, 23(12), 3385; https://doi.org/10.3390/molecules23123385 - 19 Dec 2018

Cited by 49 | Viewed by 7885

Lignans comprise a family of secondary metabolites existing widely in plants and also in human food sources. As important components, these compounds play remarkable roles in plants’ ecological functions as protection against herbivores and microorganisms. Meanwhile, foods rich in lignans have revealed potential [...] Read more.

Lignans comprise a family of secondary metabolites existing widely in plants and also in human food sources. As important components, these compounds play remarkable roles in plants’ ecological functions as protection against herbivores and microorganisms. Meanwhile, foods rich in lignans have revealed potential to decrease of risk of cancers. To date, a number of promising bioactivities have been found for lignan natural products and their unnatural analogues, including antibacterial, antiviral, antitumor, antiplatelet, phosphodiesterase inhibition, 5-lipoxygenase inhibition, HIV reverse transcription inhibition, cytotoxic activities, antioxidant activities, immunosuppressive activities and antiasthmatic activities. Therefore, the synthesis of this family and also their analogues have attracted widespread interest from the synthetic organic chemistry community. Herein, we outline advances in the synthesis of lignan natural products in the last decade. Full article

(This article belongs to the Special Issue Lignans)

► Show Figures

Scheme 1

13 pages, 2645 KiB

Open AccessFeature PaperArticle

Terpenoid Compositions of Resins from Callitris Species (Cupressaceae)

by Bernd R. T. Simoneit, Robert E. Cox, Daniel R. Oros and Angelika Otto

Molecules 2018, 23(12), 3384; https://doi.org/10.3390/molecules23123384 - 19 Dec 2018

Cited by 21 | Viewed by 5521

Abstract

The environmental fate of conifer resins and their natural product compounds as mixtures is of importance for source, alteration, and transport studies. The compound compositions of resins of the common Callitris species (Cupressaceae) based on gas chromatography-mass spectrometry have not been [...] Read more.

The environmental fate of conifer resins and their natural product compounds as mixtures is of importance for source, alteration, and transport studies. The compound compositions of resins of the common Callitris species (Cupressaceae) based on gas chromatography-mass spectrometry have not been reported. Results show that diterpenoids were the most abundant components and callitrisic acid was present in the resin extracts of all Callitris species analyzed. Significant amounts of 4-epi-pimaric and sandaracopimaric acids, with lesser communic, ozic, and lambertianic acids, were also in the mixtures. Phenolic diterpenoids, for example, ferruginol, hinokiol, were found in trace quantities in some samples. Thus, callitrisic acid and 4-epi-pimaric acid are the characteristic diterpenoids of Callitris species that are amenable to molecular biomarker analyses in geological or environmental applications. Full article

(This article belongs to the Special Issue Diversity of Terpenoids)

► Show Figures

Figure 1

15 pages, 6308 KiB

Open AccessArticle

Biodegradable and pH Sensitive Peptide Based Hydrogel as Controlled Release System for Antibacterial Wound Dressing Application

by Jie Zhu, Hua Han, Ting-Ting Ye, Fa-Xue Li, Xue-Li Wang, Jian-Yong Yu and De-Qun Wu

Molecules 2018, 23(12), 3383; https://doi.org/10.3390/molecules23123383 - 19 Dec 2018

Cited by 63 | Viewed by 7639 | Correction

Abstract

The stimuli-sensitive and biodegradable hydrogels are promising biomaterials as controlled drug delivery systems for diverse biomedical applications. In this study, we construct hybrid hydrogels combined with peptide-based bis-acrylate and acrylic acid (AAc). The peptide-based bis-acrylate/AAc hybrid hydrogel displays an interconnected and porous structure [...] Read more.

The stimuli-sensitive and biodegradable hydrogels are promising biomaterials as controlled drug delivery systems for diverse biomedical applications. In this study, we construct hybrid hydrogels combined with peptide-based bis-acrylate and acrylic acid (AAc). The peptide-based bis-acrylate/AAc hybrid hydrogel displays an interconnected and porous structure by scanning electron microscopy (SEM) observation and exhibits pH-dependent swelling property. The biodegradation of hybrid hydrogels was characterized by SEM and weight loss, and the results showed the hydrogels have a good enzymatic biodegradation property. The mechanical and cytotoxicity properties of the hydrogels were also tested. Besides, triclosan was preloaded during the hydrogel formation for drug release and antibacterial studies. In summary, the peptide-based bis-acrylate/AAc hydrogel with stimuli sensitivity and biodegradable property may be excellent candidates as drug delivery systems for antibacterial wound dressing application. Full article

(This article belongs to the Special Issue Supramolecular Gel)

► Show Figures

Figure 1

14 pages, 2577 KiB

Open AccessArticle

Theaflavins Improve Insulin Sensitivity through Regulating Mitochondrial Biosynthesis in Palmitic Acid-Induced HepG2 Cells

by Tuantuan Tong, Ning Ren, Park Soomi, Jiafan Wu, Na Guo, Hyunuk Kang, Eunhye Kim, Yuanyuan Wu, Puming He, Youying Tu and Bo Li

Molecules 2018, 23(12), 3382; https://doi.org/10.3390/molecules23123382 - 19 Dec 2018

Cited by 29 | Viewed by 7154

Abstract

Theaflavins, the characteristic and bioactive polyphenols in black tea, possess the potential improving effects on insulin resistance-associated metabolic abnormalities, including obesity and type 2 diabetes mellitus. However, the related molecular mechanisms are still unclear. In this research, we investigated the protective effects of [...] Read more.

Theaflavins, the characteristic and bioactive polyphenols in black tea, possess the potential improving effects on insulin resistance-associated metabolic abnormalities, including obesity and type 2 diabetes mellitus. However, the related molecular mechanisms are still unclear. In this research, we investigated the protective effects of theaflavins against insulin resistance in HepG2 cells induced by palmitic acid. Theaflavins significantly increased glucose uptake of insulin-resistant cells at noncytotoxic doses. This activity was mediated by upregulating the total and membrane bound glucose transporter 4 protein expressions, increasing the phosphor-Akt (Ser473) level, and decreasing the phosphorylation of IRS-1 at Ser307. Moreover, theaflavins were found to enhance the mitochondrial DNA copy number, down-regulate the PGC-1β mRNA level and increase the PRC mRNA expression. Mdivi-1, a selective mitochondrial division inhibitor, could attenuate TFs-induced promotion of glucose uptake in insulin-resistant HepG2 cells. Taken together, these results suggested that theaflavins could improve hepatocellular insulin resistance induced by free fatty acids, at least partly through promoting mitochondrial biogenesis. Theaflavins are promising functional food ingredients and medicines for improving insulin resistance-related disorders. Full article

► Show Figures

Figure 1

14 pages, 2625 KiB

Open AccessArticle

A Pseudouridine Isoxazolidinyl Nucleoside Analogue Structural Analysis: A Morphological Approach

by Giuseppe Floresta, Venerando Pistarà, Kirsten E. Christensen, Emanuele Amata, Agostino Marrazzo, Davide Gentile, Antonio Rescifina and Francesco Punzo

Molecules 2018, 23(12), 3381; https://doi.org/10.3390/molecules23123381 - 19 Dec 2018

Cited by 1 | Viewed by 3576

Abstract

An in silico study has been conducted upon (3′RS,5′SR)-5-[2′-benzyl-5′-hydroxymethyl-1′,2′-isoxazolidin-3′-yl]uracil through a molecular dynamics/docking approach that highlights its potential inhibitory activity upon the wild-type pseudouridine 5′-monophosphate glycosidase. The crystal structure of this compound has been solved by means of X-ray [...] Read more.

An in silico study has been conducted upon (3′RS,5′SR)-5-[2′-benzyl-5′-hydroxymethyl-1′,2′-isoxazolidin-3′-yl]uracil through a molecular dynamics/docking approach that highlights its potential inhibitory activity upon the wild-type pseudouridine 5′-monophosphate glycosidase. The crystal structure of this compound has been solved by means of X-ray single crystal diffraction and the data inferred were used to predict its crystal morphology. These data were compared with optical microscopy images and confirmed the validity of the computed models. This robust approach, already used for several other different compounds, provides a fast and reliable tool to standardize a crystallization method in order to get similar and good quality crystals. As different crystal shapes could be associated with different polymorphic forms, this method could be considered a fast and cheap screening to choose among different and coexistent polymorphic forms. Furthermore, a match with the original crystal structure of pseudouridine 5′-monophosphate is provided. Full article

(This article belongs to the Section Bioorganic Chemistry)

► Show Figures

Figure 1

11 pages, 1070 KiB

Open AccessArticle

Effect of Effluent Recirculation on Biogas Production Using Two-Stage Anaerobic Digestion of Citrus Waste

by Lukitawesa, Rachma Wikandari, Ria Millati, Mohammad J. Taherzadeh and Claes Niklasson

Molecules 2018, 23(12), 3380; https://doi.org/10.3390/molecules23123380 - 19 Dec 2018

Cited by 38 | Viewed by 6245

Abstract

Citrus waste is a promising potential feedstock for anaerobic digestion, yet the presence of inhibitors such as d-limonene is known to limit the process. Effluent recirculation has been proven to increase methane yield in a semi-continuous process for recalcitrant material, but it [...] Read more.

Citrus waste is a promising potential feedstock for anaerobic digestion, yet the presence of inhibitors such as d-limonene is known to limit the process. Effluent recirculation has been proven to increase methane yield in a semi-continuous process for recalcitrant material, but it has never been applied to toxic materials. This study was aimed to investigate the effect of recirculation on biogas production from citrus waste as toxic feedstock in two-stage anaerobic digestion. The first digestion was carried out in a stirred tank reactor (STR). The effluent from the first-stage was filtered using a rotary drum filter to separate the solid and the liquid phase. The solid phase, rich in hydrophobic D-limonene, was discarded, and the liquid phase containing less D-limonene was fed into the second digester in an up-flow anaerobic sludge bed (UASB) reactor. A high organic loading rate (OLR 5 g VS/(L·day)) of citrus waste was fed into the first-stage reactor every day. The effluent of the first-stage was then fed into the second-stage reactor. This experiment was run for 120 days. A reactor configuration without recirculation was used as control. The result shows that the reactor with effluent recirculation produced a higher methane yield (160–203 NmL/g·VS) compared to that without recirculation (66–113 NmL/g·VS). More stable performance was also observed in the reactor with recirculation as shown by the pH of 5–6, while without recirculation the pH dropped to the range of 3.7–4.7. The VS reduction for the reactor with recirculation was 33–35% higher than that of the control without recirculation. Recirculation might affect the hydrolysis-acidogenesis process by regulating pH in the first-stage and removing most of the D-limonene content from the substrate through filtration. Full article

(This article belongs to the Special Issue Chemicals from Food Supply Chain By-Products and Waste Streams)

► Show Figures

Graphical abstract

16 pages, 6723 KiB

Open AccessArticle

Construction of Novel Aspartokinase Mutant A380I and Its Characterization by Molecular Dynamics Simulation

by Caijing Han, Li Fang, Chunlei Liu, Yunna Gao and Weihong Min

Molecules 2018, 23(12), 3379; https://doi.org/10.3390/molecules23123379 - 19 Dec 2018

Cited by 10 | Viewed by 3144

Abstract

In this study, a novel monomer aspartokinase (AK) from Corynebacterium pekinense was identified, and its monomer model was constructed. Site 380 was identified by homologous sequencing and monomer model comparison as the key site which was conserved and located around the binding site [...] Read more.

In this study, a novel monomer aspartokinase (AK) from Corynebacterium pekinense was identified, and its monomer model was constructed. Site 380 was identified by homologous sequencing and monomer model comparison as the key site which was conserved and located around the binding site of the inhibitor Lys. Furthermore, the mutant A380I with enzyme activity 11.32-fold higher than wild type AK (WT-AK), was obtained by site-directed mutagenesis and high throughput screening. In the mutant A380I, the optimal temperature was raised from 26 °C (WT-AK) to 28 °C, the optimal pH remained unchanged at 8.0, and the half-life was prolonged from 4.5 h (WT-AK) to 6.0 h, indicating enhanced thermal stability. The inhibition of A380I was weakened at various inhibitor concentrations and even activated at certain inhibitor concentrations (10 mM of Lys, 5 mM or 10 mM of Lys + Thr, 10 mM of Lys + Met, 5 mM of Lys + Thr + Met). Molecular dynamics simulation results indicated that the occupancy rate of hydrogen bond between A380I and ATP was enhanced, the effect of Lys (inhibitor) on the protein was weakened, and the angle between Ser281-Tyre358 and Asp359-Gly427 was increased after mutation, leading to an open conformation (R-state) that favored the binding of substrate. Full article

► Show Figures

Graphical abstract

8 pages, 939 KiB

Open AccessArticle

Benzophenone Derivatives from an Algal-Endophytic Isolate of Penicillium chrysogenum and Their Cytotoxicity

by Dong-Lin Zhao, Xiao-Long Yuan, Yong-Mei Du, Zhong-Feng Zhang and Peng Zhang

Molecules 2018, 23(12), 3378; https://doi.org/10.3390/molecules23123378 - 19 Dec 2018

Cited by 22 | Viewed by 3535

Abstract

Chromatographic separation of a marine algal-derived endophytic fungus Penicillium chrysogenum AD-1540, which was isolated from the inner tissue of the marine red alga Grateloupia turuturu, yielded two new benzophenone derivatives, chryxanthones A and B (compounds 1 and 2, respectively). Their structures [...] Read more.

Chromatographic separation of a marine algal-derived endophytic fungus Penicillium chrysogenum AD-1540, which was isolated from the inner tissue of the marine red alga Grateloupia turuturu, yielded two new benzophenone derivatives, chryxanthones A and B (compounds 1 and 2, respectively). Their structures were undoubtedly determined by comprehensive analysis of spectroscopic data (1D/2D NMR and HRESIMS). The relative and absolute configurations were assigned by analysis of the coupling constants and time-dependent density functional theory (TDDFT) calculations of their electronic circular dichroism (ECD) spectra, respectively. Both compounds possessed an unusual dihydropyran ring (ring D) fused to an aromatic ring, rather than the commonly occurring prenyl moiety, and a plausible biosynthetic pathway was postulated. The cytotoxicities of compounds 1 and 2 were evaluated against six human cell lines, and both of the compounds demonstrated weak to moderate cytotoxicities with IC₅₀ values ranging from 20.4 to 46.4 μM. These new compounds further demonstrate the potential of marine-derived fungi as an untapped source of pharmaceutical components with unique properties that could be developed as drug candidates. Full article

(This article belongs to the Section Natural Products Chemistry)

► Show Figures

Graphical abstract

12 pages, 759 KiB

Open AccessArticle

Small Molecular Weight Aldose (d-Glucose) and Basic Amino Acids (l-Lysine, l-Arginine) Increase the Occurrence of PAHs in Grilled Pork Sausages

by Wen Nie, Ke-zhou Cai, Yu-zhu Li, Shuo Zhang, Yu Wang, Jie Guo, Cong-gui Chen and Bao-cai Xu

Molecules 2018, 23(12), 3377; https://doi.org/10.3390/molecules23123377 - 19 Dec 2018

Cited by 28 | Viewed by 4263

Abstract

(1) Background: Amino acids and carbohydrates are widely used as additives in the food industry. These compounds have been proven to be an influencing factor in the production of chemical carcinogenic compounds polycyclic aromatic hydrocarbons (PAHs). However, the effect of the properties of [...] Read more.

(1) Background: Amino acids and carbohydrates are widely used as additives in the food industry. These compounds have been proven to be an influencing factor in the production of chemical carcinogenic compounds polycyclic aromatic hydrocarbons (PAHs). However, the effect of the properties of the amino acids and carbohydrates on the production of PAHs is still little known. (2) Methods: We added different (i) R groups (the R group represents an aldehyde group in a glucose molecule or a ketone group in a fructose molecule); (ii) molecular weight carbohydrates; (iii) polarities, and (iv) acid-base amino acids to pork sausages. The effects of the molecular properties of carbohydrates and amino acids on the formation of PAHs in grilled pork sausages were investigated. (3) Results: The results showed that a grilled sausage with aldehyde-based d-glucose was capable of producing more PAHs than a sausage with keto-based d-fructose. A higher PAH content was determined in the grilled pork sausage when the smaller molecular weight, d-glucose, was added compared with the sausage where the larger molecular weight, 4-(α-d-glucosido)-d-glucose and cellulose were added. The addition of basic amino acids (l-lysine, l-arginine) was capable of producing more PAHs compared with the addition of acidic amino acids (l-glutamic acid, l-aspartate). When amino acid containing a benzene ring was added, a smaller volume of PAHs was produced compared with the addition of other amino acids. (4) Conclusions: Our study suggests that systematic consideration of molecule properties is necessary when using food additives (amino acids and carbohydrates) for food processing. Full article

(This article belongs to the Collection Advances in Food Analysis)

► Show Figures

Figure 1

32 pages, 30971 KiB

Open AccessReview

Recent Theoretical and Experimental Progress in Circularly Polarized Luminescence of Small Organic Molecules

by Naibo Chen and Bo Yan

Molecules 2018, 23(12), 3376; https://doi.org/10.3390/molecules23123376 - 19 Dec 2018

Cited by 99 | Viewed by 7701

Abstract

Small organic molecules (SOMs) with fascinating chiroptical properties have received much attention for their potential applications in photoelectric and biological devices. As an important research tool, circularly polarized luminescence (CPL) provides information about the chiral structures of these molecules in their excited state, [...] Read more.

Small organic molecules (SOMs) with fascinating chiroptical properties have received much attention for their potential applications in photoelectric and biological devices. As an important research tool, circularly polarized luminescence (CPL) provides information about the chiral structures of these molecules in their excited state, and has been an active area of research. With the development of the commercially available CPL instrumentation, currently, more and more research groups have attempted to enhance the CPL parameters (i.e., quantum yield and dissymmetry factor) of the chiral SOMs from all aspects. This review summarizes the latest five years progresses in research on the experimental techniques and theoretical calculations of CPL emitted from SOMs, as well as forecasting its trend of development. Full article

15 pages, 3358 KiB

Open AccessArticle

MgONPs Can Boost Plant Growth: Evidence from Increased Seedling Growth, Morpho-Physiological Activities, and Mg Uptake in Tobacco (Nicotiana tabacum L.)

by Lin Cai, Minghong Liu, Zhongwei Liu, Huikuan Yang, Xianchao Sun, Juanni Chen, Shunyu Xiang and Wei Ding

Molecules 2018, 23(12), 3375; https://doi.org/10.3390/molecules23123375 - 19 Dec 2018

Cited by 67 | Viewed by 5086

Abstract

In this study, we documented the impact of magnesium oxide nanoparticles (MgONPs) on the various morpho-physiological changes by root irrigation in tobacco plants in the matrix media, as well as the uptake and accumulation of the NPs over a range of concentrations (50–250 [...] Read more.

In this study, we documented the impact of magnesium oxide nanoparticles (MgONPs) on the various morpho-physiological changes by root irrigation in tobacco plants in the matrix media, as well as the uptake and accumulation of the NPs over a range of concentrations (50–250 μg/mL). Our results showed that the seed germination rate was not affected following exposure to MgONPs for 5 days. Enhanced plant growth together with increased peroxidase activity (39.63 U mg⁻¹ protein in the 250 μg/mL MgONPs treatment, 36.63 U mg⁻¹ protein in the control), superoxide dismutase activity (30.15 U mg⁻¹ protein compared to 26.95 U mg⁻¹ protein in the control), and chlorophyll content (the chlorophyll a and b contents in 0 and 250 μg/mL of MgONPs were 0.21, 0.12 μg/g to 1.21, 0.67 μg/g, respectively) were observed after 30 days of MgONP treatment. However, the malondialdehyde, protein, and relative water contents did not differ significantly, indicating that the NPs in the test concentrations had no phytotoxicity and even promoted plant growth. Scanning electron microscopy and paraffin section observations indicated that the MgONPs did not affect the plant tissue structures and cells. In addition, an elevated Mg content was detected in the plant tissues exposed to MgONPs, suggesting that the Mg was taken up by the tobacco roots and translocated to the shoots and leaves, which were probably the most important tools to cause an increase in the chlorophyll content and stimulate growth. In particular, compared with the controls, a substantially higher Mg content was observed in the leaves (12.93 mg/g in the MgONPs treatment, 9.30 mg/g in the control) exposed to 250 μg/mL MgONPs, especially in the lower and middle leaves. This result confirmed that the contents of plant Mg-element in the old leaves were increased by MgONPs. In summary, this study investigated increased Mg uptake and growth stimulation, as well as the induction of various positive morpho-physiological changes to tobacco plants when exposed to MgONPs. Results elucidate the promotional impact of the NPs on plant health and their implications for agricultural safety and security. Full article

(This article belongs to the Special Issue Metallic Nanoparticles: From Synthesis, Structure-Property Relationships to Applications)

► Show Figures

Figure 1

14 pages, 3612 KiB

Open AccessArticle

Diagnosis of Bacterial Pathogens in the Urine of Urinary-Tract-Infection Patients Using Surface-Enhanced Raman Spectroscopy

by Ni Tien, Tzu-Hsien Lin, Zen-Chao Hung, Hsiu-Shen Lin, I-Kuan Wang, Hung-Chih Chen and Chiz-Tzung Chang

Molecules 2018, 23(12), 3374; https://doi.org/10.3390/molecules23123374 - 19 Dec 2018

Cited by 26 | Viewed by 6317

Abstract

(1) Background: surface-enhanced Raman spectroscopy (SERS) is a novel method for bacteria identification. However, reported applications of SERS in clinical diagnosis are limited. In this study, we used cylindrical SERS chips to detect urine pathogens in urinary tract infection (UTI) patients. (2) Methods: [...] Read more.

(1) Background: surface-enhanced Raman spectroscopy (SERS) is a novel method for bacteria identification. However, reported applications of SERS in clinical diagnosis are limited. In this study, we used cylindrical SERS chips to detect urine pathogens in urinary tract infection (UTI) patients. (2) Methods: Urine samples were retrieved from 108 UTI patients. A 10 mL urine sample was sent to conventional bacterial culture as a reference. Another 10 mL urine sample was loaded on a SERS chip for bacteria identification and antibiotic susceptibility. We concentrated the urine specimen if the intensity of the Raman spectrum required enhancement. The resulting Raman spectrum was analyzed by a recognition software to compare with spectrum-form reference bacteria and was further confirmed by principal component analysis (PCA). (3) Results: There were 97 samples with single bacteria species identified by conventional urine culture and, among them, 93 can be successfully identified by using SERS without sample concentration. There were four samples that needed concentration for bacteria identification. Antibiotic susceptibility can also be found by SERS. There were seven mixed flora infections found by conventional culture, which can only be identified by the PCA method. (4) Conclusions: SERS can be used in the diagnosis of urinary tract infection with the aid of the recognition software and PCA. Full article

(This article belongs to the Special Issue Raman Spectroscopy: A Spectroscopic 'Swiss-Army Knife')

► Show Figures

Figure 1

21 pages, 4510 KiB

Open AccessArticle

Phenolic Composition, Antioxidant Properties, and Inhibition toward Digestive Enzymes with Molecular Docking Analysis of Different Fractions from Prinsepia utilis Royle Fruits

by Xuan Zhang, Yijia Jia, Yanli Ma, Guiguang Cheng and Shengbao Cai

Molecules 2018, 23(12), 3373; https://doi.org/10.3390/molecules23123373 - 19 Dec 2018

Cited by 48 | Viewed by 5104

Abstract

The present study investigated the phenolic profiles and antioxidant properties of different fractions from Prinsepia utilis Royle fruits using molecular docking analysis to delineate their inhibition toward digestive enzymes. A total of 20 phenolics was identified and quantified. Rutin, quercetin-3-O-glucoside, and [...] Read more.

The present study investigated the phenolic profiles and antioxidant properties of different fractions from Prinsepia utilis Royle fruits using molecular docking analysis to delineate their inhibition toward digestive enzymes. A total of 20 phenolics was identified and quantified. Rutin, quercetin-3-O-glucoside, and isorhamnetin-3-O-rutinoside were the major phenolic compounds in the total phenolic fraction and flavonoid-rich fraction. The anthocyanin-rich fraction mainly contained cyanidin-3-O-glucoside and cyanidin-3-O-rutinoside. All of the fractions exhibited strong radical scavenging activities and good inhibition on cellular reactive oxygen species (ROS) generation in H₂O₂-induced HepG2 cells, as evaluated by DPPH and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) assays. Moreover, the powerful inhibitory effects of those fractions against pancreatic lipase and α-glucosidase were observed. The major phenolic compounds that were found in the three fractions also showed good digestive enzyme inhibitory activities in a dose-dependent manner. Molecular docking analysis revealed the underlying inhibition mechanisms of those phenolic standards against digestive enzymes, and the theoretical analysis data were consistent with the experimental results. Full article

(This article belongs to the Special Issue Biological Activities of Plant Secondary Metabolites)

► Show Figures

Figure 1

20 pages, 3083 KiB

Open AccessArticle

Ethyl Rosmarinate Protects High Glucose-Induced Injury in Human Endothelial Cells

by Yan-Hui Shen, Li-Ying Wang, Bao-Bao Zhang, Qi-Ming Hu, Pu Wang, Bai-Qiu He, Guan-Hu Bao, Jing-Yu Liang and Fei-Hua Wu

Molecules 2018, 23(12), 3372; https://doi.org/10.3390/molecules23123372 - 19 Dec 2018

Cited by 16 | Viewed by 3809

Abstract

Ethyl rosmarinate (RAE) is one of the active constituents from Clinopodium chinense (Benth.) O. Kuntze, which is used for diabetic treatment in Chinese folk medicine. In this study, we investigated the protective effect of RAE on high glucose-induced injury in endothelial cells and [...] Read more.

Ethyl rosmarinate (RAE) is one of the active constituents from Clinopodium chinense (Benth.) O. Kuntze, which is used for diabetic treatment in Chinese folk medicine. In this study, we investigated the protective effect of RAE on high glucose-induced injury in endothelial cells and explored its underlying mechanisms. Our results showed that both RAE and rosmarinic acid (RA) increased cell viability, decreased the production of reactive oxygen species (ROS), and attenuated high glucose-induced endothelial cells apoptosis in a dose-dependent manner, as evidenced by Hochest staining, Annexin V–FITC/PI double staining, and caspase-3 activity. RAE and RA both elevated Bcl-2 expression and reduced Bax expression, according to Western blot. We also found that LY294002 (phosphatidylinositol 3-kinase, or PI3K inhibitor) weakened the protective effect of RAE. In addition, PDTC (nuclear factor-κB, or NF-κB inhibitor) and SP600125 (c-Jun N-terminal kinase, or JNK inhibitor) could inhibit the apoptosis in endothelial cells caused by high glucose. Further, we demonstrated that RAE activated Akt, and the molecular docking analysis predicted that RAE showed more affinity with Akt than RA. Moreover, we found that RAE inhibited the activation of NF-κB and JNK. These results suggested that RAE protected endothelial cells from high glucose-induced apoptosis by alleviating reactive oxygen species (ROS) generation, and regulating the PI3K/Akt/Bcl-2 pathway, the NF-κB pathway, and the JNK pathway. In general, RAE showed greater potency than RA equivalent. Full article

► Show Figures

Graphical abstract

15 pages, 3165 KiB

Open AccessArticle

Microneedle-Assisted Percutaneous Delivery of Paeoniflorin-Loaded Ethosomes

by Yahua Cui, Yujia Mo, Qi Zhang, Wanwan Tian, Yutao Xue, Jie Bai and Shouying Du

Molecules 2018, 23(12), 3371; https://doi.org/10.3390/molecules23123371 - 19 Dec 2018

Cited by 37 | Viewed by 4350

Abstract

Paeoniflorin, the main component of total glucosides of paeony (TGP), shows good therapeutic effects in arthritis, but has low bioavailability when administered orally. Avoiding such a deficiency for topical administration would expand its clinical application. This study aimed to avoid these limitations by [...] Read more.

Paeoniflorin, the main component of total glucosides of paeony (TGP), shows good therapeutic effects in arthritis, but has low bioavailability when administered orally. Avoiding such a deficiency for topical administration would expand its clinical application. This study aimed to avoid these limitations by using nanotechnology (ethosomes) and a physical approach (microneedles). Paeoniflorin-loaded ethosomal formulation (TGP-E) was optimized and evaluated in terms of entrapment efficiency (EE), particle size (PS), zeta potential (ZP), polydispersity index (PDI) and morphology. TGP-E was prepared by the hot injection method and optimized by single-factor tests and an orthogonal experimental design. The optimized paeoniflorin-loaded ethosomes had EE of 27.82 ± 1.56%, PS of 137.9 ± 7.57 nm with PDI of 0.120 ± 0.005, ZP of −0.74 ± 0.43 mV. Ethosomes showed a nearly spherical shape under the transmission electron microscope (TEM). The optimal microneedle-assisted (MN-assisted) conditions were obtained at a microneedle length of 500 μm, a pressure of 3 N and an action time of 3 min. The cumulative penetration amounts (Q_n) of TGP solution transdermal (ST) and MN-assisted TGP solution transdermal (MST) were 24.42 ± 8.35 μg/cm² and 548.11 ± 10.49 μg/cm², respectively. Q_n of TGP-E transdermal (PT) and MN-assisted TGP-E transdermal (MPT) were 54.97 ± 4.72 μg/cm² and 307.17 ± 26.36 μg/cm², respectively. These findings indicate that use of ethosomes and microneedles can both enhance the penetration ofpaeoniflorin, but for the water-soluble drug, there is no obvious synergism between nanotechnology and microneedles for enhancing penetration in a transdermal drug delivery system. Full article

► Show Figures

Figure 1

28 pages, 4839 KiB

Open AccessFeature PaperReview

Structures and Bioactive Properties of Myrtucommulones and Related Acylphloroglucinols from Myrtaceae

by Rosario Nicoletti, Maria Michela Salvatore, Pasquale Ferranti and Anna Andolfi

Molecules 2018, 23(12), 3370; https://doi.org/10.3390/molecules23123370 - 19 Dec 2018

Cited by 25 | Viewed by 5870

Abstract

Myrtaceae are a group of plants that include a number of renowned species used in ethnomedicine in many areas worldwide. Their valuable therapeutic properties have stimulated a fruitful research activity addressed to the identification of the bioactive components of their extracts yielding a [...] Read more.

Myrtaceae are a group of plants that include a number of renowned species used in ethnomedicine in many areas worldwide. Their valuable therapeutic properties have stimulated a fruitful research activity addressed to the identification of the bioactive components of their extracts yielding a great diversity of terpenes; polyphenols; and other exclusive products. Among the latter, starting with the discovery of myrtucommulone A from myrtle (Myrtus communis), a series of structurally-related acylphloroglucinol compounds have been characterized from several species that represent the basic active principles to be considered in view of possible drug development. Aspects concerning chemical and biological properties of these products are reviewed in the present paper. Full article

(This article belongs to the Special Issue Recent Advances in Natural Products Chemistry Related to Metabolites and Microbiomes)

► Show Figures

Figure 1

20 pages, 2448 KiB

Open AccessArticle

Synthesis and Evaluation of 3-Substituted-4-(quinoxalin-6-yl) Pyrazoles as TGF-β Type I Receptor Kinase Inhibitors

by Li-Min Zhao, Zhen Guo, Yi-Jie Xue, Jun Zhe Min, Wen-Jing Zhu, Xiang-Yu Li, Hu-Ri Piao and Cheng Hua Jin

Molecules 2018, 23(12), 3369; https://doi.org/10.3390/molecules23123369 - 19 Dec 2018

Cited by 19 | Viewed by 3914

Abstract

The transforming growth factor-β (TGF-β), in which overexpression has been associated with various diseases, has become an attractive molecular target for the treatment of cancers. Thirty-two quinoxaline-derivatives of 3-substituted-4-(quinoxalin-6-yl) pyrazoles 14a–d, 15a–d, 16a–d, 17a [...] Read more.

The transforming growth factor-β (TGF-β), in which overexpression has been associated with various diseases, has become an attractive molecular target for the treatment of cancers. Thirty-two quinoxaline-derivatives of 3-substituted-4-(quinoxalin-6-yl) pyrazoles 14a–d, 15a–d, 16a–d, 17a–d, 18a–d, 19a–d, 25a, 25b, 25d, 26a, 26b, 26d, 27b, and 27d were synthesized and evaluated for their activin TGF-β type I receptor kinase and p38α mitogen activated protein (MAP) kinase inhibitory activity in enzymatic assays. Among these compounds, the most active compound 19b inhibited TGF-β type I receptor kinase phosphorylation with an IC₅₀ value of 0.28 µM, with 98% inhibition at 10 µM. Compound 19b also had good selectivity index of >35 against p38α MAP kinase, with 9.0-fold more selective than clinical candidate, compound 3 (LY-2157299). A molecular docking study was performed to identify the mechanism of action of the synthesized compounds and their good binding interactions were observed. ADMET prediction of good active compounds showed that these ones possess good pharmacokinetics and drug-likeness behavior. Full article

(This article belongs to the Special Issue Recent Advances in Anticancer Drugs)

► Show Figures

Graphical abstract

12 pages, 2884 KiB

Open AccessArticle

Probing the Structural Determinants of Amino Acid Recognition: X-Ray Studies of Crystalline Ditopic Host-Guest Complexes of the Positively Charged Amino Acids, Arg, Lys, and His with a Cavitand Molecule

by Giovanna Brancatelli, Enrico Dalcanale, Roberta Pinalli and Silvano Geremia

Molecules 2018, 23(12), 3368; https://doi.org/10.3390/molecules23123368 - 19 Dec 2018

Cited by 8 | Viewed by 3962

Abstract

Crystallization of tetraphosphonate cavitand Tiiii[H, CH₃, CH₃] in the presence of positively charged amino acids, namely arginine, lysine, or histidine, afforded host-guest complex structures. The X-ray structure determination revealed that in all three structures, the fully protonated form of [...] Read more.

Crystallization of tetraphosphonate cavitand Tiiii[H, CH₃, CH₃] in the presence of positively charged amino acids, namely arginine, lysine, or histidine, afforded host-guest complex structures. The X-ray structure determination revealed that in all three structures, the fully protonated form of the amino acid is ditopically complexed by two tetraphosphonate cavitand molecules. Guanidinium, ammonium, and imidazolium cationic groups of the amino acid side chain are hosted in the cavity of a phosphonate receptor, and are held in place by specific hydrogen bonding interactions with the P=O groups of the cavitand molecule. In all three structures, the positively charged α-ammonium groups form H-bonds with the P=O groups, and with a water molecule hosted in the cavity of a second tetraphosphonate molecule. Furthermore, water-assisted dimerization was observed for the cavitand/histidine ditopic complex. In this 4:2 supramolecular complex, a bridged water molecule is held by two carboxylic acid groups of the dimerized amino acid. The structural information obtained on the geometrical constrains necessary for the possible encapsulation of the amino acids are important for the rational design of devices for analytical and medical applications. Full article

(This article belongs to the Special Issue Enantioselective Synthesis, Enantiomeric Separations and Chiral Recognition)

► Show Figures

Graphical abstract

13 pages, 1422 KiB

Open AccessArticle

Chemoinformatic Analysis of Selected Cacalolides from Psacalium decompositum (A. Gray) H. Rob. & Brettell and Psacalium peltatum (Kunth) Cass. and Their Effects on FcεRI-Dependent Degranulation in Mast Cells

by Jorge Iván Castillo-Arellano, Juan Carlos Gómez-Verjan, Nadia A. Rojano-Vilchis, Myrna Mendoza-Cruz, Manuel Jiménez-Estrada, Héctor E. López-Valdés, Hilda Martínez-Coria, Roger Gutiérrez-Juárez, Claudia González-Espinosa, Ricardo Reyes-Chilpa and Isabel Arrieta-Cruz

Molecules 2018, 23(12), 3367; https://doi.org/10.3390/molecules23123367 - 19 Dec 2018

Cited by 6 | Viewed by 4172

Abstract

Cacalolides are a kind of sesquiterpenoids natural compounds synthesized by Psacalium decompositum (A. Gray) H. Rob. & Brettell or Psacalium peltatum (Kunth) Cass. Antioxidant and hypoglycemic effects have been found for cacalolides such as cacalol, cacalone or maturine, however, their effects on inflammatory [...] Read more.

Cacalolides are a kind of sesquiterpenoids natural compounds synthesized by Psacalium decompositum (A. Gray) H. Rob. & Brettell or Psacalium peltatum (Kunth) Cass. Antioxidant and hypoglycemic effects have been found for cacalolides such as cacalol, cacalone or maturine, however, their effects on inflammatory processes are still largely unclear. The main aim of this study was to investigate the biological activities of secondary metabolites from P. decompositum and P. peltatum through two approaches: (1) chemoinformatic and toxicoinformatic analysis based on ethnopharmacologic background; and (2) the evaluation of their potential anti-inflammatory/anti-allergic effects in bone marrow-derived mast cells by IgE/antigen complexes. The bioinformatics properties of the compounds: cacalol; cacalone; cacalol acetate and maturin acetate were evaluated through Osiris DataWarrior software and Molinspiration and PROTOX server. In vitro studies were performed to test the ability of these four compounds to inhibit antigen-dependent degranulation and intracellular calcium mobilization, as well as the production of reactive oxygen species in bone marrow-derived mast cells. Our findings showed that cacalol displayed better bioinformatics properties, also exhibited a potent inhibitory activity on IgE/antigen-dependent degranulation and significantly reduced the intracellular calcium mobilization on mast cells. These data suggested that cacalol could reduce the negative effects of the mast cell-dependent inflammatory process. Full article

(This article belongs to the Special Issue Biological Activities of Plant Secondary Metabolites)

► Show Figures

Figure 1

10 pages, 4046 KiB

Open AccessArticle

Native Quercetin as a Chloride Receptor in an Organic Solvent

by Mohamed Lamin Abdi Bellau, Olga Bortolini, Giancarlo Fantin, Marco Fogagnolo, Daniele Ragno, Ignacio Delso and Pedro Merino

Molecules 2018, 23(12), 3366; https://doi.org/10.3390/molecules23123366 - 19 Dec 2018

Cited by 1 | Viewed by 3155

Abstract

The binding properties of quercetin toward chloride anions were investigated by means of ¹H-NMR, ¹³C-NMR, and electrospray ionization mass spectrometry (ESI-MS) measurements, as well as computational calculations. The results indicate that quercetin behaves primarily as a ditopic receptor with the binding [...] Read more.

The binding properties of quercetin toward chloride anions were investigated by means of ¹H-NMR, ¹³C-NMR, and electrospray ionization mass spectrometry (ESI-MS) measurements, as well as computational calculations. The results indicate that quercetin behaves primarily as a ditopic receptor with the binding site of the B ring that exhibits stronger chloride affinity compared to the A ring. However, these sites are stronger receptors than those of catechol and resorcinol because of their conjugation with the carbonyl group located on the C ring. The 1:1 and 1:2 complexation of this flavonoid with Cl⁻ was also supported by ESI mass spectrometry. Full article

► Show Figures

Graphical abstract

13 pages, 2555 KiB

Open AccessArticle

Identification of Pinocembrin as an Anti-Glycation Agent and α-Glucosidase Inhibitor from Fingerroot (Boesenbergia rotunda): The Tentative Structure–Activity Relationship towards MG-Trapping Activity

by Thammatee Potipiranun, Sirichai Adisakwattana, Wisuttaya Worawalai, Rico Ramadhan and Preecha Phuwapraisirisan

Molecules 2018, 23(12), 3365; https://doi.org/10.3390/molecules23123365 - 19 Dec 2018

Cited by 28 | Viewed by 5961

Abstract

Diabetes mellitus (DM) is a disease that is caused by a malfunction of carbohydrate metabolism, which plays an important role in the development of long-term diabetic complications. The excess glucose can be transformed to methylglyoxal (MG), a potential precursor of glycation. Glycation is [...] Read more.

Diabetes mellitus (DM) is a disease that is caused by a malfunction of carbohydrate metabolism, which plays an important role in the development of long-term diabetic complications. The excess glucose can be transformed to methylglyoxal (MG), a potential precursor of glycation. Glycation is a spontaneous non-enzymatic reaction that initially yields advanced glycation end-products (AGEs), which ultimately triggers several severe complications. Therefore, the inhibition of AGEs formation is the imperative approach for alleviating diabetic complications. The aim of this research was to investigate the glycation and α-glucosidase inhibitory abilities of compounds isolated from fingerroot. The dichloromethane extract afforded three flavanones, two chalcones, two dihydrochalcones, and one kavalactone. Most of the isolated compounds showed higher inhibition effect against AGEs formation than aminoguanidine (AG). Subsequent evaluation in MG-trapping assay indicated that their trapping potency was relatively comparable to AG. Their structure-activity relationships (SAR) of MG-trapping activity were investigated using the comparison of the structures of flavonoids. In addition, pinocembrin displayed moderate α-glucosidase inhibition against both maltase and sucrose, with IC₅₀ values of 0.35 ± 0.021 and 0.39 ± 0.020 mM, respectively. Full article

(This article belongs to the Special Issue Natural Product Isolation, Identification and Biological Activity)

► Show Figures

Graphical abstract

8 pages, 1836 KiB

Open AccessArticle

Agar Extraction By-Products from Gelidium sesquipedale as a Source of Glycerol-Galactosides

by Salim Lebbar, Mathieu Fanuel, Sophie Le Gall, Xavier Falourd, David Ropartz, Philippe Bressollier, Vincent Gloaguen and Céline Faugeron-Girard

Molecules 2018, 23(12), 3364; https://doi.org/10.3390/molecules23123364 - 19 Dec 2018

Cited by 24 | Viewed by 7656

Abstract

Alkaline treatment is a common step largely used in the industrial extraction of agar, a phycocolloid obtained from red algae such as Gelidium sesquipedale. The subsequent residue constitutes a poorly valorized by-product. The present study aimed to identify low-molecular-weight compounds in this [...] Read more.

Alkaline treatment is a common step largely used in the industrial extraction of agar, a phycocolloid obtained from red algae such as Gelidium sesquipedale. The subsequent residue constitutes a poorly valorized by-product. The present study aimed to identify low-molecular-weight compounds in this alkaline waste. A fractionation process was designed in order to obtain the oligosaccharidic fraction from which several glycerol-galactosides were isolated. A combination of electrospray ion (ESI)-mass spectrometry, ¹H-NMR spectroscopy, and glycosidic linkage analyses by GC-MS allowed the identification of floridoside, corresponding to Gal-glycerol, along with oligogalactosides, i.e., (Gal)_2–4-glycerol, among which α-d-galactopyranosyl-(1→3)-β-d-galactopyranosylα1-2–glycerol and α-d-galactopyranosyl-(1→4)-β-d-galactopyranosylα1-2–glycerol were described for the first time in red algae. Full article

(This article belongs to the Special Issue Seaweeds: Drifting from Bioactive Molecules to Health-related Effects and Cosmetic Applications)

► Show Figures

Graphical abstract

13 pages, 6592 KiB

Open AccessArticle

5-Phenyl-10,15,20-Tris(4-sulfonatophenyl)porphyrin: Synthesis, Catalysis, and Structural Studies

by Aitor Arlegui, Zoubir El-Hachemi, Joaquim Crusats and Albert Moyano

Molecules 2018, 23(12), 3363; https://doi.org/10.3390/molecules23123363 - 19 Dec 2018

Cited by 12 | Viewed by 6286

Abstract

A convenient protocol for the preparation of 5-phenyl-10,15,20-tris(4-sulfonatophenyl)porphyrin, a water-soluble porphyrin with unique aggregation properties, is described. The procedure relies on the one-pot reductive deamination of 5-(4-aminophenyl)-10,15,20-tris(4-sulfonatophenyl)porphyrin, that can be in turn easily obtained from 5,10,15,20-tetraphenylporphyrin by a known three-step sequence involving mononitration, [...] Read more.

A convenient protocol for the preparation of 5-phenyl-10,15,20-tris(4-sulfonatophenyl)porphyrin, a water-soluble porphyrin with unique aggregation properties, is described. The procedure relies on the one-pot reductive deamination of 5-(4-aminophenyl)-10,15,20-tris(4-sulfonatophenyl)porphyrin, that can be in turn easily obtained from 5,10,15,20-tetraphenylporphyrin by a known three-step sequence involving mononitration, nitro to amine reduction and sulfonation of the phenyl groups. This method provides the title porphyrin in gram scale, and compares very favorably with the up to now only described procedure based on the partial sulfonation of TPP, that involves a long and tedious chromatographic enrichment of the final compound. This has allowed us to study for the first time both the use of its zwitterionic aggregate as a supramolecular catalyst of the aqueous Diels–Alder reaction, and the morphology of the aggregates obtained under optimized experimental conditions by atomic force microscopy and also by transmission electron cryomicroscopy. Full article

(This article belongs to the Special Issue Tetrapyrrolic Macrocycles: Synthesis, Functionalization and Applications 2018)

► Show Figures

Graphical abstract

13 pages, 2910 KiB

Open AccessArticle

Determination of Bitterness of Andrographis Herba Based on Electronic Tongue Technology and Discovery of the Key Compounds of Bitter Substances

by Xiao Zhang, Hongwei Wu, Xiankuo Yu, Hanyan Luo, Yaqi Lu, Hongjun Yang, Xin Li, Zhiyong Li, Liying Tang and Zhuju Wang

Molecules 2018, 23(12), 3362; https://doi.org/10.3390/molecules23123362 - 19 Dec 2018

Cited by 26 | Viewed by 4728

Abstract

Andrographis Herba (AH), the dry aerial segments of Andrographis paniculata (Burm.f.) Nees, is a common herbal remedy with bitter properties in traditional Chinese medicine (TCM) theory. Although bitterness is one of the features representing Chinese medicine, it has not been implemented as an [...] Read more.

Andrographis Herba (AH), the dry aerial segments of Andrographis paniculata (Burm.f.) Nees, is a common herbal remedy with bitter properties in traditional Chinese medicine (TCM) theory. Although bitterness is one of the features representing Chinese medicine, it has not been implemented as an index to assess the quality and efficacy of TCM because of peoples’ subjectivity to taste. In this study, 30 batches of AH with different commercial classifications (leaves, stems, or mixtures of both) were collected. Bitterness of AH was quantified by electronic tongue technology. Meanwhile, chemical compositions were characterized through establishing high-performance liquid chromatography fingerprints. The result indicated that the radar curves of the bitterness from different AH commercial classifications displayed different taste fingerprint information. Based on six taste factors, a Principal Component Analysis (PCA) score three-dimensional (3D) plot exhibited a clear grouping trend (R²X, 0.912; Q², 0.763) among the three different commercial classifications. Six compounds (Peaks 2, 3, 4, 6, 7, 8) with positive correlation to bitterness were discovered by a Spearman correlation analysis. Peaks 2, 6, 7, 8 were identified as andrographolide, neoandrographolide, 14-deoxyandrographolide, and dehydroandrographolide, respectively. The electronic tongue can be used to distinguish AH samples with different commercial classifications and for quality evaluation. Full article

(This article belongs to the Section Analytical Chemistry)

► Show Figures

Figure 1

16 pages, 2729 KiB

Open AccessReview

Anti-Cancer Activity of Derivatives of 1,3,4-Oxadiazole

by Teresa Glomb, Karolina Szymankiewicz and Piotr Świątek

Molecules 2018, 23(12), 3361; https://doi.org/10.3390/molecules23123361 - 18 Dec 2018

Cited by 134 | Viewed by 8184

Abstract

Compounds containing 1,3,4-oxadiazole ring in their structure are characterised by multidirectional biological activity. Their anti-proliferative effects associated with various mechanisms, such as inhibition of growth factors, enzymes, kinases and others, deserve attention. The activity of these compounds was tested on cell lines of [...] Read more.

Compounds containing 1,3,4-oxadiazole ring in their structure are characterised by multidirectional biological activity. Their anti-proliferative effects associated with various mechanisms, such as inhibition of growth factors, enzymes, kinases and others, deserve attention. The activity of these compounds was tested on cell lines of various cancers. In most publications, the most active derivatives of 1,3,4-oxadiazole exceeded the effect of reference drugs, so they may become the main new anti-cancer drugs in the future. Full article

(This article belongs to the Section Medicinal Chemistry)

► Show Figures

Figure 1

13 pages, 1449 KiB

Open AccessArticle

Effect of Capsaicin and Other Thermo-TRP Agonists on Thermoregulatory Processes in the American Cockroach

by Justyna Maliszewska, Milena Jankowska, Hanna Kletkiewicz, Maria Stankiewicz and Justyna Rogalska

Molecules 2018, 23(12), 3360; https://doi.org/10.3390/molecules23123360 - 18 Dec 2018

Cited by 12 | Viewed by 5113

Abstract

Capsaicin is known to activate heat receptor TRPV1 and induce changes in thermoregulatory processes of mammals. However, the mechanism by which capsaicin induces thermoregulatory responses in invertebrates is unknown. Insect thermoreceptors belong to the TRP receptors family, and are known to be activated [...] Read more.

Capsaicin is known to activate heat receptor TRPV1 and induce changes in thermoregulatory processes of mammals. However, the mechanism by which capsaicin induces thermoregulatory responses in invertebrates is unknown. Insect thermoreceptors belong to the TRP receptors family, and are known to be activated not only by temperature, but also by other stimuli. In the following study, we evaluated the effects of different ligands that have been shown to activate (allyl isothiocyanate) or inhibit (camphor) heat receptors, as well as, activate (camphor) or inhibit (menthol and thymol) cold receptors in insects. Moreover, we decided to determine the effect of agonist (capsaicin) and antagonist (capsazepine) of mammalian heat receptor on the American cockroach’s thermoregulatory processes. We observed that capsaicin induced the decrease of the head temperature of immobilized cockroaches. Moreover, the examined ligands induced preference for colder environments, when insects were allowed to choose the ambient temperature. Camphor exposure resulted in a preference for warm environments, but the changes in body temperature were not observed. The results suggest that capsaicin acts on the heat receptor in cockroaches and that TRP receptors are involved in cockroaches’ thermosensation. Full article

(This article belongs to the Special Issue Capsaicin—2nd Edition)

► Show Figures

Graphical abstract

13 pages, 829 KiB

Open AccessArticle

Qualitative and Quantitative Analysis of C-glycosyl-flavones of Iris lactea Leaves by Liquid Chromatography/Tandem Mass Spectrometry

by Dan Chen, Yu Meng, Yan Zhu, Gang Wu, Jun Yuan, Minjian Qin and Guoyong Xie

Molecules 2018, 23(12), 3359; https://doi.org/10.3390/molecules23123359 - 18 Dec 2018

Cited by 11 | Viewed by 4060

Abstract

Iris lactea Pall. var. chinensis (Fisch.) Koidz. is a traditional medicinal plant resource. To make full use of the I. lactea plant resources, constituents of I. lactea leaves were determined by high performance liquid chromatography (HPLC)-quadrupole time-of-flight tandem mass spectrometry and 22 C [...] Read more.

Iris lactea Pall. var. chinensis (Fisch.) Koidz. is a traditional medicinal plant resource. To make full use of the I. lactea plant resources, constituents of I. lactea leaves were determined by high performance liquid chromatography (HPLC)-quadrupole time-of-flight tandem mass spectrometry and 22 C-glycosylflavones were identified or tentatively identified. Optimal extraction of I. lactea leaves was established via single factor investigations combined with response surface methodology. Then, HPLC coupled with a diode array detector was used to quantitatively analyze the six main components of 14 batches of I. lactea leaves grown in different areas. The results showed the C-glycosylflavones were the main components of I. lactea leaves, and the total contents of detected components were relatively stable for the majority of samples. These results provide a foundation for the development and utilization of I. lactea leaves. Full article

(This article belongs to the Special Issue Qualitative and Quantitative Analysis of Bioactive Natural Products 2018)

► Show Figures

Graphical abstract

20 pages, 5075 KiB

Open AccessArticle

Photochemical Reactions in Dialdehyde Starch

by Marta Ziegler-Borowska, Katarzyna Wegrzynowska-Drzymalska, Dorota Chelminiak-Dudkiewicz, Jolanta Kowalonek and Halina Kaczmarek

Molecules 2018, 23(12), 3358; https://doi.org/10.3390/molecules23123358 - 18 Dec 2018

Cited by 31 | Viewed by 6503

Abstract

In this study potato and corn starch were subjected to oxidation, using sodium periodate, to obtain dialdehyde starch (DAS) containing different amount of aldehyde groups. The obtained modified starch samples have been characterized with chemical analysis, scanning electron microscopy (SEM) and ATR-FTIR spectroscopy. [...] Read more.

In this study potato and corn starch were subjected to oxidation, using sodium periodate, to obtain dialdehyde starch (DAS) containing different amount of aldehyde groups. The obtained modified starch samples have been characterized with chemical analysis, scanning electron microscopy (SEM) and ATR-FTIR spectroscopy. Then, the samples were exposed to polychromatic UV radiation and the course of photochemical reaction has been monitored with ATR-FTIR spectroscopy. The surface properties of the native and dialdehyde starch before and after UV-irradiation have been determined by contact angle measurements and calculation of surface free energy. The crystallinity of the samples has been estimated with X-ray diffraction (XRD). It has been proved that the dialdehyded corn starch contained a higher amount of functional groups was more photostable than the oxidized potato starch. Sodium iodide(V), firmly bound to DAS macromolecules, has been found to have a significant effect on the photooxidative degradation of the tested systems. In addition, the mechanism of photoinduced reactions in the dialdehyde starch has been proposed. Full article

(This article belongs to the Special Issue Carbohydrate Chemistry)

► Show Figures

Figure 1

14 pages, 2456 KiB

Open AccessArticle

Formation of Nudicaulins In Vivo and In Vitro and the Biomimetic Synthesis and Bioactivity of O-Methylated Nudicaulin Derivatives

by Bettina Dudek, Florian Schnurrer, Hans-Martin Dahse, Christian Paetz, Anne-Christin Warskulat, Christiane Weigel, Kerstin Voigt and Bernd Schneider

Molecules 2018, 23(12), 3357; https://doi.org/10.3390/molecules23123357 - 18 Dec 2018

Cited by 5 | Viewed by 4496

Abstract

Nudicaulins are yellow flower pigments accounting for the color of the petals of Papaver nudicaule (Papaveraceae). These glucosidic compounds belong to the small group of indole/flavonoid hybrid alkaloids. Here we describe in vivo and in vitro experiments which substantiate the strongly pH-dependent conversion [...] Read more.

Nudicaulins are yellow flower pigments accounting for the color of the petals of Papaver nudicaule (Papaveraceae). These glucosidic compounds belong to the small group of indole/flavonoid hybrid alkaloids. Here we describe in vivo and in vitro experiments which substantiate the strongly pH-dependent conversion of pelargonidin glucosides to nudicaulins as the final biosynthetic step of these alkaloids. Furthermore, we report the first synthesis of nudicaulin aglycon derivatives, starting with quercetin and ending up at the biomimetic fusion of a permethylated anthocyanidin with indole. A small library of nudicaulin derivatives with differently substituted indole units was prepared, and the antimicrobial, antiproliferative and cell toxicity data of the new compounds were determined. The synthetic procedure is considered suitable for preparing nudicaulin derivatives which are structurally modified in the indole and/or the polyphenolic part of the molecule and may have optimized pharmacological activities. Full article

(This article belongs to the Section Natural Products Chemistry)

► Show Figures

Graphical abstract

16 pages, 2632 KiB

Open AccessArticle

Resveratrol-Induced White Adipose Tissue Browning in Obese Mice by Remodeling Fecal Microbiota

by Weiyao Liao, Xiaohan Yin, Qingrong Li, Hongmin Zhang, Zihui Liu, Xinjie Zheng, Lin Zheng and Xiang Feng

Molecules 2018, 23(12), 3356; https://doi.org/10.3390/molecules23123356 - 18 Dec 2018

Cited by 46 | Viewed by 7007

Abstract

Promoting the browning of white fat may be a potential means of combating obesity. Therefore, in this study, we investigated the effect of resveratrol (RES) on the body weight and browning of white fat in high-fat diet (HFD)-induced obese mice and the potential [...] Read more.

Promoting the browning of white fat may be a potential means of combating obesity. Therefore, in this study, we investigated the effect of resveratrol (RES) on the body weight and browning of white fat in high-fat diet (HFD)-induced obese mice and the potential associated mechanism in vivo. Eight-week-old male mice were randomized to receive different treatments: (1), chow without any additional treatment (chow); (2), chow plus 0.4% resveratrol (chow-RES); (3), HFD without any additional treatment (HFD); and (4), HFD plus 0.4% resveratrol (HFD-RES). After 4 weeks of feeding, additional 8-week-old male recipient mice were randomly allocated to the following 4 treatments: (5), HFD and received feces from chow-fed mice; (6), HFD and received feces from chow-RES-fed mice; (7), HFD and received feces from HFD-fed mice; and (8), HFD and received feces from HFD-RES-fed mice. RES treatment significantly inhibited increases in fat accumulation, promoted the browning of white adipose tissue (WAT) and alleviated gut microbiota dysbiosis in HFD-fed mice. Subsequent analyses showed that the gut microbiota remodeling induced by resveratrol had a positive role in WAT browning, and sirtuin-1 (Sirt1) signaling appears to be a key component of this process. Overall, the results show that RES may serve as a potential intervention to reduce obesity by alleviating dysbiosis of the gut microbiota. Full article

(This article belongs to the Special Issue Natural Bioactives in Anti-Obesity Therapy)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Molecules, Volume 23, Issue 12 (December 2018) – 335 articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI