Molecules

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Open AccessArticle

Discovery and Structure-Based Optimization of 6-Bromotryptamine Derivatives as Potential 5-HT_2A Receptor Antagonists

by Lijian Ding, Shan He, Wei Wu, Haixiao Jin, Peng Zhu, Jinrong Zhang, Tingting Wang, Ye Yuan and Xiaojun Yan

Molecules 2015, 20(9), 17675-17683; https://doi.org/10.3390/molecules200917675 - 23 Sep 2015

Cited by 5 | Viewed by 5426

Abstract

5-Hydroxytryptamine type 2A (5-HT_2A) receptor is an important target for developing innovative antipsychotic agents in neuropsychiatric disorder therapies. To search for 5-HT_2A receptor antagonists, a new indole alkaloid termed 6-bromo-N-propionyltryptamine (1), together with one known homologue [...] Read more.

5-Hydroxytryptamine type 2A (5-HT_2A) receptor is an important target for developing innovative antipsychotic agents in neuropsychiatric disorder therapies. To search for 5-HT_2A receptor antagonists, a new indole alkaloid termed 6-bromo-N-propionyltryptamine (1), together with one known homologue 6-bromo-N-acetyltryptamine (2) were isolated and identified from a marine bacterium Pseudoalteromonas rubra QD1-2. Compound 1 with an N-propionyl side chain exhibited stronger 5-HT_2A receptor antagonist activity than that of N-acetyl derivative (2), indicating that 6-bromotryptamine analogues with a longer chain acyl group perhaps displayed a more potent capacity to the target. Therefore, a series of new 6-bromotryptamine analogues (3–7) with different chain length of the acyl group (C4–C8) were prepared and evaluated activity against 5-HT_2A receptor. Remarkably, 6-bromo-N-hexanoyltryptamine (5) displayed the most effective inhibitory activity, which was 5-fold stronger than that of the parent compound 1 and showed 70% efficacy of the positive control (ketanserin tartrate). Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessReview

Small-Molecule Inhibitors of the Type III Secretion System

by Lingling Gu, Shanshan Zhou, Lanping Zhu, Cuirong Liang and Xin Chen

Molecules 2015, 20(9), 17659-17674; https://doi.org/10.3390/molecules200917659 - 23 Sep 2015

Cited by 45 | Viewed by 10442

Abstract

Drug-resistant pathogens have presented increasing challenges to the discovery and development of new antibacterial agents. The type III secretion system (T3SS), existing in bacterial chromosomes or plasmids, is one of the most complicated protein secretion systems. T3SSs of animal and plant pathogens possess [...] Read more.

Drug-resistant pathogens have presented increasing challenges to the discovery and development of new antibacterial agents. The type III secretion system (T3SS), existing in bacterial chromosomes or plasmids, is one of the most complicated protein secretion systems. T3SSs of animal and plant pathogens possess many highly conserved main structural components comprised of about 20 proteins. Many Gram-negative bacteria carry T3SS as a major virulence determinant, and using the T3SS, the bacteria secrete and inject effector proteins into target host cells, triggering disease symptoms. Therefore, T3SS has emerged as an attractive target for antimicrobial therapeutics. In recent years, many T3SS-targeting small-molecule inhibitors have been discovered; these inhibitors prevent the bacteria from injecting effector proteins and from causing pathophysiology in host cells. Targeting the virulence of Gram-negative pathogens, rather than their survival, is an innovative and promising approach that may greatly reduce selection pressures on pathogens to develop drug-resistant mutations. This article summarizes recent progress in the search for promising small-molecule T3SS inhibitors that target the secretion and translocation of bacterial effector proteins. Full article

(This article belongs to the Special Issue Design and Synthesis of Novel Conjugated and Non Conjugated Small Molecules)

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Open AccessArticle

Comparative Incorporation of PNA into DNA Nanostructures

by Ronnie O. Pedersen, Jing Kong, Catalina Achim and Thomas H. LaBean

Molecules 2015, 20(9), 17645-17658; https://doi.org/10.3390/molecules200917645 - 23 Sep 2015

Cited by 14 | Viewed by 7035

Abstract

DNA has shown great promise as a building material for self-assembling nanoscale structures. To further develop the potential of this technology, more methods are needed for functionalizing DNA-based nanostructures to increase their chemical diversity. Peptide nucleic acid (PNA) holds great promise for realizing [...] Read more.

DNA has shown great promise as a building material for self-assembling nanoscale structures. To further develop the potential of this technology, more methods are needed for functionalizing DNA-based nanostructures to increase their chemical diversity. Peptide nucleic acid (PNA) holds great promise for realizing this goal, as it conveniently allows for inclusion of both amino acids and peptides in nucleic acid-based structures. In this work, we explored incorporation of a positively charged PNA within DNA nanostructures. We investigated the efficiency of annealing a lysine-containing PNA probe with complementary, single-stranded DNA sequences within nanostructures, as well as the efficiency of duplex invasion and its dependence on salt concentration. Our results show that PNA allows for toehold-free strand displacement and that incorporation yield depends critically on binding site geometry. These results provide guidance for the design of PNA binding sites on nucleic acid nanostructures with an eye towards optimizing fabrication yield. Full article

(This article belongs to the Special Issue Frontiers in Nucleic Acid Chemistry)

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Open AccessArticle

Dichlorinated and Brominated Rugulovasines, Ergot Alkaloids Produced by Talaromyces wortmannii

by Lívia Soman De Medeiros, José Vinícius Da Silva, Lucas Magalhães Abreu, Ludwig Heinrich Pfenning, Carolina Lúcia Silva, Sérgio Secherrer Thomasi, Tiago Venâncio, Karl-Heinz Van Pée, Kristian Fog Nielsen and Edson Rodrigues-Filho

Molecules 2015, 20(9), 17627-17644; https://doi.org/10.3390/molecules200917627 - 23 Sep 2015

Cited by 9 | Viewed by 7199

Abstract

UHPLC-DAD-HRMS based dereplication guided the detection of new halogenated alkaloids co-produced by Talaromyces wortmannii. From the fungal growth in large scale, the epimers 2,8-dichlororugulovasines A and B were purified and further identified by means of a HPLC-SPE/NMR hyphenated system. Brominated rugulovasines were [...] Read more.

UHPLC-DAD-HRMS based dereplication guided the detection of new halogenated alkaloids co-produced by Talaromyces wortmannii. From the fungal growth in large scale, the epimers 2,8-dichlororugulovasines A and B were purified and further identified by means of a HPLC-SPE/NMR hyphenated system. Brominated rugulovasines were also detected when the microbial incubation medium was supplemented with bromine sources. Studies from 1D/2D NMR and HRMS spectroscopy data allowed the structural elucidation of the dichlorinated compounds, while tandem MS/HRMS data analysis supported the rationalization of brominated congeners. Preliminary genetic studies revealed evidence that FADH₂ dependent halogenase can be involved in the biosynthesis of the produced halocompounds. Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessArticle

Antibacterial and Antitumor Activities of Biscoumarin and Dihydropyran Derivatives

by Yun-Peng Sui, Hai-Ru Huo, Jia-Jia Xin, Jing Li, Xiao-Jun Li, Xin-Liang Du, Hai Ma, Hai-Yu Zhou, Hong-Dan Zhan, Zhu-Ju Wang, Chun Li, Feng Sui and Ming-Kai Li

Molecules 2015, 20(9), 17614-17626; https://doi.org/10.3390/molecules200917614 - 23 Sep 2015

Cited by 19 | Viewed by 5918

Abstract

A novel series of biscoumarin (1–4) and dihydropyran (5–13) derivatives were synthesized via a one-pot multicomponent condensation reaction and evaluated for antibacterial and antitumor activity in vitro. The X-ray crystal structure analysis of four [...] Read more.

A novel series of biscoumarin (1–4) and dihydropyran (5–13) derivatives were synthesized via a one-pot multicomponent condensation reaction and evaluated for antibacterial and antitumor activity in vitro. The X-ray crystal structure analysis of four representative compounds, 3, 7, 9 and 11, confirmed the structures of these compounds. Compounds 1–4 showed the most potent antitumor activity among the total 13 derivatives; especially for compounds 1 and 2, they also emerged as promising antibacterial members with better antibacterial activity. In addition, the results of density functional theory (DFT) showed that compared with compounds 3 and 4, biscoumarins 1 and 2 had lower intramolecular hydrogen bonds (HB) energy in their structures. Full article

(This article belongs to the Section Medicinal Chemistry)

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Open AccessArticle

The Application of Template Selectophores for the Preparation of Molecularly Imprinted Polymers

by Basil Danylec, Lachlan J. Schwarz, Simon J. Harris, Reinhard I. Boysen and Milton T. W. Hearn

Molecules 2015, 20(9), 17601-17613; https://doi.org/10.3390/molecules200917601 - 23 Sep 2015

Cited by 17 | Viewed by 7325

Abstract

Molecularly imprinted polymers are versatile materials with wide application scope for the detection, capture and separation of specific compounds present in complex feed stocks. A major challenge associated with their preparation has been the need to sacrifice one mole equivalent of the template [...] Read more.

Molecularly imprinted polymers are versatile materials with wide application scope for the detection, capture and separation of specific compounds present in complex feed stocks. A major challenge associated with their preparation has been the need to sacrifice one mole equivalent of the template molecule to generate the complementary polymer cavities that selectively bind the target molecule. Moreover, template molecules can often be difficult to synthesise, expensive or lack stability. In this study, we describe a new approach, directed at the use of synthetic selectophores, chosen as readily prepared and low cost structural analogues with recognition groups in similar three-dimensional arrangements as found in the target molecule. To validate the approach, a comparative study of selectophores related to the polyphenolic compound (E)-resveratrol has been undertaken using traditional and green chemical synthetic approaches. These molecular mimic compounds were employed as polymer templates and also as binding analytes to interrogate the recognition sites associated with the molecularly imprinted polymers. Importantly, the study confirms that the use of selectophores has the potential to confer practical advantages, including access to more efficient methods for selection and preparation of suitable template molecules with a broader range of molecular diversity, as well as delivering imprinted polymers capable of recognizing the target compound and structurally related products. Full article

(This article belongs to the Special Issue Frontier in Green Chemistry Approaches)

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Open AccessArticle

Synthesis and Pharmacological Evaluation of Novel Benzenesulfonamide Derivatives as Potential Anticonvulsant Agents

by Zhiming Wang, Jinping Li, Xiao-Dong Zeng, Xian-Ming Hu, Xiaoju Zhou and Xuechuan Hong

Molecules 2015, 20(9), 17585-17600; https://doi.org/10.3390/molecules200917585 - 23 Sep 2015

Cited by 3 | Viewed by 6397

Abstract

A novel series of benzenesulfonamide derivatives containing 4-aminobenzenesul-fonamide and α-amides branched valproic acid or 2,2-dimethylcyclopropanecarboxylic acid moieties were synthesized and screened for their anticonvulsant activities in mice maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole (scPTZ) test. The activity experimental study showed that 2,2-dipropyl- [...] Read more.

A novel series of benzenesulfonamide derivatives containing 4-aminobenzenesul-fonamide and α-amides branched valproic acid or 2,2-dimethylcyclopropanecarboxylic acid moieties were synthesized and screened for their anticonvulsant activities in mice maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole (scPTZ) test. The activity experimental study showed that 2,2-dipropyl-N¹-(4-sulfamoylphenyl)malonamide (18b) had the lowest median effective dose (ED₅₀) of 16.36 mg/kg in MES test, and 2,2-dimethyl-N-(4-sulfamoylphenyl)cyclopropane-1,1-dicarboxamide (12c) had the lowest ED₅₀ of 22.50 mg/kg in scPTZ test, which resulted in the protective indexe (PI) of 24.8 and 20.4, respectively. These promising data suggest the new compounds have good potential as new class of anticonvulsant agents with high effectiveness and low toxicity for the treatment of epilepsy. Full article

(This article belongs to the Section Medicinal Chemistry)

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Open AccessArticle

Effects of Crocetin Esters and Crocetin from Crocus sativus L. on Aortic Contractility in Rat Genetic Hypertension

by Silvia Llorens, Andrea Mancini, Jessica Serrano-Díaz, Anna Maria D’Alessandro, Eduardo Nava, Gonzalo Luis Alonso and Manuel Carmona

Molecules 2015, 20(9), 17570-17584; https://doi.org/10.3390/molecules200917570 - 22 Sep 2015

Cited by 32 | Viewed by 7717

Abstract

Background: Endothelial dysfunction, characterized by an enhancement in vasoconstriction, is clearly associated with hypertension. Saffron (Crocus sativus L.) bioactive compounds have been recognized to have hypotensive properties. Recently, we have reported that crocetin exhibits potent vasodilator effects on isolated aortic rings from [...] Read more.

Background: Endothelial dysfunction, characterized by an enhancement in vasoconstriction, is clearly associated with hypertension. Saffron (Crocus sativus L.) bioactive compounds have been recognized to have hypotensive properties. Recently, we have reported that crocetin exhibits potent vasodilator effects on isolated aortic rings from hypertensive rats. In this work, we have aimed to analyze the anticontractile ability of crocetin or crocetin esters pool (crocins) isolated from saffron. Thus, we have studied the effects of saffron carotenoids on endothelium-dependent and -independent regulation of smooth muscle contractility in genetic hypertension. Methods: We have measured the isometric responses of aortic segments with or without endothelium obtained from spontaneously hypertensive rats. The effects of carotenoids were studied by assessing the endothelial modulation of phenylephrine-induced contractions (10⁻⁹–10⁻⁵ M) in the presence or absence of crocetin or crocins. The role of nitric oxide and prostanoids was analyzed by performing the experiments with L-NAME (NG-nitro-l-arginine methyl ester) or indomethacin (both 10⁻⁵ M), respectively. Results: Crocetin, and to a minor extent crocins, diminished the maximum contractility of phenylephrine in intact rings, while crocins, but not crocetin, increased this contractility in de-endothelizated vessels. In the intact vessels, the effect of crocetin on contractility was unaffected by indomethacin but was abolished by L-NAME. However, crocetin but not crocins, lowered the already increased contractility caused by L-NAME. Conclusions: Saffron compounds, but especially crocetin have endothelium-dependent prorelaxing actions. Crocins have procontractile actions that take place via smooth muscle cell mechanisms. These results suggest that crocetin and crocins activate different mechanisms involved in the vasoconstriction pathway in hypertension. Full article

(This article belongs to the Special Issue Saffron (Crocus sativus, L.): Omics and Other Techniques in Authenticity, Quality and Bioactivity Studies)

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Open AccessArticle

The Antiaging Properties of Andrographis paniculata by Activation Epidermal Cell Stemness

by Jiyoung You, Kyung-Baeg Roh, Zidan Li, Guangrong Liu, Jian Tang, Seoungwoo Shin, Deokhoon Park and Eunsun Jung

Molecules 2015, 20(9), 17557-17569; https://doi.org/10.3390/molecules200917557 - 22 Sep 2015

Cited by 18 | Viewed by 7803

Abstract

Andrographis paniculata (A. paniculata, Chuanxinlian), a medicinal herb with an extremely bitter taste that is native to China and other parts of Southeast Asia, possesses immense therapeutic value; however, its therapeutic properties have rarely been applied in the field of [...] Read more.

Andrographis paniculata (A. paniculata, Chuanxinlian), a medicinal herb with an extremely bitter taste that is native to China and other parts of Southeast Asia, possesses immense therapeutic value; however, its therapeutic properties have rarely been applied in the field of skin care. In this study, we investigated the effect of an A. paniculata extract (APE) on human epidermal stem cells (EpSCs), and confirmed its anti-aging effect through in vitro, ex vivo, and in vivo study. An MTT assay was used to determine cell proliferation. A flow cytometric analysis, with propidium iodide, was used to evaluate the cell cycle. The expression of integrin β1 (CD29), the stem cell marker, was detected with antibodies, using flow cytometry in vitro, and immunohistochemical assays in ex vivo. Type 1 collagen and VEGF (vascular endothelial growth factor) were measured using an enzyme-linked immunosorbent assay (ELISA). During the clinical study, skin hydration, elasticity, wrinkling, sagging, and dermal density were evaluated before treatment and at four and eight weeks after the treatment with the test product (containing the APE) on the face. The proliferation of the EpSCs, treated with the APE, increased significantly. In the cell cycle analysis, the APE increased the G2/M and S stages in a dose-dependent manner. The expression of integrin β1, which is related to epidermal progenitor cell expansion, was up-regulated in the APE-treated EpSCs and skin explants. In addition, the production of VEGF in the EpSCs increased significantly in response to the APE treatment. Consistent with these results, the VEGF and APE-treated EpSCs conditioned medium enhanced the Type 1 collagen production in normal human fibroblasts (NHFs). In the clinical study, the APE improved skin hydration, dermal density, wrinkling, and sagging significantly. Our findings revealed that the APE promotes a proliferation of EpSCs, through the up-regulation of the integrin β1 and VEGF expression. The VEGF might affect the collagen synthesis of NHF as a paracrine factor. Clinical studies further suggested that treatment with formulations containing APE confers anti-aging benefits. Based on these results, we suggest that APE may be introduced as a possible anti-aging agent. Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessArticle

Three New Cytotoxic ent-Kaurane Diterpenes from Isodon excisoides

by Li-Ping Dai, Chun Li, Han-Ze Yang, Yan-Qing Lu, Hong-Yan Yu, Hui-Min Gao and Zhi-Min Wang

Molecules 2015, 20(9), 17544-17556; https://doi.org/10.3390/molecules200917544 - 22 Sep 2015

Cited by 19 | Viewed by 5583

Abstract

Three types of ent-kaurane diterpenoids were isolated from the aerial parts of Isodon excisoides, including three new diterpenoids, 1α,7α,14β-trihydroxy-20-acetoxy-ent-kaur-15-one (1); 1α,7α,14β,18-tetrahydroxy-20-acetoxy-ent-kaur-15-one (2); and 1α-acetoxy-14β-hydroxy-7α,20-epoxy-ent-kaur-16-en-15-one (3); together with six known [...] Read more.

Three types of ent-kaurane diterpenoids were isolated from the aerial parts of Isodon excisoides, including three new diterpenoids, 1α,7α,14β-trihydroxy-20-acetoxy-ent-kaur-15-one (1); 1α,7α,14β,18-tetrahydroxy-20-acetoxy-ent-kaur-15-one (2); and 1α-acetoxy-14β-hydroxy-7α,20-epoxy-ent-kaur-16-en-15-one (3); together with six known diterpenes henryin (4); kamebanin (5); reniformin C (6); kamebacetal A (7); kamebacetal B (8); and oridonin (9). The structures of the isolated compounds were elucidated by means of nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry in conjunction with published data for their analogs, as well as their fragmentation patterns. Compounds 5 and 9 were isolated from Isodon excisoides for the first time. To explore the structure-activity relationships of the isolated compounds, they were tested for their cytotoxic effects against five human cancer cell lines: HCT-116, HepG2, A2780, NCI-H1650, and BGC-823. Most of the isolated compounds showed certain cytotoxic activity against the five cancer cell lines with IC₅₀ values ranging from 1.09–8.53 µM. Among the tested compounds, compound 4 exhibited the strongest cytotoxic activity in the tested cell lines, with IC₅₀ values ranging from 1.31–2.07 µM. Compounds 1, 6, and 7 exhibited selective cytotoxic activity. Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessArticle

Electrical Properties of Multi-Pyrene/Porphyrin-Dendrimers

by Mark Euguenii Martínez-Klimov, Ulises Organista-Mateos, Andrés Borja-Miranda, Margarita Rivera, Oscar Amelines-Sarria and Marcos Martínez-García

Molecules 2015, 20(9), 17533-17543; https://doi.org/10.3390/molecules200917533 - 22 Sep 2015

Cited by 6 | Viewed by 5913

Abstract

Dendrimers bearing pyrene donor groups have been obtained and act as efficient light-harvesting antennae capable of transferring light energy through space from their periphery to their core. The light-harvesting ability increases with each generation due to an increase in the number of peripheral [...] Read more.

Dendrimers bearing pyrene donor groups have been obtained and act as efficient light-harvesting antennae capable of transferring light energy through space from their periphery to their core. The light-harvesting ability increases with each generation due to an increase in the number of peripheral pyrenes. In order to evaluate the photovoltaic properties of the compounds, thermal evaporated thin films were produced and the voltage response in the presence of visible light was obtained. The energy transfer efficiency was found to be almost quantitative for the first and second generations. The dendrimers have the potential to become integral components of molecular photonic devices. Full article

(This article belongs to the Special Issue Tetrapyrroles, Porphyrins and Phthalocyanines)

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Open AccessReview

G-Quadruplex Forming Oligonucleotides as Anti-HIV Agents

by Domenica Musumeci, Claudia Riccardi and Daniela Montesarchio

Molecules 2015, 20(9), 17511-17532; https://doi.org/10.3390/molecules200917511 - 22 Sep 2015

Cited by 53 | Viewed by 10532

Abstract

Though a variety of different non-canonical nucleic acids conformations have been recognized, G-quadruplex structures are probably the structural motifs most commonly found within known oligonucleotide-based aptamers. This could be ascribed to several factors, as their large conformational diversity, marked responsiveness of their folding/unfolding [...] Read more.

Though a variety of different non-canonical nucleic acids conformations have been recognized, G-quadruplex structures are probably the structural motifs most commonly found within known oligonucleotide-based aptamers. This could be ascribed to several factors, as their large conformational diversity, marked responsiveness of their folding/unfolding processes to external stimuli, high structural compactness and chemo-enzymatic and thermodynamic stability. A number of G-quadruplex-forming oligonucleotides having relevant in vitro anti-HIV activity have been discovered in the last two decades through either SELEX or rational design approaches. Improved aptamers have been obtained by chemical modifications of natural oligonucleotides, as terminal conjugations with large hydrophobic groups, replacement of phosphodiester linkages with phosphorothioate bonds or other surrogates, insertion of base-modified monomers, etc. In turn, detailed structural studies have elucidated the peculiar architectures adopted by many G-quadruplex-based aptamers and provided insight into their mechanism of action. An overview of the state-of-the-art knowledge of the relevance of putative G-quadruplex forming sequences within the viral genome and of the most studied G-quadruplex-forming aptamers, selectively targeting HIV proteins, is here presented. Full article

(This article belongs to the Special Issue Frontiers in Nucleic Acid Chemistry)

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Open AccessArticle

Quantitative Structure–Property Relationship (QSPR) Models for a Local Quantum Descriptor: Investigation of the 4- and 3-Substituted-Cinnamic Acid Esterification

by Cláudio E. Rodrigues-Santos, Aurea Echevarria, Carlos M. R. Sant’Anna, Thiago B. Bitencourt, Maria G. Nascimento and Glauco F. Bauerfeldt

Molecules 2015, 20(9), 17493-17510; https://doi.org/10.3390/molecules200917493 - 22 Sep 2015

Cited by 2 | Viewed by 6156

Abstract

In this work, the theoretical description of the 4- and 3-substituted-cinnamic acid esterification with different electron donating and electron withdrawing groups was performed at the B3LYP and M06-2X levels, as a two-step process: the O-protonation and the nucleophile attack by ethanol. In [...] Read more.

In this work, the theoretical description of the 4- and 3-substituted-cinnamic acid esterification with different electron donating and electron withdrawing groups was performed at the B3LYP and M06-2X levels, as a two-step process: the O-protonation and the nucleophile attack by ethanol. In parallel, an experimental work devoted to the synthesis and characterization of the substituted-cinnamate esters has also been performed. In order to quantify the substituents effects, quantitative structure–property relationship (QSPR) models based on the atomic charges, Fukui functions and the Frontier Effective-for-Reaction Molecular Orbitals (FERMO) energies were investigated. In fact, the Fukui functions, ƒ⁺C and ƒ⁻O, indicated poor correlations for each individual step, and in contrast with the general literature, the O-protonation step is affected both by the FERMO energies and the O-charges of the carbonyl group. Since the process was shown to not be totally described by either charge- or frontier-orbitals, it is proposed to be frontier-charge-miscere controlled. Moreover, the observed trend for the experimental reaction yields suggests that the electron withdrawing groups favor the reaction and the same was observed for Step 2, which can thus be pointed out as the determining step. Full article

(This article belongs to the Section Medicinal Chemistry)

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Open AccessArticle

Insecticidal Constituents and Activity of Alkaloids from Cynanchum mongolicum

by Yang Ge, Pingping Liu, Rui Yang, Liu Zhang, Hongxing Chen, Ibrahima Camara, Yiqing Liu and Wangpeng Shi

Molecules 2015, 20(9), 17483-17492; https://doi.org/10.3390/molecules200917483 - 21 Sep 2015

Cited by 33 | Viewed by 6080

Abstract

Based on MS and NMR data and bioassay-guided tracing, three insecticidal alkaloids I, II and III from Cynanchum mongolicum were identified to be antofine N-oxide, antofine and tylophorine. Alkaloid I was more toxic than alkaloids II and III, but they [...] Read more.

Based on MS and NMR data and bioassay-guided tracing, three insecticidal alkaloids I, II and III from Cynanchum mongolicum were identified to be antofine N-oxide, antofine and tylophorine. Alkaloid I was more toxic than alkaloids II and III, but they were less active against Spodoptera litura than total alkaloids. The contact toxicity from these alkaloids against the aphid Lipaphis erysimi was significant, as the 24 h-LC₅₀ values of alkaloids I, II, III and total alkaloids were 292.48, 367.21, 487.791 and 163.52 mg/L, respectively. The development disruption of S. litura larvae was tested, the pupation and emergence rates of S. litura decreased and the acute mortality of S. litura increased significantly by day 3 after being injected in their body cavity with 10–40 mg/L of total alkaloid. The ecdysone titer of treated S. litura larvae and prepupae declined with increasing alkaloid concentration. The alkaloids of Cynanchum mongolicum are potential insect growth inhibitors. Full article

(This article belongs to the Collection Bioactive Compounds)

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Open AccessArticle

Synthesis of Biscoumarin and Dihydropyran Derivatives and Evaluation of Their Antibacterial Activity

by Jing Li, Chang-Wei Lv, Xiao-Jun Li, Di Qu, Zheng Hou, Min Jia, Xiao-Xing Luo, Xia Li and Ming-Kai Li

Molecules 2015, 20(9), 17469-17482; https://doi.org/10.3390/molecules200917469 - 18 Sep 2015

Cited by 54 | Viewed by 5819

Abstract

In an attempt to find a new class antibacterial agents, a series of biscoumarins (1–4) and dihydropyrans (5–13) were successfully prepared. The molecular structures of four representative compounds, that is, 4, 5, 8 [...] Read more.

In an attempt to find a new class antibacterial agents, a series of biscoumarins (1–4) and dihydropyrans (5–13) were successfully prepared. The molecular structures of four representative compounds, that is, 4, 5, 8 and 12 were confirmed by single crystal X-ray diffraction study. These synthesized compounds were screened for their antibacterial activity in vitro against Staphylococcus aureus (S. aureus ATCC 29213), methicillin-resistant S. aureus (MRSA XJ 75302), vancomycin-intermediate S. aureus (Mu50 ATCC 700699), USA 300 (Los Angeles County clone, LAC), Staphylococcus epidermidis (S. epidermidis ATCC 14990), methicillin-resistant S. epidermidis (MRSE XJ 75284) and Escherichia coli (E. coli ATCC 25922). Additionally, there are two classical intramolecular O–H···O hydrogen bonds (HBs) in biscoumarins 1–4 and the corresponding HB energies were further performed with the density functional theory (DFT) [B3LYP/6-31G*] method. Full article

(This article belongs to the Section Medicinal Chemistry)

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Open AccessReview

Metabolic and Microbial Modulation of the Large Intestine Ecosystem by Non-Absorbed Diet Phenolic Compounds: A Review

by Juana I. Mosele, Alba Macià and Maria-José Motilva

Molecules 2015, 20(9), 17429-17468; https://doi.org/10.3390/molecules200917429 - 18 Sep 2015

Cited by 193 | Viewed by 16168

Abstract

Phenolic compounds represent a diverse group of phytochemicals whose intake is associated with a wide spectrum of health benefits. As consequence of their low bioavailability, most of them reach the large intestine where, mediated by the action of local microbiota, a series of [...] Read more.

Phenolic compounds represent a diverse group of phytochemicals whose intake is associated with a wide spectrum of health benefits. As consequence of their low bioavailability, most of them reach the large intestine where, mediated by the action of local microbiota, a series of related microbial metabolites are accumulated. In the present review, gut microbial transformations of non-absorbed phenolic compounds are summarized. Several studies have reached a general consensus that unbalanced diets are associated with undesirable changes in gut metabolism that could be detrimental to intestinal health. In terms of explaining the possible effects of non-absorbed phenolic compounds, we have also gathered information regarded their influence on the local metabolism. For this purpose, a number of issues are discussed. Firstly, we consider the possible implications of phenolic compounds in the metabolism of colonic products, such as short chain fatty acids (SCFA), sterols (cholesterol and bile acids), and microbial products of non-absorbed proteins. Due to their being recognized as affective antioxidant and anti-inflammatory agents, the ability of phenolic compounds to counteract or suppress pro-oxidant and/or pro-inflammatory responses, triggered by bowel diseases, is also presented. The modulation of gut microbiota through dietetic maneuvers including phenolic compounds is also commented on. Although the available data seems to assume positive effects in terms of gut health protection, it is still insufficient for solid conclusions to be extracted, basically due to the lack of human trials to confirm the results obtained by the in vitro and animal studies. We consider that more emphasis should be focused on the study of phenolic compounds, particularly in their microbial metabolites, and their power to influence different aspects of gut health. Full article

(This article belongs to the Special Issue Dietary Bioactive Compounds: Metabolism, Mechanisms and Translational Significance for Health and Prevention of Diseases)

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Open AccessArticle

Clinacanthus nutans (Burm. f.) Lindau Ethanol Extract Inhibits Hepatoma in Mice through Upregulation of the Immune Response

by Danmin Huang, Wenjie Guo, Jing Gao, Jun Chen and Joshua Opeyemi Olatunji

Molecules 2015, 20(9), 17405-17428; https://doi.org/10.3390/molecules200917405 - 18 Sep 2015

Cited by 54 | Viewed by 10834

Abstract

Clinacanthans nutans (Burm. f.) Lindau is a popular medicinal vegetable in Southern Asia, and its extracts have displayed significant anti-proliferative effects on cancer cells in vitro. However, the underlying mechanism for this effect has yet to be established. This study investigated the antitumor [...] Read more.

Clinacanthans nutans (Burm. f.) Lindau is a popular medicinal vegetable in Southern Asia, and its extracts have displayed significant anti-proliferative effects on cancer cells in vitro. However, the underlying mechanism for this effect has yet to be established. This study investigated the antitumor and immunomodulatory activity of C. nutans (Burm. f.) Lindau 30% ethanol extract (CN30) in vivo. CN30 was prepared and its main components were identified using high-performance liquid chromatography (HPLC) and mass spectrometry (LC/MS/MS). CN30 had a significant inhibitory effect on tumor volume and weight. Hematoxylin and eosin (H & E) staining and TUNEL assay revealed that hepatoma cells underwent significant apoptosis with CN30 treatment, while expression levels of proliferation markers PCNA and p-AKT were significantly decreased when treated with low or high doses of CN30 treatment. Western blot analysis of PAPR, caspase-3, BAX, and Bcl2 also showed that CN30 induced apoptosis in hepatoma cells. Furthermore, intracellular staining analysis showed that CN30 treatment increased the number of IFN-γ⁺ T cells and decreased the number of IL-4⁺ T cells. Serum IFN-γ and interleukin-2 levels also significantly improved. Our findings indicated that CN30 demonstrated antitumor properties by up-regulating the immune response, and warrants further evaluation as a potential therapeutic agent for the treatment and prevention of cancers. Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessArticle

Selected Phytochemicals and Culinary Plant Extracts Inhibit Fructose Uptake in Caco-2 Cells

by Yurim Lee, Yeni Lim and Oran Kwon

Molecules 2015, 20(9), 17393-17404; https://doi.org/10.3390/molecules200917393 - 18 Sep 2015

Cited by 25 | Viewed by 7840

Abstract

This study compared the ability of nine culinary plant extracts containing a wide array of phytochemicals to inhibit fructose uptake and then explored the involvement of intestinal fructose transporters and phytochemicals for selected samples. The chemical signature was characterized by high performance liquid [...] Read more.

This study compared the ability of nine culinary plant extracts containing a wide array of phytochemicals to inhibit fructose uptake and then explored the involvement of intestinal fructose transporters and phytochemicals for selected samples. The chemical signature was characterized by high performance liquid chromatography with mass spectrometry. Inhibition of [¹⁴C]-fructose uptake was tested by using human intestinal Caco-2 cells. Then, the relative contribution of the two apical-facing intestinal fructose transporters, GLUT2 and GLUT5, and the signature components for fructose uptake inhibition was confirmed in naive, phloretin-treated and forskolin-treated Caco-2 cells. HPLC/MS analysis of the chemical signature revealed that guava leaf contained quercetin and catechin, and turmeric contained curcumin, bisdemethoxycurcumin and dimethoxycurcumin. Similar inhibition of fructose uptake (by ~50%) was observed with guava leaf and turmeric in Caco-2 cells, but with a higher contribution of GLUT2 for turmeric and that of GLUT5 for guava leaf. The data suggested that, in turmeric, demethoxycurcumin specifically contributed to GLUT2-mediated fructose uptake inhibition, and curcumin did the same to GLUT5-mediated fructose uptake inhibition, but GLUT2 inhibition was more potent. By contrast, in guava leaf, catechin specifically contributed to GLUT5-mediated fructose uptake inhibition, and quercetin affected both GLUT5- and GLUT2-mediated fructose uptake inhibition, resulting in the higher contribution of GLUT5. These results suggest that demethoxycurcumin is an important contributor to GLUT2-mediated fructose uptake inhibition for turmeric extract, and catechin is the same to GLUT5-mediated fructose uptake inhibition for guava leaf extract. Quercetin, curcumin and bisdemethoxycurcumin contributed to both GLUT5- and GLUT2-mediated fructose uptake inhibition, but the contribution to GLUT5 inhibition was higher than the contribution to GLUT2 inhibition. Full article

(This article belongs to the Collection Herbal Medicine Research)

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Open AccessArticle

Preparation of Thermo-Responsive Poly(ionic liquid)s-Based Nanogels via One-Step Cross-Linking Copolymerization

by Jing Zhang, Jingjiang Liu, Yong Zuo, Rongmin Wang and Yubing Xiong

Molecules 2015, 20(9), 17378-17392; https://doi.org/10.3390/molecules200917378 - 18 Sep 2015

Cited by 17 | Viewed by 7731

Abstract

In this study, thermo-responsive polymeric nanogels were facilely prepared via one-step cross-linking copolymerization of ethylene glycol dimethacrylate/divinylbenzene and ionic liquid (IL)-based monomers, 1,n-dialkyl-3,3′-bis-1-vinyl imidazolium bromides ([C_nVIm]Br; n = 6, 8, 12) in selective solvents. The results revealed that stable and blue [...] Read more.

In this study, thermo-responsive polymeric nanogels were facilely prepared via one-step cross-linking copolymerization of ethylene glycol dimethacrylate/divinylbenzene and ionic liquid (IL)-based monomers, 1,n-dialkyl-3,3′-bis-1-vinyl imidazolium bromides ([C_nVIm]Br; n = 6, 8, 12) in selective solvents. The results revealed that stable and blue opalescent biimidazolium (BIm)-based nanogel solutions could be obtained without any precipitation when the copolymerizations were conducted in methanol. Most importantly, these novel nanogels were thermo-response, and could reversibly transform to precipitation in methanol with temperature changes. Turbidity analysis and dynamic light scatting (DLS) measurement illustrated that PIL-based nanogel solutions presented the phase transform with upper critical solution temperature (UCST) in the range of 5–25 °C. The nanogels were characterized using Fourier transform infrared (FTIR), thermogravimetric analyses (TGA), and scanning electron microscopy (SEM). In addition, BIm-based nanogels could also be used as highly active catalysts in the cycloaddition reaction of CO₂ and epoxides. As a result, our attributes build a robust platform suitable for the preparation of polymeric nanomaterials, as well as CO₂ conversion. Full article

(This article belongs to the Special Issue Ionic Liquids in Organic Synthesis)

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Open AccessArticle

Isoindigo-Based Small Molecules with Varied Donor Components for Solution-Processable Organic Field Effect Transistor Devices

by Hemlata Patil, Jingjing Chang, Akhil Gupta, Ante Bilic, Jishan Wu, Prashant Sonar and Sheshanath V. Bhosale

Molecules 2015, 20(9), 17362-17377; https://doi.org/10.3390/molecules200917362 - 18 Sep 2015

Cited by 11 | Viewed by 8816

Abstract

Two solution-processable small organic molecules, (E)-6,6′-bis(4-(diphenylamino)phenyl)-1,1′-bis(2-ethylhexyl)-(3,3′-biindolinylidene)-2,2′-dione (coded as S10) and (E)-6,6′-di(9H-carbazol-9-yl)-1,1′-bis(2-ethylhexyl)-(3,3′-biindolinylidene)-2,2′-dione (coded as S11) were successfully designed, synthesized and fully characterized. S10 and S11 are based on a donor-acceptor-donor structural motif and contain a common [...] Read more.

Two solution-processable small organic molecules, (E)-6,6′-bis(4-(diphenylamino)phenyl)-1,1′-bis(2-ethylhexyl)-(3,3′-biindolinylidene)-2,2′-dione (coded as S10) and (E)-6,6′-di(9H-carbazol-9-yl)-1,1′-bis(2-ethylhexyl)-(3,3′-biindolinylidene)-2,2′-dione (coded as S11) were successfully designed, synthesized and fully characterized. S10 and S11 are based on a donor-acceptor-donor structural motif and contain a common electron accepting moiety, isoindigo, along with different electron donating functionalities, triphenylamine and carbazole, respectively. Ultraviolet-visible absorption spectra revealed that the use of triphenylamine donor functionality resulted in an enhanced intramolecular charge transfer transition and reduction of optical band gap, when compared with its carbazole analogue. Both of these materials were designed to be donor semiconducting components, exerted excellent solubility in common organic solvents, showed excellent thermal stability, and their promising optoelectronic properties encouraged us to scrutinize charge-carrier mobilities using solution-processable organic field effect transistors. Hole mobilities of the order of 2.2 × 10⁻⁴ cm²/Vs and 7.8 × 10⁻³ cm²/Vs were measured using S10 and S11 as active materials, respectively. Full article

(This article belongs to the Section Molecular Diversity)

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1666 KiB

Open AccessReview

Biological and Nutritional Properties of Palm Oil and Palmitic Acid: Effects on Health

by Annamaria Mancini, Esther Imperlini, Ersilia Nigro, Concetta Montagnese, Aurora Daniele, Stefania Orrù and Pasqualina Buono

Molecules 2015, 20(9), 17339-17361; https://doi.org/10.3390/molecules200917339 - 18 Sep 2015

Cited by 348 | Viewed by 56315

Abstract

A growing body of evidence highlights the close association between nutrition and human health. Fat is an essential macronutrient, and vegetable oils, such as palm oil, are widely used in the food industry and highly represented in the human diet. Palmitic acid, a [...] Read more.

A growing body of evidence highlights the close association between nutrition and human health. Fat is an essential macronutrient, and vegetable oils, such as palm oil, are widely used in the food industry and highly represented in the human diet. Palmitic acid, a saturated fatty acid, is the principal constituent of refined palm oil. In the last few decades, controversial studies have reported potential unhealthy effects of palm oil due to the high palmitic acid content. In this review we provide a concise and comprehensive update on the functional role of palm oil and palmitic acid in the development of obesity, type 2 diabetes mellitus, cardiovascular diseases and cancer. The atherogenic potential of palmitic acid and its stereospecific position in triacylglycerols are also discussed. Full article

(This article belongs to the Special Issue Dietary Bioactive Compounds: Metabolism, Mechanisms and Translational Significance for Health and Prevention of Diseases)

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836 KiB

Open AccessArticle

New Hydrazones Bearing Thiazole Scaffold: Synthesis, Characterization, Antimicrobial, and Antioxidant Investigation

by Cristina Nastasă, Brîndușa Tiperciuc, Mihaela Duma, Daniela Benedec and Ovidiu Oniga

Molecules 2015, 20(9), 17325-17338; https://doi.org/10.3390/molecules200917325 - 18 Sep 2015

Cited by 39 | Viewed by 6849

Abstract

New series of hydrazones 5–18 were synthesized, in good yields, by reacting 4-methyl-2-(4-(trifluoromethyl)phenyl)thiazole-5-carbohydrazide with differently substituted benzaldehyde. The resulting compounds were characterized via elemental analysis, physico-chemical and spectral data. An antimicrobial screening was done, using Gram (+), Gram (−) bacteria and one fungal [...] Read more.

New series of hydrazones 5–18 were synthesized, in good yields, by reacting 4-methyl-2-(4-(trifluoromethyl)phenyl)thiazole-5-carbohydrazide with differently substituted benzaldehyde. The resulting compounds were characterized via elemental analysis, physico-chemical and spectral data. An antimicrobial screening was done, using Gram (+), Gram (−) bacteria and one fungal strain. Tested molecules displayed moderate-to-good growth inhibition activity. 2,2-Diphenyl-1-picrylhydrazide assay was used to test the antioxidant properties of the compounds. Monohydroxy (14–16), para-fluorine (13) and 2,4-dichlorine (17) derivatives exhibited better free-radical scavenging ability than the other investigated molecules. Full article

(This article belongs to the Section Medicinal Chemistry)

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743 KiB

Open AccessArticle

Acylphloroglucinol Derivatives from the South African Helichrysum niveum and Their Biological Activities

by Olugbenga K. Popoola, Jeanine L. Marnewick, Fanie Rautenbach, Emmanuel I. Iwuoha and Ahmed A. Hussein

Molecules 2015, 20(9), 17309-17324; https://doi.org/10.3390/molecules200917309 - 18 Sep 2015

Cited by 17 | Viewed by 6192

Abstract

Phytochemical investigation of aerial parts of Helichrysum niveum (H. niveum) using different chromatographic methods including semi-preparative HPLC afforded three new (1–3) and six known (4–10) acylphloroglucinols alongside a known dialcohol triterpene (11 [...] Read more.

Phytochemical investigation of aerial parts of Helichrysum niveum (H. niveum) using different chromatographic methods including semi-preparative HPLC afforded three new (1–3) and six known (4–10) acylphloroglucinols alongside a known dialcohol triterpene (11). The structures of the isolated compounds were characterized accordingly as 1-benzoyl-3 (3-methylbut-2-enylacetate)-phloroglucinol (helinivene A, 1), 1-benzoyl-3 (2S-hydroxyl-3-methylbut-3-enyl)-phloroglucinol (helinivene B, 2), 8-(2-methylpropanone)-3S,5,7-trihydroxyl-2,2-dimethoxychromane (helinivene C, 3), 1-(2-methylbutanone)-4-O-prenyl-phloroglucinol (4), 1-(2-methylpropanone)-4-O-prennyl-phloroglucinol (5), 1-(butanone)-3-prenyl-phloroglucinol (6), 1-(2-methylbutanone)-3-prenyl-phloroglucinol (7), 1-butanone-3-(3-methylbut-2-enylacetate)-phloroglucinol (8), 1-(2-methylpropanone)-3-prenylphloroglucinol (9), caespitate (10), and 3β-24-dihydroxyterexer-14-ene (11). Excellent total antioxidant capacities were demonstrated by helinivenes A and B (1 and 2) when measured as oxygen radicals absorbance capacity (ORAC), ferric-ion reducing antioxidant power (FRAP), trolox equivalent absorbance capacity (TEAC) and including the inhibition of Fe²⁺-induced lipid peroxidation (IC₅₀ = 5.12 ± 0.90; 3.55 ± 1.92) µg/mL, while anti-tyrosinase activity at IC₅₀ = 35.63 ± 4.67 and 26.72 ± 5.05 µg/mL were also observed for 1 and 2, respectively. This is the first chemical and in vitro biological study on H. niveum. These findings underpin new perspectives for the exploitation of these natural phenolic compounds in applications such as in the natural cosmeceutical and pharmaceutical sectors. Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessArticle

Effect of Amaranthus on Advanced Glycation End-Products Induced Cytotoxicity and Proinflammatory Cytokine Gene Expression in SH-SY5Y Cells

by Warisa Amornrit and Rachana Santiyanont

Molecules 2015, 20(9), 17288-17308; https://doi.org/10.3390/molecules200917288 - 18 Sep 2015

Cited by 25 | Viewed by 7803

Abstract

Amaranthus plants, or spinach, are used extensively as a vegetable and are known to possess medicinal properties. Neuroinflammation and oxidative stress play a major role in the pathogenesis of many neurodegenerative diseases, such as Alzheimer’s disease and Parkinson’s disease. Advanced glycation end-products (AGEs) [...] Read more.

Amaranthus plants, or spinach, are used extensively as a vegetable and are known to possess medicinal properties. Neuroinflammation and oxidative stress play a major role in the pathogenesis of many neurodegenerative diseases, such as Alzheimer’s disease and Parkinson’s disease. Advanced glycation end-products (AGEs) cause cell toxicity in the human neuronal cell line, SH-SY5Y, through an increase in oxidative stress, as shown by reducing cell viability and increasing cell toxicity in a dose-dependent manner. We found that preincubation of SH-SY5Y cells with either petroleum ether, dichloromethane or methanol extracts of A. lividus and A. tricolor dose-dependently attenuated the neuron toxicity caused by AGEs treatment. Moreover, the results showed that A. lividus and A. tricolor extracts significantly downregulated the gene expression of the pro-inflammatory cytokines, TNF-α, IL-1 and IL-6 genes in AGEs-induced cells. We concluded that A. lividus and A. tricolor extracts not only have a neuroprotective effect against AGEs toxicity, but also have anti-inflammatory activity by reducing pro-inflammatory cytokine gene expression. This suggests that Amaranthus may be useful for treating chronic inflammation associated with neurodegenerative disorders. Full article

(This article belongs to the Collection Herbal Medicine Research)

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Open AccessArticle

The Guareschi Pyridine Scaffold as a Valuable Platform for the Identification of Selective PI3K Inhibitors

by Ubaldina Galli, Elisa Ciraolo, Alberto Massarotti, Jean Piero Margaria, Giovanni Sorba, Emilio Hirsch and Gian Cesare Tron

Molecules 2015, 20(9), 17275-17287; https://doi.org/10.3390/molecules200917275 - 18 Sep 2015

Cited by 6 | Viewed by 8592

Abstract

A novel series of 4-aryl-3-cyano-2-(3-hydroxyphenyl)-6-morpholino-pyridines have been designed as potential phosphatidylinositol-3-kinase (PI3K) inhibitors. The compounds have been synthesized using the Guareschi reaction to prepare the key 4-aryl-3-cyano-2,6-dihydroxypyridine intermediate. A different selectivity according to the nature of the aryl group has been observed. Compound [...] Read more.

A novel series of 4-aryl-3-cyano-2-(3-hydroxyphenyl)-6-morpholino-pyridines have been designed as potential phosphatidylinositol-3-kinase (PI3K) inhibitors. The compounds have been synthesized using the Guareschi reaction to prepare the key 4-aryl-3-cyano-2,6-dihydroxypyridine intermediate. A different selectivity according to the nature of the aryl group has been observed. Compound 9b is a selective inhibitor against the PI3Kα isoform, maintaining a good inhibitory activity. Docking studies were also performed in order to rationalize its profile of selectivity. Full article

(This article belongs to the Special Issue Kinase Inhibitor Chemistry)

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763 KiB

Open AccessReview

Editorial of Special Issue Ruthenium Complex: The Expanding Chemistry of the Ruthenium Complexes

by Ileana Dragutan, Valerian Dragutan and Albert Demonceau

Molecules 2015, 20(9), 17244-17274; https://doi.org/10.3390/molecules200917244 - 18 Sep 2015

Cited by 68 | Viewed by 10195

Abstract

Recent trends in Ru complex chemistry are surveyed with emphasis on the development of anticancer drugs and applications in catalysis, polymers, materials science and nanotechnology. Full article

(This article belongs to the Special Issue Ruthenium Complex)

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Open AccessArticle

Chemical Composition Analysis, Antimicrobial Activity and Cytotoxicity Screening of Moss Extracts (Moss Phytochemistry)

by Laura Klavina, Gunta Springe, Vizma Nikolajeva, Illia Martsinkevich, Ilva Nakurte, Diana Dzabijeva and Iveta Steinberga

Molecules 2015, 20(9), 17221-17243; https://doi.org/10.3390/molecules200917221 - 18 Sep 2015

Cited by 66 | Viewed by 10729

Abstract

Mosses have been neglected as a study subject for a long time. Recent research shows that mosses contain remarkable and unique substances with high biological activity. The aim of this study, accordingly, was to analyze the composition of mosses and to screen their [...] Read more.

Mosses have been neglected as a study subject for a long time. Recent research shows that mosses contain remarkable and unique substances with high biological activity. The aim of this study, accordingly, was to analyze the composition of mosses and to screen their antimicrobial and anticancer activity. The total concentration of polyphenols and carbohydrates, the amount of dry residue and the radical scavenging activity were determined for a preliminary evaluation of the chemical composition of moss extracts. In order to analyze and identify the substances present in mosses, two types of extrahents (chloroform, ethanol) and the GC/MS and LC-TOF-MS methods were used. The antimicrobial activity was tested on four bacteria strains, and the anticancer activity on six cancer cell lines. The obtained results show the presence of a high number of primary (fatty acids and amino acids), but mainly secondary metabolites in moss extracts—including, sterols, terpenoids, polyphenols and others—and a high activity with respect to the studied test organisms. Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessArticle

Asymmetric Synthesis of 1,3-Oxazolidine Derivatives with Multi-Component Reaction and Research of Kinetic Resolution

by Xiao-Wei Hong, Yu-Qiang Zhou, Cui-Bing Bai, Nai-Xing Wang, Yalan Xing, Wei Zhang, Yan-Jing Wang, Xing-Wang Lan, Yu Xie and Yi-He Li

Molecules 2015, 20(9), 17208-17220; https://doi.org/10.3390/molecules200917208 - 18 Sep 2015

Cited by 6 | Viewed by 6320

Abstract

An efficient multi-component reaction to synthesize multi-substituted 1,3-oxazolidine compounds of high optical purity was described. All the products were well-characterized and the absolute configuration of one chiral center was determined. The plausible mechanism was proposed and a kinetic resolution of epoxides process was [...] Read more.

An efficient multi-component reaction to synthesize multi-substituted 1,3-oxazolidine compounds of high optical purity was described. All the products were well-characterized and the absolute configuration of one chiral center was determined. The plausible mechanism was proposed and a kinetic resolution of epoxides process was confirmed. Full article

(This article belongs to the Section Organic Chemistry)

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Open AccessArticle

Influence of Laccase and Tyrosinase on the Antioxidant Capacity of Selected Phenolic Compounds on Human Cell Lines

by Matthias Riebel, Andrea Sabel, Harald Claus, Petra Fronk, Ning Xia, Huige Li, Helmut König and Heinz Decker

Molecules 2015, 20(9), 17194-17207; https://doi.org/10.3390/molecules200917194 - 18 Sep 2015

Cited by 10 | Viewed by 6825

Abstract

Polyphenolic compounds affect the color, odor and taste of numerous food products of plant origin. In addition to the visual and gustatory properties, they serve as radical scavengers and have antioxidant effects. Polyphenols, especially resveratrol in red wine, have gained increasing scientific and [...] Read more.

Polyphenolic compounds affect the color, odor and taste of numerous food products of plant origin. In addition to the visual and gustatory properties, they serve as radical scavengers and have antioxidant effects. Polyphenols, especially resveratrol in red wine, have gained increasing scientific and public interest due to their presumptive beneficial impact on human health. Enzymatic oxidation of phenolic compounds takes place under the influence of polyphenol oxidases (PPO), including tyrosinase and laccase. Several studies have demonstrated the radical scavenger effect of plants, food products and individual polyphenols in vitro, but, apart from resveratrol, such impact has not been proved in physiological test systems. Furthermore, only a few data exist on the antioxidant capacities of the enzymatic oxidation products of phenolic compounds generated by PPO. We report here first results about the antioxidant effects of phenolic substances, before and after oxidation by fungal model tyrosinase and laccase. In general, the common chemical 2,2-diphenyl-1-picrylhydrazyl assay and the biological tests using two different types of cell cultures (monocytes and endothelial cells) delivered similar results. The phenols tested showed significant differences with respect to their antioxidant activity in all test systems. Their antioxidant capacities after enzymatic conversion decreased or increased depending on the individual PPO used. Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessArticle

Investigation of Film with β-Galactosidase Designed for Stabilization and Handling in Dry Configuration

by Liguang Zhang, Andrew Otte, Min Xiang, Dexiu Liu and Rodolfo Pinal

Molecules 2015, 20(9), 17180-17193; https://doi.org/10.3390/molecules200917180 - 18 Sep 2015

Cited by 4 | Viewed by 6249

Abstract

Gelatin-based films with an immobilized enzyme designed for extending the stability of the protein in dry, non-powder configuration with precise dosing attributes were subjected to stress conditions of temperature and relative humidity. β-galactosidase was used as model functional protein. The film configuration preserved [...] Read more.

Gelatin-based films with an immobilized enzyme designed for extending the stability of the protein in dry, non-powder configuration with precise dosing attributes were subjected to stress conditions of temperature and relative humidity. β-galactosidase was used as model functional protein. The film configuration preserved the activity of the enzyme under the different storage conditions investigated, which include room temperature under low (ambient) and high (75%) relative humidity, and 36 °C under low (oven) and high relative humidity conditions for a period of 46 days. The influence of the enzyme and plasticizer (glycerol) on the physical and mechanical properties of the films was investigated using DMA (dynamic mechanical analysis). Films containing 5% β-galactosisdase and glycerol concentrations of 14% or greater exhibited greater tensile strength, Young’s modulus, and elongation at break than films with equal concentrations of plasticizer but devoid of any enzyme. The surface texture of the films was analyzed using scanning electron microscopy (SEM). β-galactosidase and glycerol have opposite effects on the surface morphology of the films. Increasing concentrations of the enzyme result in rougher film surface, whereas increasing the concentration of glycerol leads to films with denser and smoother surface. The results obtained suggest that the dry film configuration approach can help in facilitating the stabilization, handling, storage, and transportation of functional proteins in a cost effective manner. Full article

(This article belongs to the Section Molecular Diversity)

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Molecules, Volume 20, Issue 9 (September 2015) – 126 articles , Pages 15449-17683

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