Molecules

1682 KiB

Open AccessArticle

Design of Novel, Water Soluble and Highly Luminescent Europium Labels with Potential to Enhance Immunoassay Sensitivities

by Henri Sund, Kaj Blomberg, Niko Meltola and Harri Takalo

Molecules 2017, 22(10), 1807; https://doi.org/10.3390/molecules22101807 - 24 Oct 2017

Cited by 7 | Viewed by 4970

Abstract

To meet the continual demands of more-sensitive immunoassays, the synthesis of novel luminescent Eu(III) chelate labels having similar substituted 4-(phenylethynyl)pyridine chromophores in three different chelate structure classes are reported. Significantly enhanced luminescence intensities were obtained, evidently caused by the intra-ligand charge transfer (ILCT) [...] Read more.

To meet the continual demands of more-sensitive immunoassays, the synthesis of novel luminescent Eu(III) chelate labels having similar substituted 4-(phenylethynyl)pyridine chromophores in three different chelate structure classes are reported. Significantly enhanced luminescence intensities were obtained, evidently caused by the intra-ligand charge transfer (ILCT) mediated sensitization, but the alternative ligands triplet state process cannot be ruled out. Based on the present study, even quite small changes on the chelate structure, and, especially, on the substituents’ donor/acceptor strength on both ends of 4-(phenylethynyl)pyridine subunits have an unpredictable effect on the luminescence. The highest observed brightness was 16,400 M⁻¹cm⁻¹ in solution and 69,500 M⁻¹cm⁻¹ on dry surface, being 3.4 and 8.7 fold higher compared to the reference chelate. The new label chelates provide solutions for improved assay sensitivity up-to tenfold from the present concepts. Full article

(This article belongs to the Special Issue Lanthanide Luminescence: Fundamental Research and Applications)

► Show Figures

Figure 1

453 KiB

Open AccessArticle

Enhanced Glucose Uptake in Human Liver Cells and Inhibition of Carbohydrate Hydrolyzing Enzymes by Nordic Berry Extracts

by Giang Thanh Thi Ho, Thi Kim Yen Nguyen, Eili Tranheim Kase, Margey Tadesse, Hilde Barsett and Helle Wangensteen

Molecules 2017, 22(10), 1806; https://doi.org/10.3390/molecules22101806 - 24 Oct 2017

Cited by 29 | Viewed by 6043

Abstract

A Western lifestyle with low physical activity and a diet rich in sugar, fat and processed food contribute to higher incidences of diabetes and obesity. Enhanced glucose uptake in human liver cells was observed after treatment with phenolic extracts from different Nordic berries. [...] Read more.

A Western lifestyle with low physical activity and a diet rich in sugar, fat and processed food contribute to higher incidences of diabetes and obesity. Enhanced glucose uptake in human liver cells was observed after treatment with phenolic extracts from different Nordic berries. All berry extracts showed higher inhibition against α-amylase and α-glucosidase than the anti-diabetic agent acarbose. Total phenolic content and phenolic profiles in addition to antioxidant activities, were also investigated. The berries were extracted with 80% methanol on an accelerated solvent extraction system (ASE) and then purified by C-18 solid phase extraction (SPE). Among the ASE methanol extracts, black chokeberry, crowberry and elderberry extracts showed high stimulation of glucose uptake in HepG2 cells and also considerable inhibitory effect towards carbohydrate hydrolyzing enzymes. SPE extracts with higher concentrations of phenolics, resulted in increased glucose uptake and enhanced inhibition of α-amylase and α-glucosidase compared to the ASE extracts. Crowberry and cloudberry were the most potent 15-lipoxygenase inhibitors, while bog whortleberry and lingonberry were the most active xanthine oxidase inhibitors. These results increase the value of these berries as a component of a healthy Nordic diet and have a potential benefit against diabetes. Full article

(This article belongs to the Collection Bioactive Compounds)

► Show Figures

Graphical abstract

5073 KiB

Open AccessArticle

Dermaseptin-PH: A Novel Peptide with Antimicrobial and Anticancer Activities from the Skin Secretion of the South American Orange-Legged Leaf Frog, Pithecopus (Phyllomedusa) hypochondrialis

by Linyuan Huang, Dong Chen, Lei Wang, Chen Lin, Chengbang Ma, Xinping Xi, Tianbao Chen, Chris Shaw and Mei Zhou

Molecules 2017, 22(10), 1805; https://doi.org/10.3390/molecules22101805 - 24 Oct 2017

Cited by 62 | Viewed by 8140

Abstract

The dermaseptin peptides, mainly derived from the skin secretions of Hylidae frogs, belong to a superfamily of antimicrobial peptides and exhibit diverse antimicrobial and anticancer activities with low cytotoxicity. Here, we reported a novel dermaseptin peptide, from the South American orange-legged leaf frogs, [...] Read more.

The dermaseptin peptides, mainly derived from the skin secretions of Hylidae frogs, belong to a superfamily of antimicrobial peptides and exhibit diverse antimicrobial and anticancer activities with low cytotoxicity. Here, we reported a novel dermaseptin peptide, from the South American orange-legged leaf frogs, Pithecopus (Phyllomedusa) hypochondrialis, processing the shortest peptide length, namely Dermaseptin-PH. The complementary DNA (cDNA) encoding biosynthetic precursor of Dermaseptin-PH was initially identified by the rapid amplification of cDNA ends PCR (RACE-PCR) technique from the skin secretion. The predicted primary structure was confirmed by a combination of reverse-phase high performance liquid chromatography (RP-HPLC) and MS/MS fragmentation from the skin secretion. Chemically-synthetic Dermaseptin-PH was investigated using a range of bioactivity assessment assays to evaluate the biological activities and cytotoxicity of Dermaseptin-PH. Dermaseptin-PH inhibited the growth of Gram-negative bacteria, Gram-positive bacteria, and pathogenic yeast Candida albicans. In addition, Dermaseptin-PH showed a broad-spectrum of anticancer activities against several cancer cell lines including MCF-7, H157, U251MG, MDA-MB-435S, and PC-3. The potent antimicrobial and anticancer activities of Dermaseptin-PH make it a promising candidate in the discovery of new drugs for clinical applications, and the relatively short sequence of Dermaseptin-PH can provide new insight for the research and structural modification of new peptide drugs. Full article

(This article belongs to the Special Issue Bioactive Natural Peptides As A Pipeline For Therapeutics)

► Show Figures

Figure 1

1869 KiB

Open AccessArticle

Single Actin Bundle Rheology

by Dan Strehle, Paul Mollenkopf, Martin Glaser, Tom Golde, Carsten Schuldt, Josef A. Käs and Jörg Schnauß

Molecules 2017, 22(10), 1804; https://doi.org/10.3390/molecules22101804 - 24 Oct 2017

Cited by 11 | Viewed by 4999

Abstract

Bundled actin structures play an essential role in the mechanical response of the actin cytoskeleton in eukaryotic cells. Although responsible for crucial cellular processes, they are rarely investigated in comparison to single filaments and isotropic networks. Presenting a highly anisotropic structure, the determination [...] Read more.

Bundled actin structures play an essential role in the mechanical response of the actin cytoskeleton in eukaryotic cells. Although responsible for crucial cellular processes, they are rarely investigated in comparison to single filaments and isotropic networks. Presenting a highly anisotropic structure, the determination of the mechanical properties of individual bundles was previously achieved through passive approaches observing bending deformations induced by thermal fluctuations. We present a new method to determine the bending stiffness of individual bundles, by measuring the decay of an actively induced oscillation. This approach allows us to systematically test anisotropic, bundled structures. Our experiments revealed that thin, depletion force-induced bundles behave as semiflexible polymers and obey the theoretical predictions determined by the wormlike chain model. Thickening an individual bundle by merging it with other bundles enabled us to study effects that are solely based on the number of involved filaments. These thicker bundles showed a frequency-dependent bending stiffness, a behavior that is inconsistent with the predictions of the wormlike chain model. We attribute this effect to internal processes and give a possible explanation with regard to the wormlike bundle theory. Full article

(This article belongs to the Special Issue Natural Polymers and Biopolymers)

► Show Figures

Figure 1

2228 KiB

Open AccessArticle

Association, Distribution, Liberation, and Rheological Balances of Alkyldimethylbenzylammonium Chlorides (C12–C16)

by Zuzana Vitková, Jarmila Oremusová, Petra Herdová, Oľga Ivánková and Anton Vitko

Molecules 2017, 22(10), 1802; https://doi.org/10.3390/molecules22101802 - 24 Oct 2017

Cited by 5 | Viewed by 3571

Abstract

It is known that cationic surfactants have an antimicrobial effect and act as enhancers. This paper studies three cationic surfactants from the group of alkyldimethylbenzylammonium chlorides (dodecyl-, tetradecyl-, and hexadecyl). Interest is focused on the association of the surfactants with respect to temperature, [...] Read more.

It is known that cationic surfactants have an antimicrobial effect and act as enhancers. This paper studies three cationic surfactants from the group of alkyldimethylbenzylammonium chlorides (dodecyl-, tetradecyl-, and hexadecyl). Interest is focused on the association of the surfactants with respect to temperature, partition balances and their influence on drug release, rheological properties, and the pH of hydrogels. The critical micelle concentrations (CMC) of the surfactants were estimated from dependencies of conductivity, density, spectrofluorimetry, and UV–VIS spectrophotometry on molarity in the temperature range of 25–50 °C. It was found that the temperature dependence of a CMC is U-shaped, with its minimum at 30 °C, and the CMC value decreases as the length of the chain increases. The pseudo-phase separation model was used for the calculation of various thermodynamic parameters, such as the Gibbs free energies (spontaneous process), enthalpies (exothermic process), and entropies of the micelles’ formation, CMCs, and the degree of counterion binding. All thermodynamic parameters, as functions of the temperature, were estimated. It was found that partition coefficients increase as the length of the alkyl chain and the pH = (5.0–7.0) increase. The influences of surfactants, below and above the CMC, on drug (chlorhexidine dihydrochloride) release from hydrogels, rheological properties, and pH at 30 °C were studied. Also, the amounts of the released drug increase as the alkyl chains of the surfactants prolongate. The amounts of the released drug with the surfactant below the CMC are greater than that above the CMC. All hydrogels (regardless of the length of the alkyl chain) exhibit a non-Newtonian pseudo-plastic flow. The results obtained will be used in the formulation of the drug and surfactants into dosage forms. Full article

► Show Figures

Figure 1

1472 KiB

Open AccessArticle

GC-MS Profiling of Volatile Components in Different Fermentation Products of Cordyceps Sinensis Mycelia

by Hongyang Zhang, Yahui Li, Jianing Mi, Min Zhang, Yuerong Wang, Zhihong Jiang and Ping Hu

Molecules 2017, 22(10), 1800; https://doi.org/10.3390/molecules22101800 - 24 Oct 2017

Cited by 29 | Viewed by 8105

Abstract

The fermentation products of Cordyceps sinensis (C. sinensis) mycelia are sustainable substitutes for natural C. sinensis. However, the volatile compositions of the commercial products are still unclear. In this paper, we have developed a simultaneous distillation-extraction (SDE) and gas chromatography-mass [...] Read more.

The fermentation products of Cordyceps sinensis (C. sinensis) mycelia are sustainable substitutes for natural C. sinensis. However, the volatile compositions of the commercial products are still unclear. In this paper, we have developed a simultaneous distillation-extraction (SDE) and gas chromatography-mass spectrometry (GC-MS) method for the profiling of volatile components in five fermentation products. A total of 64, 39, 56, 52, and 44 components were identified in the essential oils of Jinshuibao capsule (JSBC), Bailing capsule (BLC), Zhiling capsule (ZLC), Ningxinbao capsule (NXBC), and Xinganbao capsule (XGBC), respectively. 5,6-Dihydro-6-pentyl-2H-pyran-2-one (massoia lactone) was first discovered as the dominant component in JSBC volatiles. Fatty acids including palmitic acid (C16:0) and linoleic acid (C18:2) were also found to be major volatile compositions of the fermentation products. The multivariate partial least squares-discriminant analysis (PLS-DA) showed a clear discrimination among the different commercial products as well as the counterfeits. This study may provide further chemical evidences for the quality evaluation of the fermentation products of C. sinensis mycelia. Full article

► Show Figures

Graphical abstract

5037 KiB

Open AccessArticle

Equol, a Clinically Important Metabolite, Inhibits the Development and Pathogenicity of Magnaporthe oryzae, the Causal Agent of Rice Blast Disease

by Jiaoyu Wang, Ling Li, Yeshi Yin, Zhuokan Gu, Rongyao Chai, Yanli Wang and Guochang Sun

Molecules 2017, 22(10), 1799; https://doi.org/10.3390/molecules22101799 - 24 Oct 2017

Cited by 7 | Viewed by 6449

Abstract

Equol, a metabolite of soybean isoflavone daidzein, has been proven to have various bioactivities related to human health, but little is known on its antifungal activity to plant fungal pathogens. Magnaporthe oryzae is a phytopathogenic fungus that causes rice blast, a devastating disease [...] Read more.

Equol, a metabolite of soybean isoflavone daidzein, has been proven to have various bioactivities related to human health, but little is known on its antifungal activity to plant fungal pathogens. Magnaporthe oryzae is a phytopathogenic fungus that causes rice blast, a devastating disease on rice. Here, we demonstrated that equol influences the development and pathogenicity of M. oryzae. Equol showed a significant inhibition to the mycelial growth, conidial generation and germination, and appressorial formation of M. oryzae. As a result, equol greatly reduced the virulence of M. oryzae on rice and barley leaves. The antifungal activity of equol was also found in several other plant fungal pathogens. These findings expand our knowledge on the bioactivities of equol. Full article

(This article belongs to the Collection Bioactive Compounds)

► Show Figures

Figure 1

613 KiB

Open AccessReview

Pharmabiotics as an Emerging Medication for Metabolic Syndrome and Its Related Diseases

by Thi Thanh Binh Nguyen, Yan Yan Jin, Hea-Jong Chung and Seong-Tschool Hong

Molecules 2017, 22(10), 1795; https://doi.org/10.3390/molecules22101795 - 24 Oct 2017

Cited by 22 | Viewed by 8438

Abstract

Metabolic syndrome (MetS) is a cluster of metabolic risk factors associated with central obesity, hyperglycemia, insulin resistance, dyslipidemia and high blood pressure. In recent decades, because of the remarkable increase in both prevalence and severity, MetS and its related diseases such as cardiovascular [...] Read more.

Metabolic syndrome (MetS) is a cluster of metabolic risk factors associated with central obesity, hyperglycemia, insulin resistance, dyslipidemia and high blood pressure. In recent decades, because of the remarkable increase in both prevalence and severity, MetS and its related diseases such as cardiovascular diseases (CVDs), obesity, hypertension and diabetes have become the main global burden and challenge in strategic management involving prevention and treatment. However, currently, the preventions and treatments based on pharmaceutical interventions do not provide a solution for MetS and its related diseases. Recently, gut microbiota showed clear evidence of preventing and/or treating MetS, shedding light on treating MetS and its related diseases through a completely different approach. In this review, we will interpret the effects of current pharmaceutical drugs used in preventing and treating MetS and its related diseases to understand remaining issues of those interventions. We will explore the possibility of developing gut microbiota as pharmabiotics in a completely new medication option for treating MetS and its related diseases. Full article

(This article belongs to the Special Issue Bioactive Compounds for Metabolic Syndrome and Type 2 Diabetes)

► Show Figures

Figure 1

5276 KiB

Open AccessArticle

Ni(II) Complexes with Schiff Base Ligands: Preparation, Characterization, DNA/Protein Interaction and Cytotoxicity Studies

by Hui Yu, Wei Zhang, Qing Yu, Fu-Ping Huang, He-Dong Bian and Hong Liang

Molecules 2017, 22(10), 1772; https://doi.org/10.3390/molecules22101772 - 24 Oct 2017

Cited by 43 | Viewed by 6066

Abstract

In this study, two Ni(II) complexes, namely [Ni(HL1)₂(OAc)₂] (1) and [Ni(L2)₂] (2) (where HL1 and HL2 are (E)-1-((1-(2-hydroxyethyl)-1H-pyrazol-5-ylimino)methyl)-naphthalen-2-ol) and (E)-ethyl-5-((2-hydroxynaphthalen-1-yl)methyleneamino)-1-methyl-1H-pyrazole-4-carboxylate, respectively), were synthesized and characterized [...] Read more.

In this study, two Ni(II) complexes, namely [Ni(HL1)₂(OAc)₂] (1) and [Ni(L2)₂] (2) (where HL1 and HL2 are (E)-1-((1-(2-hydroxyethyl)-1H-pyrazol-5-ylimino)methyl)-naphthalen-2-ol) and (E)-ethyl-5-((2-hydroxynaphthalen-1-yl)methyleneamino)-1-methyl-1H-pyrazole-4-carboxylate, respectively), were synthesized and characterized by X-ray crystallography, Electrospray Ionization Mass Spectrometry (ESI-MS), elemental analysis, and IR. Their uptake in biological macromolecules and cancer cells were preliminarily investigated through electronic absorption (UV-Vis), circular dichroism (CD) and fluorescence quenching measurements. Bovine serum albumin (BSA) interaction experiments were investigated by spectroscopy which showed that the complexes and ligands could quench the intrinsic fluorescence of BSA through an obvious static quenching process. The spectroscopic studies indicated that these complexes could bind to DNA via groove, non-covalent, and electrostatic interactions. Furthermore, in vitro methyl thiazolyl tetrazolium (MTT) assays and Annexin V/PI flow cytometry experiments were performed to assess the antitumor capacity of the complexes against eight cell lines. The results show that both of the complexes possess reasonable cytotoxicities. Full article

(This article belongs to the Special Issue Metal Complexes of Biological Ligands)

► Show Figures

Figure 1

1661 KiB

Open AccessArticle

Synthesis and Antitumor Activity of Triazole-Containing Sorafenib Analogs

by Wenjing Ye, Qi Yao, Simiao Yu, Ping Gong and Mingze Qin

Molecules 2017, 22(10), 1759; https://doi.org/10.3390/molecules22101759 - 24 Oct 2017

Cited by 14 | Viewed by 5087

Abstract

Using a highly effective binuclear Cu complex as the catalyst, the 1,3-dipolar cycloaddition reactions between 16 alkynes and two azides were successfully performed and resulted in the production of 25 new triazole-containing sorafenib analogs. Several compounds were evaluated as potent antitumor agents. Among [...] Read more.

Using a highly effective binuclear Cu complex as the catalyst, the 1,3-dipolar cycloaddition reactions between 16 alkynes and two azides were successfully performed and resulted in the production of 25 new triazole-containing sorafenib analogs. Several compounds were evaluated as potent antitumor agents. Among them, 4-(4-(4-(3-fluorophenyl)-1H-1,2,3-triazol-1-yl)phenoxy)-N-methylpicolinamide (8f) potently suppressed the proliferation of HT-29 cancer cells by inducing apoptosis and almost completely inhibited colony formation at a low micromolar concentration. Full article

► Show Figures

Graphical abstract

896 KiB

Open AccessArticle

Molecular Affinity of Mabolo Extracts to an Octopamine Receptor of a Fruit Fly

by Francoise Neil D. Dacanay, Ma. Carmina Joyce A. Ladra, Hiyas A. Junio and Ricky B. Nellas

Molecules 2017, 22(10), 1677; https://doi.org/10.3390/molecules22101677 - 24 Oct 2017

Cited by 11 | Viewed by 9537

Abstract

Essential oils extracted from plants are composed of volatile organic compounds that can affect insect behavior. Identifying the active components of the essential oils to their biochemical target is necessary to design novel biopesticides. In this study, essential oils extracted from Diospyros discolor [...] Read more.

Essential oils extracted from plants are composed of volatile organic compounds that can affect insect behavior. Identifying the active components of the essential oils to their biochemical target is necessary to design novel biopesticides. In this study, essential oils extracted from Diospyros discolor (Willd.) were analyzed using gas chromatography mass spectroscopy (GC-MS) to create an untargeted metabolite profile. Subsequently, a conformational ensemble of the Drosophila melanogaster octopamine receptor in mushroom bodies (OAMB) was created from a molecular dynamics simulation to resemble a flexible receptor for docking studies. GC-MS analysis revealed the presence of several metabolites, i.e. mostly aromatic esters. Interestingly, these aromatic esters were found to exhibit relatively higher binding affinities to OAMB than the receptor’s natural agonist, octopamine. The molecular origin of this observed enhanced affinity is the

π

-stacking interaction between the aromatic moieties of the residues and ligands. This strategy, computational inspection in tandem with untargeted metabolomics, may provide insights in screening the essential oils as potential OAMB inhibitors. Full article

► Show Figures

Graphical abstract

1731 KiB

Open AccessArticle

Pharmacological Effects of Two Novel Bombesin-Like Peptides from the Skin Secretions of Chinese Piebald Odorous Frog (Odorrana schmackeri) and European Edible Frog (Pelophylax kl. esculentus) on Smooth Muscle

by Xiaowei Zhou, Chengbang Ma, Mei Zhou, Yuning Zhang, Xinping Xi, Ruimin Zhong, Tianbao Chen, Chris Shaw and Lei Wang

Molecules 2017, 22(10), 1798; https://doi.org/10.3390/molecules22101798 - 23 Oct 2017

Cited by 7 | Viewed by 5458

Abstract

Bombesin-like peptides, which were identified from a diversity of amphibian skin secretions, have been demonstrated to possess several biological functions such as stimulation of smooth muscle contraction and regulation of food intake. Here, we report two novel bombesin-like peptides, bombesin-OS and bombesin-PE, which [...] Read more.

Bombesin-like peptides, which were identified from a diversity of amphibian skin secretions, have been demonstrated to possess several biological functions such as stimulation of smooth muscle contraction and regulation of food intake. Here, we report two novel bombesin-like peptides, bombesin-OS and bombesin-PE, which were isolated from Odorrana schmackeri and Pelophylax kl. esculentus, respectively. The mature peptides were identified and structurally confirmed by high performance Scliquid chromatography (HPLC) and tandem mass spectrometry (MS/MS). Subsequently, the effects of these purified chemically-synthetic peptides on smooth muscle were determined in bladder, uterus, and ileum. The synthetic replications were revealed to have significant pharmacological effects on these tissues. The EC₅₀ values of bombesin-OS for bladder, uterus and ileum, were 10.8 nM, 33.64 nM, and 12.29 nM, respectively. Furthermore, compared with bombesin-OS, bombesin-PE showed similar contractile activity on ileum smooth muscle and uterus smooth muscle, but had a higher potency on bladder smooth muscle. The EC₅₀value of bombesin-OS for bladder was around 1000-fold less than that of bombesin-PE. This suggests that bombesin-OS and bombesin-PE have unique binding properties to their receptors. The precursor of bombesin-OS was homologous with that of a bombesin-like peptide, odorranain-BLP-5, and bombesin-PE belongs to the ranatensin subfamily. We identified the structure of bombesin-OS and bombesin-PE, two homologues peptides whose actions may provide a further clue in the classification of ranid frogs, also in the provision of new drugs for human health. Full article

(This article belongs to the Special Issue Bioactive Natural Peptides As A Pipeline For Therapeutics)

► Show Figures

Figure 1

1658 KiB

Open AccessArticle

Ureidopyrazine Derivatives: Synthesis and Biological Evaluation as Anti-Infectives and Abiotic Elicitors

by Ghada Bouz, Martin Juhás, Pavlína Niklová, Ondřej Janďourek, Pavla Paterová, Jiří Janoušek, Lenka Tůmová, Zuzana Kovalíková, Petr Kastner, Martin Doležal and Jan Zitko

Molecules 2017, 22(10), 1797; https://doi.org/10.3390/molecules22101797 - 23 Oct 2017

Cited by 7 | Viewed by 4972

Abstract

Tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) has become a frequently deadly infection due to increasing antimicrobial resistance. This serious issue has driven efforts worldwide to discover new drugs effective against Mtb. One research area is the synthesis and evaluation [...] Read more.

Tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) has become a frequently deadly infection due to increasing antimicrobial resistance. This serious issue has driven efforts worldwide to discover new drugs effective against Mtb. One research area is the synthesis and evaluation of pyrazinamide derivatives as potential anti-TB drugs. In this paper we report the synthesis and biological evaluations of a series of ureidopyrazines. Compounds were synthesized by reacting alkyl/aryl isocyanates with aminopyrazine or with propyl 5-aminopyrazine-2-carboxylate. Reactions were performed in pressurized vials using a CEM Discover microwave reactor with a focused field. Purity and chemical structures of products were assessed, and the final compounds were tested in vitro for their antimycobacterial, antibacterial, and antifungal activities. Propyl 5-(3-phenylureido)pyrazine-2-carboxylate (compound 4, MIC_Mtb = 1.56 μg/mL, 5.19 μM) and propyl 5-(3-(4-methoxyphenyl)ureido)pyrazine-2-carboxylate (compound 6, MIC_Mtb = 6.25 μg/mL, 18.91 μM) had high antimycobacterial activity against Mtb H37Rv with no in vitro cytotoxicity on HepG2 cell line. Therefore 4 and 6 are suitable for further structural modifications that might improve their biological activity and physicochemical properties. Based on the structural similarity to 1-(2-chloropyridin-4-yl)-3-phenylurea, a known plant growth regulator, two selected compounds were evaluated for similar activity as abiotic elicitors. Full article

(This article belongs to the Special Issue Selected Papers from the 46th EuroCongress on Drug Synthesis and Analysis (ECDSA-2017))

► Show Figures

Figure 1

1239 KiB

Open AccessReview

Cyclodipeptides: An Overview of Their Biosynthesis and Biological Activity

by Awdhesh Kumar Mishra, Jaehyuk Choi, Seong-Jin Choi and Kwang-Hyun Baek

Molecules 2017, 22(10), 1796; https://doi.org/10.3390/molecules22101796 - 23 Oct 2017

Cited by 93 | Viewed by 10307

Abstract

Cyclodipeptides (CDP) represent a diverse family of small, highly stable, cyclic peptides that are produced as secondary functional metabolites or side products of protein metabolism by bacteria, fungi, and animals. They are widespread in nature, and exhibit a broad variety of biological and [...] Read more.

Cyclodipeptides (CDP) represent a diverse family of small, highly stable, cyclic peptides that are produced as secondary functional metabolites or side products of protein metabolism by bacteria, fungi, and animals. They are widespread in nature, and exhibit a broad variety of biological and pharmacological activities. CDP synthases (CDPSs) and non-ribosomal peptide synthetases (NRPSs) catalyze the biosynthesis of the CDP core structure, which is further modified by tailoring enzymes often associated with CDP biosynthetic gene clusters. In this review, we provide a comprehensive summary of CDP biosynthetic pathways and modifying enzymes. We also discuss the biological properties of some known CDPs and their possible applications in metabolic engineering. Full article

(This article belongs to the Collection Phytochemicals: Biosynthesis, Metabolism and Biological Activities)

► Show Figures

Figure 1

8082 KiB

Open AccessArticle

Silver Nanoparticles Stabilised by Cationic Gemini Surfactants with Variable Spacer Length

by Martin Pisárčik, Josef Jampílek, Miloš Lukáč, Renáta Horáková, Ferdinand Devínsky, Marián Bukovský, Michal Kalina, Jakub Tkacz and Tomáš Opravil

Molecules 2017, 22(10), 1794; https://doi.org/10.3390/molecules22101794 - 23 Oct 2017

Cited by 36 | Viewed by 7722

Abstract

The present study is focused on the synthesis and investigation of the physicochemical and biological properties of silver nanoparticles stabilized with a series of cationic gemini surfactants having a polymethylene spacer of variable length. UV-VIS spectroscopy, dynamic light scattering, scanning electron microscopy and [...] Read more.

The present study is focused on the synthesis and investigation of the physicochemical and biological properties of silver nanoparticles stabilized with a series of cationic gemini surfactants having a polymethylene spacer of variable length. UV-VIS spectroscopy, dynamic light scattering, scanning electron microscopy and zeta potential measurements were applied to provide physicochemical characterization of the silver nanoparticles. The mean size values of the nanoparticles were found to be in the 50 to 115 nm range. From the nanoparticle size distributions and scanning electron microscopy images it results that a population of small nanoparticles with the size of several nanometers was confirmed if the nanoparticles were stabilized with gemini molecules with either a short methylene spacer (two or four −CH₂− groups) or a long spacer (12 −CH₂− groups). The average zeta potential value for silver nanoparticles stabilized with gemini molecules is roughly independent of gemini surfactant spacer length and is approx. +58 mV. An interaction model between silver nanoparticles and gemini molecules which reflects the gained experimental data, is suggested. Microbicidal activity determinations revealed that the silver nanoparticles stabilized with gemini surfactants are more efficient against Gram-negative bacteria and yeasts, which has a direct relation to the interaction mechanism of nanoparticles with the bacterial cell membrane and its structural composition. Full article

(This article belongs to the Special Issue Selected Papers from the 46th EuroCongress on Drug Synthesis and Analysis (ECDSA-2017))

► Show Figures

Graphical abstract

2661 KiB

Open AccessArticle

The Regulatory Mechanism of MLT/MT1 Signaling on the Growth of Antler Mesenchymal Cells

by Feifei Yang, Changjiu He, Xuyang Sun, Jing Wang, Can Luo, Guoshi Liu, Liguo Yang, Jiajun Xiong and Lijun Huo

Molecules 2017, 22(10), 1793; https://doi.org/10.3390/molecules22101793 - 23 Oct 2017

Cited by 9 | Viewed by 5825

Abstract

Melatonin (MLT) plays an important role in regulating the physiological cycle of seasonal breeding animals. Melatonin receptor I (MT1) is effectively expressed in the cambium layer of deer antler. However, the function and metabolic mechanism of MLT/MT1 signaling in the mesenchymal cells of [...] Read more.

Melatonin (MLT) plays an important role in regulating the physiological cycle of seasonal breeding animals. Melatonin receptor I (MT1) is effectively expressed in the cambium layer of deer antler. However, the function and metabolic mechanism of MLT/MT1 signaling in the mesenchymal cells of sika deer remain to be further elucidated. In this work, we detected the effects of MLT/MT1 signaling on mesenchymal cells proliferation and the interaction between MLT/MT1 and IGF1/IGF1-R signaling. The results show that (1) deer antler mesenchymal cells actually express MT1; (2) exogenous melatonin significantly promotes mesenchymal cells proliferation, while MT1 knock-down significantly impairs the positive effects of melatonin; and (3) melatonin significantly enhanced IGF1/IGF1-R signaling, as both the expression of IGF1 and IGF-1R increased, while MT1 knock-down significantly decreased IGF1-R expression and IGF1 synthesis. In summary, these data verified that MLT/MT1 signaling plays a crucial role in antler mesenchymal proliferation, which may be mediated by IGF1/IGF1-R. Full article

(This article belongs to the Special Issue Melatonin as an Antioxidant and a Functionally Pleiotropic Molecule: Synthesis, Metabolism and Activities in Organisms)

► Show Figures

Graphical abstract

983 KiB

Open AccessArticle

Phenolic Compounds Present Schinus terebinthifolius Raddi Influence the Lowering of Blood Pressure in Rats

by Lorena De Lima Glória, Mariana Barreto de Souza Arantes, Silvia Menezes de Faria Pereira, Guilherme De Souza Vieira, Camilla Xavier Martins, Almir Ribeiro de Carvalho Junior, Fernanda Antunes, Raimundo Braz-Filho, Ivo José Curcino Vieira, Larissa Leandro da Cruz, Douglas Siqueira de Almeida Chaves, Silvério De Paiva Freitas and Daniela Barros de Oliveira

Molecules 2017, 22(10), 1792; https://doi.org/10.3390/molecules22101792 - 23 Oct 2017

Cited by 23 | Viewed by 5833

Abstract

This study identified two phenolic compounds in Schinus terebinthifolius Raddi fruits: naringenin (first report in this species) and gallic acid. Their structures were elucidated by nuclear magnetic resonance (NMR) data (¹H-, ¹³C-NMR) and a high-performance liquid chromatography (HPLC) technique. A [...] Read more.

This study identified two phenolic compounds in Schinus terebinthifolius Raddi fruits: naringenin (first report in this species) and gallic acid. Their structures were elucidated by nuclear magnetic resonance (NMR) data (¹H-, ¹³C-NMR) and a high-performance liquid chromatography (HPLC) technique. A high content of phenolics (659.21 mg of gallic acid equivalents/g of sample—Folin-Ciocalteau method) and total flavonoids (140.69 mg of rutin equivalents/g of sample—aluminum chloride method) were quantified in S. terebinthifolius, as well as high antioxidant activity (77.47%—2,2-diphenyl-1-picrylhydrazyl, DPPH method). The antihypertensive activity related to its phenolic content was investigated. After intravenous infusion in Wistar rats, these phenolics significantly reduced (p < 0.05) the systolic, median, and diastolic arterial pressures of individuals. The rotarod test was performed to determine the mechanism of action of the sample vasorelaxant effect. It was found that its action exceeded that of the positive control used (diazepam). This confirmed the vasodilatory activity exerted by S. terebinthifolius fruits is related to the phenolic compounds present in the plant, which are potent antioxidants and inhibit oxidative stress, mainly in the central nervous system. Full article

(This article belongs to the Collection Bioactive Compounds)

► Show Figures

Figure 1

2357 KiB

Open AccessCommunication

Cadmium Disrupts Subcellular Organelles, Including Chloroplasts, Resulting in Melatonin Induction in Plants

by Hyoung-Yool Lee and Kyoungwhan Back

Molecules 2017, 22(10), 1791; https://doi.org/10.3390/molecules22101791 - 23 Oct 2017

Cited by 39 | Viewed by 5780

Abstract

Cadmium is a well-known elicitor of melatonin synthesis in plants, including rice. However, the mechanisms by which cadmium induces melatonin induction remain elusive. To investigate whether cadmium influences physical integrities in subcellular organelles, we treated tobacco leaves with either CdCl₂ or AlCl [...] Read more.

Cadmium is a well-known elicitor of melatonin synthesis in plants, including rice. However, the mechanisms by which cadmium induces melatonin induction remain elusive. To investigate whether cadmium influences physical integrities in subcellular organelles, we treated tobacco leaves with either CdCl₂ or AlCl₃ and monitored the structures of subcellular organelles—such as chloroplasts, mitochondria, and the endoplasmic reticulum (ER)—using confocal microscopic analysis. Unlike AlCl₃ treatment, CdCl₂ (0.5 mM) treatment significantly disrupted chloroplasts, mitochondria, and ER. In theory, the disruption of chloroplasts enabled chloroplast-expressed serotonin N-acetyltransferase (SNAT) to encounter serotonin in the cytoplasm, leading to the synthesis of N-acetylserotonin followed by melatonin synthesis. In fact, the disruption of chloroplasts by cadmium, not by aluminum, gave rise to a huge induction of melatonin in rice leaves, which suggests that cadmium-treated chloroplast disruption plays an important role in inducing melatonin in plants by removing physical barriers, such as chloroplast double membranes, allowing SNAT to gain access to the serotonin substrate enriched in the cytoplasm. Full article

(This article belongs to the Special Issue Melatonin as an Antioxidant and a Functionally Pleiotropic Molecule: Synthesis, Metabolism and Activities in Organisms)

► Show Figures

Figure 1

2511 KiB

Open AccessArticle

Analysis of Floral Volatile Components and Antioxidant Activity of Different Varieties of Chrysanthemum morifolium

by Lu Yang, Aobulikasimu·Nuerbiye, Ping Cheng, Jin-Hui Wang and Hong Li

Molecules 2017, 22(10), 1790; https://doi.org/10.3390/molecules22101790 - 23 Oct 2017

Cited by 51 | Viewed by 8170

Abstract

This study investigated the volatile flavor compounds and antioxidant properties of the essential oil of chrysanthemums that was extracted from the fresh flowers of 10 taxa of Chrysanthemum morifolium from three species; namely Dendranthema morifolium (Ramat.) Yellow, Dendranthema morifolium (Ramat.) Red, Dendranthema morifolium [...] Read more.

This study investigated the volatile flavor compounds and antioxidant properties of the essential oil of chrysanthemums that was extracted from the fresh flowers of 10 taxa of Chrysanthemum morifolium from three species; namely Dendranthema morifolium (Ramat.) Yellow, Dendranthema morifolium (Ramat.) Red, Dendranthema morifolium (Ramat.) Pink, Dendranthema morifolium (Ramat.) White, Pericallis hybrid Blue, Pericallis hybrid Pink, Pericallis hybrid Purple, Bellis perennis Pink, Bellis perennis Yellow, and Bellis perennis White. The antioxidant capacity of the essential oil was assayed by spectrophotometric analysis. The volatile flavor compounds from the fresh flowers were collected using dynamic headspace collection, analyzed using auto thermal desorber–gas chromatography/mass spectrometry, and identified with quantification using the external standard method. The antioxidant activities of Chrysanthemum morifolium were evaluated by DPPH and FRAP assays, and the results showed that the antioxidant activity of each sample was not the same. The different varieties of fresh Chrysanthemum morifolium flowers were distinguished and classified by fingerprint similarity evaluation, principle component analysis (PCA), and cluster analysis. The results showed that the floral volatile component profiles were significantly different among the different Chrysanthemum morifolium varieties. A total of 36 volatile flavor compounds were identified with eight functional groups: hydrocarbons, terpenoids, aromatic compounds, alcohols, ketones, ethers, aldehydes, and esters. Moreover, the variability among Chrysanthemum morifolium in basis to the data, and the first three principal components (PC1, PC2, and PC3) accounted for 96.509% of the total variance (55.802%, 30.599%, and 10.108%, respectively). PCA indicated that there were marked differences among Chrysanthemum morifolium varieties. The cluster analysis confirmed the results of the PCA analysis. In conclusion, the results of this study provide a basis for breeding Chrysanthemum cultivars with desirable floral scents, and they further support the view that some plants are promising sources of natural antioxidants. Full article

(This article belongs to the Special Issue Selected Papers from the 6th International Conference on Biotechnology and Bioengineering (6-ICBB 2017))

► Show Figures

Figure 1

1961 KiB

Open AccessArticle

Nucleophilicities of Lewis Bases B and Electrophilicities of Lewis Acids A Determined from the Dissociation Energies of Complexes B⋯A Involving Hydrogen Bonds, Tetrel Bonds, Pnictogen Bonds, Chalcogen Bonds and Halogen Bonds

by Ibon Alkorta and Anthony C. Legon

Molecules 2017, 22(10), 1786; https://doi.org/10.3390/molecules22101786 - 23 Oct 2017

Cited by 36 | Viewed by 5434

Abstract

It is shown that the dissociation energy

D_{e}

for the process B⋯A = B + A for 250 complexes B⋯A composed of 11 Lewis bases B (N₂, CO, HC≡CH, CH₂=CH₂, C₃H₆, PH [...] Read more.

It is shown that the dissociation energy

D_{e}

for the process B⋯A = B + A for 250 complexes B⋯A composed of 11 Lewis bases B (N₂, CO, HC≡CH, CH₂=CH₂, C₃H₆, PH₃, H₂S, HCN, H₂O, H₂CO and NH₃) and 23 Lewis acids (HF, HCl, HBr, HC≡CH, HCN, H₂O, F₂, Cl₂, Br₂, ClF, BrCl, H₃SiF, H₃GeF, F₂CO, CO₂, N₂O, NO₂F, PH₂F, AsH₂F, SO₂, SeO₂, SF₂, and SeF₂) can be represented to good approximation by means of the equation

D_{e} = c^{'} N_{B} E_{A}

, in which

N_{B}

is a numerical nucleophilicity assigned to B,

E_{A}

is a numerical electrophilicity assigned to A, and

c^{'}

is a constant, conveniently chosen to have the value 1.00 kJ mol⁻¹ here. The 250 complexes were chosen to cover a wide range of non-covalent interaction types, namely: (1) the hydrogen bond; (2) the halogen bond; (3) the tetrel bond; (4) the pnictogen bond; and (5) the chalcogen bond. Since there is no evidence that one group of non-covalent interaction was fitted any better than the others, it appears the equation is equally valid for all the interactions considered and that the values of

N_{B}

and

E_{A}

so determined define properties of the individual molecules. The values of

N_{B}

and

E_{A}

can be used to predict the dissociation energies of a wide range of binary complexes B⋯A with reasonable accuracy. Full article

(This article belongs to the Special Issue Halogen Bonds and Beyond)

► Show Figures

Graphical abstract

1481 KiB

Open AccessReview

Synthesis and Properties of MQ Copolymers: Current State of Knowledge

by Elena Tatarinova, Nataliya Vasilenko and Aziz Muzafarov

Molecules 2017, 22(10), 1768; https://doi.org/10.3390/molecules22101768 - 23 Oct 2017

Cited by 27 | Viewed by 8051

Abstract

In this review, we discuss currently available studies on the synthesis and properties of MQ copolymers. The data on methods of producing hydrolytic and heterofunctional polycondensation of functional organosilanes as well as the obtaining MQ copolymers based on silicic acids and nature silicates [...] Read more.

In this review, we discuss currently available studies on the synthesis and properties of MQ copolymers. The data on methods of producing hydrolytic and heterofunctional polycondensation of functional organosilanes as well as the obtaining MQ copolymers based on silicic acids and nature silicates are considered. The ratio of M and Q monomers and the production method determine the structure of MQ copolymers and, accordingly, their physicochemical characteristics. It is shown that the most successful synthetic approach is a polycondensation of organoalkoxysilanes in the medium of anhydrous acetic acid, which reduces the differences in reactivity of M and Q monomers and leads to obtaining a product with uniform composition in all fractions, with full absence of residual alkoxy-groups. The current concept of MQ copolymers is that of organo-inorganic hybrid systems with nanosized crosslinked inorganic regions limited by triorganosilyl groups and containing residual hydroxyl groups. The systems can be considered as a peculiar molecular composites consisting of separate parts that play the role of a polymer matrix, a plasticizer, and a nanosized filler. Full article

(This article belongs to the Special Issue Progress in Silicon and Organosilicon Chemistry)

► Show Figures

Graphical abstract

423 KiB

Open AccessArticle

New Triterpenoid Saponins from the Herb Hylomecon japonica

by Yan-Fei Qu, Jing-Yu Gao, Jing Wang, Yan-Mei Geng, Yu Zhou, Cheng-Xin Sun, Fei Li, Lei Feng, Meng-Juan Yu and Guang-Shu Wang

Molecules 2017, 22(10), 1731; https://doi.org/10.3390/molecules22101731 - 23 Oct 2017

Cited by 12 | Viewed by 4404

Abstract

Background: Hylomecon japonica, a plant of the Papaveraceae family which is well-known for the alkaloids they produce, is a perennial plant widely distributed in the northeast, central and east regions of China. Although a variety of chemical constituents, including alkaloids, flavonoids, [...] Read more.

Background: Hylomecon japonica, a plant of the Papaveraceae family which is well-known for the alkaloids they produce, is a perennial plant widely distributed in the northeast, central and east regions of China. Although a variety of chemical constituents, including alkaloids, flavonoids, and megastigmoids, have been isolated from H. japonica, the investigation of saponins in H. japonica has not been reported until now. Methods: Various separation techniques, including polyporous resin column chromatography, silica gel column chromatography and hemi-preparative HPLC were applied to the isolation of triterpenoid saponins, and chemical methods such as acid hydrolysis and spectroscopic methods including HRESIMS and NMR were applied to their structure elucidation, and the XTT reduction method was used to assay cytotoxicity. Results: Two new triterpenoid saponins, named hylomeconoside A (1) and B (2) which were identified as 3-O-β-d-galactopyranosyl-(1→2)-β-d-glucuronopyranosyl-gypsogenin-28-O-β-d-xylopyranosyl-(1→3)-β-d-xylopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→2)-β-d-quinovopyranoside (1) and 3-O-β-d-galactopyranosyl-(1→2)-β-d-glucuronopyranosyl-gypsogenin-28-O-β-d-xylopyranosyl-(1→3)-β-d-xylopyranosyl-(1→4)-α-l-rhamnopyranosyl-(1→2)-α-l-arabinopyranoside (2), and two known triterpenoid saponins identified as dubioside C (3) and lucyoside P (4) on the basis of spectroscopic and chemical evidence, were isolated from H. japonica. Compound 1 exhibited moderate cytotoxicity on MGC-803 and HL-60 cells, with IC₅₀ values of 43.8 and 32.4 μg·mL⁻¹, respectively. Conclusions: Compounds 1 and 2 are new saponins, and 1 is considered to be one of the antitumor principles in this plant. This is the first time that triterpenoid saponins have been isolated from plants of the Papaveraceae family. Full article

► Show Figures

Figure 1

1621 KiB

Open AccessArticle

Recovery of Oil with Unsaturated Fatty Acids and Polyphenols from Chaenomelessinensis (Thouin) Koehne: Process Optimization of Pilot-Scale Subcritical Fluid Assisted Extraction

by Zhenzhou Zhu, Rui Zhang, Shaoying Zhan, Jingren He, Francisco J. Barba, Giancarlo Cravotto, Weizhong Wu and Shuyi Li

Molecules 2017, 22(10), 1788; https://doi.org/10.3390/molecules22101788 - 22 Oct 2017

Cited by 7 | Viewed by 6056

Abstract

The potential effects of three modern extraction technologies (cold-pressing, microwaves and subcritical fluids) on the recovery of oil from Chaenomelessinensis (Thouin) Koehne seeds have been evaluated and compared to those of conventional chemical extraction methods (Soxhlet extraction). This oil contains unsaturated fatty acids [...] Read more.

The potential effects of three modern extraction technologies (cold-pressing, microwaves and subcritical fluids) on the recovery of oil from Chaenomelessinensis (Thouin) Koehne seeds have been evaluated and compared to those of conventional chemical extraction methods (Soxhlet extraction). This oil contains unsaturated fatty acids and polyphenols. Subcritical fluid extraction (SbFE) provided the highest yield—25.79 g oil/100 g dry seeds—of the three methods. Moreover, the fatty acid composition in the oil samples was analysed using gas chromatography–mass spectrometry. This analysis showed that the percentages of monounsaturated (46.61%), and polyunsaturated fatty acids (42.14%), after applying SbFE were higher than those obtained by Soxhlet, cold-pressing or microwave-assisted extraction. In addition, the oil obtained under optimized SbFE conditions (35 min extraction at 35 °C with four extraction cycles), showed significant polyphenol (527.36 mg GAE/kg oil), and flavonoid (15.32 mg RE/kg oil), content, had a good appearance and was of high quality. Full article

(This article belongs to the Special Issue Green Extraction of Natural Product: Innovative Techniques, Alternative Solvents and Original Procedures)

► Show Figures

Figure 1

8576 KiB

Open AccessArticle

Trace Oxygen Sensitive Material Based on Two Porphyrin Derivatives in a Heterodimeric Complex

by Eugenia Fagadar-Cosma, Valentin Badea, Gheorghe Fagadar-Cosma, Anca Palade, Anca Lascu, Ionela Fringu and Mihaela Birdeanu

Molecules 2017, 22(10), 1787; https://doi.org/10.3390/molecules22101787 - 21 Oct 2017

Cited by 5 | Viewed by 6888

Abstract

The successful preparation of a novel dimer complex formed between 5,10,15,20-tetrakis(3,4-dimethoxyphenyl)-porphyrin Fe(III) chloride and (5,10,15,20-tetraphenylporphinato) dichlorophosphorus(V) chloride using the well-known reactivity of the P–X bond is reported. The obtained complex was characterized by UV-vis, Fourier transform infrared spectroscopy (FT-IR), fluorescence, ¹H-NMR, ¹³ [...] Read more.

The successful preparation of a novel dimer complex formed between 5,10,15,20-tetrakis(3,4-dimethoxyphenyl)-porphyrin Fe(III) chloride and (5,10,15,20-tetraphenylporphinato) dichlorophosphorus(V) chloride using the well-known reactivity of the P–X bond is reported. The obtained complex was characterized by UV-vis, Fourier transform infrared spectroscopy (FT-IR), fluorescence, ¹H-NMR, ¹³C-NMR, and ³¹P-NMR spectroscopic techniques and also by additional Heteronuclear Single Quantum Coherence (HSQC) and Heteronuclear Multiple Bond Correlation (HMBC) experiments in order to correctly assign the NMR signals. Scanning electron microscopy (SEM) and EDX quantifications completed the characterizations. This novel porphyrin dimer complex demonstrated fluorescence sensing of H₂O₂ in water for low oxygen concentrations in the range of 40–90 µM proving medical relevance for early diagnosis of diseases such as Alzheimer’s, Parkinson’s, Huntington’s, and even cancer because higher concentrations of H₂O₂ than 50 μM are consideredcytotoxic for life. Due to its optical properties, this novel metalloporphyrin–porphyrin based complex is expected to show PDT and bactericidal activity under visible-light irradiation. Full article

(This article belongs to the Section Molecular Diversity)

► Show Figures

Figure 1

4072 KiB

Open AccessArticle

Inhibitory Effects of Siegesbeckia orientalis Extracts on Advanced Glycation End Product Formation and Key Enzymes Related to Metabolic Syndrome

by Wei-Chin Hung, Xue-Hua Ling, Chi-Chang Chang, Hsia-Fen Hsu, Shih-Wei Wang, Yi-Chen Lee, Ci Luo, Yun-Tzu Lee and Jer-Yiing Houng

Molecules 2017, 22(10), 1785; https://doi.org/10.3390/molecules22101785 - 21 Oct 2017

Cited by 17 | Viewed by 7276

Abstract

Metabolic syndrome typically includes Type 2 diabetes associated with hyperglycemia, central obesity, dyslipidemia and hypertension. It is highly related to oxidative stress, formation of advanced glycated end products (AGEs) and key enzymes, such as carbohydrate digesting enzymes like pancreatic α-amylase and intestinal α-glucosidase, [...] Read more.

Metabolic syndrome typically includes Type 2 diabetes associated with hyperglycemia, central obesity, dyslipidemia and hypertension. It is highly related to oxidative stress, formation of advanced glycated end products (AGEs) and key enzymes, such as carbohydrate digesting enzymes like pancreatic α-amylase and intestinal α-glucosidase, pancreatic lipase and angiotensin I-converting enzyme (ACE). This study used an in vitro approach to assess the potential of four extracts of Siegesbeckia orientalis linne on key enzymes relevant to metabolic syndrome. In this research, S. orientailis was firstly extracted by ethanol. The ethanol extract (SE) was then partitioned sequentially with hexane, ethyl acetate and methanol, and these extracts were named SE-Hex, SE-EA and SE-MeOH, respectively. The experimental results showed that SE-EA had the highest total phenolic content (TPC, 76.9 ± 1.8 mg/g) and the total flavonoids content (TFC, 5.3 ± 0.3 mg/g). This extract exhibited the most significant antioxidant activities, including DPPH radical-scavenging capacity (IC₅₀ = 161.8 ± 2.4 μg/mL), ABTS radical-scavenging capacity (IC₅₀ = 13.9 ± 1.5 μg/mL) and reducing power. For anti-glycation activities, SE-EA showed the best results in the inhibition of AGEs, as well as inhibitory activities against α-glucosidase (IC₅₀ = 362.3 ± 9.2 μg/mL) and α-amylase (IC₅₀ = 119.0 ± 17.7 μg/mL). For anti-obesity activities, SE-EA indicated the highest suppression effect on pancreatic lipase (IC₅₀ = 3.67 ± 0.52 mg/mL). Finally, for anti-hypertension activity, SE-EA also demonstrated the strongest inhibitory activity on ACE (IC₅₀ = 626.6 ± 15.0 μg/mL). Close relationships were observed among the parameters of TPC, antioxidant activities, inhibitory activities on α-amylase, α-glucosidase, lipase and ACE (R > 0.9). Moderate correlations were found among the parameters of TFC, antioxidant activities, and suppression of dicarbonyl compounds formation (R = 0.5–0.9). Taken together these in vitro studies reveal the therapeutic potential of SE-EA extract in the prevention and treatment of metabolic disorders. Full article

(This article belongs to the Special Issue Bioactive Compounds for Metabolic Syndrome and Type 2 Diabetes)

► Show Figures

Graphical abstract

4540 KiB

Open AccessArticle

Effect of Steam Deactivation Severity of ZSM-5 Additives on LPG Olefins Production in the FCC Process

by Andrey A. Gusev, Antonios C. Psarras, Konstantinos S. Triantafyllidis, Angelos A. Lappas and Paul A. Diddams

Molecules 2017, 22(10), 1784; https://doi.org/10.3390/molecules22101784 - 21 Oct 2017

Cited by 23 | Viewed by 8543

Abstract

ZSM-5-containing catalytic additives are widely used in oil refineries to boost light olefin production and improve gasoline octanes in the Fluid Catalytic Cracking (FCC) process. Under the hydrothermal conditions present in the FCC regenerator (typically >700 °C and >8% steam), FCC catalysts and [...] Read more.

ZSM-5-containing catalytic additives are widely used in oil refineries to boost light olefin production and improve gasoline octanes in the Fluid Catalytic Cracking (FCC) process. Under the hydrothermal conditions present in the FCC regenerator (typically >700 °C and >8% steam), FCC catalysts and additives are subject to deactivation. Zeolites (e.g., Rare Earth USY in the base catalyst and ZSM-5 in Olefins boosting additives) are prone to dealumination and partial structural collapse, thereby losing activity, micropore surface area, and undergoing changes in selectivity. Fresh catalyst and additives are added at appropriate respective levels to the FCC unit on a daily basis to maintain overall targeted steady-state (equilibrated) activity and selectivity. To mimic this process under accelerated laboratory conditions, a commercial P/ZSM-5 additive was hydrothermally equilibrated via a steaming process at two temperatures: 788 °C and 815 °C to simulate moderate and more severe equilibration industrial conditions, respectively. n-Dodecane was used as probe molecule and feed for micro-activity cracking testing at 560 °C to determine the activity and product selectivity of fresh and equilibrated P-doped ZSM-5 additives. The fresh/calcined P/ZSM-5 additive was very active in C₁₂ cracking while steaming limited its activity, i.e., at catalyst-to-feed (C/F) ratio of 1, about 70% and 30% conversion was obtained with the fresh and steamed additives, respectively. A greater activity drop was observed upon increasing the hydrothermal deactivation severity due to gradual decrease of total acidity and microporosity of the additives. However, this change in severity did not result in any selectivity changes for the LPG (liquefied petroleum gas) olefins as the nature (Brønsted-to-Lewis ratio) of the acid/active sites was not significantly altered upon steaming. Steam deactivation of ZSM-5 had also no significant effect on aromatics formation which was enhanced at higher conversion levels. Coke remained low with both fresh and steam-deactivated P/ZSM-5 additives. Full article

(This article belongs to the Special Issue Zeolites and Related Nanoporous Materials: Synthesis, Characterization and Applications in Catalysis and Green Chemistry)

► Show Figures

Graphical abstract

1556 KiB

Open AccessCommunication

Cinnamic Acid Analogs as Intervention Catalysts for Overcoming Antifungal Tolerance

by Jong H. Kim, Kathleen L. Chan and Luisa W. Cheng

Molecules 2017, 22(10), 1783; https://doi.org/10.3390/molecules22101783 - 21 Oct 2017

Cited by 8 | Viewed by 6126

Abstract

Disruption of fungal cell wall should be an effective intervention strategy. However, the cell wall-disrupting echinocandin drugs, such as caspofungin (CAS), cannot exterminate filamentous fungal pathogens during treatment. For potency improvement of cell wall-disrupting agents (CAS, octyl gallate (OG)), antifungal efficacy of thirty-three [...] Read more.

Disruption of fungal cell wall should be an effective intervention strategy. However, the cell wall-disrupting echinocandin drugs, such as caspofungin (CAS), cannot exterminate filamentous fungal pathogens during treatment. For potency improvement of cell wall-disrupting agents (CAS, octyl gallate (OG)), antifungal efficacy of thirty-three cinnamic acid derivatives was investigated against Saccharomyces cerevisiae slt2Δ, bck1Δ, mutants of the mitogen-activated protein kinase (MAPK), and MAPK kinase kinase, respectively, in cell wall integrity system, and glr1Δ, mutant of CAS-responsive glutathione reductase. Cell wall mutants were highly susceptible to four cinnamic acids (4-chloro-α-methyl-, 4-methoxy-, 4-methyl-, 3-methylcinnamic acids), where 4-chloro-α-methyl- and 4-methylcinnamic acids possessed the highest activity. Structure-activity relationship revealed that 4-methylcinnamic acid, the deoxygenated structure of 4-methoxycinnamic acid, overcame tolerance of glr1Δ to 4-methoxycinnamic acid, indicating the significance of para substitution of methyl moiety for effective fungal control. The potential of compounds as chemosensitizers (intervention catalysts) to cell wall disruptants (viz., 4-chloro-α-methyl- or 4-methylcinnamic acids + CAS or OG) was assessed according to Clinical Laboratory Standards Institute M38-A. Synergistic chemosensitization greatly lowers minimum inhibitory concentrations of the co-administered drug/agents. 4-Chloro-α-methylcinnamic acid further overcame fludioxonil tolerance of Aspergillus fumigatus antioxidant MAPK mutants (sakAΔ, mpkCΔ). Collectively, 4-chloro-α-methyl- and 4-methylcinnamic acids possess chemosensitizing capability to augment antifungal efficacy of conventional drug/agents, thus could be developed as target-based (i.e., cell wall disruption) intervention catalysts. Full article

(This article belongs to the Special Issue Small Molecule Catalysts with Therapeutic Potential)

► Show Figures

Graphical abstract

2025 KiB

Open AccessArticle

Protective Effect of Prunus Cerasus (Sour Cherry) Seed Extract on the Recovery of Ischemia/Reperfusion-Induced Retinal Damage in Zucker Diabetic Fatty Rat

by Balázs Varga, Dániel Priksz, Nóra Lampé, Mariann Bombicz, Andrea Kurucz, Adrienn Mónika Szabó, Anikó Pósa, Renáta Szabó, Ádám Kemény-Beke, Judit Remenyik, Rudolf Gesztelyi and Béla Juhász

Molecules 2017, 22(10), 1782; https://doi.org/10.3390/molecules22101782 - 21 Oct 2017

Cited by 21 | Viewed by 5757

Abstract

Among diabetes patients, ophthalmological complications are very frequent. High blood glucose and (consequential) ischemia-reperfusion (I/R) injury contribute significantly to the severity of retinopathies. Diabetic retinopathy is among the leading causes of blindness. Our study demonstrates the effect of sour cherry seed extract (SCSE) [...] Read more.

Among diabetes patients, ophthalmological complications are very frequent. High blood glucose and (consequential) ischemia-reperfusion (I/R) injury contribute significantly to the severity of retinopathies. Diabetic retinopathy is among the leading causes of blindness. Our study demonstrates the effect of sour cherry seed extract (SCSE) on blood glucose and function of the retina with electroretinography (ERG) in a diabetic setting with or without ischemia-reperfusion (I/R) injury in Zucker Diabetic Fatty (ZDF) rats. Our results prove that the SCSE has a retinoprotective effect in diabetic rats: according to ERG measurements, SCSE treatment mitigated the retinal function-damaging effect of diabetes, and proved to be protective in the diabetic eye against ischemia-reperfusion injuries of the retina. Outcomes suggest that the protective effects of SCSE may occur through several pathways, including HO-1 dependent mechanisms. The observation that SCSE treatment decreases blood glucose is also novel. These findings offer the possibility for development of novel therapeutic strategies utilizing this emerging functional food, in particular in the prevention of conditions resulting from high blood glucose or I/R injury, such as deterioration of retinal microcirculation. Full article

(This article belongs to the Special Issue Bioactive Compounds for Metabolic Syndrome and Type 2 Diabetes)

► Show Figures

Figure 1

858 KiB

Open AccessReview

Phytotherapeutics: The Emerging Role of Intestinal and Hepatocellular Transporters in Drug Interactions with Botanical Supplements

by Ghulam Murtaza, Naveed Ullah, Farah Mukhtar, Shamyla Nawazish, Saiqa Muneer and Mariam

Molecules 2017, 22(10), 1699; https://doi.org/10.3390/molecules22101699 - 21 Oct 2017

Cited by 14 | Viewed by 8334

Abstract

In herbalism, botanical supplements are commonly believed to be safe remedies, however, botanical supplements and dietary ingredients interact with transport and metabolic processes, affecting drug disposition. Although a large number of studies have described that botanical supplements interfere with drug metabolism, the mode [...] Read more.

In herbalism, botanical supplements are commonly believed to be safe remedies, however, botanical supplements and dietary ingredients interact with transport and metabolic processes, affecting drug disposition. Although a large number of studies have described that botanical supplements interfere with drug metabolism, the mode of their interaction with drug transport processes is not well described. Such interactions may result in serious undesired effects and changed drug efficacy, therefore, some studies on interaction between botanical supplement ingredients and drug transporters such as P-gp and OATPs are described here, suggesting that the interaction between botanical supplements and the drug transporters is clinically significant. Full article

(This article belongs to the Section Natural Products Chemistry)

► Show Figures

Figure 1

11442 KiB

Open AccessArticle

Protective Effect of Flavonoids from Ziziphus jujuba cv. Jinsixiaozao against Acetaminophen-Induced Liver Injury by Inhibiting Oxidative Stress and Inflammation in Mice

by Weizhen Huang, Yongjie Wang, Xiaoyan Jiang, Yueyue Sun, Zhongxi Zhao and Siying Li

Molecules 2017, 22(10), 1781; https://doi.org/10.3390/molecules22101781 - 20 Oct 2017

Cited by 58 | Viewed by 7151

Abstract

This study was aimed to investigate the chemical composition, antioxidant activities and hepatoprotective effect of flavonoids from Ziziphus jujuba cv. Jinsixiaozao (ZJF). The composition of ZJF was analyzed by high performance liquid chromatography (HPLC) and Liquid chromatography–mass spectrometry (LC–MS), and antioxidant properties [...] Read more.

This study was aimed to investigate the chemical composition, antioxidant activities and hepatoprotective effect of flavonoids from Ziziphus jujuba cv. Jinsixiaozao (ZJF). The composition of ZJF was analyzed by high performance liquid chromatography (HPLC) and Liquid chromatography–mass spectrometry (LC–MS), and antioxidant properties were investigated by biological assays in vitro. The hepatoprotective activity of ZJF was evaluated in acetaminophen (APAP)-treated BALB/c mice. Results indicate that ZJF displayed significant antioxidant capacity. Pretreatment with ZJF significantly decreased APAP-elevated serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and total bilirubin (TB). Activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were enhanced with ZJF administration, while malondialdehyde (MDA) level and glutathione (GSH) depletion were reduced. Meanwhile, ZJF reversed the suppression of nuclear factor erythroid 2-related factor 2 (Nrf2) nuclear translocation, and up-regulated the protein expression of NAD(P)H: quinone oxidoreductase 1(NQO1) in liver damage mice. Furthermore, ZJF attenuated APAP-induced inflammatory mediator production, such as nitric oxide (NO), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and interleukin-1β (IL-1β). Expression of p65 showed that ZJF dampened nuclear factor-κB (NF-κB) activation. The results strongly indicate that the hepatoprotective role of ZJF in APAP-induced hepatotoxicity might result from its induction of antioxidant defense via activation of Nrf2 and reduction of inflammation via inhibition of NF-κB. Full article

► Show Figures

Figure 1

Journal Menu

Journal Browser

Molecules, Volume 22, Issue 10 (October 2017) – 225 articles

Further Information

Guidelines

MDPI Initiatives

Follow MDPI