Molecules

1259 KiB

Open AccessArticle

Genetic Variability and Population Structure of the Potential Bioenergy Crop Miscanthus sinensis (Poaceae) in Southwest China Based on SRAP Markers

by Gang Nie, Xin-Quan Zhang, Lin-Kai Huang, Wen-Zhi Xu, Jian-Ping Wang, Yun-Wei Zhang, Xiao Ma, Yan-Hong Yan and Hai-Dong Yan

Molecules 2014, 19(8), 12881-12897; https://doi.org/10.3390/molecules190812881 - 21 Aug 2014

Cited by 21 | Viewed by 7032

Abstract

The genus Miscanthus has great potential as a biofuel feedstock because of its high biomass, good burning quality, environmental tolerance, and good adaptability to marginal land. In this study, the genetic diversity and the relationship of 24 different natural Miscanthus sinensis populations collected [...] Read more.

The genus Miscanthus has great potential as a biofuel feedstock because of its high biomass, good burning quality, environmental tolerance, and good adaptability to marginal land. In this study, the genetic diversity and the relationship of 24 different natural Miscanthus sinensis populations collected from Southwestern China were analyzed by using 33 pairs of Sequence Related Amplified Polymorphism (SRAP) primers. A total of 688 bands were detected with 646 polymorphic bands, an average of 19.58 polymorphic bands per primer pair. The average percentage of polymorphic loci (P), gene diversity (H), and Shannon’s diversity index (I) among the 24 populations are 70.59%, 0.2589, and 0.3836, respectively. The mean value of total gene diversity (H_T) was 0.3373 ± 0.0221, while the allelic diversity within populations (H_S) was 0.2589 ± 0.0136 and the allelic diversity among populations (D_ST) was 0.0784. The mean genetic differentiation coefficient (Gst = 0.2326) estimated from the detected 688 loci indicated that there was 76.74% genetic differentiation within the populations, which is consistent with the results from Analysis of Molecular Variance (AMOVA) analysis. Based upon population structure and phylogenetic analysis, five groups were formed and a special population with mixed ancestry was inferred indicating that human-mediated dispersal may have had a significant effect on population structure of M. sinensis. Evaluating the genetic structure and genetic diversity at morphological and molecular levels of the wild M. sinensis in Southwest China is critical to further utilize the wild M. sinensis germplasm in the breeding program. The results in this study will facilitate the biofuel feedstock breeding program and germplasm conservation. Full article

(This article belongs to the Section Molecular Diversity)

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2104 KiB

Open AccessArticle

Conjugates of 1'-Aminoferrocene-1-carboxylic Acid and Proline: Synthesis, Conformational Analysis and Biological Evaluation

by Monika Kovačević, Krešimir Molčanov, Kristina Radošević, Višnja Gaurina Srček, Sunčica Roca, Alan Čače and Lidija Barišić

Molecules 2014, 19(8), 12852-12880; https://doi.org/10.3390/molecules190812852 - 21 Aug 2014

Cited by 16 | Viewed by 10061

Abstract

Our previous studies showed that alteration of dipeptides Y-Fca-Ala-OMe (III) into Y-Ala-Fca-OMe (IV) (Y = Ac, Boc; Fca = 1'-aminoferrocene-1-carboxylic acid) significantly influenced their conformational space. The novel bioconjugates Y-Fca-Pro-OMe (1, Y = Ac; 2, Y [...] Read more.

Our previous studies showed that alteration of dipeptides Y-Fca-Ala-OMe (III) into Y-Ala-Fca-OMe (IV) (Y = Ac, Boc; Fca = 1'-aminoferrocene-1-carboxylic acid) significantly influenced their conformational space. The novel bioconjugates Y-Fca-Pro-OMe (1, Y = Ac; 2, Y = Boc) and Y-Pro-Fca-OMe (3, Y = Boc; 4, Y = Ac) have been prepared in order to investigate the influence of proline, a well-known turn-inducer, on the conformational properties of small organometallic peptides with an exchanged constituent amino acid sequences. For this purpose, peptides 1–4 were subjected to detailed spectroscopic analysis (IR, NMR, CD spectroscopy) in solution. The conformation of peptide 3 in the solid state was determined. Furthermore, the ability of the prepared conjugates to inhibit the growth of estrogen receptor-responsive MCF-7 mammary carcinoma cells and HeLa cervical carcinoma cells was tested. Full article

(This article belongs to the Special Issue Intramolecular Hydrogen Bonding)

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1477 KiB

Open AccessArticle

Unusual Product Distribution from Friedländer Reaction of Di- and Triacetylbenzenes with 3-Aminonaphthalene-2-carbaldehyde and Properties of New Benzo[g]quinoline-Derived Aza-aromatics

by Moinul Karim and Yurngdong Jahng

Molecules 2014, 19(8), 12842-12851; https://doi.org/10.3390/molecules190812842 - 21 Aug 2014

Cited by 6 | Viewed by 6505

Abstract

The Friedländer reactions of acetylbenzenes and 2-acetylpyridine with 3-aminonaphthalene-2-carbaldehyde afforded the corresponding 2-phenylbenzo[g]quinoline and 2-(pyrid-2-yl)benzo[g]quinoline, respectively. The same reactions of 3-aminonaphthalene-2-carbaldehyde with 1,2-, 1,3-, 1,4-di- and 1,3,5-triacetylbenzenes, however, afforded a series of corresponding (benzo[g]quinolin-2-yl)benzenes as new N [...] Read more.

The Friedländer reactions of acetylbenzenes and 2-acetylpyridine with 3-aminonaphthalene-2-carbaldehyde afforded the corresponding 2-phenylbenzo[g]quinoline and 2-(pyrid-2-yl)benzo[g]quinoline, respectively. The same reactions of 3-aminonaphthalene-2-carbaldehyde with 1,2-, 1,3-, 1,4-di- and 1,3,5-triacetylbenzenes, however, afforded a series of corresponding (benzo[g]quinolin-2-yl)benzenes as new N,C-bidentate and unexpected benzo[g]quinoline. Crystallinity, thermal properties, absorption and emission spectral properties of the products were studied. Full article

(This article belongs to the Section Molecular Diversity)

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1490 KiB

Open AccessArticle

Anti-Inflammatory Effect of the Blueberry Anthocyanins Malvidin-3-Glucoside and Malvidin-3-Galactoside in Endothelial Cells

by Wu-Yang Huang, Ya-Mei Liu, Jian Wang, Xing-Na Wang and Chun-Yang Li

Molecules 2014, 19(8), 12827-12841; https://doi.org/10.3390/molecules190812827 - 21 Aug 2014

Cited by 117 | Viewed by 14057

Abstract

Blueberry fruits have a wide range of health benefits because of their abundant anthocyanins, which are natural antioxidants. The purpose of this study was to investigate the inhibitory effect of blueberry’s two main anthocyanins (malvidin-3-glucoside and malvidin-3-galactoside) on inflammatory response in endothelial cells. [...] Read more.

Blueberry fruits have a wide range of health benefits because of their abundant anthocyanins, which are natural antioxidants. The purpose of this study was to investigate the inhibitory effect of blueberry’s two main anthocyanins (malvidin-3-glucoside and malvidin-3-galactoside) on inflammatory response in endothelial cells. These two malvidin glycosides could inhibit tumor necrosis factor-alpha (TNF-α) induced increases of monocyte chemotactic protein-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) production both in the protein and mRNA levels in a concentration-dependent manner. Mv-3-glc at the concentration of 1 μM could inhibit 35.9% increased MCP-1, 54.4% ICAM-1, and 44.7% VCAM-1 protein in supernatant, as well as 9.88% MCP-1 and 48.6% ICAM-1 mRNA expression (p < 0.05). In addition, they could decrease IκBα degradation (Mv-3-glc, Mv-3-gal, and their mixture at the concentration of 50 μM had the inhibition rate of 84.8%, 75.3%, and 43.2%, respectively, p < 0.01) and block the nuclear translocation of p65, which suggested their anti-inflammation mechanism was mediated by the nuclear factor-kappa B (NF-κB) pathway. In general malvidin-3-glucoside had better anti-inflammatory effect than malvidin-3-galactoside. These results indicated that blueberry is good resource of anti-inflammatory anthocyanins, which can be promising molecules for the development of nutraceuticals to prevent chronic inflammation in many diseases. Full article

(This article belongs to the Special Issue Anthocyanins)

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731 KiB

Open AccessArticle

Copaiba Oil Suppresses Inflammatory Cytokines in Splenocytes of C57Bl/6 Mice Induced with Experimental Autoimmune Encephalomyelitis (EAE)

by Débora S. Dias, Lívia B. A. Fontes, Antônio E. M. Crotti, Beatriz J. V. Aarestrup, Fernando M. Aarestrup, Ademar A. Da Silva Filho and José O. A. Corrêa

Molecules 2014, 19(8), 12814-12826; https://doi.org/10.3390/molecules190812814 - 21 Aug 2014

Cited by 33 | Viewed by 15210

Abstract

Experimental autoimmune encephalomyelitis (EAE) is a murine autoimmune disease used to study multiple sclerosis. We have investigated the immunomodulatory effects of copaiba oil (100, 50 and 25 µg/mL) on NO, H₂O₂, TNF-α, IFN-γ and IL-17 production in cultured cells [...] Read more.

Experimental autoimmune encephalomyelitis (EAE) is a murine autoimmune disease used to study multiple sclerosis. We have investigated the immunomodulatory effects of copaiba oil (100, 50 and 25 µg/mL) on NO, H₂O₂, TNF-α, IFN-γ and IL-17 production in cultured cells from EAE-mice. Copaiba oil (100 µg/mL) inhibited H₂O₂, NO, IFN-γ TNF-α and IL-17 production spontaneously or after ConA and MOG_35–55 stimulation. It is suggested that copaiba oil acts on the mechanism of development of EAE by IFN-γ, IL-17 and TNF-α inhibition, modulating the immune response on both Th1 and Th17 cells. Full article

(This article belongs to the Section Medicinal Chemistry)

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1566 KiB

Open AccessReview

Thiosulfoxide (Sulfane) Sulfur: New Chemistry and New Regulatory Roles in Biology

by John I. Toohey and Arthur J. L. Cooper

Molecules 2014, 19(8), 12789-12813; https://doi.org/10.3390/molecules190812789 - 21 Aug 2014

Cited by 140 | Viewed by 13963

Abstract

The understanding of sulfur bonding is undergoing change. Old theories on hypervalency of sulfur and the nature of the chalcogen-chalcogen bond are now questioned. At the same time, there is a rapidly expanding literature on the effects of sulfur in regulating biological systems. [...] Read more.

The understanding of sulfur bonding is undergoing change. Old theories on hypervalency of sulfur and the nature of the chalcogen-chalcogen bond are now questioned. At the same time, there is a rapidly expanding literature on the effects of sulfur in regulating biological systems. The two fields are inter-related because the new understanding of the thiosulfoxide bond helps to explain the newfound roles of sulfur in biology. This review examines the nature of thiosulfoxide (sulfane, S⁰) sulfur, the history of its regulatory role, its generation in biological systems, and its functions in cells. The functions include synthesis of cofactors (molybdenum cofactor, iron-sulfur clusters), sulfuration of tRNA, modulation of enzyme activities, and regulating the redox environment by several mechanisms (including the enhancement of the reductive capacity of glutathione). A brief review of the analogous form of selenium suggests that the toxicity of selenium may be due to over-reduction caused by the powerful reductive activity of glutathione perselenide. Full article

(This article belongs to the Special Issue Sulfur Atom: Element for Adaptation to an Oxidative Environment)

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835 KiB

Open AccessArticle

Anti-Inflammatory Effect of Momordica Charantia in Sepsis Mice

by Che-Yi Chao, Ping-Jyun Sung, Wei-Hsien Wang and Yueh-Hsiung Kuo

Molecules 2014, 19(8), 12777-12788; https://doi.org/10.3390/molecules190812777 - 21 Aug 2014

Cited by 58 | Viewed by 10367

Abstract

Wild bitter gourd (Momordica charantia L. var. abbreviate Seringe), a common vegetable in Asia, is used in traditional medicine to treat various diseases, including inflammation. Extant literature indicates that wild bitter gourds have components that activate PPARα and PPARγ. This research probed [...] Read more.

Wild bitter gourd (Momordica charantia L. var. abbreviate Seringe), a common vegetable in Asia, is used in traditional medicine to treat various diseases, including inflammation. Extant literature indicates that wild bitter gourds have components that activate PPARα and PPARγ. This research probed the influence of adding wild bitter gourd to diets on inflammation responses in mice with sepsis induced by intraperitoneal injection of LPS. Male BALB/c mice were divided normal, sepsis, positive control, and three experimental groups. The latter ate diets with low (1%), moderate (2%), and high (10%) ratios of wild bitter gourd lyophilized powder. Before mice were sacrificed, with the exception of the normal group, intraperitoneal injection of LPS induced sepsis in each group; positive control group was injected with LPS after PDTC. This experiment revealed starkly lower weights in groups with added wild bitter gourd than those of the remaining groups. Blood lipids (TG, cholesterol, and NEFA) were also lower in comparison to the sepsis group, and blood glucose concentrations recovered and approached normal levels. Blood biochemistry values related to inflammation reactions indicated GOT, GPT, C-RP, and NOconcentrations of groups with added wild bitter gourd were all lower than those of the sepsis group. Secretion levels of the spleen pro-inflammatory cytokines IL-1, IL-6, and TNF-α tallied significantly lower in comparison to the sepsis group, whereas secretion levels of IL-10 anti-inflammatory cytokine increased. Expression level of proteins NF-κB, iNOS, and COX-2 were significantly inhibited. Results indicate wild bitter gourd in diets promoted lipid metabolism, reducing fat accumulation, and improving low blood glucose in sepsis. Addition of wild bitter gourd can reduce inflammation biochemical markers or indicators and pro-inflammatory cytokines in the body, hence improving the inflammation responses in mice with sepsis. Full article

(This article belongs to the Section Medicinal Chemistry)

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5178 KiB

Open AccessArticle

Effects of Drying Methods on Physicochemical and Immunomodulatory Properties of Polysaccharide-Protein Complexes from Litchi Pulp

by Fei Huang, Yajuan Guo, Ruifen Zhang, Yang Yi, Yuanyuan Deng, Dongxiao Su and Mingwei Zhang

Molecules 2014, 19(8), 12760-12776; https://doi.org/10.3390/molecules190812760 - 20 Aug 2014

Cited by 35 | Viewed by 7036

Abstract

Dried litchi pulp has been used in traditional remedies in China for many years to treat various diseases, and the therapeutic activity has been, at least partly, attributed to the presence of bioactive polysaccharides. Polysaccharide-protein complexes from vacuum freeze-(VF), vacuum microwave-(VM) and heat [...] Read more.

Dried litchi pulp has been used in traditional remedies in China for many years to treat various diseases, and the therapeutic activity has been, at least partly, attributed to the presence of bioactive polysaccharides. Polysaccharide-protein complexes from vacuum freeze-(VF), vacuum microwave-(VM) and heat pump (HP) dried litchi pulp, which were coded as LP-VF, LP-VM and LP-HP, were comparatively studied on the physicochemical and immunomodulatory properties. LP-HP had a predominance of galactose, while glucose was the major sugar component in LP-VF and LP-VM. Compared with LP-VF and LP-VM, LP-HP contained more aspartate and glutamic in binding protein. LP-HP also exhibited a stronger stimulatory effect on splenocyte proliferation at 200 μg/mL and triggered higher NO, TNF-α and IL-6 secretion from RAW264.7 macrophages. Different drying methods caused the difference in physicochemical properties of polysaccharide-protein complexes from dried litchi pulp, which resulted in significantly different immunomodulatory activity. HP drying appears to be the best method for preparing litchi pulp to improve its immunomodulatory properties. Full article

(This article belongs to the Section Natural Products Chemistry)

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2967 KiB

Open AccessReview

Effect of Redox Modulating NRF2 Activators on Chronic Kidney Disease

by Bo-hyun Choi, Kyung-Shin Kang and Mi-Kyoung Kwak

Molecules 2014, 19(8), 12727-12759; https://doi.org/10.3390/molecules190812727 - 20 Aug 2014

Cited by 129 | Viewed by 18169

Abstract

Chronic kidney disease (CKD) is featured by a progressive decline of kidney function and is mainly caused by chronic diseases such as diabetes mellitus and hypertension. CKD is a complex disease due to cardiovascular complications and high morbidity; however, there is no single [...] Read more.

Chronic kidney disease (CKD) is featured by a progressive decline of kidney function and is mainly caused by chronic diseases such as diabetes mellitus and hypertension. CKD is a complex disease due to cardiovascular complications and high morbidity; however, there is no single treatment to improve kidney function in CKD patients. Since biological markers representing oxidative stress are significantly elevated in CKD patients, oxidative stress is receiving attention as a contributing factor to CKD pathology. Nuclear factor erythroid-2 related factor 2 (NRF2) is a predominant transcription factor that regulates the expression of a wide array of genes encoding antioxidant proteins, thiol molecules and their generating enzymes, detoxifying enzymes, and stress response proteins, all of which can counteract inflammatory and oxidative damages. There is considerable experimental evidence suggesting that NRF2 signaling plays a protective role in renal injuries that are caused by various pathologic conditions. In addition, impaired NRF2 activity and consequent target gene repression have been observed in CKD animals. Therefore, a pharmacological intervention activating NRF2 signaling can be beneficial in protecting against kidney dysfunction in CKD. This review article provides an overview of the role of NRF2 in experimental CKD models and describes current findings on the renoprotective effects of naturally occurring NRF2 activators, including sulforaphane, resveratrol, curcumin, and cinnamic aldehyde. These experimental results, coupled with recent clinical experiences with a synthetic triterpenoid, bardoxolone methyl, have brought a light of hope for ameliorating CKD progression by preventing oxidative stress and maintaining cellular redox homeostasis. Full article

(This article belongs to the Special Issue Redox Active Natural Products and Their Interaction with Cellular Signalling Pathways)

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1343 KiB

Open AccessReview

Magnetite Nanostructures as Novel Strategies for Anti-Infectious Therapy

by Ioannis Liakos, Alexandru Mihai Grumezescu and Alina Maria Holban

Molecules 2014, 19(8), 12710-12726; https://doi.org/10.3390/molecules190812710 - 20 Aug 2014

Cited by 61 | Viewed by 9001

Abstract

This review highlights the current situation of antimicrobial resistance and the use of magnetic nanoparticles (MNPs) in developing novel routes for fighting infectious diseases. The most important two directions developed recently are: (i) improved delivery of antimicrobial compounds based on a drastic decrease [...] Read more.

This review highlights the current situation of antimicrobial resistance and the use of magnetic nanoparticles (MNPs) in developing novel routes for fighting infectious diseases. The most important two directions developed recently are: (i) improved delivery of antimicrobial compounds based on a drastic decrease of the minimal inhibition concentration (MIC) of the drug used independently; and (ii) inhibition of microbial attachment and biofilm development on coated medical surfaces. These new directions represent promising alternatives in the development of new strategies to eradicate and prevent microbial infections that involve resistant and biofilm-embedded bacteria. Recent promising applications of MNPs, as the development of delivery nanocarriers and improved nanovehicles for the therapy of different diseases are discussed, together with the mechanisms of microbial inhibition. Full article

(This article belongs to the Special Issue Bio and Nanomaterials Based on Fe3O4)

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1297 KiB

Open AccessArticle

Identification of Two Novel α₁-AR Agonists Using a High-Throughput Screening Model

by Fang Xu, Hong Chen, Xuelan He, Jingyi Xu, Bingbing Xu, Biyun Huang, Xue Liang and Mu Yuan

Molecules 2014, 19(8), 12699-12709; https://doi.org/10.3390/molecules190812699 - 20 Aug 2014

Cited by 7 | Viewed by 5462

Abstract

α₁-Adrenoceptors (ARs; 1A, 1B, and 1D) have been determined to perform different prominent functions in the physiological responses of the sympathetic nervous system. A high-throughput screening assay (HTS) was set up to detect α₁-AR subtype-selective agonists by a dual-luciferase [...] Read more.

α₁-Adrenoceptors (ARs; 1A, 1B, and 1D) have been determined to perform different prominent functions in the physiological responses of the sympathetic nervous system. A high-throughput screening assay (HTS) was set up to detect α₁-AR subtype-selective agonists by a dual-luciferase reporter assay in HEK293 cells. Using the HTS assay, two novel compounds, CHE3 and CHK3, were discovered as α₁-ARs agonists in α₁-ARs expressed in HEK293 cells. These compounds also showed moderate/weak anti-proliferative activities against tested cancer cell lines. The HTS assay proposed in this study represents a potential method for discovering more α₁-AR subtype-selective ligands. Full article

(This article belongs to the Section Medicinal Chemistry)

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733 KiB

Open AccessArticle

Oligo-Carrageenan Kappa-Induced Reducing Redox Status and Activation of TRR/TRX System Increase the Level of Indole-3-acetic Acid, Gibberellin A₃ and trans-Zeatin in Eucalyptus globulus Trees

by Alberto González, Rodrigo A. Contreras, Gustavo Zúiga and Alejandra Moenne

Molecules 2014, 19(8), 12690-12698; https://doi.org/10.3390/molecules190812690 - 20 Aug 2014

Cited by 22 | Viewed by 6418

Abstract

Eucalyptus globulus trees treated with oligo-carrageenan (OC) kappa showed an increase in NADPH, ascorbate and glutathione levels and activation of the thioredoxin reductase (TRR)/thioredoxin (TRX) system which enhance photosynthesis, basal metabolism and growth. In order to analyze whether the reducing redox status and [...] Read more.

Eucalyptus globulus trees treated with oligo-carrageenan (OC) kappa showed an increase in NADPH, ascorbate and glutathione levels and activation of the thioredoxin reductase (TRR)/thioredoxin (TRX) system which enhance photosynthesis, basal metabolism and growth. In order to analyze whether the reducing redox status and the activation of thioredoxin reductase (TRR)/thioredoxin (TRX) increased the level of growth-promoting hormones, trees were treated with water (control), with OC kappa, or with inhibitors of ascorbate synthesis, lycorine, glutathione synthesis, buthionine sulfoximine (BSO), NADPH synthesis, CHS-828, and thioredoxin reductase activity, auranofine, and with OC kappa, and cultivated for four additional months. Eucalyptus trees treated with OC kappa showed an increase in the levels of the auxin indole 3-acetic acid (IAA), gibberellin A3 (GA₃) and the cytokinin trans-zeatin (t-Z) as well as a decrease in the level of the brassinosteroid epi-brassinolide (EB). In addition, treatment with lycorine, BSO, CHS-828 and auranofine inhibited the increase in IAA, GA₃ and t-Z as well as the decrease in EB levels. Thus, the reducing redox status and the activation of TRR/TRX system induced by OC kappa increased the levels of IAA, GA₃ and t-Z levels determining, at least in part, the stimulation of growth in Eucalyptus trees. Full article

(This article belongs to the Section Metabolites)

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Open AccessArticle

Cucurbitane Glycosides Derived from Mogroside II_E: Structure-Taste Relationships, Antioxidant Activity, and Acute Toxicity

by Lei Wang, Ziming Yang, Fenglai Lu, Jinglei Liu, Yunfei Song and Dianpeng Li

Molecules 2014, 19(8), 12676-12689; https://doi.org/10.3390/molecules190812676 - 20 Aug 2014

Cited by 25 | Viewed by 8296

Abstract

Mogroside IIE is a bitter triterpenoid saponin which is the main component of unripe Luo Han Guo fruit and a precursor of the commercially available sweetener mogroside V. In this study, we developed an enzymatic glycosyl transfer method, by which bitter mogroside IIE [...] Read more.

Mogroside IIE is a bitter triterpenoid saponin which is the main component of unripe Luo Han Guo fruit and a precursor of the commercially available sweetener mogroside V. In this study, we developed an enzymatic glycosyl transfer method, by which bitter mogroside IIE could be converted into a sweet triterpenoid saponin mixture. The reactant concentration, temperature, pH and buffer system were studied. New saponins with the α-glucose group were isolated from the resulting mixtures, and the structures of three components of the extract were determined. The structure-taste relationships of these derivatives were also studied together with those of the natural mogrosides. The number and stereoconfiguration of glucose groups present in the mogroside molecules were found to be the main factor to determine the sweet or bitter taste of a compound. The antioxidant and food safety properties were initially evaluated by their radical scavenging ability and via 7 day mice survival tests, respectively. The results showed that the sweet triterpenoid saponin mixture has the same favorable physiological and safety characteristics as the natural mogrosides. Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessArticle

Prebiotic Potential of Agave angustifolia Haw Fructans with Different Degrees of Polymerization

by José Rodolfo Velázquez-Martínez, Rina M. González-Cervantes, Minerva Aurora Hernández-Gallegos, Roberto Campos Mendiola, Antonio R. Jiménez Aparicio and Martha L. Arenas Ocampo

Molecules 2014, 19(8), 12660-12675; https://doi.org/10.3390/molecules190812660 - 19 Aug 2014

Cited by 59 | Viewed by 10717

Abstract

Inulin-type fructans are the most studied prebiotic compounds because of their broad range of health benefits. In particular, plants of the Agave genus are rich in fructans. Agave-derived fructans have a branched structure with both β-(2→1) and β-(2→6) linked fructosyl chains attached to [...] Read more.

Inulin-type fructans are the most studied prebiotic compounds because of their broad range of health benefits. In particular, plants of the Agave genus are rich in fructans. Agave-derived fructans have a branched structure with both β-(2→1) and β-(2→6) linked fructosyl chains attached to the sucrose start unit with a degree of polymerization (DP) of up to 80 fructose units. The objective of this work was to assess the prebiotic potential of three Agave angustifolia Haw fructan fractions (AFF) with different degrees of polymerization. The three fructan fractions were extracted from the agave stem by lixiviation and then purified by ultrafiltration and ion exchange chromatography: AFF1, AFF2 and AFF3 with high (3–60 fructose units), medium (2–40) and low (2–22) DP, respectively. The fructan profile was determined with high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD), which confirmed a branched fructan structure. Structural elucidation was performed by Fourier Transform Infra-Red Spectroscopy. The AFF spectrum shows characteristic fructan bands. The prebiotic effect of these fractions was assessed in vitro through fermentation by Bifidobacterium and Lactobacillus strains. Four growth patterns were observed. Some bacteria did not grow with any of the AFF, while other strains grew with only AFF3. Some bacteria grew according to the molecular weight of the AFF and some grew indistinctly with the three fructan fractions. Full article

(This article belongs to the Section Metabolites)

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Open AccessArticle

Ultrasound-Assisted Extraction of Antioxidants in Misai Kucing (Orthosiphon stamineus)

by Swee Kheng Ho, Chin Ping Tan, Yin Yin Thoo, Faridah Abas and Chun Wai Ho

Molecules 2014, 19(8), 12640-12659; https://doi.org/10.3390/molecules190812640 - 19 Aug 2014

Cited by 38 | Viewed by 7637

Abstract

Ultrasound-assisted extraction (UAE) with ethanol was used to extract the compounds responsible for the antioxidant activities of Misai Kucing (Orthosiphon stamineus). Response surface methodology (RSM) was used to optimize four independent variables: ethanol concentration (%), amplitude (%), duty cycle (W/s) and [...] Read more.

Ultrasound-assisted extraction (UAE) with ethanol was used to extract the compounds responsible for the antioxidant activities of Misai Kucing (Orthosiphon stamineus). Response surface methodology (RSM) was used to optimize four independent variables: ethanol concentration (%), amplitude (%), duty cycle (W/s) and extraction time (min). Antioxidant compounds were determined by total phenolic content and total flavonoid content to be 1.4 g gallic acid equivalent/100 g DW and 45 g catechin equivalent/100 g DW, respectively. Antioxidant activities were evaluated using the 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS^•+) radical scavenging capacity assay and the 2,2-diphenyl-1-picrylhydrazyl (DPPH•) radical scavenging capacity assay to be 1,961.3 and 2,423.3 µmol Trolox Equivalent Antioxidant Capacity (TEAC)/100 g DW, respectively. Based on the optimal conditions, experimental values were reported to be close to the predicted value by RSM modeling (p > 0.05), indicating the suitability of UAE for extracting the antioxidants of Misai Kucing. Rosmarinic acid, kaempferol-rutinoside and sinesetine were identified by high performance liquid chromatography-mass spectrometry. Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessArticle

Studies of the in Vitro Antibacterial Activities of Several Polyphenols against Clinical Isolates of Methicillin-Resistant Staphylococcus aureus

by Yanli Su, Liyan Ma, Yan Wen, Hong Wang and Shuwen Zhang

Molecules 2014, 19(8), 12630-12639; https://doi.org/10.3390/molecules190812630 - 19 Aug 2014

Cited by 68 | Viewed by 7766

Abstract

In this study, we report the antibacterial activities of six polyphenols (i.e., luteolin, quercetin, scutellarin, apigenin, chlorogenic acid, and resveratrol) against 29 clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA), and in vitro antibacterial activities of two-drug combinations. All of the MRSA [...] Read more.

In this study, we report the antibacterial activities of six polyphenols (i.e., luteolin, quercetin, scutellarin, apigenin, chlorogenic acid, and resveratrol) against 29 clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA), and in vitro antibacterial activities of two-drug combinations. All of the MRSA strains evaluated were clinical isolates from patients with MRSA bacteremia. The antibacterial activities were determined by agar dilution method, and the two-drug antibacterial activities were determined by the checkerboard agar dilution method. It was found that luteolin, quercetin and resveratrol show obvious antibacterial activities against MRSA, and the results of two-drug antibacterial activity show either synergy or additivity, without evidences of antagonistic effects. Full article

(This article belongs to the Section Medicinal Chemistry)

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Open AccessArticle

Preparative Isolation of Seven Diterpenoid Alkaloids from Aconitum coreanum by pH-Zone-Refining Counter-Current Chromatography

by Xueyong Wang, Xikai Shu, Xiao Wang, Jinqian Yu and Feng Jing

Molecules 2014, 19(8), 12619-12629; https://doi.org/10.3390/molecules190812619 - 19 Aug 2014

Cited by 9 | Viewed by 7196

Abstract

The aim of this paper was to seek an efficient method to preparative separation of alkaloid compounds from Aconitum coreanum (Guanbaifu), a well-known traditional Chinese medicinal plant for heart disease. Seven alkaloid compounds were successfully purified by pH-zone-refining counter-current chromatography with two-phase solvent [...] Read more.

The aim of this paper was to seek an efficient method to preparative separation of alkaloid compounds from Aconitum coreanum (Guanbaifu), a well-known traditional Chinese medicinal plant for heart disease. Seven alkaloid compounds were successfully purified by pH-zone-refining counter-current chromatography with two-phase solvent system of petroleum ether–ethyl acetate–methanol–water (5:5:1:9, v/v/v/v), 10 mM triethylamine in upper phase and 10 mM hydrochloric acid in lower phase. From 3.5 g of crude extract, 356 mg of Guanfu base I, 578 mg of Guanfu base A, 74 mg of atisine, 94 mg of Guanfu base F, 423 mg of Guanfu base G, 67 mg of Guanfu base R and 154 mg of Guanfu base P were obtained with the purity of 96.40%, 97.2%, 97.5%, 98.1%, 98.9%, 98.3% and 98.4%. Their chemical structures were identified by TOF-MS and ¹H-NMR. This study indicated that pH-zone-refining counter-current chromatography was an efficient method for separating the kind of alkaloids with low absorbance values. Full article

(This article belongs to the Special Issue Alkaloids: Novel Therapeutic Perspectives)

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Open AccessReview

Allicin: Chemistry and Biological Properties

by Jan Borlinghaus, Frank Albrecht, Martin C. H. Gruhlke, Ifeanyi D. Nwachukwu and Alan J. Slusarenko

Molecules 2014, 19(8), 12591-12618; https://doi.org/10.3390/molecules190812591 - 19 Aug 2014

Cited by 577 | Viewed by 65939

Abstract

Allicin (diallylthiosulfinate) is a defence molecule from garlic (Allium sativum L.) with a broad range of biological activities. Allicin is produced upon tissue damage from the non-proteinogenic amino acid alliin (S-allylcysteine sulfoxide) in a reaction that is catalyzed by the enzyme alliinase. [...] Read more.

Allicin (diallylthiosulfinate) is a defence molecule from garlic (Allium sativum L.) with a broad range of biological activities. Allicin is produced upon tissue damage from the non-proteinogenic amino acid alliin (S-allylcysteine sulfoxide) in a reaction that is catalyzed by the enzyme alliinase. Current understanding of the allicin biosynthetic pathway will be presented in this review. Being a thiosulfinate, allicin is a reactive sulfur species (RSS) and undergoes a redox-reaction with thiol groups in glutathione and proteins that is thought to be essential for its biological activity. Allicin is physiologically active in microbial, plant and mammalian cells. In a dose-dependent manner allicin can inhibit the proliferation of both bacteria and fungi or kill cells outright, including antibiotic-resistant strains like methicillin-resistant Staphylococcus aureus (MRSA). Furthermore, in mammalian cell lines, including cancer cells, allicin induces cell-death and inhibits cell proliferation. In plants allicin inhibits seed germination and attenuates root-development. The majority of allicin’s effects are believed to be mediated via redox-dependent mechanisms. In sub-lethal concentrations, allicin has a variety of health-promoting properties, for example cholesterol- and blood pressure-lowering effects that are advantageous for the cardio-vascular system. Clearly, allicin has wide-ranging and interesting applications in medicine and (green) agriculture, hence the detailed discussion of its enormous potential in this review. Taken together, allicin is a fascinating biologically active compound whose properties are a direct consequence of the molecule’s chemistry. Full article

(This article belongs to the Special Issue Redox Active Natural Products and Their Interaction with Cellular Signalling Pathways)

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Open AccessReview

Developments in the Fermentation Process and Quality Improvement Strategies for Mead Production

by Antonio Iglesias, Ananias Pascoal, Altino Branco Choupina, Carlos Alfredo Carvalho, Xesús Feás and Leticia M. Estevinho

Molecules 2014, 19(8), 12577-12590; https://doi.org/10.3390/molecules190812577 - 19 Aug 2014

Cited by 51 | Viewed by 22613

Abstract

Mead is a traditional alcoholic drink derived from the fermentation of diluted honey in the presence of appropriate yeast. Its modern production, in general terms, involves the addition of nutrients to initial diluted honey, pasteurization, yeast inoculation, fermentation and removal of impurities. Undesirable [...] Read more.

Mead is a traditional alcoholic drink derived from the fermentation of diluted honey in the presence of appropriate yeast. Its modern production, in general terms, involves the addition of nutrients to initial diluted honey, pasteurization, yeast inoculation, fermentation and removal of impurities. Undesirable events along the process have been reported; among them, we highlight: delayed or arrested fermentations, modified and unpleasant sensory and quality parameters of the final product. These problems have been linked to the inability of yeasts to accomplish their role in extreme growth conditions. Emphasis has also been placed on the long fermentation times required, ranging from weeks to months, particularly when traditional procedures are applied and when the honey concentration is low. A series of alterations to the must and technological changes have been proposed in order to optimize the mead production process. In this context, this review examines the evidence that aims to improve meads’ quality and make the production process easier and more efficient, by clarifying the source of unexpected events, describing the implementation of different fermentative microorganisms and using new methodologies. Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessArticle

Effects of Ursolic Acid Derivatives on Caco-2 Cells and Their Alleviating Role in Streptozocin-Induced Type 2 Diabetic Rats

by Panpan Wu, Ping He, Suqing Zhao, Tianming Huang, Yujing Lu and Kun Zhang

Molecules 2014, 19(8), 12559-12576; https://doi.org/10.3390/molecules190812559 - 19 Aug 2014

Cited by 22 | Viewed by 9190

Abstract

In this study, the effect and mechanism of a series of ursolic acid (UA) derivatives on glucose uptake were investigated in a Caco-2 cells model. Their effect on hyperglycemia, hyperlipidemia and oxidative stress were also demonstrated in streptozocin (STZ)-induced diabetic rats. 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-glucose (2-NBDG) [...] Read more.

In this study, the effect and mechanism of a series of ursolic acid (UA) derivatives on glucose uptake were investigated in a Caco-2 cells model. Their effect on hyperglycemia, hyperlipidemia and oxidative stress were also demonstrated in streptozocin (STZ)-induced diabetic rats. 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-glucose (2-NBDG) was used as a fluorescein in Caco-2 cells model to screen UA derivatives by glucose uptake and expression of glucose transporter protein (SGLT-1, GLUT-2). Moreover, STZ-induced diabetic rats were administered with these derivatives for 4 weeks of treatment. The fasting blood glucose (FBG), insulin levels, biochemical parameters, lipid levels, and oxidative stress markers were finally evaluated. The results of this study indicated that compounds 10 and 11 significantly inhibited 2-NBDG uptake under both Na⁺-dependent and Na⁺-independent conditions by decreasing SGLT-1 and GLUT-2 expression in the Caco-2 cells model. Further in vivo studies revealed that compound 10 significantly reduced hyperglycemia by increasing levels of serum insulin, total protein, and albumin, while the fasting blood glucose, body weight and food intake were restored much closer to those of normal rats. Compounds 10 and 11 showed hypolipidemic activity by decreasing the total amounts of cholesterol (TC) and triglycerides (TG). Furthermore, compound 10 showed antioxidant potential which was confirmed by elevation of glutathione (GSH) and superoxide dismutase (SOD) and reduction of malondialdehyde (MDA) levels in the liver and kidney of diabetic rats. It was concluded that compound 10 caused an apparent inhibition of intestinal glucose uptake in Caco-2 cells and hypoglycemia, hypolipidemia and augmented oxidative stress in STZ-induced diabetic rats. Thus, compound 10 could be developed as a potentially complementary therapeutic or prophylactic agent for diabetics mellitus and its complications. Full article

(This article belongs to the Special Issue Prodrugs)

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Open AccessArticle

Fumigant Toxicity of Oriental Sweetgum (Liquidambar orientalis) and Valerian (Valeriana wallichii) Essential Oils and Their Components, Including Their Acetylcholinesterase Inhibitory Activity, against Japanese Termites (Reticulitermes speratus)

by Il-Kwon Park

Molecules 2014, 19(8), 12547-12558; https://doi.org/10.3390/molecules190812547 - 19 Aug 2014

Cited by 29 | Viewed by 6413

Abstract

This study investigated the fumigant toxicity of oriental sweetgum (Liquidambar orientalis) and valerian (Valeriana wallichii) essential oils and their components against the Japanese termite (Reticulitermes speratus). The fumigant toxicity of oriental sweetgum and valerian oil differed significantly [...] Read more.

This study investigated the fumigant toxicity of oriental sweetgum (Liquidambar orientalis) and valerian (Valeriana wallichii) essential oils and their components against the Japanese termite (Reticulitermes speratus). The fumigant toxicity of oriental sweetgum and valerian oil differed significantly according to exposure time. Oriental sweetgum showed toxicity at short exposure times (2 days), and the toxicity of valerian oil was high 7 days after treatment. The main constituents of oriental sweetgum and valerian oils were tested individually for their fumigant toxicity against Japanese termites. Among the test compounds, benzyl alcohol, acetophenone, 1-phenyl-1-ethanol, hydrocinnamyl alcohol, trans-cinnamyl aldehyde, trans-cinnamyl alcohol, cis-asarone, styrene, and cis-ocimene showed toxicity against Japanese termites 7 days after treatment. Hydrocinnamyl alcohol and trans-cinnamyl alcohol were found to be the major contributors to the fumigant antitermitic toxicity of oriental sweetgum oil. The acetylcholinesterase (AChE) inhibition activity of two oils and their constituents was tested to determine their mode of action. Only cis-ocimene showed strong AChE inhibition activity with an IC₅₀ value of 0.131 mg/mL. Further studies are warranted to determine the potential of these essential oils and their constituents as fumigants for termite control. Full article

(This article belongs to the Section Natural Products Chemistry)

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Open AccessArticle

pH-Dependent Deformations of the Energy Landscape of Avidin-like Proteins Investigated by Single Molecule Force Spectroscopy

by Melanie Köhler, Andreas Karner, Michael Leitner, Vesa P. Hytönen, Markku Kulomaa, Peter Hinterdorfer and Andreas Ebner

Molecules 2014, 19(8), 12531-12546; https://doi.org/10.3390/molecules190812531 - 18 Aug 2014

Cited by 12 | Viewed by 11095

Abstract

Avidin and avidin-like proteins are widely used in numerous techniques since the avidin-biotin interaction is known to be very robust and reliable. Within this study, we investigated this bond at the molecular level under harsh conditions ranging from very low to very high [...] Read more.

Avidin and avidin-like proteins are widely used in numerous techniques since the avidin-biotin interaction is known to be very robust and reliable. Within this study, we investigated this bond at the molecular level under harsh conditions ranging from very low to very high pH values. We compared avidin with streptavidin and a recently developed avidin-based mutant, chimeric avidin. To gain insights of the energy landscape of these interactions we used a single molecule approach and performed the Single Molecule Force Spectroscopy atomic force microscopy technique. There, the ligand (biotin) is covalently coupled to a sharp AFM tip via a distensible hetero-bi-functional crosslinker, whereas the receptor of interest is immobilized on the probe surface. Receptor-ligand complexes are formed and ruptured by repeatedly approaching and withdrawing the tip from the surface. Varying both pulling velocity and pH value, we could determine changes of the energy landscape of the complexes. Our results clearly demonstrate that avidin, streptavidin and chimeric avidin are stable over a wide pH range although we could identify differences at the outer pH range. Taking this into account, they can be used in a broad range of applications, like surface sensors at extreme pH values. Full article

(This article belongs to the Special Issue Single Molecule Techniques)

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Open AccessArticle

Influence of the Morphology of Core-Shell Supports on the Immobilization of Lipase B from Candida antarctica

by Martina C. C. Pinto, Denise M. G. Freire and José Carlos Pinto

Molecules 2014, 19(8), 12509-12530; https://doi.org/10.3390/molecules190812509 - 18 Aug 2014

Cited by 43 | Viewed by 7179

Abstract

Core-shell polymer particles with different properties were produced through combined suspension-emulsion polymerizations and employed as supports for immobilization of lipase B from Candida antarctica. In order to evaluate how the morphology of the particles affects the immobilization parameters, empirical models were developed [...] Read more.

Core-shell polymer particles with different properties were produced through combined suspension-emulsion polymerizations and employed as supports for immobilization of lipase B from Candida antarctica. In order to evaluate how the morphology of the particles affects the immobilization parameters, empirical models were developed to describe the performance of the biocatalysts as a function of the specific area, volume of pores and average pore diameter of the supports. It was observed that the average pore sizes did not affect the enzymatic activities in the analyzed range of pore sizes. It was also observed that the increase of the specific area (and of the volume of pores) led to higher enzyme loadings, also leading to an increase in the esterification activity, as expected. However, when the specific area (and volume of pores) increased, the hydrolytic activity and the retention of hydrolytic activity of the biocatalysts decreased, indicating the existence of diffusional limitations for some hydrolytic reactions, probably because of the high reaction rates. Full article

(This article belongs to the Special Issue Enzyme Immobilization)

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Effectiveness of Phenolic Compounds against Citrus Green Mould

by Simona M. Sanzani, Leonardo Schena and Antonio Ippolito

Molecules 2014, 19(8), 12500-12508; https://doi.org/10.3390/molecules190812500 - 18 Aug 2014

Cited by 50 | Viewed by 7388

Abstract

Stored citrus fruit suffer huge losses because of the development of green mould caused by Penicillium digitatum. Usually synthetic fungicides are employed to control this disease, but their use is facing some obstacles, such public concern about possible adverse effects on human [...] Read more.

Stored citrus fruit suffer huge losses because of the development of green mould caused by Penicillium digitatum. Usually synthetic fungicides are employed to control this disease, but their use is facing some obstacles, such public concern about possible adverse effects on human and environmental health and the development of resistant pathogen populations. In the present study quercetin, scopoletin and scoparone—phenolic compounds present in several agricultural commodities and associated with response to stresses—were firstly tested in vitro against P. digitatum and then applied in vivo on oranges cv. Navelina. Fruits were wound-treated (100 µg), pathogen-inoculated, stored and surveyed for disease incidence and severity. Although only a minor (≤13%) control effect on P. digitatum growth was recorded in vitro, the in vivo trial results were encouraging. In fact, on phenolic-treated oranges, symptoms appeared at 6 days post-inoculation (DPI), i.e., with a 2 day-delay as compared to the untreated control. Moreover, at 8 DPI, quercetin, scopoletin, and scoparone significantly reduced disease incidence and severity by 69%–40% and 85%–70%, respectively, as compared to the control. At 14 DPI, scoparone was the most active molecule. Based on the results, these compounds might represent an interesting alternative to synthetic fungicides. Full article

(This article belongs to the Special Issue Phytoalexins: Current Progress and Future Prospects)

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Caffeic Acid Inhibits the Formation of 7-Carboxyheptyl Radicals from Oleic Acid under Flavin Mononucleotide Photosensitization by Scavenging Singlet Oxygen and Quenching the Excited State of Flavin Mononucleotide

by Marie Asano and Hideo Iwahashi

Molecules 2014, 19(8), 12486-12499; https://doi.org/10.3390/molecules190812486 - 18 Aug 2014

Cited by 11 | Viewed by 7614

Abstract

We examined the effects of caffeic acid (CA) and related compounds on 7-carboxyheptyl radical formation. This analysis was performed using a standard D₂O reaction mixture containing 4.3 mM oleic acid, 25 μM flavin mononucleotide (FMN), 160 mM phosphate buffer (pH 7.4), [...] Read more.

We examined the effects of caffeic acid (CA) and related compounds on 7-carboxyheptyl radical formation. This analysis was performed using a standard D₂O reaction mixture containing 4.3 mM oleic acid, 25 μM flavin mononucleotide (FMN), 160 mM phosphate buffer (pH 7.4), 10 mM cholic acid, 100 mM α-(4-pyridyl-1-oxide)-N-tert-butylnitrone, and 1 mM Fe(SO₄)₂(NH₄)₂ during irradiation with 7.8 J/cm² at 436 nm. 7-Carboxyheptyl radical formation was inhibited by CA, catechol, gallic acid, chlorogenic acid, ferulic acid, noradrenalin, 2-hydroxybenzoic acid, 3-hydroxybenzoic acid, and 4-hydroxybenzoic acid. Quinic acid, benzoic acid, and p-anisic acid had no effect on radical formation. These results suggest that a phenol moiety is essential for these inhibitory effects. The fluorescence intensity of FMN decreased by 69% ± 2% after CA addition, suggesting that CA quenches the singlet excited state of FMN. When 1 mM CA was added to a standard reaction mixture containing 25 μM FMN, 140 mM phosphate buffer (pH 7.4), and 10 mM 4-oxo-2,2,6,6-tetramethylpiperidine, the electron spin resonance signal of 4-oxo-2,2,6,6-tetramethylpiperidinooxy disappeared. This finding suggests that singlet oxygen was scavenged completely by CA. Therefore, CA appears to inhibit 7-carboxyheptyl radical formation by scavenging singlet oxygen and quenching the excited state of FMN. Full article

(This article belongs to the Section Medicinal Chemistry)

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Trends in Protein-Based Biosensor Assemblies for Drug Screening and Pharmaceutical Kinetic Studies

by Ana M. Gonçalves, Augusto Q. Pedro, Fátima M. Santos, Luís M. Martins, Cláudio J. Maia, João A. Queiroz and Luís A. Passarinha

Molecules 2014, 19(8), 12461-12485; https://doi.org/10.3390/molecules190812461 - 18 Aug 2014

Cited by 32 | Viewed by 7782

Abstract

The selection of natural and chemical compounds for potential applications in new pharmaceutical formulations constitutes a time-consuming procedure in drug screening. To overcome this issue, new devices called biosensors, have already demonstrated their versatility and capacity for routine clinical diagnosis. Designed to perform [...] Read more.

The selection of natural and chemical compounds for potential applications in new pharmaceutical formulations constitutes a time-consuming procedure in drug screening. To overcome this issue, new devices called biosensors, have already demonstrated their versatility and capacity for routine clinical diagnosis. Designed to perform analytical analysis for the detection of a particular analyte, biosensors based on the coupling of proteins to amperometric and optical devices have shown the appropriate selectivity, sensibility and accuracy. During the last years, the exponential demand for pharmacokinetic studies in the early phases of drug development, along with the need of lower molecular weight detection, have led to new biosensor structure materials with innovative immobilization strategies. The result has been the development of smaller, more reproducible biosensors with lower detection limits, and with a drastic reduction in the required sample volumes. Therefore in order to describe the main achievements in biosensor fields, the present review has the main aim of summarizing the essential strategies used to generate these specific devices, that can provide, under physiological conditions, a credible molecule profile and assess specific pharmacokinetic parameters. Full article

(This article belongs to the Special Issue Enzyme Immobilization)

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Towards the Development of Functionalized PolypyridineLigands for Ru(II) Complexes as Photosensitizers inDye-Sensitized Solar Cells (DSSCs)

by Adewale O. Adeloye and Peter A. Ajibade

Molecules 2014, 19(8), 12421-12460; https://doi.org/10.3390/molecules190812421 - 15 Aug 2014

Cited by 65 | Viewed by 12158

Abstract

A number of novel ruthenium(II) polypyridine complexes have been designedand synthesized for use as photosensitizers in dye-sensitized solar cells (DSSCs) due totheir rich photophysical properties such as intense absorption, long-lived lifetimes, highemission quantum yields and unique redox characteristics. Many of these complexesexhibit photophysical [...] Read more.

A number of novel ruthenium(II) polypyridine complexes have been designedand synthesized for use as photosensitizers in dye-sensitized solar cells (DSSCs) due totheir rich photophysical properties such as intense absorption, long-lived lifetimes, highemission quantum yields and unique redox characteristics. Many of these complexesexhibit photophysical behavior that can be readily controlled through a careful choice ofligands and/or substituents. With this perspective, we review the design and general syntheticmethods of some polypyridine ligands based on bipyridine, phenanthroline, terpyridine andquaterpyridine with/without anchoring groups with a view to correlate functionality ofligand structures with the observed photophysical, electroredox and power conversionefficiency of some examples of Ru(II) polypyridyl complexes that have been reported andparticularly used in the DSSCs applications. The main interest, however, is focused onshowing the development of new polypyridine ligand materials containing long-rangeelectron transfer motifs such as the alkenyl, alkynyl and polyaromatic donor functionalities. Full article

(This article belongs to the Special Issue Ruthenium Complex)

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Cyclodepsipeptides: A Rich Source of Biologically Active Compounds for Drug Research

by Sivatharushan Sivanathan and Jürgen Scherkenbeck

Molecules 2014, 19(8), 12368-12420; https://doi.org/10.3390/molecules190812368 - 15 Aug 2014

Cited by 80 | Viewed by 12099

Abstract

Faced with the need to find new drugs for all kinds of diseases, science sees that Nature offers numerous classes of compounds showing an impressively high biological potential. Among those are the cyclodepsipeptides, hybrid structures composed of amino and hydroxy acids. In the [...] Read more.

Faced with the need to find new drugs for all kinds of diseases, science sees that Nature offers numerous classes of compounds showing an impressively high biological potential. Among those are the cyclodepsipeptides, hybrid structures composed of amino and hydroxy acids. In the past decades numerous cyclodepsipeptides have been isolated and their potential as drugs has been studied extensively. For several cyclodepsipeptides total syntheses both in solution and on solid-phase have been established, allowing the production of combinatorial libraries. In addition, the biosynthesis of specific cyclodepsipeptides has been elucidated and used for the chemoenzymatic preparation of nonnatural analogues. This review summarizes the recent literature on cyclic tetra- to decadepsipeptides, composed exclusively of α-amino- and α-hydroxy acids. Full article

(This article belongs to the Special Issue Peptide Chemistry)

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Berberine, an Epiphany Against Cancer

by Luis Miguel Guamán Ortiz, Paolo Lombardi, Micol Tillhon and Anna Ivana Scovassi

Molecules 2014, 19(8), 12349-12367; https://doi.org/10.3390/molecules190812349 - 15 Aug 2014

Cited by 225 | Viewed by 30279

Abstract

Alkaloids are used in traditional medicine for the treatment of many diseases. These compounds are synthesized in plants as secondary metabolites and have multiple effects on cellular metabolism. Among plant derivatives with biological properties, the isoquinoline quaternary alkaloid berberine possesses a broad range [...] Read more.

Alkaloids are used in traditional medicine for the treatment of many diseases. These compounds are synthesized in plants as secondary metabolites and have multiple effects on cellular metabolism. Among plant derivatives with biological properties, the isoquinoline quaternary alkaloid berberine possesses a broad range of therapeutic uses against several diseases. In recent years, berberine has been reported to inhibit cell proliferation and to be cytotoxic towards cancer cells. Based on this evidence, many derivatives have been synthesized to improve berberine efficiency and selectivity; the results so far obtained on human cancer cell lines support the idea that they could be promising agents for cancer treatment. The main properties of berberine and derivatives will be illustrated. Full article

(This article belongs to the Special Issue Alkaloids: Novel Therapeutic Perspectives)

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Partial Characterization of an Enzymatic Extract from Bentong Ginger (Zingiber officinale var. Bentong)

by Ahmad Nafi', Foo Hooi Ling, Jamilah Bakar and Hasanah M. Ghazali

Molecules 2014, 19(8), 12336-12348; https://doi.org/10.3390/molecules190812336 - 15 Aug 2014

Cited by 25 | Viewed by 9612

Abstract

Extraction of protease from a local ginger rhizome (Zingiber officinale var. Bentong) was carried out. The effect of extraction pH (6.4, 6.8, 7.0, 7.2, 7.6, 8.0, 8.4, and 8.8) and stabilizers (0.2% ascorbic acid, 0.2% ascorbic acid and 5 mM EDTA, or [...] Read more.

Extraction of protease from a local ginger rhizome (Zingiber officinale var. Bentong) was carried out. The effect of extraction pH (6.4, 6.8, 7.0, 7.2, 7.6, 8.0, 8.4, and 8.8) and stabilizers (0.2% ascorbic acid, 0.2% ascorbic acid and 5 mM EDTA, or 10 mM cysteine and 5 mM EDTA) on protease activity during extraction was examined. pH 7.0 potassium phosphate buffer and 10 mM cysteine in combination with 5 mM EDTA as stabilizer were found to be the most effective conditions. The extraction procedure yielded 0.73% of Bentong ginger protease (BGP) with a specific activity of 24.8 ± 0.2 U/mg protein. Inhibitory tests with some protease inhibitors classified the enzyme as a cysteine protease. The protease showed optimum activity at 60 °C and pH 6–8, respectively. The enzyme was completely inhibited by heavy metal cations such as Cu²⁺, and Hg²⁺. SDS stimulated the activity of enzyme, while emulsifiers (Tween 80 and Tween 20) slightly reduced its activity. The kinetic analysis showed that the protease has K_m and V_max values of 0.21 mg mL⁻¹ and 34.48 mg mL⁻¹ min⁻¹, respectively. The dried enzyme retained its activity for 22 months when stored at −20 °C. Full article

(This article belongs to the Section Natural Products Chemistry)

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Molecules, Volume 19, Issue 8 (August 2014) – 120 articles , Pages 10670-12897

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