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Molecules, Volume 19, Issue 6 (June 2014), Pages 6911-8706

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Open AccessArticle Effects of Propylene Glycol Alginate and Sucrose Esters on the Physicochemical Properties of Modified Starch-Stabilized Beverage Emulsions
Molecules 2014, 19(6), 8691-8706; https://doi.org/10.3390/molecules19068691
Received: 17 March 2014 / Revised: 31 May 2014 / Accepted: 12 June 2014 / Published: 24 June 2014
Cited by 3 | PDF Full-text (246 KB) | HTML Full-text | XML Full-text
Abstract
This study was conducted to investigate the effect of main emulsion components namely, modified starch, propylene glycol alginate (PGA), sucrose laurate and sucrose stearate on creaming index, cloudiness, average droplet size and conductivity of soursop beverage emulsions. Generally, the use of different emulsifiers
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This study was conducted to investigate the effect of main emulsion components namely, modified starch, propylene glycol alginate (PGA), sucrose laurate and sucrose stearate on creaming index, cloudiness, average droplet size and conductivity of soursop beverage emulsions. Generally, the use of different emulsifiers or a mixture of emulsifiers has a significant (p < 0.05) effect on the response variables studied. The addition of PGA had a significant (p < 0.05) effect on the creaming index at 55 °C, while PGA-stabilized (PGA1) emulsions showed low creaming stability at both 25 °C and 55 °C. Conversely, the utilization of PGA either as a mixture or sole emulsifier, showed significantly (p < 0.05) higher cloudiness, as larger average droplet size will affect the refractive index of the oil and aqueous phases. Additionally, the cloudiness was directly proportional to the mean droplet size of the dispersed phase. The inclusion of PGA into the formulation could have disrupted the properties of the interfacial film, thus resulting in larger droplet size. While unadsorbed ionized PGA could have contributed to higher conductivity of emulsions prepared at low pH. Generally, emulsions prepared using sucrose monoesters or as a mixture with modified starch emulsions have significantly (p < 0.05) lower creaming index and conductivity values, but higher cloudiness and average droplet size. Full article
Open AccessArticle Production of the Anti-Inflammatory Compound 6-O-Palmitoyl-3-O-β-D-glucopyranosylcampesterol by Callus Cultures of Lopezia racemosa Cav. (Onagraceae)
Molecules 2014, 19(6), 8679-8690; https://doi.org/10.3390/molecules19068679
Received: 7 May 2014 / Revised: 13 June 2014 / Accepted: 16 June 2014 / Published: 24 June 2014
Cited by 5 | PDF Full-text (351 KB) | HTML Full-text | XML Full-text
Abstract
Lopezia racemosa Cav. is a plant used in Mexican traditional medicine to heal inflammatory diseases. From this plant we isolated the novel compound 6-O-palmitoyl- 3-O-β-D-glucopyranosylcampesterol (1) and 6-O-palmitoyl-3-O-β-D-glucopyranosyl-β-sitosterol (2), previously reported
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Lopezia racemosa Cav. is a plant used in Mexican traditional medicine to heal inflammatory diseases. From this plant we isolated the novel compound 6-O-palmitoyl- 3-O-β-D-glucopyranosylcampesterol (1) and 6-O-palmitoyl-3-O-β-D-glucopyranosyl-β-sitosterol (2), previously reported to have cytotoxic activity on several cancer cell lines. We evaluated the anti-inflammatory activity of 1 in vivo by mouse ear edema induced with 12-O-tetradecanoylphorbol-13-acetate (TPA) and 57.14% inhibition was observed. The aim of our study was to obtain callus cultures derived from this plant species with the ability to produce the compounds of interest. Callus cultures were initiated on MS basal medium amended with variable amounts of naphthaleneacetic acid (NAA), or 2,4-dichlorophenoxyacetic acid (2,4-D), combined or not with 6-benzylaminopurine (BAP). Ten treatments with these growth regulators were carried out, using in vitro germinated seedlings as source of three different explants: hypocotyl, stem node, and leaf. Highest yield of 1 was observed on callus derived from leaf explants growing in medium containing 1.0 mg/L 2,4-D and 0.5 mg/L BAP. Selected callus lines produced less 1 than wild plants but the in vitro cultured seedlings showed higher production. So we conclude that it could be attractive to further investigate their metabolic potential. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Three-Dimensional Heterocycles: New Uracil-Based Structures Obtained by Nucleophilic Substitution at the sp2 Carbon of Bromoisoxazoline
Molecules 2014, 19(6), 8661-8678; https://doi.org/10.3390/molecules19068661
Received: 7 May 2014 / Revised: 4 June 2014 / Accepted: 13 June 2014 / Published: 24 June 2014
Cited by 1 | PDF Full-text (344 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
The regioisomeric cycloadducts of bromonitrile oxide and N-benzoyl-2,3-oxaza-norborn-5-ene were easily prepared and elaborated into a novel class of uracil-based scaffolds. The key-synthetic step is the nucleophilic substitution at the sp2 carbon atom of the bromoisoxazoline three-dimensional heterocycles. The protocol to perform
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The regioisomeric cycloadducts of bromonitrile oxide and N-benzoyl-2,3-oxaza-norborn-5-ene were easily prepared and elaborated into a novel class of uracil-based scaffolds. The key-synthetic step is the nucleophilic substitution at the sp2 carbon atom of the bromoisoxazoline three-dimensional heterocycles. The protocol to perform the nucleophilic substitution of uracil anions was optimized and adapted to the steric requirements of the substrates. A library of pyrimidine derivatives was prepared in very good yields and the products were fully characterized. They are proposed as nucleoside analogues and as synthons for β-turn motifs within PNA structures. Full article
(This article belongs to the Special Issue Cycloaddition Chemistry)
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Open AccessArticle Potential Anti-Inflammatory Effects of the Hydrophilic Fraction of Pomegranate (Punica granatum L.) Seed Oil on Breast Cancer Cell Lines
Molecules 2014, 19(6), 8644-8660; https://doi.org/10.3390/molecules19068644
Received: 23 April 2014 / Revised: 9 June 2014 / Accepted: 18 June 2014 / Published: 24 June 2014
Cited by 29 | PDF Full-text (614 KB) | HTML Full-text | XML Full-text
Abstract
In this work, we characterized conjugated linolenic acids (e.g., punicic acid) as the major components of the hydrophilic fraction (80% aqueous methanol extract) from pomegranate (Punica granatum L.) seed oil (PSO) and evaluated their anti-inflammatory potential on some human colon (HT29 and
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In this work, we characterized conjugated linolenic acids (e.g., punicic acid) as the major components of the hydrophilic fraction (80% aqueous methanol extract) from pomegranate (Punica granatum L.) seed oil (PSO) and evaluated their anti-inflammatory potential on some human colon (HT29 and HCT116), liver (HepG2 and Huh7), breast (MCF-7 and MDA-MB-231) and prostate (DU145) cancer lines. Our results demonstrated that punicic acid and its congeners induce a significant decrease of cell viability for two breast cell lines with a related increase of the cell cycle G0/G1 phase respect to untreated cells. Moreover, the evaluation of a great panel of cytokines expressed by MCF-7 and MDA-MB-231 cells showed that the levels of VEGF and nine pro-inflammatory cytokines (IL-2, IL-6, IL-12, IL-17, IP-10, MIP-1α, MIP-1β, MCP-1 and TNF-α) decreased in a dose dependent way with increasing amounts of the hydrophilic extracts of PSO, supporting the evidence of an anti-inflammatory effect. Taken together, the data herein suggest a potential synergistic cytotoxic, anti-inflammatory and anti-oxidant role of the polar compounds from PSO. Full article
(This article belongs to the Section Medicinal Chemistry)
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Open AccessReview Polyhydroyxalkanoate Synthase Fusions as a Strategy for Oriented Enzyme Immobilisation
Molecules 2014, 19(6), 8629-8643; https://doi.org/10.3390/molecules19068629
Received: 16 May 2014 / Revised: 19 June 2014 / Accepted: 19 June 2014 / Published: 24 June 2014
Cited by 15 | PDF Full-text (279 KB) | HTML Full-text | XML Full-text
Abstract
Polyhydroxyalkanoate (PHA) is a carbon storage polymer produced by certain bacteria in unbalanced nutrient conditions. The PHA forms spherical inclusions surrounded by granule associate proteins including the PHA synthase (PhaC). Recently, the intracellular formation of PHA granules with covalently attached synthase from Ralstonia
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Polyhydroxyalkanoate (PHA) is a carbon storage polymer produced by certain bacteria in unbalanced nutrient conditions. The PHA forms spherical inclusions surrounded by granule associate proteins including the PHA synthase (PhaC). Recently, the intracellular formation of PHA granules with covalently attached synthase from Ralstonia eutropha has been exploited as a novel strategy for oriented enzyme immobilisation. Fusing the enzyme of interest to PHA synthase results in a bifunctional protein able to produce PHA granules and immobilise the active enzyme of choice to the granule surface. Functionalised PHA granules can be isolated from the bacterial hosts, such as Escherichia coli, and maintain enzymatic activity in a wide variety of assay conditions. This approach to oriented enzyme immobilisation has produced higher enzyme activities and product levels than non-oriented immobilisation techniques such as protein inclusion based particles. Here, enzyme immobilisation via PHA synthase fusion is reviewed in terms of the genetic designs, the choices of enzymes, the control of enzyme orientations, as well as their current and potential applications. Full article
(This article belongs to the Special Issue Enzyme Immobilization)
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Open AccessArticle Catalytic Behavior of Lipase Immobilized onto Congo Red and PEG-Decorated Particles
Molecules 2014, 19(6), 8610-8628; https://doi.org/10.3390/molecules19068610
Received: 4 May 2014 / Revised: 20 June 2014 / Accepted: 20 June 2014 / Published: 24 June 2014
Cited by 7 | PDF Full-text (565 KB) | HTML Full-text | XML Full-text
Abstract
Poly(ethylene glycol) (PEG)-decorated polystyrene (PS) nanoparticles with mean hydrodynamic diameter (D) and zeta–potential (ζ) of (286 ± 15) nm and (−50 ± 5) mV, respectively, were modified by the adsorption of Congo red (CR). The PS/PEG/CR particles presented D
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Poly(ethylene glycol) (PEG)-decorated polystyrene (PS) nanoparticles with mean hydrodynamic diameter (D) and zeta–potential (ζ) of (286 ± 15) nm and (−50 ± 5) mV, respectively, were modified by the adsorption of Congo red (CR). The PS/PEG/CR particles presented D and ζ values of (290 ± 19) nm and (−36 ± 5) mV, respectively. The adsorption of lipase onto PS/PEG or PS/PEG/CR particles at (24 ± 1) °C and pH 7 changed the mean D value to (380 ± 20) and (405 ± 11) nm, respectively, and ζ value to (−32 ± 4) mV and (−25 ± 2) mV, respectively. The kinetic parameters of the hydrolysis of p-nitrophenyl butyrate were determined for free lipase, lipase immobilized onto PS/PEG and PS/PEG/CR particles. Lipase on PS/PEG/CR presented the largest Michaelis-Menten constant (KM), but also the highest Vmax and kcat values. Moreover, it could be recycled seven times, losing a maximum 10% or 30% of the original enzymatic activity at 40 °C or 25 °C, respectively. Although lipases immobilized onto PS/PEG particles presented the smallest KM values, the reactions were comparatively the slowest and recycling was not possible. Hydrolysis reactions performed in the temperature range of 25 °C to 60 °C with free lipases and lipases immobilized onto PS/PEG/CR particles presented an optimal temperature at 40 °C. At 60 °C free lipases and lipases immobilized onto PS/PEG/CR presented ~80% and ~50% of the activity measured at 40 °C, indicating good thermal stability. Bioconjugation effects between CR and lipase were evidenced by circular dichroism spectroscopy and spectrophotometry. CR molecules mediate the open state conformation of the lipase lid and favor the substrate approaching. Full article
(This article belongs to the Special Issue Enzyme Immobilization)
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Open AccessReview Self-Assembly: From Amphiphiles to Chromophores and Beyond
Molecules 2014, 19(6), 8589-8609; https://doi.org/10.3390/molecules19068589
Received: 30 April 2014 / Revised: 17 June 2014 / Accepted: 17 June 2014 / Published: 23 June 2014
Cited by 33 | PDF Full-text (1713 KB) | HTML Full-text | XML Full-text
Abstract
Self-assembly has been recognised as a ubiquitous aspect of modern chemistry. Our understanding and applications of self-assembly are substantially based on what has been learned from biochemical systems. In this review, we describe various aspects of self-assembly commencing with an account of the
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Self-assembly has been recognised as a ubiquitous aspect of modern chemistry. Our understanding and applications of self-assembly are substantially based on what has been learned from biochemical systems. In this review, we describe various aspects of self-assembly commencing with an account of the soft structures that are available by assembly of surfactant amphiphiles, which are important scientific and industrial materials. Variation of molecular design using rules defined by surfactant self-assembly permits synthesis of functional nanostructures in solution and at surfaces while increasing the strength of intermolecular interactions through π-π stacking, metal cation coordination and/or hydrogen bonding leads to formation of highly complex bespoke nanostructured materials exemplified by DNA assemblies. We describe the origins of self-assembly involving aggregation of lipid amphiphiles and how this subject has been expanded to include other highly advanced chemical systems. Full article
(This article belongs to the Special Issue Template Directed Synthesis and Self-Assembly in Organic Systems)
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Open AccessArticle Evaluation of a Triple-Helical Peptide with Quenched Fluorophores for Optical Imaging of MMP-2 and MMP-9 Proteolytic Activity
Molecules 2014, 19(6), 8571-8588; https://doi.org/10.3390/molecules19068571
Received: 18 April 2014 / Revised: 5 June 2014 / Accepted: 11 June 2014 / Published: 23 June 2014
Cited by 8 | PDF Full-text (2155 KB) | HTML Full-text | XML Full-text
Abstract
Matrix metalloproteinases (MMP) 2 and 9, the gelatinases, have consistently been associated with tumor progression. The development of gelatinase-specific probes will be critical for identifying in vivo gelatinoic activity to understand the molecular role of the gelatinases in tumor development. Recently, a self-assembling
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Matrix metalloproteinases (MMP) 2 and 9, the gelatinases, have consistently been associated with tumor progression. The development of gelatinase-specific probes will be critical for identifying in vivo gelatinoic activity to understand the molecular role of the gelatinases in tumor development. Recently, a self-assembling homotrimeric triple-helical peptide (THP), incorporating a sequence from type V collagen, with high substrate specificity to the gelatinases has been developed. To determine whether this THP would be suitable for imaging protease activity, 5-carboxyfluorescein (5FAM) was conjugated, resulting in 5FAM3-THP and 5FAM6-THP, which were quenched up to 50%. 5FAM6-THP hydrolysis by MMP-2 and MMP-9 displayed kcat/KM values of 1.5 × 104 and 5.4 × 103 M−1 s−1, respectively. Additionally 5FAM6-THP visualized gelatinase activity in gelatinase positive HT-1080 cells, but not in gelatinase negative MCF-7 cells. Furthermore, the fluorescence in the HT-1080 cells was greatly attenuated by the addition of a MMP-2 and MMP-9 inhibitor, SB-3CT, indicating that the observed fluorescence release was mediated by gelatinase proteolysis and not non-specific proteolysis of the THPs. These results demonstrate that THPs fully substituted with fluorophores maintain their substrate specificity to the gelatinases in human cancer cells and may be useful in in vivo molecular imaging of gelatinase activity. Full article
(This article belongs to the Special Issue Fluorescent Probes)
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Open AccessArticle Mycelium-Bound Lipase from a Locally Isolated Strain of Geotrichum candidum
Molecules 2014, 19(6), 8556-8570; https://doi.org/10.3390/molecules19068556
Received: 10 April 2014 / Revised: 29 May 2014 / Accepted: 10 June 2014 / Published: 23 June 2014
Cited by 3 | PDF Full-text (396 KB) | HTML Full-text | XML Full-text
Abstract
Mycelium-bound lipase (MBL), from a locally isolated Geotrichum candidum strain, was produced and characterized as a natural immobilized lipase. A time course study of its lipolytic activity in 1 L liquid broth revealed the maximum MBL activity at 4 h for mycelium cells
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Mycelium-bound lipase (MBL), from a locally isolated Geotrichum candidum strain, was produced and characterized as a natural immobilized lipase. A time course study of its lipolytic activity in 1 L liquid broth revealed the maximum MBL activity at 4 h for mycelium cells harvested after 54 h. The yield and specific activity of MBL were 3.87 g/L dry weight and 508.33 U/g protein, respectively, while less than 0.2 U/mL lipase activity was detected in the culture supernatant. Prolonged incubation caused release of the bound lipase into the growth medium. The growth pattern of G. candidum, and production and properties of MBL were not affected by the scale. The stability of mycelia harboring lipase (MBL), harvested and lyophilized after 54 h, studied at 4 °C depicted a loss of 4.3% and 30% in MBL activity after 1 and 8 months, while the activity of free lipase was totally lost after 14 days of storage. The MBL from G. candidum displayed high substrate selectivity for unsaturated fatty acids containing a cis-9 double bond, even in crude form. This unique specificity of MBL could be a direct, simple and inexpensive way in the fats and oil industry for the selective hydrolysis or transesterification of cis-9 fatty acid residues in natural triacylglycerols. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Loddigesiinols G–J: α-Glucosidase Inhibitors from Dendrobium loddigesii
Molecules 2014, 19(6), 8544-8555; https://doi.org/10.3390/molecules19068544
Received: 10 May 2014 / Revised: 10 June 2014 / Accepted: 13 June 2014 / Published: 23 June 2014
Cited by 8 | PDF Full-text (448 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Four new polyphenols, loddigesiinols G–J (compounds 14) and a known compound, crepidatuol B (5), were isolated from the stems of Dendrobium loddigesii that have long been used in Traditional Chinese Medicine and have recently been used to treat
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Four new polyphenols, loddigesiinols G–J (compounds 14) and a known compound, crepidatuol B (5), were isolated from the stems of Dendrobium loddigesii that have long been used in Traditional Chinese Medicine and have recently been used to treat type 2 diabetes. Compounds 15 structures were elucidated based on spectroscopic analysis. The absolute configurations of compounds 14 were determined using theoretical calculations of electronic circular dichroism (ECD), and the absolute configuration of compound 5 was determined by a comparison of the experimental ECD spectra and the literature data. Compounds 15 are strong inhibitors of α-glucosidase, with IC50 values of 16.7, 10.9, 2.7, 3.2, and 18.9 μM, respectively. Their activities were significantly stronger than trans-resveratrol as a positive control (IC50 values of 27.9 μM). Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle Cis-[Cr(C2O4)(pm)(OH2)2]+ Coordination Ion as a Specific Sensing Ion for H2O2 Detection in HT22 Cells
Molecules 2014, 19(6), 8533-8543; https://doi.org/10.3390/molecules19068533
Received: 8 April 2014 / Revised: 30 May 2014 / Accepted: 10 June 2014 / Published: 23 June 2014
Cited by 6 | PDF Full-text (351 KB) | HTML Full-text | XML Full-text
Abstract
The purpose of this study was to examine the application of the coordinated cis-[Cr(C2O4)(pm)(OH)2]+ cation where pm denotes pyridoxamine, as a specific sensing ion for the detection of hydrogen peroxide (H2O2).
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The purpose of this study was to examine the application of the coordinated cis-[Cr(C2O4)(pm)(OH)2]+ cation where pm denotes pyridoxamine, as a specific sensing ion for the detection of hydrogen peroxide (H2O2). The proposed method for H2O2 detection includes two key steps. The first step is based on the nonenzymatic decarboxylation of pyruvate upon reaction with H2O2, while the second step is based on the interaction of cis-[Cr(C2O4)(pm)(OH2)2]+ with the CO2 released in the previous step. Using this method H2O2 generated during glutamate-induced oxidative stress was detected in HT22 hippocampal cells. The coordination ion cis-[Cr(C2O4)(pm)(OH2)2]+ and the spectrophotometric stopped-flow technique were applied to determine the CO2 concentration in cell lysates, supernatants and cell-free culture medium. Prior to CO2 assessment pyruvate was added to all samples studied. Pyruvate reacts with H2O2 with 1:1 stoichiometry, and consequently the amount of CO2 released in this reaction is equivalent to the amount of H2O2. Full article
(This article belongs to the Section Medicinal Chemistry)
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Open AccessArticle Physico-Chemical Properties, Antioxidant Activity and Mineral Contents of Pineapple Genotypes Grown in China
Molecules 2014, 19(6), 8518-8532; https://doi.org/10.3390/molecules19068518
Received: 24 April 2014 / Revised: 12 June 2014 / Accepted: 12 June 2014 / Published: 23 June 2014
PDF Full-text (305 KB) | HTML Full-text | XML Full-text
Abstract
The fruit physico-chemical properties, antioxidant activity and mineral contents of 26 pineapple [Ananas comosus (L.) Merr.] genotypes grown in China were measured. The results showed great quantitative differences in the composition of these pineapple genotypes. Sucrose was the dominant sugar in all
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The fruit physico-chemical properties, antioxidant activity and mineral contents of 26 pineapple [Ananas comosus (L.) Merr.] genotypes grown in China were measured. The results showed great quantitative differences in the composition of these pineapple genotypes. Sucrose was the dominant sugar in all 26 genotypes, while citric acid was the principal organic acid. Potassium, calcium and magnesium were the major mineral constituents. The ascorbic acid (AsA) content ranged from 5.08 to 33.57 mg/100 g fresh weight (FW), while the total phenolic (TP) content varied from 31.48 to 77.55 mg gallic acid equivalents (GAE)/100 g FW. The two parameters in the predominant cultivars Comte de Paris and Smooth Cayenne were relative low. However, MD-2 indicated the highest AsA and TP contents (33.57 mg/100 g and 77.55 mg GAE/100 g FM, respectively), and it also showed the strongest antioxidant capacity 22.85 and 17.30 μmol TE/g FW using DPPH and TEAC methods, respectively. The antioxidant capacity of pineapple was correlated with the contents of phenolics, flavonoids and AsA. The present study provided important information for the further application of those pineapple genotypes. Full article
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Open AccessArticle Dehydroabietic Acid Isolated from Commiphora opobalsamum Causes Endothelium-Dependent Relaxation of Pulmonary Artery via PI3K/Akt-eNOS Signaling Pathway
Molecules 2014, 19(6), 8503-8517; https://doi.org/10.3390/molecules19068503
Received: 12 March 2014 / Revised: 16 June 2014 / Accepted: 17 June 2014 / Published: 23 June 2014
Cited by 5 | PDF Full-text (1229 KB) | HTML Full-text | XML Full-text
Abstract
Commiphora opobalsamum is a Traditional Chinese Medicine used to treat traumatic injury, mainly by relaxing blood vessels. In this study, two diterpenes, dehydroabietic acid (DA) and sandaracopimaric acid (SA) were obtained from it by a bioassay-guided approach using isolated
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Commiphora opobalsamum is a Traditional Chinese Medicine used to treat traumatic injury, mainly by relaxing blood vessels. In this study, two diterpenes, dehydroabietic acid (DA) and sandaracopimaric acid (SA) were obtained from it by a bioassay-guided approach using isolated rat pulmonary artery rings. The structures of the two compounds were elucidated by spectroscopic methods (IR, 1H- and 13C-NMR, HR-ESI-MS). Both DA and SA reduced the contraction of phenylephrine-induced pulmonary arteries in a concentration-dependent manner, and endothelium contributed greatly to the vasodilatory effect of DA. This effect of DA was attenuated by NG-Nitro-L-arginine methyl ester (L-NAME, an eNOS inhibitor). Meanwhile, DA increased nitric oxide (NO) production, along with the increase of phosphorylation level of eNOS and Akt in endothelial cells. LY294002 (a PI3K inhibitor) could reverse this effect, which suggested the endothelial PI3K/Akt pathway involved in the mechanism underlying DA-induced relaxation of pulmonary artery. This work provided evidence of vasorelaxant substances in Commiphora opobalsamum and validated that PI3K/Akt-eNOS pathway was associated with DA-induced pulmonary artery vasodilation. Full article
(This article belongs to the Section Natural Products Chemistry)
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Open AccessArticle In Vivo Anti-Trypanosoma cruzi Activity of Hydro-Ethanolic Extract and Isolated Active Principles from Aristeguietia glutinosa and Mechanism of Action Studies
Molecules 2014, 19(6), 8488-8502; https://doi.org/10.3390/molecules19068488
Received: 16 March 2014 / Revised: 20 May 2014 / Accepted: 5 June 2014 / Published: 23 June 2014
Cited by 10 | PDF Full-text (505 KB) | HTML Full-text | XML Full-text
Abstract
The currently available treatments for Chagas disease show limited therapeutic potential and are associated with serious side effects. Attempting to find alternative drugs isolated from Nature as agents against Trypanosoma cruzi has been our goal. Recently, we have demonstrated the in vitro
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The currently available treatments for Chagas disease show limited therapeutic potential and are associated with serious side effects. Attempting to find alternative drugs isolated from Nature as agents against Trypanosoma cruzi has been our goal. Recently, we have demonstrated the in vitro anti-T. cruzi activities of two secondary metabolites isolated from the hydro-ethanolic extract of the aerial parts of Aristeguietia glutinosa (Lam.), (family Asteraceae). These active principles displayed poor hemolytic activity, low toxicity against murine macrophages, and absence of mutagenicity. Herein, proof of concept in vivo studies of the whole hydro-ethanolic extract of the aerial parts of Aristeguietia glutinosa and of the most active component isolated from the hydro-ethanolic extract, i.e., (+)-15-hydroxy-7-labden-17-al, was done in a murine acute model of Chagas disease. Both treatments caused a decrease in the animals’ parasitemia. Metabolomic mechanism of action studies were done by 1H-NMR, both on the extract and on the active compounds, examining the effects of the metabolites both on membrane sterol biosynthesis and mitochondrial dehydrogenases, whereby we found that one of the metabolites inhibited the activity of the parasite mitochondrial dehydrogenases and the other inhibited the biosynthesis of parasite membrane sterols. The results are interesting in the context of popular use of plants for the treatment of Chagas disease. Full article
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Open AccessArticle Matrilin-2 Is Proteolytically Cleaved by ADAMTS-4 and ADAMTS-5
Molecules 2014, 19(6), 8472-8487; https://doi.org/10.3390/molecules19068472
Received: 8 April 2014 / Revised: 7 June 2014 / Accepted: 10 June 2014 / Published: 23 June 2014
Cited by 3 | PDF Full-text (1324 KB) | HTML Full-text | XML Full-text
Abstract
Matrilin-2 is a widely distributed, oligomeric extracellular matrix protein that forms a filamentous network by binding to a variety of different extracellular matrix proteins. We found matrilin-2 proteolytic products in transfected cell lines in vitro and in mouse tissues in vivo. Two
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Matrilin-2 is a widely distributed, oligomeric extracellular matrix protein that forms a filamentous network by binding to a variety of different extracellular matrix proteins. We found matrilin-2 proteolytic products in transfected cell lines in vitro and in mouse tissues in vivo. Two putative cleavage sites were identified in the unique domain of matrilin-2; the first site was located between D851 and L852 in the middle of the domain and the second, at the boundary with the coiled-coil domain at the C-terminus. Deletion of the entire unique domain eliminated the proteolysis of matrilin-2. While the first cleavage site was present in all matrilin-2 oligomers, the second cleavage site became apparent only in the matrilin-2 hetero-oligomers with matrilin-1 or matrilin-3. Analysis using a variety of extracellular protease inhibitors suggested that this proteolytic activity was derived from a member or several members of the ADAMTS family. Recombinant human ADAMTS-4 (aggrecanase-1) and ADAMTS-5 (aggrecanase-2), but not ADAMTS-1, cleaved recombinant matrilin-2, thereby yielding matrilin-2 proteolytic peptides at the predicted sizes. These results suggest that ADAMTS-4 and ADAMTS-5 may destabilize the filamentous network in the extracellular matrix by cleaving matrilin-2 in both homo-oligomers and hetero-oligomers. Full article
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