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Vernica Rodríguez-Lpez Csar Milln-Pacheco Judith Gonzlez-Christen Maricruz Anaya-Ruíz Omar Aristeo Pea-Morn 《Molecules (Basel, Switzerland)》2021,26(20)
Podophyllotoxins are natural lignans with known cytotoxic activity on several cell lines. The structural basis for their actions is mainly by the aryltetralin-lignan skeleton. Authors have proposed a cytotoxic mechanism of podophyllotoxins through the topoisomerase-II inhibition activity; however, several studies have also suggested that podophyllotoxins can inhibit the microtubules polymerization. In this work, the two possible mechanisms of action of two previously isolated compounds from the stem bark of Bursera fagaroides var. fagaroides: acetylpodophyllotoxin (1) and 5’-desmethoxydeoxypodophyllotoxin (2), was analyzed. An in vitro anti-tubulin epifluorescence on the MCF10A cell line and enzymatic topoisomerase II assays were performed. The binding affinities of compounds 1 and 2 in the colchicine binding site of tubulin by using rigid- and semiflexible-residues were calculated and compared using in silico docking methods. The two lignans were active by the in vitro anti-tubulin assay but could not inhibit TOP2 activity. In the in silico analysis, the binding modes of compounds into both rigid- and semiflexible-residues of tubulin were predicted, and only for the semiflexible docking method, a linear correlation between the dissociation constant and IC50 previously reported was found. Our results suggest that a simple semiflexible-residues modification in docking methods could provide an in vitro correlation when analyzing very structurally similar compounds. 相似文献
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Amina M. G. Zedan Mohamed I. Sakran Omar Bahattab Yousef M. Hawsawi Osama Al-Amer Atif A. A. Oyouni Samah K. Nasr Eldeen Mohammed A. El-Magd 《Molecules (Basel, Switzerland)》2021,26(11)
The use of insects as a feasible and useful natural product resource is a novel and promising option in alternative medicine. Several components from insects and their larvae have been found to inhibit molecular pathways in different stages of cancer. This study aimed to analyze the effect of aqueous and alcoholic extracts of Vespa orientalis larvae on breast cancer MCF7 cells and investigate the underlying mechanisms. Our results showed that individual treatment with 5% aqueous or alcoholic larval extract inhibited MCF7 proliferation but had no cytotoxic effect on normal Vero cells. The anticancer effect was mediated through (1) induction of apoptosis, as indicated by increased expression of apoptotic genes (Bax, caspase3, and p53) and decreased expression of the anti-apoptotic gene Bcl2; (2) suppression of intracellular reactive oxygen species; (3) elevation of antioxidant enzymes (CAT, SOD, and GPx) and upregulation of the antioxidant regulator Nrf2 and its downstream target HO-1; (4) inhibition of migration as revealed by in vitro wound healing assay and downregulation of the migration-related gene MMP9 and upregulation of the anti-migratory gene TIMP1; and (5) downregulation of inflammation-related genes (NFκB and IL8). The aqueous extract exhibited the best anticancer effect with higher antioxidant activities but lower anti-inflammatory properties than the alcoholic extract. HPLC analysis revealed the presence of several flavonoids and phenolic compounds with highest concentrations for resveratrol and naringenin in aqueous extract and rosmarinic acid in alcoholic extract. This is the first report to explain the intracellular pathway by which flavonoids and phenolic compounds-rich extracts of Vespa orientalis larvae could induce MCF7 cell viability loss through the initiation of apoptosis, activation of antioxidants, and inhibition of migration and inflammation. Therefore, these extracts could be used as adjuvants for anticancer drugs and as antioxidant and anti-inflammatory agents. 相似文献
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The heat of lysozyme adsorption on mesostructured cellular foam (MCF) silica was measured using flow microcalorimetry (FMC) to investigate the influence of a neutral salt, sodium sulfate. At concentrations up to 0.5 M sodium sulfate, a complex initial exotherm was followed by an endotherm. Protein surface coverage, the magnitudes of the exothermic heat signals and the magnitudes of the net heat of adsorption increased with sodium sulfate concentration. These observations suggest that electrostatic interactions are the principal driving force at low ionic strengths; van der Waals interactions become dominant at higher salt concentrations. Each exotherm could be deconvoluted into two exotherms, indicating multiple modes of lysozyme attachment to the silica surface. The endothermic peak, associated with protein desorption, disappeared at the highest sodium sulfate concentration (1.0 M), indicating irreversible adsorption of the protein on the MCF silica surface. The data are consistent with an adsorption mechanism in which the initial attachment of lysozyme to the surface is followed by a reorientation and formation of a secondary or stronger attachment to the surface. 相似文献
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通过原位合成法将[(EtO)3SiPMIm]Cl固载在MCF材料上,制得MCF固载化离子液体催化剂[(EtO)3Si PMIm]Cl/MCF。用N2吸附-脱附、TEM和FT-IR等手段表征催化剂,并考察其在CO2与环氧丙烷(PO)环加成合成碳酸丙烯酯(PC)反应中的催化性能。结果表明,嫁接等量离子液体后,MCF固载化离子液体催化剂体系对CO2环加成合成PC反应的催化活性高于SBA-15催化剂体系。在2.5MPa、140℃反应条件下,PO的转化率高达85.4%,且催化剂具有良好的循环使用性。 相似文献
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空分复用中的多芯光纤 总被引:1,自引:0,他引:1
介绍了近年来出现的光纤通信用单/多模多芯光纤(MCF)的基本特性和结构轮廓,列举了部分试验传输实例。指出人们对光纤通信容量的追求在时分、波分、偏分复用及多级调制方式的基础上,已开始将目光关注在基于MCF的空分复用(SDM)上,相信MCF的规模化商用已为时不远。 相似文献
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From the methanolic extract of the leaves of Planchonella duclitan, 2α,3α,19α,23‐tetrahydroxy‐13,27‐cyclours‐11‐en‐28‐oic acid (1), myrianthic acid (2), 2‐hydroxyursolic acid (3), ursolic acid (4), pomolic acid (5), rotundic acid (6), and jacoumaric acid (7) were isolated, and their structures were elucidated on the basis of their spectroscopic analysis. Among them, compound 1 was a new cyclopropyl ursane‐type triterpene acid. Additionally, compounds 4 and 7 showed significant cytotoxicity toward human colorectal carcinoma cell line HT29 and human breast carcinoma cell line MCF‐7 with IC50 values ranging from 5.8 ± 1.4 to 6.5 ± 1.9 μM. 相似文献
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Frank Podebrad Martin Heil Saandra Leib Bernhard Geier Thomas Beck Armin Mosandl Adrian C. Sewell Hans Bhles 《Journal of separation science》1997,20(7):355-362
Maple Syrup Urine disease (USUD) is an autosomal recessive inherited metabolic disorder of branched-chain amino acid (L-valin, L-leucine, and L-isoleucine metabolism named after the characteristic smell of affected patients urine. MSUD is caused by a deficiency of the branched-chain α-keto acid dehydrogenase compex resulting in an accumulation of branched-chain aamino acids and the corresponding α-keto-and α-hydroxy acids in blood, urine and cerebrospinal fluid causing neurological damage and mental retardation. The enantioselective analysis of chiral MSUD metabolites and analysis of achiral compounds as corresponding N,O-methoxycarbonyl methyl esters by derivatization with methyl chloroformate (MCF) has been achieved simultaneusly by enantioselective multidimensional gas chromatography-mass spectrometry using heptakis (2,3-di-O-methyl-6-O-tert-butyl-dimethyl-silyl)-β-cyclodextrin as chiral stationary phase. Derivatization with MCF allows the analysis of the structurally different metabolitetes such as branched-chain-carboxylic-, α-oxo-, α-hydroxy- and α-amino acids in a single chromaatographic run. Mass selective detection immensely improves the unequivocaaal identification of metabolites even when they occur as trace compound. The described method allows a reliable screening of MSUD metabolites in patients' urine without time consuming sample preparation and is also suitable for label enrichment analysis without any methodical changes. During this investigation urine sample from three MSUD paatients were analyzed. 相似文献