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Abstract The synthesis of poly(3-hydroxy-2-phenylpropionic acid), prepared from tropic acid and 1,3-dialkylcarbodiimide (cyclohexyl or isopropyl) with p-toluenesulfonic acid (PTSA) and/or dimethylaminopyridine (DMAP) as catalysts, has been investigated. Molecular weight and yield have been found to vary inversely with temperature and solvent polarity. Dialkylcarbodiimide activation of the carboxylic acid is enhanced when PTSA and DMAP are used in equal concentrations. Highest molecular weights and yields were achieved at ? 20°C with 50% (mol% of monomer) DMAP and PTSA in a cyclohexane/THF solvent system. 相似文献
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Li Jian LIU* Li Qiong LIAO Chao ZHANG Feng HE Ren Xi ZHUO Department of Polymer Science College of Chemistry Molecular Science Wuhan University The Research Laboratory of SEDC of Biomedical Polymer Materials at Wuhan University Wuhan 《中国化学快报》2001,(9)
The attempts to prepare novel biodegradable polymer carriers for drug controlled release systems have been tried in our group1,2. Poly (L-2-hydroxy-3-phenylpropanoic acid) (PLHPPA) can be considered as derivative of poly (lactic acid) (PLA) which has been applied as biomaterials in drug delivery systems, surgical repair and tissue engineering materials3 for its excellent biodegradability and biocompatibility. PLHPPA contains phenyl groups in its structure. It is designed as a hydrophobic… 相似文献
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以1,8-辛二醇(1)为起始原料,经4步反应合成了(E)-10-羟基-2-癸烯酸,其结构经1H NMR, 13C NMR和MS确证。考察了乙酰氯、缚酸剂种类及其用量[r=n(1): n(乙酰氯): n(缚酸剂)]对8-乙酰氧基-1-辛醇(2)收率的影响以及反应温度、三乙胺滴加温度、低温停留时间对8-乙酰氧基辛醛(3)收率的影响。结果表明:以三乙胺为缚酸剂,r=1.0 : 1.1 : 2.0时,2产率达78%;反应温度为-65 ℃、三乙胺滴加温度低于-50 ℃、低温反应3 h, 3产率达97%。 相似文献
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Treatment of 2-ketoglutaric acid with diazomethane gave 2-(metoxycarbonyl)-oxiranepropanoic acid methyl ester (2) wich lead to 2-hydroxy-2-methyl-glutaric acid dimethyl ester (3) by catalytic hydrogenation, wich was further processed to the title compound. 相似文献
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Kuankuan Gao Bei Su Jing Dai Piwu Li Ruiming Wang Xiaohui Yang 《Molecules (Basel, Switzerland)》2022,27(5)
Persistent infections caused by Staphylococcus aureus biofilms pose a major threat to global public health. 10-Hydroxy-2-decenoic acid (10-HDA), a main fatty acid in royal jelly, has been shown to possess various biological activities. The purpose of this study was to explore the effects of 10-HDA on the biofilms and virulence of S. aureus and its potential molecular mechanism. Quantitative crystal violet staining indicated that 10-HDA significantly reduced the biofilm biomass at sub-minimum inhibitory concentration (MIC) levels (1/32MIC to 1/2MIC). Scanning electron microscope (SEM) observations demonstrated that 10-HDA inhibited the secretion of extracellular polymeric substances, decreased bacterial adhesion and aggregation, and disrupted biofilm architecture. Moreover, 10-HDA could significantly decrease the biofilm viability and effectively eradicated the mature biofilms. It was also found that the hemolytic activity of S. aureus was significantly inhibited by 10-HDA. qRT-PCR analyses revealed that the expressions of global regulators sarA, agrA, and α-hemolysin gene hla were downregulated by 10-HDA. These results indicate that 10-HDA could be used as a potential natural antimicrobial agent to control the biofilm formation and virulence of S. aureus. 相似文献
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R. Ya. Kharisov O. V. Botsman L. P. Botsman N. M. Ishmuratova G. Yu. Ishmuratov G. A. Tolstikov 《Chemistry of Natural Compounds》2002,38(2):145-148
A practical synthesis of biologically active 10-hydroxy- and 9-oxo-2E-decenoic acids, components of mandibular gland secretion of honeybee (Apis mellifera L.), is developed using ozonolysis-reduction of oleic acid and 1,9-diacetoxynon-1-ene in the key steps. 相似文献
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色酚AS中2-羟基-3萘甲酸的萃取-分光光度测定 总被引:1,自引:0,他引:1
1 引 言在冰染染料偶合组分中 ,2 羟基 3萘甲酰基芳胺类产量最大 ,用途最广。此类色酚中 2 羟基 3萘甲酸 (简称 2 ,3 酸 )的测定目前国外和国家标准均采用纸层析分离后紫外光照下 (或与重氮盐偶合显色 )目测斑点大小的方法 ,未见有分光光度法测定的报道。本文研究了色酚中 2 ,3 酸的萃取分离方法和条件、Fe3 + 与 2 ,3 酸的络合条件及络合物的组成比、铁盐中阴离子对发色的影响等 ,建立了色酚AS中 2 ,3 酸的萃取分离分光光度测定法。本法与标准方法相比较 ,灵敏度和准确度均有大幅度提高。本方法具有操作简便、准确、易行等优点… 相似文献
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A reverse phase HPLC method was developed and validated for the simultaneous determination of 2-hydroxy-4-methoxybenzaldehyde
and 2-hydroxy-4-methoxybenzoic acid in the root extracts of Hemidesmus indicus. A comprehensive validation of the method including sensitivity, linearity, reproducibility, accuracy, limit of detection
(LOD) and limit of quantification (LOQ) was conducted using the optimized chromatographic conditions. The method was found
to be linear (r > 0.998) in the range of 5–350 μg mL−1 for 2-hydroxy-4-methoxybenzaldehyde and for 2-hydroxy-4-methoxybenzoic acid (r > 0.999) in the range 10–300 μg mL−1. The method was found to be precise with inter-day precision values (% RSD) in the ranges of 0.61–1.76% for 2-hydroxy-4-methoxybenzaldehyde
and 1.3–2.8% for 2-hydroxy-4-ethoxybenzoic acid while intra-day precisions (% RSD) of two analytes were in the range of 0.41–1.07
and 0.95–2.5%. The limits of detection (LODs) for 2-hydroxy-4-methoxybenzaldehyde and 2-hydroxy-4-methoxybenzoic acid were
0.84 and 2.34 μg mL−1. The described method was fast, sensitive and reproducible, and thus well suited for routine analysis of these two compounds
from root extracts of H. indicus and other plants. 相似文献
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