新型染料木素磺酸酯的合成及对小鼠血吸虫病肝肉芽肿的影响

为寻找抗血吸虫病的新候选化合物,通过正交实验,高选择性、高产率地合成了染料木素的磺酸酯衍生物。结果表明:小鼠感染血吸虫病,经过衍生物治疗后,由血吸虫导致的肉芽肿面积有不同程度的降低,其中低剂量组降低到23.2%,与溶剂组比较,差异显著(P<0.05),优于原药的27.1%及阳性对照组秋水仙碱的27.0%。说明该化合物对血吸虫导致的肉芽肿有一定抑制作用,该化合物有进一步研究价值。     

根皮素乙酰阿魏酸酯的合成及抗氧化活性研究

以阿魏酸和根皮素为原料,合成了三种根皮素乙酰阿魏酸酯,采用IR、1H NMR、13C NMR和HPLC-MS对其结构进行表征.并测定根皮素及其酯的还原能力、清除DPPH自由基及·OH自由基能力,结果表明根皮素乙酰阿魏酸酯的抗氧化活性显著优于根皮素.     

染料木素体外抑制人低密度脂蛋白氧化修饰作用

为探讨染料木素对人低密度脂蛋白(LDL)氧化修饰的影响,采用铜离子(10 umol/L)体外氧化LDL的方法,观察大豆异黄酮主要成分染料木素(genistein)对LDL氧化过程中脂质过氧化产物丙二醛(MDA)含量和维生素E(VitE)水平的影响。结果:10 umol/LCuSO4与100 mg/L LDL共同孵育18 h,MDA含量明显升高,VitE含量明显降低,染料木素(0.25、1.25、2.5、12.5、25、50、125、250 umol/L)能显著降低MDA含量,升高VitE含量(P<0.01,P<0.05,P<0.02),且呈剂量依赖性。提示一定浓度范围的染料木素体外有抗LDL氧化修饰作用。     

染料木素4′-O-β-D-吡喃木糖苷的合成与表征

以染料木素为原料,采用相转移催化法与乙酰溴代木糖反应,首次选择性地合成了染料木素4′-O-β-D-吡喃木糖苷.采用聚酰胺柱层析、制备高效液相色谱进行分离纯化得到产物并对其进行了IR、1H、13C NMR和MS结构表征.     

染料木素4＇-O-β-D-吡喃木糖苷的合成与表征

以染料木素为原料,采用相转移催化法与乙酰溴代木糖反应,首次选择性地合成了染料木素4＇-O-β-D-吡喃木糖苷。采用聚酰胺柱层析、制备高效液相色谱进行分离纯化得到产物并对其进行了IR、^1H、^13CNMR和MS结构表征。     

环糊精葡萄糖基转移酶182位点定点改造催化合成糖基化染料木素

染料木素及其单糖苷衍物在食品和医药领域具有重要作用,但难溶于水的特性极大地限制了其应用范围,研究表明糖基化反应可有效提高其水溶性.文中针对来源于软化芽孢杆菌的环糊精葡萄糖基转移酶,研究其对染料木素单糖苷衍生物槐角苷的糖基化反应.通过对D182位点的定点饱和突变,突变酶D182C较WT转化率提高了13.42％,主要糖基化...     

高效液相色谱法测定大鼠血清染料木素浓度

目的:建立大鼠血清中染料木素浓度的HPLC测定方法.方法:大鼠血清以叔丁基甲醚萃取,萃取物用氮气吹干后,用甲醇溶解用于色谱分析.色谱条件:采用Thermo C18柱(250ram×4.6mm,5μm);以乙腈-0.02mol/L磷酸二氢钾(35:65,pH=4.3)为流动相;流速为1.0mL/min;检测波长为260hm;柱温为40℃;进样量为10μL.结果:染料木素最低检测浓度为0.01mg/L;标准曲线线性范围为0.01～10.00μg/mL(r=0.9998);相对回收率为(101.31±3.47)%;日内RSD与日间RSD均小于10.00%.结论:该方法简便、快速、灵敏度高,重现性及稳定性较好,适用于大鼠血清染料木素浓度测定和药代动力学的研究.     

微波辅助提取木豆根中染料木素工艺

以木豆根为原料,利用微波辅助提取技术进行提取,在单因素实验的基础上对提取条件进行了考察,根据BBD(Box-Behnken design)实验设计原理,采用3因素3水平的响应面分析法,以木豆根中主要异黄酮染料木素(genistein)为指标,对提取过程进行优化,得到最佳工艺参数为：提取温度为68℃,固液比为32∶1 mL·g^-1,乙醇浓度为78%,提取功率700 W,提取时间15 min。在最佳提取条件下染料木素的提取率可达到0.465±0.032 mg·g^-1。本研究对于微波提取技术的应用及木豆根的开发和利用都具有显著的意义。     

新型染料木素磺酸酯的前药判定与大鼠体内生物利用度

为寻找染料木素(GE)新的前药,采用建立的生物样品中药物浓度测定的液相色谱法对新型大豆异黄酮染料木素磺酸酯(GB)进行前药判定以及大鼠体内药物动力学研究,以考察前药中染料木素的口服生物利用度是否改善.在大鼠体内药物代谢实验中,灌胃给予GB的大鼠血浆中能检测到明显的GE.在临床前药物动力学实验中,该前体静注给药和以40 mg/kg灌胃药后,GE在大鼠体内的动力学过程均符合一室模型.GB中GE的相对口服生物利用度为原药的110.9％.研究表明,相对于原药GE,前药中GE的相对口服生物利用度达到预期的改善,该前药有进一步研究意义.     

RP-HPLC法测定怀槐中染料木素和芒柄花黄素含量

怀槐(Maackia amurensis Rupr.et Maxim.)广泛分布于中国东北三省及内蒙古等地,尤以黑龙江省为多.怀槐作为民间药,其茎、枝可治疗风湿性关节炎; 叶、枝皮可治疗肿瘤; 内皮可治疗深度伤口及久不愈合的溃疡.另外,怀槐树皮在民间还作为祛风湿、消炎、镇痛、健胃、止血等药广泛应用,疗效甚佳.从怀槐的根、枝、叶、果实和心材中分别分得异黄酮、生物碱、NC442类化合物,据报道,其中的异黄酮类化合物表现出对心血管系统的复合作用和明显的抗肿瘤活性[1].作者在对怀槐进行系统的化学成分研究过程中,分离鉴定了9个异黄酮类化合物[2,3],并进行了抑制肿瘤细胞增殖作用研究[4],其中,染料木素(genistein)对胃腺癌细胞(BGC)增殖有一定程度的抑制作用,芒柄花黄素(formononetin)则对白血病细胞(HL-60)增殖有一定的抑制作用.染料木素和芒柄花黄素作为马鞍树属(Maackia Rupr.)植物中普遍存在的2个异黄酮类化合物,其活性研究日益受到重视.采用HPLC法测定染料木素等异黄酮类化合物含量在大豆等其他植物中曾有文献报道[5].为了尽早开发怀槐资源,同时为其资源的综合利用提供科学依据,本文采用HPLC法对怀槐不同部位的染料木素和芒柄花黄素2个有效成分进行了含量测定.     

Fatty Acid Specificity in Lipase-Catalyzed Synthesis of Glucoside Esters

The fatty acid specificity of the B-lipase derived from Candida antarctica was investigated in the synthesis of esters of ethyl D-glucopyranoside. The specificity was almost identical with respect to straight-chain fatty acids with 10 to 18 carbon atoms. However, lower fatty acids such as hexanoic and octanoic acid and the unsaturated 9-cis-octadecenoic acid were found to be poor substrates of the enzyme. As a consequence of this selectivity, these fatty acids were accumulated in the unconverted fraction when ethyl D-glucopyranoside was esterified with an excess of a mixture of fatty acids. This accumulation can reduce the overall effectiveness of the process as the activity of the lipase was found to be reduced when exposed to high concentrations of short-chain fatty acids. Finally, using a simplified experimental set-up, the specificity of the C. antarctica B-lipase was compared to the specificity of lipases derived from C. rugosa, Mucor miehei, Humicola, and Pseudomonas. Apart from the C. rugosa lipase, which exhibited a very poor performance, all the enzymes showed a very similar specificity with respect to fatty acids longer than octanoic acid while only the C. antarctica B-lipase showed activity towards sort-chain fatty acids.     

Fatty Acid Specificity in Lipase-Catalyzed Synthesis of Glucoside Esters

The fatty acid specificity of the B-lipase derived from Candida antarctica was investigated in the synthesis of esters of ethyl D-glucopyranoside. The specificity was almost identical with respect to straight-chain fatty acids with 10 to 18 carbon atoms. However, lower fatty acids such as hexanoic and octanoic acid and the unsaturated 9-cis-octadecenoic acid were found to be poor substrates of the enzyme. As a consequence of this selectivity, these fatty acids were accumulated in the unconverted fraction when ethyl D-glucopyranoside was esterified with an excess of a mixture of fatty acids. This accumulation can reduce the overall effectiveness of the process as the activity of the lipase was found to be reduced when exposed to high concentrations of short-chain fatty acids. Finally, using a simplified experimental set-up, the specificity of the C. antarctica B-lipase was compared to the specificity of lipases derived from C. rugosa, Mucor miehei, Humicola, and Pseudomonas. Apart from the C. rugosa lipase, which exhibited a very poor performance, all the enzymes showed a very similar specificity with respect to fatty acids longer than octanoic acid while only the C. antarctica B-lipase showed activity towards sort-chain fatty acids.     

The Use of Fatty Acid Esters to Enhance Free Acid Sophorolipid Synthesis

Fatty acid esters were prepared by transesterification of soy oil with methanol (methyl-soyate, Me-Soy), ethanol (ethyl-soyate, Et-Soy) and propanol (propyl-soyate, Pro-Soy) and used with glycerol as fermentation substrates to enhance production of free-acid sophorolipids (SLs). Fed-batch fermentations of Candida bombicola resulted in SL yields of 46 ± 4 g/l, 42 ± 7 g/l and 18 ± 6 g/l from Me-Soy, Et-Soy, and Pro-Soy, respectively. Liquid chromatography with atmospheric pressure ionization mass spectrometry (LC/API-MS) showed that Me-Soy resulted in 71% open-chain SLs with 59% of those molecules remaining esterified at the carboxyl end of the fatty acids. Et-Soy and Pro-Soy resulted in 43% and 80% open-chain free-acid SLs, respectively (containing linoleic acid and oleic acid as the principal fatty acid species linked to the sophorose sugar at the omega-1 position), with no evidence of residual esterification. Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture.     

Candida Antarctica Lipase B-Catalysed Synthesis Of Dihydroxyacetone Fatty Acid Esters

The enzymatic syntheses of 1-lauroyl-dihydroxyacetone and 1, 3-dilauroyl-dihydroxyacetone were investigated. Lipase B from Candida Antarctica (SP435) was used to catalyse the acylation of dihydroxyacetone (DHA) with lauric acid in organic solvent media at controlled water activity. High conversions of dihydroxyacetone (< 90%) are achieved when the water activity is 0.11 or below in solvents of various hydrophobicities, such as diethyl ether, methyl-terr-butyl ether (MTBE) and diphenyl ether. The main product in the esterification of DHA with lauric acid is 1-lauroyl-DHA, while the amount of 1, 3-dilauroyl-DHA that is produced can be increased by changing the reaction conditions. Thus, hasing the water activity from 0.75 to 0.06 resulted in an increase in the total yield of 1, 3-dilauroyl-DHA from 3% to 20%. Solvents which have high logP values favoured the acylation of 1-lauroyl-DHA and thereby the formation of 1, 3-dilauroyl-DHA. Thus, when diphenyl ether was used in this reaction, the yield of 1, 3-dilauroyl-DHA was 45%. Complete acylation to 1, 3-dilauroyl-DHA was achieved when a fatty acid vinyl ester was used as acyl donor in a closed reactor.     

Lipase-Catalyzed Synthesis of Fatty Acid Esters Useful in the Food Industry

Enzyme reactions are very attractive in food technology because they can be carried out under mild conditions and without toxic solvents and other catalysts. Lipases can esterify various alcohols with fatty acids. There are opportunities to synthesize useful compounds with special functions as food materials by using the catalytic function of lipase. Reverse micellar systems are discussed as reaction systems for lipases in organic solvents, especially in triacylglycerol synthesis using phosphatidylcholine as the surfactant. Syntheses of some amphiphilic substances including O-acyl-L-homoserine are also discussed.     

Lipase-Catalyzed Synthesis of Fatty Acid Esters Useful in the Food Industry

Enzyme reactions are very attractive in food technology because they can be carried out under mild conditions and without toxic solvents and other catalysts. Lipases can esterify various alcohols with fatty acids. There are opportunities to synthesize useful compounds with special functions as food materials by using the catalytic function of lipase. Reverse micellar systems are discussed as reaction systems for lipases in organic solvents, especially in triacylglycerol synthesis using phosphatidylcholine as the surfactant. Syntheses of some amphiphilic substances including O-acyl-L-homoserine are also discussed.     

染料木素的乳糖糖苷化修饰及其产物的结构表征

为了改善染料木素在机体内作用的靶向性,本文研究了用具有与肿瘤细胞表面受体定向结合的乳糖来修饰染料木素。采用相转移催化法,首次合成了两种新的化合物:染料木素7-O-β-D-吡喃乳糖苷(4)和染料木素7,4′-二-O-β-D-吡喃乳糖苷(5),并对其进行了IR、MS、1HNMR和13C NMR结构表征。