Pharmacological Mechanisms Underlying Gastroprotective Activities of the Fractions Obtained from Polygonum minus in Sprague Dawley Rats

The leaves of Polygonum minus were fractionated using an eluting solvent to evaluate the pharmacological mechanisms underlying the anti-ulcerogenic activity of P. minus. Different P. minus fractions were obtained and evaluated for their ulcer preventing capabilities using the ethanol induction method. In this study, Sprague Dawley rats weighing 150-200 g were used. Different parameters were estimated to identify the active fraction underlying the mechanism of the gastroprotective action of P. minus: the gastric mucus barrier, as well as superoxide dismutase, total hexosamine, and prostaglandin synthesis. Amongst the five fractions from the ethanolic extract of P. minus, the ethyl acetate:methanol 1:1 v/v fraction (F2) significantly (p < 0.005) exhibited better inhibition of ulcer lesions in a dose-dependent manner. In addition, rats pre-treated with F2 showed a significant elevation in superoxide dismutase (SOD), hexosamine and PGE2 levels in the stomach wall mucosa in a dose-dependent matter. Based on these results, the ethyl acetate:methanol 1:1 v/v fraction was considered to be the best fraction for mucous protection in the ethanol induction model. The mechanisms underlying this protection were attributed to the synthesis of antioxidants and PGE2.     

热处理对何首乌抗氧化能力的影响

通过总抗氧化能力、羟自由基清除能力、超氧阴离子自由基清除能力和DPPH自由基清除能力实验,研究了热处理对何首乌4种溶剂提取物(甲醇、乙醇、乙醚和正己烷)抗氧化能力的影响,并与传统煎制工艺的水提取物进行对比。结果表明:热处理对乙醇提取物的4种抗氧化能力都有显著的增强效应,且抗氧化能力均高于水提取物。对热处理前后各样品中总酚和总黄酮含量的测定及其与抗氧化活性的相关性分析发现,热处理导致各溶剂提取物中总酚含量降低,显著提高了乙醇提取物总黄酮含量;总酚含量与提取物的抗氧化活性具有较好的正向线性相关性,表明热处理对多酚物质的影响可能是抗氧化活性改变的主要因素。     

虎杖中大黄素提取技术的研究进展

虎杖药用历史悠久,分布广泛,富含多种药用有效成分,主要含有蒽醌类、二苯乙烯类、黄酮类等。其中蒽醌类大黄素和二苯乙烯类白藜芦醇成分含量较高,具有广泛的药理活性。目前对虎杖的研究多侧重于白藜芦醇的提取及应用,对虎杖大黄素的报道相对较少。大黄素不仅可以应用于医疗,也可用于保健和日用化工品中。本文对虎杖中大黄素的提取技术进行了综述,为更好地开发利用虎杖资源提供依据。     

酶辅助超声波提取何首乌多糖及其抗氧化性研究

采用酶辅助超声提取法,从何首乌中提取多糖,用苯酚-硫酸比色法测定多糖含量.探讨了何首乌多糖的工艺条件,为酶辅助超声提取在工业生产上的应用积累参数.结果表明,提取何首乌多糖的最佳工艺条件:提取时间为15 min、浸取液倍数为30倍、pH值为6.0、提取温度为43℃、酶添加量为2.5%、提取功率150 W,多糖提取率为25.26%,何首乌多糖对HO·的还原率为36.23%.此方法是一种简单快捷和高效的提取方法.     

Morphological and Crystalline Properties of Starches from New Sources‐Traditional Chinese Medicines (TCMs)

In China, there are many starch‐rich Traditional Chinese Medicines (TCMs) such as Fritillaria, Rhizoma Dioscorea Thunb., Pueraria Lobata Ohwi, Alisma Orientalis Juzep. and Polygonum Multiflorum Thunb. The low‐molecular weight bioactive ingredients present in these TCMs have been studied widely. However, starches are always ignored and discarded during the isolation of the small‐molecule active components, which results in large wastes of TCM resources. In order to understand and explore these new starches, the morphological and crystalline properties of starches from six TCMs have been evaluated. The starches differ in granular shape and size. The F. ussurensis Maxim. (FUM), F. cirrhosa D. Don. (FCD) and Rhizoma Dioscorea Thunb. (RDT) starches have larger granules than the other three TCM starches. Alisma Orientalis Juzep. (AOJ) starch possesses the smallest granules among the six starches. Polygonum Multiflorum Thunb. (PMT) starch has the lowest integrity of granule shape. RDT starch and Pueraria Lobata Ohwi (PLO) starches display the characteristics of typical C‐type diffraction pattern. FUM starch and FCD starch show typical B‐type diffraction pattern. AOJ and PMT starches have the strongest diffraction peaks at 17.8°, 20.1° and 27.4º which is indicative of an A‐type diffraction pattern.     

辣蓼草对小曲质量的影响研究

研究了添加不同量的辣蓼草对小曲中的微生物种类和数量、糖化力、液化力及发酵率的影响。结果表明,在一定范围内添加辣蓼草对小曲质量具有良好的促进作用,其合理添加量为12％;探讨和分析了辣蓼草对小曲pH值、透气性等方面影响的机理。（孙悟）     

虎杖内生真菌Aspergillus aculeatus HZ001产β-葡萄糖苷酶的酶学特性

中药虎杖含有丰富的虎杖苷,利用生物转化技术将其转化为白藜芦醇是制备天然白藜芦醇的有效方法.虎杖内生真菌Aspergillus aculeatus HZ001细胞可催化虎杖苷转化为白藜芦醇,该文对该菌株产胞内 β-葡萄糖苷酶的酶学性质进行研究.结果表明:该酶的最适反应温度为60℃,在低于60℃时有较好的稳定性;最适反应p...     

虎杖中DNA裂解成分的研究

从中药虎杖(Polygonum cusp idatum)根中通过溶剂提取、硅胶柱层析、Sephadex LH-20柱层析和聚酰胺柱层析等方法分得5个化合物。波谱分析(核磁共振氢谱、碳谱和质谱)确定它们的结构分别为大黄素-8-O-β-D-葡萄吡喃糖苷(1,emod in-8-O--βD-glucopyranoside)、6-羟基芦荟大黄素(2,citreorosein)、5,7-二羟基(3H)-异苯骈呋喃酮[3,5,7-d ihydroxy1(3H)-isobenzofuranone]、没食子酸(4,gallic acid)和胡萝卜苷(5,daucosterol)。化合物3和4具有不同程度的DNA裂解作用。     

Biostabilised icosahedral gold nanoparticles: synthesis,cyclic voltammetric studies and catalytic activity towards 4-nitrophenol reduction

A green and cost-effective biosynthetic approach for the preparation of icosahedral gold nanoparticles (AuNPs) using an aqueous leaf extract of Polygonum minus as reducing and stabilising factor is described. The reduction of Au³⁺ ions to elemental Au rapidly occurred and is completed within 20 minutes at room temperature. The size of the nanoparticles is highly sensitive to the AuCl₄^?/leaf extract concentration ratio and pH. Transmission electron microscopy and X-ray diffraction data indicated that the nanoparticles were in a crystalline shape (face-centred cubic), mostly icosahedral and nearly monodispersed with an average size of 23 nm. Cyclic voltammetric studies suggested that flavonoids, such as quercetin and myricetin present in the leaf extract had a tendency to donate electrons to Au³⁺ ions and the formation of elemental Au was possible due to the transfer of electrons from these flavonoids to Au³⁺ ions. Infrared absorption of the AuNPs and the leaf extract revealed that the oxidised (quinone) form of quercetin and myricetin were presumably the main stabilising agents in the formation of stable nanoparticles. The present biosynthesis of AuNPs was simple, rapid, cost-effective and environmentally friendly. The newly prepared biostabilised icosahedral AuNPs show good catalytic activity in the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP).     

超声波-微波协同萃取虎杖中大黄素

以大黄素含量为指标对虎杖中有效成分进行了超声波-微波协同萃取。采用正交设计法优化了萃取条件。试验结果表明在超声波功率内置为50 W的仪器条件下影响大黄素萃取的主要因素依次是：乙醇浓度、提取时间、乙醇用量、微波功率。大黄素的最佳萃取条件是：乙醇浓度为90%,乙醇用量为75 mL,提取时间为5 min,微波功率为30 W。正交优化条件下,大黄素得率可达1.26%。萃取效果明显优于传统的溶剂回流方法和超临界流体萃取。