Antioxidant Activity and Phytochemical Screening in Acacia rigidula Benth. Leaves

This study aimed to compare the total phenolic content (TPC) and antioxidant activities of A. rigidula extracts. It also aimed to identify phenolic acids present in the extracts. The 2,2-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP), and ferric thiocyanate lipid peroxidation antioxidant assays were performed. High performance liquid chromatography was used to identify phenolic acids. There was no solvent effect on TPC nor on scavenging activities, and inhibition of lipid peroxidation (p > 0.05) among solvent extracts. On the other hand, 1:1:3 water: acetone: methanol extract (10.22 mg GAE/g sample) had significantly higher reducing potential than 50% ethanol extract (EE) (9.259 mg GAE/g sample) (p < 0.05);but EE was not significantly different from 80% methanol extract (9.781 mg GAE/g sample) (p > 0.05). Phenolic fraction designated as fraction 4 had the highest antioxidant activity (p < 0.05) with 69.49% ABTS scavenging activity and FRAP reducing potential, 22.26 mg of GAE/g sample. DPPH scavenging activities of fractions 4 (55.59%) and 5 (55.64%) were significantly higher than the other fractions (p A. rigidula extracts contain gallic, caffeic, vanillic, p-coumaric, salicylic acids and vanillin.

鱼腥草中酚类物质及其与土壤酶活性的相关性分析

收集贵州省不同来源的35个鱼腥草(Houttuynia cordata Thunb.)样品及其生长地土壤样品,利用高效液相色谱仪和紫外可见分光光度计分别测定植株样品中多酚、总黄酮、总绿原酸、山奈酚-3-O-葡萄糖苷、金丝桃苷、槲皮苷、芦丁、槲皮素、山奈素和异鼠李素含量以及土壤中的土壤酶活性,并用SPSS软件对化合物含量与土壤酶活性进行相关性分析。研究结果表明,样品中多酚、总黄酮和总绿原酸含量有显著差异;多酚与土壤中过氧化氢酶、多酚氧化酶和蔗糖酶活性具有极显著正相关;总黄酮和总绿原酸均分别与磷酸酶和尿酶、多酚氧化酶具有极显著正相关;样品中山奈酚-3-O-葡萄糖苷、金丝桃苷、槲皮苷、芦丁、槲皮素、山奈素和异鼠李素含量有显著差异,除磷酸酶、尿酶活性与山奈素和异鼠李素含量具有显著正相关外,与过氧化氢酶、多酚氧化酶和蔗糖酶相关不显著。试验结果表明,土壤酶活性引起的土壤代谢性能可揭示土壤代谢作用强度及其适应外界环境和维持植物生长条件的能力,植物生长条件反过来作用于土壤代谢从而影响酶的活性,其酚类物质通过根系分泌影响酶的活性作用,单个化合物代谢主要受其他环境因子的影响。