黑米抗氧化活性成分的分离纯化和结构鉴定

 【目的】分离、纯化和鉴定黑米抗氧化的主要活性成分。【方法】以体外总抗氧化能力为活性跟踪指标，对黑米抗氧化提取物用石油醚、氯仿、乙酸乙酯和正丁醇等不同极性溶剂萃取分部后得到抗氧化能力最强的部分，再用Sephadex LH-20分离得到抗氧化主活性成分，采用紫外-可见光谱、红外光谱、ESI-MS质谱和核磁共振（1HNMR和13CNMR）波谱法对其进行结构解析。【结果】黑米抗氧化提取物的5种溶剂萃取物以水部和正丁醇部的抗氧化能力最强，其总抗氧化能力分别为383和392 ku·g-1，其中，从水部可得到4种抗氧化主活性成分，总抗氧化能力分别为976、878、1 134和1 087 ku·g-1。波谱结构解析表明，4种成分均为花色苷类化合物，分别是锦葵素、天竺葵素-3.5-二葡萄糖苷、矢车菊素-3-葡萄糖苷和矢车菊素-3, 5-二葡萄糖苷。【结论】花色苷类化合物是黑米抗氧化作用的主要物质基础。

Separation, Purification and Identification of Antioxidant Compositions in Black Rice

【Objective】To separate, purify and identify the antioxidant compositions of black rice.【Method】Using total antioxidative capacity (TAC) as an activity monitoring parameter，different fractions of black rice antioxidative extracts were obtained with different polarities of solvents such as petroleum ether, chloroform, ethyl acetate and normal butyl alcohol. The main antioxidative components from the strongest antioxidative fractions were separated by using Sephadex LH-20 resin and the structures were analyzed by ultraviolet-vis, infra-red, ESI-MS, 1H-NMR and 13C-NMR spectrums.【Result】The water fraction and normal-butyl alcohol fraction of antioxidative extracts of black rice of had the strongest antioxidative capacities and their TACs reached 383 ku·g-1 and 392 ku·g-1, respectively. Four main antioxidative components were separated from the water fraction and their TACs reached 976 ku·g-1, 878 ku·g-1, 1 134 ku·g-1 and 1 087 ku·g-1, respectively. The spectroscopy analysis indicated that the 4 active components of the antioxidative extract of black rice were 4 anthocyanin compounds of malvidin, pelargonidin-3, 5-diglucoside, cyaniding-3-glucoside and cyaniding-3, 5-diglucoside. 【Conclusion】 It is concluded that the anthocyanin compounds are the most important substance basis for antioxidation.