【摘要】 利用MALDI-TOF MS分析了红树植物木榄花萼缩合单宁的结构单元组成类型、平均聚合度和平均分子质量。并以木榄花萼缩合单宁为原料,通过HCl-正丁醇法酸解反应制备了花青定粗产品,同时测定了花青定粗产品对二苯基苦基苯肼自由基(DPPH.)的清除能力及铁离子还原/抗氧化能力(FRAP)。结果表明:木榄花萼缩合单宁结构单元组成类型主要为儿茶素或表儿茶素,平均聚合度为7.5,平均分子质量为2081.60u;花青定粗产品具有较强的清除自由基能力,DPPH.半数抑制浓度(IC50)为43.889mg/L,并具有较高的FRAP((7.718±0.109)mmol/g)。更多还原

【Abstract】 Type of structural units,degree of polymerization and mean molecular weight of condensed tannins extracted from calyx of large red mangrove (Bruguiera gymnorrhiza) were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Crude cyanidin products were prepared from condensed tannins of B. gymnorrhiza by means of butanol/HCl reaction. In addition,the free radical-scavenging activity and antioxidant ability of crude cyanidin products were determined by using 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·) and ferric reducing/antioxidant power (FRAP) model systems respectively. The results showed that catechin/epicatechin were the structural units occurring in condensed tannins of B. gymnorrhiza. Average degree of polymerization was 7.5,and mean molecular mass was 2 081.60 u. Crude cyanidin products showed a very good DPPH radical scavenging activity (IC50 of 43.889 mg/L) and ferric reducing/antioxidant ability ((7.718± 0.109)mmol/g).更多还原