Characterization and antioxidative properties of condensed tannins from the mangrove plant Aegiceras corniculatum

Freeze‐dried leaf, stem bark, and root bark powders of Aegiceras corniculatum were extracted with three different types of polar solvents: methanol, ethyl acetate, and water. The methanol extracts had the highest concentrations in total phenolics and extractable condensed tannins, followed by water and ethyl acetate extracts. Analysis by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) suggested that condensed tannins from leaf, stem bark, and root bark contained prodelphinidins and procyanidins, with the predominance of prodelphinidins and high level of galloylation. Acid‐catalyzed degradation in the presence of benzyl mercaptan indicated that gallocatechin, epigallocatechin, epigallocatechin‐3‐O‐gallate, and epicatechin‐3‐O‐gallate occurred as the terminal units and (epi)gallocatechin, (epi)gallocatechin‐3‐O‐gallate, (epi)catechin, and (epi)catechin‐3‐O‐gallate occurred as the extension units. The mean degrees of polymerization (mDP) of condensed tannins from leaf, stem bark, and root bark were 13.5, 7.4, and 12.3, respectively. The condensed tannins from leaf and stem bark exhibited a higher DPPH radical scavenging activity and ferric reducing/antioxidant power compared to that of synthetic antioxidant butylated hydroxyanisole (BHA). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

桐花树树皮化学成分的研究

桐花树(Aegiceras Corniculatum)为紫金牛科(myrsinaceae)蜡烛果属(Aegiceras gaertn)真红树植物,其种子和树皮可以用来毒鱼。利用多种吸附材料和分离方法对桐花树树皮95%乙醇提取物乙酸乙酯萃取部位进行了系统的分离,共分离得到10个化合物,根据现代波谱技术和文献对照,鉴定了它们的结构,包括3个有机酸(1,4,8):香草酸,丁香酸,原儿茶酸;4个甾醇(2,3,5,10):豆甾醇,β-谷甾醇,α-菠菜甾醇,5α-豆甾-7,22-二烯-3β-醇;1个醌类化合物(7):5-O-methylembelin;2个三萜类化合物(6,9):embelinone,3,28-dihydroxy-16-oxo-12-oleanene。