Salvador Marcos J, Ferreira Eliane O, Mertens-Talcott Susanne U, De Castro Whocely Victor, Butterweck Veronika, Derendorf Hartmut, Dias Diones A
Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Avenida dos Bandeirantes, 3900, 14040-901 Ribeirão Preto, São Paulo, Brasil.
Z Naturforsch C J Biosci. 2006 Jan-Feb;61(1-2):19-25. doi: 10.1515/znc-2006-1-204.
Phytochemical analysis of the antioxidant ethanolic extract of Alternanthera tenella Colla led to the isolation of six flavonoids, acacetin 8-C-[alpha-L-rhamnopyranosyl-(1 --> 2)-beta-D-glucopyranoside] (1), 2"-O-alpha-L-rhamnopyranosyl-vitexin (2), 2"-O-beta-D-glucopyranosyl-vitexin (3), vitexin (4), quercetin (5) and kaempferol (6). All the structures were established by ESI-MS and NMR spectroscopic methods. Antioxidant capacity of extract, fractions and isolated compounds was determined using the oxygen radical absorbance capacity (ORAC) assay and extract, fractions and flavonoids isolated showed antioxidant activity in vitro. Moreover, the total soluble phenolic contents of the extract and fractions were measured using the Folin-Ciocalteau reagent and the quantitative analysis of flavone C-glycosides major constituents was performed by HPLC.
对 Alternanthera tenella Colla 的抗氧化乙醇提取物进行植物化学分析，从中分离出六种黄酮类化合物，即刺槐素 8-C-[α-L-鼠李糖基-(1→2)-β-D-葡萄糖苷]（1）、2″-O-α-L-鼠李糖基牡荆素（2）、2″-O-β-D-葡萄糖基牡荆素（3）、牡荆素（4）、槲皮素（5）和山柰酚（6）。所有结构均通过电喷雾电离质谱（ESI-MS）和核磁共振（NMR）光谱法确定。使用氧自由基吸收能力（ORAC）测定法测定提取物、馏分和分离出的化合物的抗氧化能力，所分离出的提取物、馏分和黄酮类化合物在体外均表现出抗氧化活性。此外，使用福林-酚试剂测定提取物和馏分的总可溶性酚含量，并通过高效液相色谱法（HPLC）对黄酮碳苷主要成分进行定量分析。
