Coumarins from branch of Fraxinus sieboldiana and their antioxidative activity / 中国中药杂志

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the chemical constituents from the branch of Fraxinus sieboldiana, and evaluate their antioxidative activity.</p><p><b>METHOD</b>The chemical constituents were isolated and purified by chromatographic techniques over silica gel, macroporous adsorbent resin, Sephadex LH-20, and preparative HPLC. Structures of the compounds were identified by spectroscopic methods. The antioxidant activity was evaluated by Fe(+2)-cystine induced rat liver microsomal lipid peroxidation.</p><p><b>RESULT</b>Eight coumarins were obtained and their structures were elucidated as esculin (1) , esculetin (2), fraxin (3), fraxetin (4), 6, 7-di-O-beta-D-glucopyranosylesculetin (5), scopoletin (6), cleomiscosin D (7) and cleomiscosin B (8). At a concentration of 10(-6) mol x L(-1), compound 4 showed antioxidative activity inhibiting Fe(+2)-cystine induced rat liver microsomal lipid peroxidation with inhibitory rate of 60%.</p><p><b>CONCLUSION</b>Compounds 5, 7 and 8 were obtained from the genus Fraxinus for the first time. Compound 4 showed remarkable antioxidative activity, which was higher than that of VE (35%).</p>