RESUMEN
<p><b>OBJECTIVE</b>To investigate the antidepressant components of Polygala tenuifolia.</p><p><b>METHOD</b>The chromatographic method was used to isolate and purify the chemical constituents, their structures were identified by spectral analysis, MTT method was applied to investigate their cytotoxic activities.</p><p><b>RESULT</b>Nine compounds were isolated from the roots of P. tenuifolia. Their structures were identified as sibiricose A, (1), sibiricose A5 (2), tenuifoliside A (3) and 3', 6-disinapoyl sucrose (4), sibiricose A6 (5), 3, 4, 5-trimethoxycinnamate (6), polygalaxanthone III (7), tenuifolioses A (8), tenuifolioses H (9) and some compounds' activities to PC12 were observed.</p><p><b>CONCLUSION</b>Compound 1 was isolated from this plant for the first time. Compounds 2,3 could protect PC12 cells damage induced by P. tenuifolia.</p>