Preparative purification of plasmin activity stimulating phenolic derivatives from Gastrodia elata using centrifugal partition chromatography.

Gastrodia rhizome, a dried and steamed tuber of Gastrodia elata Blume (Orchidaceae), has been traditionally used in Korea, China and Japan for the treatment of neurological and nervous disorders such as headaches, dizziness, vertigo and convulsive illnesses. The ethyl acetate and water extracts of G. elata stimulated plasmin activity. The active ethyl acetate fraction was subjected to centrifugal partition chromatography (CPC) with a two-phase solvent system, composed of n-hexane-ethyl acetate-methanol-water (3:7:4:6, v/v) followed by semi-preparative HPLC purification to separate active compounds and the water fraction was purified by Diaion HP-20 resin and semi-preparative HPLC. In ethyl acetate extract, 4-hydroxybenzyl alcohol (1), 4-hydroxybenzoic acid (2), 4-hydroxybenzaldehyde (3), 4-ethoxymethylphenol (4), 4,4'-oxybis(methylene)diphenol (5) and 4,4'-methylenediphenol (6) were obtained with high purities. Parishin (7) and parishin B (8) were isolated from water extract. Among isolated compounds, 4-hydroxybenzyl alcohol (1), 4-hydroxybenzaldehyde (3) and 4-ethoxymethylphenol (4) significantly stimulated plasmin activity.