Preparative isolation and purification of six diterpenoids from the Chinese medicinal plant Salvia miltiorrhiza by high-speed counter-current chromatography

A high-speed counter-current chromatography (HSCCC) method was developed fo r the preparative separation and purification of six diterpenoids, dihydrot anshinone I, cryptotanshinone, methylenetanshiquinone, tanshinone I, tanshi none IIA and danshenxinkun B from the Chinese medicinal plant Salvia miltio rrhiza Bunge. The crude diterpenoids were obtained by extraction with ethan ol-n-hexane (1:1, v/v) from S. miltiorrhiza Bunge. Preparative HSCCC with t he two-phase solvent systems A composed of n-hexane-ethanol-water (10:5.5:4 .5, v/v) and B composed of n-hexane-ethanol-water (10:7:3, v/v) was success fully performed in a stepwise elution yielding six relatively pure diterpen oids from 300 mg of the crude extract in a single run. The purities of dihy drotanshinone I, cryptotanshinone, methylenetanshiquinone, tanshinone I, ta nshinone IIA and danshenxinkun B were 88.1, 98.8, 97.6, 93.5, 96.8 and 94.3 %, respectively. (C) 2001 Elsevier Science B.V. All rights reserved.