Abstract
The constituents of the MeOH extract of Salvia miltiorhiza BUNGE, which showed strong aldose reductase (AR) inhibitory activity, were examined, and two new abietane-type diterpenoids, danshenol A (1) and danshenol B (2), were isolated together with six known ones : dihydrotanshinone I (3), cryptotanshinone (4), tanshinone I (5), tanshinone IIA (6), (-)-danshexinkun A (7), and sugiol (8). Among them, 4, 5, and 8 were weak AR inhibitors with IC50 from 4.80 to >10.0μM, while 1, 2, 3, 6, and 7 were strong inhibitors (IC50 from 0.10 to 1.75μM). Danshenol A (1), the strongest inhibitor, had IC50 of 0.10μM which is comparable to that of epalrestat in clinical use.Moreover, from a consideration of IC50 and yield of each compound, it was concluded that tanshinone IIA (6) is the major active constituent of the MeOH extract and danshenol A (1) and (-)-danshexinkun A (7) are the minor ones.
