Chem. Pharm. Bull. 55(9) 1412—1415 (2007)

soapnuts, generally grows in tropical and sub-tropical regions of Asia. It was reported that S. mukorossi possessed efficient natural surfactants and has served as commercial ingredient of shampoo and cosmetic cleansers. In addition, some pharmacological effects including anthelmintic, antidermatophytic, antiinflammatory, antimicrobial, antitussive, cytotoxic, haemolytic, and molluscicidal activities were found in the plant. As for the principal constitutes of this plants, various triterpenoid saponins containing dammaranetype, hederagenin-type, tirucallane-type as well as sesquiterpene oligoglycosides, have been isolated from the fruit, gall, pericarp, root, and stem. Recently, we have isolated and characterized antitumor dammarane saponins, sapinmusaponins A—E and anti-platelet aggregation tirucallane saponins, sapinmusaponins F—J from the galls of S. mukorossi. We report herein that two new tirucallane saponins, named sapinmusaponins Q (1) and R (2), were isolated from the other anti-platelet aggregation fraction derived from EtOH extract of galls of the titled plant. Structural elucidation of the new isolates was based on spectroscopic analysis including 1D and 2D NMR techniques (H–H COSY, HMQC, HMBC, TOCSY and NOESY) and chemical hydrolysis. Biological assay of 1—5 for anti-platelet aggregation, is also reported here. The EtOH extract of the galls of S. mukorossi was partitioned with MeOH/CHCl3/H2O (7/10/3), then the CHCl3 layer was partitioned with MeOH/n-hexane to give a MeOH residue. Chromatography of the MeOH layer on Diaion HP20, Sephadex LH-20, silica gel, and then after repeated RPHPLC purification afforded two new saponins (1, 2) and three known saponins (3—5). Compound 1 was isolated as an amorphous powder. Its molecular formula was established as C43H70O13 from the HR-FAB-MS pseudomolecular ion peak at m/z 817.4710 [M Na] (Calcd 817.4714). The H-NMR spectrum (Table 1) showed signals characteristic for five tertiary singlet methyls at d 0.76, 0.87, 0.92, 1.01, and 1.05, two allylic1412 Vol. 55, No. 9