Bidesmosidic saponins from the fruits of Diploclisia glaucescens Lalith Jayasinghe a, *, Noriyuki Hara b , Yoshinori Fujimoto b a Institute of Fundamental Studies, Hantana Road, Kandy, Sri Lanka b Department of Chemistry and Materials Science, Tokyo Institute of Technology, Meguro, Tokyo 152-8551, Japan Received 27 June 2002; received in revised form 27 September 2002; accepted 14 October 2002 Abstract Chemical investigation of methanol extract of the fruits of Diploclisia glaucescens (Menispermaceae) furnished two new bidesmosidic saponins 3-O-[b-d-glucopyranosyl-(1!3)-b-d-glucopyranosyl]phytolaccagenic acid 28-O-b-d-glucopyranosyl ester, 3-O-[a-l-rhamno- pyranosyl-(1!2)-b-d-glucopyranosyl-(1!2)-b-d-glucopyranosyl]phytolaccagenic acid 28-O-b-d-glucopyranosyl ester, together with known 3-O-b-d-glucopyranosylphytolaccagenic acid 28-O-b-d-glucopyranosyl ester and 3-O-[a-l-rhamnopyranosyl-(1!2)-b- d-glucopyranosyl-(1!2)-b-d-glucopyranosyl]serjanic acid 28-O-b-d-glucopyranosyl ester. The last saponin is reported for the first time from the family Menispermaceae. # 2002 Elsevier Science Ltd. All rights reserved. Keywords: Diploclisia glaucescens; Menispermaceae; Phytolaccagenic acid; Serjanic acid; Triterpenoid glycosides; Saponins 1. Introduction Diploclisia glaucescens (Bl.) Diels (=Cocculus macro- carpus W. & A.) (Menispermaceae) is a liana growing in India and Sri Lanka. D. glaucescens is the only species of Diploclisia found in Sri Lanka. The leaves of the plant have been used in the treatment of biliousness and venereal diseases (Chopra et al., 1956). We have pre- viously reported the isolation of stepharine (Jayasinghe et al., 1992), stigmasterol (Bandara et al., 1989a), serja- nic acid (3b-hydroxyolean-12-ene-28,30-dioic acid 30- methyl ester), phytolaccagenic acid (3b, 23-di- hydroxyolean-12-ene-28,30-dioic acid 30-methyl ester) (Bandara et al., 1990), 20-hydroxyecdysone (Bandara et al., 1989a) and six new phytolaccagenic acid and serjanic acid saponins from the stem of the plant (Bandara et al., 1989b, 1990; Jayasinghe et al., 1993, 1998). In this paper we report the isolation and structure elucidation of four bidesmosidic saponins 3-O-b-d-glucopyranosylphyto- laccagenic acid 28-O-b-d-glucopyranosyl ester (1), 3-O- [b-d-glucopyranosyl-(1!3)- b-d-glucopyranosyl]phyto- laccagenic acid 28-O-b-d- glucopyranosyl ester (2), 3-O- [a-l-rhamnopyranosyl-(1!2)-b -d- glucopyranosyl-(1!2)- b-d-glucopyranosyl]phytolaccagenic acid 28-O-b-d-glu- copyranosyl ester (3) and 3-O-[a-l-rhamnopyranosyl - (1!2)- b-d-glucopyranosyl-(1!2)- b-d-glucopyranosyl] serjanic acid 28-O-b-d-glucopyranosyl ester (4) from the fruits of D. glaucescens. Compounds 2 and 3 are new tri- terpenoid saponins while compound 4 is isolated for the first time from the family Menispermaceae. 2. Results and discussion The dry ground fruits of D. glaucescens were defatted with n-hexane and extracted with methanol. Chromato- graphic separations of the methanol extract over silica gel, sephadex LH-20 and reversed phase HPLC afforded compounds 1, 2, 3 and 4. The structures of these four saponins were established by detailed analysis of spec- tral data and their acetates 3a and 4a, including NOE, H–H COSY, HMQC and HMBC experiments, positive FAB and ESI mass spectrometry (MS) and the analysis of acid hydrolysis products. Acid hydrolysis of 1–3 with 4 N HCl afforded phyto- laccagenic acid (5) and the similar treatment of 4 affor- ded serjanic acid (6) as the aglycones previously described (Jayasinghe et al., 1993). TLC analysis of the acid hydrolysates of 1–4 indicated that the presence of d-glucose in 1 and 2, and d-glucose and l-rhamnose in 3 and 4. 0031-9422/03/$ - see front matter # 2002 Elsevier Science Ltd. All rights reserved. PII: S0031-9422(02)00535-6 Phytochemistry 62 (2003) 563–567 www.elsevier.com/locate/phytochem * Corresponding author. Tel.: +94-8-232002; fax: +94-8-232131. E-mail address: lalith@ifs.ac.lk (L. Jayasinghe).