Structure elucidation of two triterpenoids from Ficus ®stulosa N.v. Tuyen a, b , D. S. H. L. Kim a, *, H.S. Fong a , D.D. Soejarto a , T.-C. Khanh b , M.V. Tri b , L.T. Xuan c a Program for Collaborative Research in the Pharmaceutical Sciences, Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The University of Illinois at Chicago, Chicago, IL 60612-7231, USA b Institute of Chemistry, Vietnam National Center for Natural Sciences and Technology, Nghia do, Tu Liem, Hanoi, Vietnam c Department of Botany, Hanoi College of Pharmacy, Hanoi, Vietnam Received 13 March 1998; revised 6 August 1998 Abstract From Ficus ®stulosa two triterpenoids 3b-acetyl ursa-14:15-en-16-one and lanosterol-11-one acetate were isolated along with ®ve known triterpenoids, 3b-acetyl-22,23,24,25,26,27-hexanordamaran-20-one, 24-methylenecycloartenol, sorghumol (isoarborinol), 11a,12a-oxidotaraxeryl acetate, and ursa-9(11):12-dien-3b-ol acetate. Their structures were elucidated on the basis of spectral data interpretation. # 1998 Elsevier Science Ltd. All rights reserved. Keywords: Ficus ®stulosa; Moraceae; 3b-acetyl ursa-14:15-en-16-one; Lanosterol-11-one acetate; Biodiversity conservation study; Cuc Phuong National Park, Vietnam 1. Introduction As part of a biodiversity conservation study, Ficus ®stulosa Reiw ex. Bl (Moraceae), indigenous to Vietnam, was collected from the forest of the Cuc Phuong National Park, Vietnam for study. No work on the plant has been reported. MeOH extracts of the leaves and barks exhibited antiplasmodial activity. Fractionation of the bark MeOH extract led to the iso- lation of seven triterpenes, two of which are new. The isolation and structure identi®cation/elucidation of the compounds are reported herein. 2. Results and discussion The MeOH extract was prepared from the bark ma- terials of F. ®stulosa. Fractionation by silica gel col- umn chromatography, followed by HPLC puri®cation aorded seven triterpenoids. The structures of the compounds were elucidated by using 1-D and 2-D 1 H and 13 C NMR spectroscopic techniques (APT, 1 H± 1 H COSY, HMBC and HETCOR) and mass spectral analysis. (Fig. 1). The known triterpenes 3b-acetyl-22,23,24,25,26,27- hexanordamaran-20-one (Tanaka, Matsuda & Matsunaga, 1987), 24-methylenecyclo artenol (Anjaneyulu & Raju, 1987), sorghumol (isoarborinol) (Nes, Heupel, Benson, Staord & Haddon, 1984; Nes, Wong, Grin & Duax, 1991), 11a,12a-oxidotaraxeryl acetate (Nes et al., 1984; Nes et al., 1991; Tanaka & Matsunaga, 1988; Matsunaga, Tanaka & Akagi, 1988) and ursa-9(11):12±dien±3b±ol acetate (Ito & Lai, 1979) were identi®ed by comparison of their physical and spectral data with literature values. The molecular formula of compound 1 (C 32 H 52 O 3 ) was established by CIMS, 1 H and 13 C NMR, and APT experiments. The 1 H NMR and APT experiment showed that compound 1 contains eight methyl groups (d H 0.65, 0.88, 0.91, 0.92, 0.93, 1.18, 1.60, and 1.68), an acetyl group (d H 2.06), a ketone (d C 189.74), nine quartenary carbons (d C 36.43, 37.73, 39.55, 44.87, 130.99, 139.05, 164.70, 170.83, and 189.74), an ole®nic proton (d H 5.10), and four ole®nic carbons (d C 125.09, 130.99, 139.05, and 164.70). Two of the methyl groups [d H 1.60 (singlet) and 1.68 (singlet)] were attached to a quarternary ole®nic carbon at d C 130.99, suggesting that they are at the terminal position of a side-chain. Phytochemistry 50 (1998) 467±469 0031-9422/98 $19.00 # 1998 Elsevier Science Ltd. All rights reserved. PII: S0031-9422(98)00578-0 PERGAMON * Corresponding author. Tel.: +001-312-996-1230; Fax: +001-312- 996-7107; E-mail: dshlkim@uic.edu.