708 NEW SOURCE REPORTS

Acknowledgements--This study was supported in part by Grants-in-Aid for Nihon University Ohta Overseas Academic Interchange.

References Yasukawa, K., Ogawa, H. and Takido, M. (1990) Phytochemistry 29, 1707; Yasukawa, K., Sekine, H. and Takido, M. (1989) Phytochemistry 28, 2215; Yasukawa, K. and Takido, M. (1986) Yakugaku Zasshi 106, 938; Yasukawa, K. and Takido, M. (1987) Phytochemistry 26, 1224; Yasukawa, K. and Takido, M. (1988) Phyto- chemistry 27, 3017.

Biochemical Systematics and Ecology, Vol. 20, No. 7, pp. 708-709, 1992. Printed in Great Britain.

0305-1978/92 $5.00 + 0.00 ,# 1992 Pergamon Press Ltd.

Triterpenes from the Fruit of Elaeocarpus chelonimorphus*

RICHARD C. CAMBIE, ALLICK R. LAL, PETER S. RUTLEDGE and PAUL D. WOODGATE

Department of Chemistry, University of Auckland, New Zealand

Key Word Index--Elaeocarpus chelonimorphus; Tiliaceae; sorghumol; friedelin; epifriedelinoL

Subject and Source Elaeocarpus che/onimorphusGillespie (faro. Tiliaceae) is a moderately common endemic Fijian tree, the kernel of which is reported to be edible. Foliage of the tree was authenticated by Dr J. Ash, former curator of the Fijian National Herbarium, University of the South Pacific.

Present Study Soxhlet extraction of the dried fruit with MeOH followed by multiple column chromatography of the EtOAc soluble fraction and p.l.c. (PhMe) yielded epifriedelinol (0.12%), friedelin (0.02%), and a further triterpene sorghumol (1) (0.009%), needles (CHCI3), mp 283-285 ° (Found: M ÷ 426.3923. Calc. for C30H500, M 426.3861), (lit. mp 277-282 °, correct MS, Nes eta/., 1984). Comparison of its 13C NMR spectrum (Table 1) with those of arborenes (Blunt and Munro, 1980) and fernenes (Wilkins et al., 1987) supported the presence of an arborene skeleton, and the chemical shifts of C-6 and C-7 (621.40, 28.20), which correspond more closely with those of isoarborinol ((~21.4, 28.2) than those of fern-9(11)-enol (17.8, 19.0), established that the C-13 methyl group was 6. However, although the similarity in the '3C NMR chemical shifts (Blunt and Munro, 1980; Wilkins et al., 1989) supported the presence of the same polycyclic skelton, the 1H NMR chemical shifts for the methyl groups of (1) differed from those of isoarborinol but were identical with those of sorghumol (Nes et al., 1984).

From a 2D NMR study of 12cx-acetoxyfern-9(11)-en-3~-ol, Wilkins et al. (1989) have substantiated methyl proton assignments proposed by Ageta et al. (1984) for fern-9(11)-en-3j]-ol rather than those assigned by Nes et al. (1984). Moreover, they have suggested that the methyl proton assignments of the three related groups of triterpenes, including those of sorghumol, should be revised. In the present study, 13C NMR assignments for sorghumol were based on those given for cylindrin (2) and were supported by DEPT spectra. Despite the small sample available (2 rag), an XHCoRR spectrum allowed correlation of the carbon and hydrogens of all methyl and methine groups but not those of methylene groups, and showed that revision of methyl proton assign- ments (Nes eta/., 1984) for sorghumol was required as in Table 1. Further proton assignments were obtained or confirmed from COSY and phase-sensitive double-quantum-filtered COSY experiments (Wilkins et al., 1989).

*Chemistry of Fijian Plants, Part 10. For Part 9 see Cambie, R. C., Lal, A. R. and Pausler, M. G. (1992) Biochem. Syst. Ecol. 20, 265.

(Received 11 March 1992).

709 NEW SOURCE REPORTS

(1) (2)

TABLE 1. ~H AND ~3C NMR ASSIGNMENTS (6) FOR SORGHUMOL (CDCI 3)

C ~3C ~H C ~3C ~H

1 35.90 t* 16 36.02 t 2 26.65 t 1.63, 1.72 m 17 42.82 s 3 78.94 d 3.22 ddt 18 52.30 d 0.85 m 4 39.04 s 19 20.15 t 5 52.05 d 1.60 m 20 27.78 t 6 21.40 t 21 59.82 d 0.92 rn 7 28.20 t 22 30.77 d 1.45 m 8 40.93 d 2.01 s 23 28.20 q 0.982 s 9 148.84 s 24 15.61 q 0.815 s

10 39.64 s 25 22.11 q 1.03 s 11 114.30 d 5.23 dd 26 15.26 q 0.767 s 12 35.97 t* 1.46, 1.70 m 27 17.01 q 0.806 s 13 36.74 s 28 13.97 q 0.757 s 14 38.16 s 29 22.11 q 0.826 d$ 15 29.62 t 30 22.99 q 0.887 d~:

*Assignments may be interchanged. tJ = 11.5, 4.2 Hz. $J= 6.5 Hz.

Chemotaxonomic Significance Hitherto, sorghumol has been isolated only f rom Sorghum bico/or (faro. Gramineae). Its occurrence in E/aeocarpus che/onimorphus is the first report o f a tr i terpene with a migrated hopane skeleton in the family Tiliaceae.

References Ageta, H. and Ageta, T. (1984) Chem. Pharm. 8u//. 32, 369; Blunt, J. W. and Munro , M. H. G. (1980) Org. Magn. Reson. 13, 26; Nes, W. D., Heupel, R. C., Benson, M., Staf ford, A. E. and Haddon, W. E (1984) J. Chem. Soc., Chem. Commun. 223; Wi lk ins, A. L., Bird, R W. and Jager, R M. (1987) Magn. Reson. Chem. 25, 503; Wilkins, A. L., Elix, J. A., Gonzalez, A. G. and Perez, C. (1989) AusL J. Chem. 42, 1185.