Apotirucallane triterpenoids from Luvunga sarmentosa (Rutaceae)

The leaves of Luvungu sarmentosa (Bl.) Kurz. yielded eight apotirucallane triterpenoids named luvungins A-G. and 1alpha-acetoxyluvungin A. Characteristic of the structure arc the seven-membered lactone-ring A, the alpha-hydroxyl or alpha-acetoxyl group at C-7 and an oxygen bridge in the side chain giving five-, six- or seven-membered rings, respectively. Because of a hemiacetal function at C-21, luvungin C occurred as a mixture of 21-epimers. The structures have been elucidated on the basis of MS and NMR spectral data. In addition, two known coumarins ostruthin (6-geranyl-7-hydroxycoumarin) and 8-geranyl-7-hydroxycoumarin as well as five known triterpenes friedelin, flindissone, melianone. niloticin and limonin were isolated. (C) 2002 Elsevier Science Ltd. All rights reserved.