Apotirucallane triterpenoids from Luvunga sarmentosa (Rutaceae)

The leaves of Luvunga sarmentosa (Bl.) Kurz. yielded eight apotirucallane triterpenoids named luvungins A–G, and 1α-acetoxyluvungin A. Characteristic of the structure are the seven-membered lactone-ring A, the α-hydroxyl or α-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. The leaves of Luvunga sarmentosa (Bl.) Kurz. yielded eight apotirucallane triterpenoids named luvungins A–G and 1α-acetoxyluvungin A. Characteristic for the luvungins were the seven-membered lactone-ring A, the α-hydroxyl or α-acetoxyl group at C-7 and an oxygen bridge in the side chain giving five-, six- or seven-membered rings.