Biosynthesis of friedelane and quinonemethide triterpenoids is compartmentalized in Maytenus aquifolium and Salacia campestris

Maytenus aquifolium (Celastraceae) and Salacia campestris (Hippocrateaceae) species accumulate friedelane and quinonemethide triterpenoids in their le aves and root bark, respectively. Enzymatic extracts obtained from leaves d isplayed cyclase activity with conversion of the substrate oxidosqualene to the triterpenes, 3 beta -friedelanol and friedelin. In addition, administr ation of (+/-)5-H-3 mevalonolactone in leaves of M. aquifolium seedlings pr oduced radio labelled friedelin in the leaves, twigs and stems, while the r oot bark accumulated labelled maytenin and pristimerin. These experiments i ndicated that the triterpenes once biosynthesized in the leaves are translo cated to the root bark and further transformed to the antitumoral quinoneme thide triterpenoids. (C) 2000 Elsevier Science Ltd. All rights reserved.