Antimalarial and cytotoxic activities of schizogane alkaloids isolated from Schizozygia coffaeoides

Schizozygia coffaeoides Baill. (Apocynaceae) is a monotypic shrub used in Kenyan folk medicine for treatment of various infections as skin diseases caused by fungi [1]. Schizogane alkaloids represent a small group of hexacyclic N-acyl compounds that were first isolated from the roots of S. coffaeoides by Renner and co-workers [2, 3] but with doubts on the structure of two of the isolated compounds (isoschizogamine and isoschizogaline). Both structures were later revised [4, 5] and named isoschizoganes in which a five-membered (as in 2 and 3) rather than a six-membered (as in 1) lactam ring is present, thus revealing a hexacyclic skeleton of N-acyl tetrahydroquinoline type with an aminal moiety. We present here the key 13C-NMR signals to distinguish schizoand isoschizoganes alkaloids and also in vitro antimalarial and cytotoxic evaluation of crude CH2Cl2 extracts of roots and stems of S. coffaeoides and 3 isoand shizogane alkaloids isolated from the CH2Cl2 roots extract Antimalarial and cytotoxic activities of schizogane alkaloids isolated from Schizozygia coffaeoides