T~~~~ new cucurbitane ttiterpenoids, 1, 3, and 6, have been isolated from the leaves of Monrmdica charant& along with two other known compounds, momordicines I [8] and I1 [9]. The structures of the new metabolites were determined by interpretation of spectral data.Momordica charantia L. (Cucurbitaceae), trivially called African cucumber or balsam pear (l), is widely distributed in West Africa, India, and Japan. The sample used in this study originated in Kano, a city in northern Nigeria. A related species, Momordica balsamina L., which is found in southern Nigeria, is uncommon in Kano. However, the two species are used both as a bitter stomachic and a purgative. M . cbarantia is available at local herbal drug stores in Kano city.The leaves of M . cbarantia contain antibacterial and insecticidal principles (2-4). A number of cucurbitane triterpenoids, named momordicosides and momordicines, respectively (5,6), have previously been isolated from the fruits and leaves ofM. cbarantia. This paper details the isolation and structure elucidation of three new compounds 1, 3, and 6 obtained from the leaves of M. cbarantia.
RESULTS AND DISCUSSIONThe MeOH extract of the dried leaves of M . cbarantia was redissolved in 90% MeOH and extracted successively with n-hexane, CCI,, and CHCI,. Extensive chromatography of the CHC13-soluble fraction over Si gel and Lobar RP-8 columns gave compounds 1, 3, and 6 together with the known momordicines I (81 and I1 (91 (5).Compound 1, E~D + 89.0" (MeOH) , was obtained as an amorphous powder, and H 1 R=H 2 R=Ac