Sianne L. Schwikkard

Antimalarial activity of plant metabolites

This review covers the structures of compounds with antiplasmodial activity isolated from plants and is organized according to plant family. A total of 170 structures has been reviewed from 186 references found in the literature up to December 2000.

Delevoyin C, a tetranortriterpenoid from Entandrophragma delevoyi.

The hexane extract of the bark of Entandrophragma delevoyi has yielded a novel tetranortriterpenoid, delevoyin C. This compound contains a cyclobutanyl ring incorporating C-19 and a cycloheptanyl ring C including C-30. Gedunin and 11beta-Acetoxygedunin were isolated from the hexane extract of the wood.

Limonoid derivatives from Astrotrichilia voamatata

The stem bark of Astrotrichilia voamatata (Meliaceae) has yielded the novel limonoids voamatins C and D. These compounds represent a new type of pentanortriterpenoid and are unique in containing a ring A cyclic ether.

Limonoids from Astrotrichilia voamatata

The stem bark of Astrotrichilia voamatata (Meliaceae) yielded the novel limonoids voamatin A and voamatin B. The stem bark of Cipadessa boivinina (Meliaceae) yielded sitosterol and stigmast-4-en-3-one, but no limonoids.

Phaeophytins from Tapura fischeri

Abstract The ethyl acetate extract of the leaves of Tapura fischeri yielded four novel phaeophytins, 17 3 -ethoxyphaeophorbide a, phaeophytin a-13 2 -carboxylic acid, 17 3 -ethoxy-phaeophorbide a-13 2 -carboxylic acid and 17 3 -ethoxyphaeophytin b and the known phaeophytin a. Phaeophorbide a methyl ester was isolated from the hexane extract of the leaves of T. fischeri .

Useful methods for targeted plant selection in the discovery of potential new drug candidates

The efficient and effective selection of appropriate plants for investigative purposes in a drug discovery program is of crucial importance for a successful outcome. A variety of approaches have been used by researchers with varying levels of success. A variety of different approaches to plant selection are discussed, including the ethnomedicinal approach, some ecological approaches, and the use of combinatorial and computational methodologies.

Phytochemical Investigations of Three Rhodocodon (Hyacinthaceae Sensu APG II) Species

The genus Rhodocodon (Hyacinthaceae sensu APG II) is endemic to Madagascar, and its phytochemistry has not been described previously. The phytochemistry of three species in this genus has been investigated, and eight compounds, including three bufadienolides (compounds 1, 4, and 5), a norlignan (2), and four homoisoflavonoids (compounds 3 and 6-8), have been isolated and identified. Compounds 1-3 and 6-8 have not been described previously. The COX-2 inhibitory activity of compound 6 and compound 7 acetate (compound 7A) was investigated on isolated colorectal cancer cells. Compounds 6 and 7A inhibited COX-2 by 10% and 8%, respectively, at a concentration of 12.5 μM compared to 12% for 1 mM aspirin (the positive control).