I  U  P  A  C

News & Notices

Organizations & People

Standing Committees




. . CI
. . PAC
. . Macro. Symp.

. . Books
. . Solubility Data



Links of Interest

Search the Site

Home Page


Pure Appl. Chem. Vol. 73, No. 7, pp. 1197-1208 (2001)

Pure and Applied Chemistry

Vol. 73, Issue 7


Recent results from natural product research at the University of Botswana*

Runner R. T. Majinda1**, Berhanu M. Abegaz1, Merhatibeb Bezabih1, Bonaventure T. Ngadjui2, Cornelius C. W. Wanjala1, Ladislaus K. Mdee1, Gomotsang Bojase1, Alfonse Silayo1, Ishmael Masesane, and Samuel O. Yeboah1

1Department of Chemistry, University of Botswana, Private Bag 0022, Gaborone, Botswana; 2Department of Organic Chemistry, University of Yaounde, BP 812, Yaounde, Cameroon

Abstract: Marketed plants are very important items of trade in many parts of the world. The community uses these for a variety of purposes such as foods, cosmetics, flavors, spices, and medicines. It seems that plants that are used for medicinal purposes form the most common category. Four plants used for treatment of microbial infections, viz., Bolusanthus speciosus, Erythrina latissima, Crotalaria podocarpa, and Elephantorrhiza goetzei, were investigated, and these yielded several known and novel structures, some with appreciable antibiotic activity against the test organisms. The activity of some of the isolated plants and the parts of the plant from which these were obtained lend support to their traditional use. Bulbine abyssinica and B. capitata yielded phenylanthraquinones, some of which were shown to possess strong antiplasmodial activity. In addition, these yielded isofuranonaphthoquinones, which were also found to be weakly antiplasmodial and antioxidant. Scilla nervosa yielded several known and novel homoisoflavoinds of the 3-benzylchroman-4-ones and 3-benzylidinechroman-4-one type, as well as some stilbenoids. The homoisoflavonoids showed strong antitumor activity against various cancer cell lines. Rhus pyroides gave a novel bichalcone, which showed weak antifeedant activity, consistent with the observation by farmers that the plant was avoided by corn cricket. Results from investigated Dorstenia species originating from Cameroon, Ethiopia, and Tanzania yielded styrenes, coumarins, chalcones, and flavonoids. The chalcones and flavonoids showed various levels of prenylation or geranylation, and an observation made so far is that prenylated flavonoids are only found in Dorstenia species of African origin. The only example of a bis-geranylated chalcone is found in Dorstenia.

*Lecture presented at the 8th International Chemistry Conference in Africa (8th ICCA), 30 July-4 August 2001, Dakar, Sénégal. Other presentations are published in this issue, pp. 1147-1223.

**Corresponding Author

Back to Contents for access to full text

Page last modified 24 October 2001.
Copyright © 2001 International Union of Pure and Applied Chemistry.
Questions or comments about IUPAC, please contact, the Secretariat.
Questions regarding the website, please contact web manager.