Study of the secondary metabolites of Dorstenia angusticornis and Dorstenia barteri var. subtriangularis (Moraceae). Evaluation of the antimicrobial activity and cyclization and hydrogenation reactions of some isolated flavonoids

The work of Ingrid Simo Konga, in outline, aims to find links between the antimicrobial activity of Dorstenia angusticornis and Dorstenia barteri, two species of plant belonging to the family Moraceae, and their secondary metabolites.
In the thesis most attention is given to the isolation, identification and characterization of thirty components. Eighteen of these belong to the chemical classes of steroids, triterpenes and particularly flavonoids. After purification and isolation, their chemical structure was determined, making use of modern spectroscopic techniques. Among the results is the description of four new chalcone compounds.
Some of the flavonoids isolated were chemically modified by cyclization or hydrogenation.
With the aid of classic microbiological methods the activity of most of these compounds was determined with regard to gram-positive and gram-negative bacteria and a number of yeasts. With her awarded work Ingrid Simo Konga reaches a high scientific level. The work includes steps from isolation, to clarification of the structure and microbiological research of the isolated substances. The output volume of the chemical findings will impress any reader.
Another point of strength is that the thesis responds to the priorities formulated by the World Health Organization (WHO), namely the evaluation of indigenous plants used by traditional healers in Cameroon.
 

report: Prof. emeritus J. Totté, Department of Pharmaceutical Sciences, Universiteit Antwerpen, Belgium