During the past fifteen years, African Strychnos species have been pharmacologically and chemically screened by some European Universities, sometimes with the collaboration of some African Institutes. Strychnos usambarensis will be discussed here because of our interest in it, after the discovery of its use in the preparation arrow poison with curarizing activity.
The European studies have show thah the African species of Strychnoschemically are very similar to certain South-American species. Indeed, the occurrence in the African species of curarizing quaternary bases, and in the American species of tetanizing tertiary bases, such as akagerine, emphasizes the unity of genus Strychnos in terms of it alkaloids. Many biological activities (antmicrobial, hypotensive, smasmolytic, amoebicial...) have been detected.
Finally, the antimitotic properties of some alkaloids will be presented. Besides know antitumor drugs, e.g. alstonine and ellipticine, African species possess new antimitotic products, e.g. strychnopentamine present in Strychnos usambarensis.
Because of these findings, the main reasons why further investigate Brazilian Strychnos species are the lack of knowledge about:
- the distribution on the species in the southern part of the great Amazon Basin.
Accordin to Krukoff, it is possible that new species may be found there.
- the distribution of alkaloids in many of know species. Indeed, there is little information on the variation in compposition of the alkaloidal mixtures in the different parts of the plants.
- the biological of alkaloids. In the past, interest has been focused too narrowly on possible curarizing properties.
Why should Brazilian species not cantain alkaloids with properties similar to those found in the African species?