ANTIFUNGAL ACTIVITY ON LASIODIPLODIA THEOBROMAE AND PHYTOCHEMICAL STUDY OF MITRACARPUS VILLOSUS AND MORINGA OLEIFERA FROM KISANGANI (D.R.CONGO)

Kwembe JTK., Onautshu D.O., Mpiana P.T.*, Bekaert B. and Haesaert G.

ABSTRACT

Lasiodiplodia theobromae is one of the fungal strains that attacks cocoa crops. This strain has become a critical threat to cocoa cultivation in some regions of the word including in the Kisangani region in the Democratic Republic of Congo. This work involved the identification, extraction and in vitro evaluation of the antifungal activity of the phytochemical groups of Mitracarpus villosus and Moringa oleifera on the strain of Lasiodiplodia theobromae. The aqueous, 95% ethanolic and ethereal extracts of M. oleifera are more antifungal (respective percentages of inhibition PI: 85.8; 77.8 and 77.4%) compared to those of M. villosus (71.4; 74.2 and 80.0%). The minimum inhibition concentration, MIC of the aqueous extract of M. oleifera is the lowest (20 mg/mL with a PI at the MIC of 85%) followed by that of the ethanolic extract, (25 mg/mL with a PI at 77% MIC). The chemical screening revealed the very abundant presence of tannins in the two plants and abundant presence of saponins in M. villosus. The extraction yields of tannins in M. villosus and M. oleifera are 16.91 and 21.25%, respectively, and that of saponins in M. villosus, 3.83%. M. villosus contains two kind of tannins (gallic and catechetical) when M. oleifera contains condensed tannins. M. oleifera tannins have a PI of 69.6% while those of M. villosus are 45.6%; both have PI lower than that of M. villosus saponins, 74.4%. Determination of active molecules from the tannins of M. oleifera and the saponins of M. villosus is undergoing.

Keywords: Lasiodiplodia theobromae, Mitracarpus villosus, Moringa oleifera, antifungal activity, cacao.