Phytoconstituents of extracts from the roots of Dissotis thollonii Cogn. (Melastomataceae) and their antimicrobial, antioxidant, and anti-inflammatory activities

Dissotis thollonii Cogn. (Malastomataceae) is traditionally used in the west region of Cameroon for the treatment of inflammation, kidney diseases, pregnancy control and sinusitis, and no scientific report or information was found in the literature regarding neither its biological activity nor its chemical composition. The present work was designed to determine the antimicrobial, antioxidant and anti-inflammatory activities of different extracts of the roots of D. thollonii Cogn., and perform a bio-guided isolation of the bioactive chemical constituents. According to the antimicrobial and antioxidant assays, the EtOAc and n-BuOH extracts were purified, leading to the isolation of twelve compounds: 3,3′-di-O-methylellagic acid 4′-O-β-D-xylopyranoside, 3-O-methylellagic acid 4′-O-β-D-arabinopyranoside, casuarinin, betulinic acid, β-sitosterol-3-O-D-glucopyranosyl-6′-mirystate, cellobiosylsterol, β-sitosterol, β-sitosterol-3-O-β-D-glucopyranoside, arjunolic acid, 3,3′-di-O-methylellagic acid, ellagic acid, and 3,3′-di-O-methylellagic acid 4′-O-β-D-glucopyranoside. The structures of compounds were identified by mass spectrometry and extensive NMR spectroscopy, and by comparison with reported data. The presence of well-documented antimicrobial and antioxidant compounds allowed the correlation between chemical constituents and traditional use of D. thollonii