The methanol extract from the stem bark of Terminalia superba (TSB), fractions
(TSB1 - 7) and two compounds isolated following bio-assay guided fractionation namely 3,4'-
di-O-methylellagic acid 3'-O-β-D-xylopyranoside (1) and 4'-O-galloy-3,3'-di-O-methylellagic
acid 4-O-β-D-xylopyranoside (2) were evaluated for their antimycobacterial, antibacterial and
antifungal activities. The broth microdilution, microplate Alamar Blue assay (MABA) and
agar disc diffusion methods were used for the investigations. The results of the
antimycobacterial assays showed that the crude extract, fraction TSB5-7 and compound 1
were able to prevent the growth of all the studied mycobacteria. The lowest minimal
inhibitory concentration (MIC) value of 39.06 μg/ml for this extract was recorded on both M.
smegmatis and M. tuberculosis MTCS2. The corresponding values were 19.53 μg/ml and
4.88 μg/ml for fractions and compounds respectively. The MIC determinations results on
other organisms indicate values ranging from 19.53 to 78.12 μg/ml for TSB and compound 2
on 90.9% of the tested organisms, meanwhile compounds 1 as well as fractions TSB 6 and 7
exhibited detectable MIC values on all studied microorganisms.
The overall results provide promising baseline information for the potential use of the
crude extract from Terminalia superba, fractions 6-7 and the tested compounds in the
treatment of tuberculosis, bacterial and fungal infections.