title: Diospyrone, crassiflorone and plumbagin: three antimycobacterial and antigonorrhoeal naphthoquinones from two Diospyros spp.
abstract: The aim of this study was to evaluate the antimycobacterial and antigonorrhoeal activities of three naphthoquinones (diospyrone, crassiflorone and plumbagin) from Diospyros canaliculata and Diospyros crassiflora as well as the crude extracts from these plants. The agar disk diffusion assay, broth microdilution method, microplate Alamar blue assay (MABA) and radiometric respiratory technique using the BACTEC 460 TB system were used. Results of the antimycobacterial assays indicated that the minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations ranged from 1.22 microg/mL to 39.06 microg/mL for Mycobacterium smegmatis and all studied Mycobacterium tuberculosis strains for the crude extract from D. crassiflora, diospyrone and crassiflorone. Results of the killing rate experiment revealed that a total inhibition effect on M. tuberculosis H37Rv strain was observed at Day 18 for D. crassiflora and Day 21 for the crude extract from D. canaliculata and diospyrone at 4x MIC as determined by MABA. Results of the antigonorrhoeal assay indicated that diospyrone was able to prevent the growth of all studied strains of Neisseria gonorrhoeae. The overall results of this work provide evidence that the studied plant extracts (diospyrone, crassiflorone and plumbagin) might be potential sources of new antimicrobial drugs against tuberculosis and gonorrhoea.
authors.affiliation: Department of Biochemistry, University of Dschang, P.O. Box 67, Dschang, Cameroon. kuetevictor@yahoo.fr
authors.forename: Victor
authors.initials: V
authors.lastname: Kuete
authors.forename: Jean G
authors.initials: JG
authors.lastname: Tangmouo
authors.forename: J J Marion
authors.initials: JJ
authors.lastname: Meyer
authors.forename: Namrita
authors.initials: N
authors.lastname: Lall
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology*; D000995:Antitubercular Agents / Q000494:pharmacology; D029788:Diospyros / Q000737:chemistry* / Q000145:classification; D008826:Microbial Sensitivity Tests / Q000379:methods; D020102:Mycobacterium smegmatis / Q000187:drug effects; D009169:Mycobacterium tuberculosis / Q000187:drug effects*; D009285:Naphthoquinones / Q000737:chemistry / Q000494:pharmacology*; D009344:Neisseria gonorrhoeae / Q000187:drug effects*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D000995:Antitubercular Agents; D009285:Naphthoquinones; D010936:Plant Extracts; C014758:plumbagin