Antimicrobial activity of the crude extracts and five flavonoids from the twigs of Dorstenia barteri (Moraceae)

Abstract

The aim of this study was to evaluate the antimicrobial activity of the crude extract of the twigs of Dorstenia barteri (DBT) as well as that of four of the five flavonoids isolated from this extract. Gram-positive bacteria (six species), Gram-negative bacteria (12 species) and fungi (four species) were used. The agar disc diffusion test was used to determine the sensitivity of the tested samples while the well micro-dilution was used to determine the minimal inhibition concentrations (MIC) and the minimal microbicidal concentration (MMC) of the active samples. The results of the disc diffusion assay openUP (May 2008) showed that DBT, isobavachalcone (1), and kanzonol C (4) prevented the growth of all the 22 tested microbial species. Other compounds showed selective activity. The inhibitory activity of the most active compounds namely compounds 1 and 4 was noted on 86.4% of the tested microorganisms and that of 4-hydroxylonchocarpin (3) Abbreviations

Potency of extracts of selected plant species from Mbeere, Embu County-Kenya against Mycobacterium tuberculosis

“…The procedure was repeated using plant extracts at 1.0 g/ml in place of SIRE. The general antimicrobial activity using Escherichia coli (ATCC 2592), Staphylococcus aureus (ATCC 25923) and Candida albican (ATCC 90028) was assayed by standard disc diffusion method according to Ayo et al (2007), Mbaveng et al (2008), Ngoci et al (2012) and Mwitari et al (2013).…”

Antibacterial activity of some natural products against bacteria expressing a multidrug-resistant phenotype

“…1) were obtained from the chemical bank of the Laboratory of Organic Chemistry, University of Yaoundé I, Cameroon. Isolation and identification of the following compounds have been reported previously [10][11][12][13]: crotozambefurans A, B and C; bartericin C; MAB3; mammeisin; norcassaide; norerythrosuaveolide; 1,8-dihydroxy-6-methoxy-3-methylanthraquinone; 3-geranyloxy-6-methyl-1,8-dihydroxyanthraquinone; vismiaquinone and vismiaquinone C; bivismiaquinone; laurentixanthone B; kaempferol; lapachol; 2-acetylfuro-1,4-naphathoquinone; newbouldiaquinone and newbouldiaquinone A; hardwickiic acid; 3-friedelanone; betulinic acid; oleanolic acid; 7-methoxycoumarin; 7-hydroxycoumarin; 1,5-dihydroxyxanthone; smeathxanthone A and smeathxanthone B; gancaonin Q; stipulin; angusticornin B; 1,7-dihydroxyxanthone; 4-hydroxylonchocarpin; and quercetin.…”

Antioxidant, antitumor and antimicrobial activities of the crude extract and compounds of the root bark ofAllanblackia floribunda

“…Their identification was confirmed before use at the Laboratory of Applied Microbiology and Molecular Pharmacology (LMP) (Faculty of Science, University of Yaoundé I). This was followed by culturing on the specific media and biochemical test using the API system (Mbaveng et al, 2008b).…”