Phytochemical and antimicrobial studies on the leaves and stem ofDesmodium scorpiurus Der (sw)

Phytochemical studies on the aerial parts of Desmodium scorpiurus Der (sw) revealed the presence of alkaloids, saponins, glycosides, steroids and carbohydrates. The petroleum spirit, chloroform and methanol extracts were screened for antimicrobial activity using clinical isolates of Escherichia coli, Staphylococcus aureus, Salmonella typhi, Bacillus cereus, Streptococcus pyrogenes and Klebsiella pneumoniae. The results showed that the plant is very active against Pseudomonas aeruginosa,Escherichia coli and Streptococcus pyrogenes with minimum inhibitory concentration (MIC) of 2 x 102 mg/ml

Phytochemical and antimicrobial screening of the crude petroleum spirit and methanol extracts of the stem bark, leaves and roots of Ficus thoningii (blume)

Ficus thoningii which has some traditional medicinal uses was investigated. Phytochemical screening of the stem bark, leaves and roots gave positive results for carbohydrates, glycosides, saponins and alkaloids. Antimicrobial screening of the crude petroleum spirit and methanol extracts showed activity against Klebsiella pneumoniae, Staphylococcus aureus, Escherichia coli, Providencia stauti and Bacillus subtilis but no activity was observed against Salmonella typhi. The crude petroleum spiritextracts of the leaves and stem bark of the plant had minimum inhibitory concentrations at 50 mg/ml while the roots had no minimum inhibitory concentration at the test concentration. The crude methanolextracts of the various plant parts showed minimum inhibitory concentration at 50 mg/ml on all the pathogens tested for

Phytochemical and antimicrobial screening of the crude extracts from the root, stem bark and leaves of Vitellaria paradoxa (GAERTN. F)

The root, stem and leaves of Vitellaria paradoxa, belonging to the Sapotaceae family and which have some ethnomedicinal applications were studied. Phytochemical screening of the plant parts reveals thepresence of carbohydrates (free reducing sugars, ketoses, pentoses and starch), saponins, steroids, tannins and alkaloids. The antimicrobial screening of the crude methanol extract carried out in vitro onthe following clinical isolates; Bacillus cereus, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pnuemoniae and Salmonella typhi showed that the crude methanol extracts hadwider range of activity on these organisms than the petroleum ether extracts. The crude stem extracts inhibited the growth of P. aeruginosa, K. pneumoniae, B. cereus and S. typhi at concentration of 50mg/ml while the leaf had a minimal inhibition concentration (MIC) of 70 mg/ml on S. aureus, E. coli and S. typhi. The root had an MIC of 60 mg/ml on S. aureus, E. coli, P. aeruginosa, K. pneumoniae and S.typhi. The MBC in all the cases were slightly higher than the MIC and was lowest in the stem extracts which indicates that the stem bark may contain the most active components

Phytochemical analysis and antimicrobial screening of crude extracts from the leaves, stem bark and root bark of Ekebergia senegalensis A. Juss

The leaves, stem bark and root bark of Ekebergia senegalensis, which has some traditional medicinal applications were investigated. Phytochemical analysis gave positive results for carbohydrates, glycosides, saponins, tannins and alkaloids. The crude methanol extracts showed growth inhibitory effects on Salmonella typhi, Pseudomonas, Klebsiella, Bacillus subtilis, Escherichia coli and Staphylococcus aureus. The minimum inhibitory concentration (MIC) of these extracts on the bacteriais 0.125 x 103 mg/ml for the methanol extracts. The minimum bactericidal concentration (MBC) determination showed that a concentration of 0.03125 x 103 mg/ml of the methanol extract of the leaves could completely kill S. typhi. The petroleum spirit extract did not show marked antimicrobial activity

Isolation and Characterization of Lup-20(29)-ene-3, 28-diol (Betulin) from the Stem-Bark of Adenium obesum ( Apocynaceae)

Purpose: To isolate and characterize chemical compound(s) of biological importance from the stembark of the plant, Adenium obesum . Methods: The stem-bark, after air-drying and powdering, was subjected to sequential hot-continuous extraction using petroleum spirit (60 - 80 oC) and methanol in that order. The petroleum spirit extract was chromatographed using thin layer and column chromatographic techniques. Recrystallization was used to further purify the isolated compound. Characterization of the isolated compound was by melting point, as well as by 1H and 13C nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS). Results: A triterpenoid (lup-20(29)-ene-3, 28-diol), commonly known as betulin, was isolated from the crude petroleum ether extract of the plant stem-bark. The isolated compound’s melting point was 256 - 257 °C. The name, betulin, was assigned to this compound by comparison of its spectroscopic data from 1H-NMR, 13C-NMR and MS analysis with those of authenticated samples reported in the literature. Conclusion: A known compound, betulin ( lup-20(29)-ene-3, 28-diol) was isolated from the petroleum ether extract of the stem-bark of Adenium obesum

Antimicrobial and antioxidant effects of phenolic constituents from Klainedoxa gabonensis

Wansi JD, Chiozem DD, Tcho MT, et al. Antimicrobial and antioxidant effects of phenolic constituents from Klainedoxa gabonensis. PHARMACEUTICAL BIOLOGY. 2010;48(10):1124-1129.Bioassay-guided fractionation of the methanol extract of the stem bark of Klainedoxa gabonensis Pierre ex Engl. (Irvingiaceae) afforded 12 compounds, namely, ellagic acid (1), ellagic acid 3,3'-dimethylether (2), gallic acid (3), methyl gallate (4), lupeol (5), beta-amyrin (7), erythrodiol (8), oleanolic acid (9), betulinic acid (6), hederagenin (10), bayogenin acid (11), and stigmasterol-3-O-beta-D-glucopyranoside (12). Compounds 1-3 and 7-12 were isolated for the first time from this genus. The structures were established on the basis of 1D/2D NMR experiments and mass spectrometric data. Crude extract, fractions (A, B, C and D) and pure compounds were tested for their antimicrobial activity using paper disk agar diffusion assay. The test delivered a range of low to high activities for phenolic compounds 1-4, low or missing activities for terpenoid compounds 5-11, and impressive very high antibacterial/antifungal values for two fractions C and D probably due to synergistic effects of compounds. The broth microdilution assay revealed MICs of 15.4-115.1 mu g/mL for phenolic compounds, MICs higher than 1 mg/mL for terpenoids and MICs of 4.5-30.3 mu g/mL for fractions C and D. The determination of the radical scavenging activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay gave high antioxidant values for the methanol extract and fraction D (IC50 10.45 and 5.50 mu g/mL) as well as for the phenolic compounds 1-4 (IC50 45.50-48.25 mM) compared to the standard 3-t-butyl-4-hydroxyanisole (BHA) (IC50 44.20 mM)