In vitro assays for bioactivity-guided isolation of antisalmonella and antioxidant compounds in Thonningia sanguinea flowers

Bioguided fractionation of the aqueous extract of Thonningia sanguinea flowers, used traditionally in the treatment of microbial diseases, led to the isolation of two phenolic compounds. The structure of these compounds was elucidated by 1H, 13C 1D NMR and mass spectrometry experiments. The antibacterial activity against Salmonella strains and antioxidant activity of the crude extract, fractions and isolated compounds was evaluated using the DPPH method. The isolated compounds identified asbrevifolin carboxylic acid and gallic acid demonstrates moderate antibacterial activity against Salmonella enteritidis, Salmonella typhimurium, and Salmonella abony. The results indicated that thetwo isolated compounds, gallic acid (IC50 = 13.5 ìM) and brevifolin carboxylic acid (IC50 = 18.0 ìM) were mainly responsible for the good scavenging activity of the aqueous extract

Identification and phytochemical screening of Endophytic fungi from stems of Phragmanthera capitata (Sprengel) S. Balle (Loranthaceae)

Objective: The purpose of this study was to identify some endophytic fungi, which were associated with the stems of Phragmanthera capitata (Loranthaceae), and to determine the phytochemical composition of their extracts.Methodology and results: The isolation of endophytic fungi was made on PDA medium (Potato dextrose agar) and the identification was based on macroscopic and microscopic observations of the different strains isolated and using identification keys. The qualitative phytochemical analysis of acetate ethyl extracts of the endophytes was carried out using standard procedures. Eleven fungi species belonging to 4 genera were isolated: Aspergillus (06 species), Penicillium (03), Trichoderma (01) and Fusarium (01). The phytochemical analysis revealed the presence of flavonoids, anthroquinones, tannins, phenols, steroids, coumarins and terpenoids and absence of alkaloids and saponins in all the extracts.Conclusion and application of results: The study shows that endophytic fungi of P. capitata could be a potential source of new bioactive compounds, which can be used in the fields of health and agriculture

An Antibacterial Isovaleronitrile Diglycoside From Detarium microcarpum Guill. Perr. (Fabaceae)

Feudjou WF, Mbock AM, Ouahouo MBW, et al. An Antibacterial Isovaleronitrile Diglycoside From Detarium microcarpum Guill. Perr. (Fabaceae). NATURAL PRODUCT COMMUNICATIONS. 2020;15(7): UNSP 1934578X20936939.A new isovaleronitrile diglycoside, named microcarposide (1), together with 6 known compounds: lupeol (2), betulinic acid (3), beta-sitosterol glucoside (4), methyl gallate (5), luteolin (6), and epicatechin (7), was isolated from the methanolic extract of the fruits of Detarium microcarpum Guill. Perr. The structures of the compounds were determined by extensive analysis of 1D- and 2D-H-1 and C-13 NMR spectroscopic data in conjunction with mass spectrometry and by comparison with data reported in the literature. Compound 1 was characterized as (2R)-2-[(6 ''-O-beta-L-rhamnopyranosyl-beta-D-glucopyranosyl)oxy]-3-methylbutanenitrile. Some of the isolated compounds were evaluated for their antibacterial activities against several microorganisms; only compound 1 was active against Salmonella typhi, Salmonella enteritidis, and Salmonella typhimurium with minimum inhibition concentration values of 153.4, 76.7, and 76.7 mu M, respectively

Chemical constituents from the bark of the Cameroonian mahogany Trichilia emetica Vahl (Meliaceae)

Tsopgni WDT, Happi GM, Stammler H-G, et al. Chemical constituents from the bark of the Cameroonian mahogany Trichilia emetica Vahl (Meliaceae). Phytochemistry Letters. 2019;33:49-54.Phytochemical investigation of the stem bark extract of Trichilia emetica led to the isolation of two new naturally occurring compounds including a prieurianin-class limonoid named trichirokin (1) and the steroid ergosta-5,24(28)-diene-3S, 16S, 20S-triol (4), along with nine known compounds characterized as rohituka-3 (3), rohituka-9 (2), scopoletin, benzoic acid, protocatechuic acid, lignoceric acid, beta-sitosterol, stigmasterol and beta-sitosterol-3-O-beta-D-glucopyranoside. The crystal structures of rohituka-3 (3) and ergosta-5,24(28)-diene-3S, 16S, 20S-triol (4) are reported here for the first time. The structures of the compounds were elucidated by extensive spectroscopic and spectrometric data interpretation. The stereochemistry of compound 1 was established on the basis of its NOESY spectrum and the comparison of its optical rotation value with that of its congener 2. None of the reported compounds displayed antibacterial or cytotoxic activity