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Phytochemical investigation of the stem bark of Stereospermum acuminatissimum resulted in the isolation of seventeen compounds, including four tirucallanes (1 – 4), three hopanes (5 – 7), one oleanane (8), three sterols (9 – 11), three saponins (12 – 14), two cinnamic acids (15 – 16), and one iridoid (17). The dehydration of compound 5 led to compound 5a. The structures of all compounds were elucidated by analysis of spectroscopic and mass spectrometric data. Compounds 1 , 6 and 7 are reported from the Bignoniaceae family for the first time, while compounds 11 – 14 and 16 are reported from S. acuminatissimum for the first time. The in vitro antibacterial activities of some compounds (1 – 5 , 8 , 5a), the crude extract and the ethyl acetate fraction were assessed. The crude extract showed significant antibacterial activity against Staphylococcus aureus , Salmonea pneumonia and Klebsiella pneumoniae with MIC values of 62 μg/mL. Compound 1 revealed moderate antibacterial activities against K. pneumoniae , Shigella flexneri and Methycillin resistant S. aureus with MIC values of 62, 62 and 31 μg/mL respectively. [Display omitted] • Phytochemical investigation of Stereospermum acuminatissimum K. Schum. • Dehydration of one of the isolated compound. • Chemophenetic significance of the isolated compounds. • Antibacterial activities of crude extract, fractions and compounds. [ABSTRACT FROM AUTHOR]

Background: The continuous emergence of multidrug-resistant (MDR) bacteria drastically reduced the efficacy of our antibiotic armory and consequently, increased the frequency of therapeutic failure. The search for bioactive constituents from endophytic fungi against MDR bacteria became a necessity for alternative and promising strategies, and for the development of novel therapeutic solutions. We report here the isolation and structure elucidation of antibacterial and cytotoxic compounds from Phomopsis sp., an endophytic fungus associated with Garcinia kola nuts. Methods: The fungus Phomopsis sp. was isolated from the nut of Garcinia kola. The crude extract was prepared from mycelium of Phomopsis sp. by maceration in ethyl acetate and sequentially fractionated by column chromatography. The structures of isolated compounds were elucidated on the basis of spectral studies and comparison with published data. The isolated compounds were evaluated for their antibacterial and anticancer properties by broth microdilution and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide methods respectively. The samples were also tested spectrophotometrically for their hemolytic properties against human red blood cells. Results: The fractionation of the crude extract afforded three known cytochalasins including 18-metoxycytochalasin J (1), cytochalasins H (2) and J (3) together with alternariol (4). The cytochalasin compounds showed different degrees of antibacterial activities against the tested bacterial pathogens. Shigella flexneri was the most sensitive microorganism while Vibrio cholerae SG24 and Vibrio cholerae PC2 were the most resistant. Ampicillin did not show any antibacterial activity against Vibrio cholerae NB2, Vibrio cholerae PC2 and Shigella flexneri at concentrations up to 512 µg/mL, but interestingly, these multi-drug resistant bacterial strains were sensitive to the cytochalasin metabolites. These compounds also showed significant cytotoxic properties against human cancer cells (LC50 = 3.66-35.69 µg/mL) with low toxicity to normal non-cancer cells. Conclusion: The three cytochalasin compounds isolated from the Phomopsis sp. crude extract could be a clinically useful alternative for the treatment of cervical cancer and severe infections caused by MDR Shigella and Vibrio cholerae. [ABSTRACT FROM AUTHOR]

The chemical investigation of the CH 2 Cl 2 /MeOH (1:1) extract of the leaves of Rothmannia hispida (K. Schum.) Fagerl. (Rubiaceae) led to the isolation of a new ceramide rothmanniamide (1) and a naturally isolated alkyl cinnamate derivative n -heptadecyl-4-hydroxy- trans -cinnamate (2), along with fifteen known compounds including lupeol palmitate (3), lupeol (4), a mixture of uvaol (5) and erythrodiol (6), ursolic acid (7), 30- nor -2 α, 3 β -dihydroxyurs-12-ene (8), hederagenin (9), stigmast-22-en-3-ol (10), a mixture of β -sitosterol (11) and stigmasterol (12), stigmast-4,22-dien-3-ol (13), stigmasterol 3- O - β -D-glucoside (14), triacontan-1-ol (15), kaempferol 3- O - β -D-glucopyranoside (16) and D-mannitol (17). Their structures were elucidated with the help of MS and NMR data. Compounds 8 , 10 and 15 were isolated for the first time from the Rubiaceae family. The crude extract and the isolates were assessed in vitro for their antileishmanial activity against Leishmania donovani 1 S (MHOM/SD/62/1 S) promastigotes and cytotoxicity on RAW 264.7 macrophage cells. Compounds 7 and 8 exhibited a highly potent antileishmanial activity with IC 50 values of 0.88 and 1.75 μg/mL, respectively, with good selectivity indexes (SI > 57). The chemophenetic significance of these compounds is also discussed. Image 1 • New secondary metabolites in Rothmannia hispida (K. Schum.) Fagerl. (Rubiaceae). • Three compounds were isolated for the first time from the Rubiaceae family. • Antileishmanial compounds from R. hispida. • The chemophenetic significance of the isolated compounds was discussed. [ABSTRACT FROM AUTHOR]