New phytoconstituents, anti-microbial and cytotoxic activities of Acacia etbaica Schweinf.

Acacia etbaica is wild plant growing in the desert of Egypt, and it has folkloric medicinal uses. Phytochemical investigation of Acacia etbaica extracts led to the isolation and identification of seven compounds. Among these compounds are three new simple phenolics: Resacetophenone-6-methyl [1], Resorcinol [2], Resorcinol-O- ß -Glucoside [3]; phenolic ester; and other four known compounds: Methylparaben [4]; two chromones, Noreugenin [5], Eugenin [6]; and one cyclitol: pinitol [7]. Compounds [1-3] isolated and identified for the first time from natural origin. In contrast, compounds [4-6] isolated for the first time from the family Fabaceae. The biological investigation was conducted on plant extracts and showed that the methylene chloride extract had a strong efficacy against Bacillus subtilis and good activity against Candida albicans. In contrast, the n-butanol extract showed extreme cytotoxic activity against Mammary gland breast cancer (MCF-7), and strong activity against Hepatocellular carcinoma (HEPG-2), and Colorectal carcinoma (HCT-116) cell lines.

Antileukemic α-pyrone derivatives from the endophytic fungus Alternaria phragmospora.

Four new (1-4) and two known (5 and 6) α-pyrone derivatives have been isolated from Alternaria phragmospora, an endophytic fungus from Vinca rosea, leaves. The isolated compounds were chemically identified to be 5-butyl-4-methoxy-6-methyl-2H-pyran-2-one (1), 5-butyl-6-(hydroxymethyl)-4-methoxy-2H-pyran-2-one (2), 5-(1-hydroxybutyl)-4-methoxy-6-methyl-2H-pyran-2-one (3), 4-methoxy-6-methyl-5-(3-oxobutyl)-2H-pyran-2-one (4), 5-(2-hydroxyethyl)-4-methoxy-6-methyl-2H-pyran-2-one (5), and 5-[(2E)-but-2-en-1-yl]-4-methoxy-6-methyl-2H-pyran-2-one (6). Compounds 2 and 4 showed moderate antileukemic activities against HL60 cells with IC50 values of 2.2 and 0.9 µM and against K562 cells with IC50 values of 4.5 and 1.5 µM, respectively.

Nigrosphaerin A a new isochromene derivative from the endophytic fungus Nigrospora sphaerica.

Nigrosphaerin A, a new isochromene derivative (1), was isolated from the endophytic fungus Nigrospora sphaerica and chemically identified as 3-(3,4-dihydroxyphenyl)-4,6,8-trihydroxy-1H-isochromen-1-one-6-O-ß-d-glucopyranoside. In addition nineteen known compounds (2-20) were isolated from the same fungus and chemically identified. Compounds (1-3, 5, and 7-16) were isolated for the first time from this fungus. In vitro antileukemic, antileishmanial, antifungal, antibacterial and antimalarial activities of (1-20) were examined. Compounds 5, 7, 9 and 10 showed good antileukemic activity against HL60 cells with IC50 values of 0.03, 0.39, 0.2 and 0.4 µg/mL, respectively and against K562 cells with IC50 values of 0.35, 0.35, 0.49 and 0.01 µg/mL, respectively. Compounds 3, 4 and 6 showed moderate antileishmanial activity with IC50 values of 30.2, 26.4 and 36.4 µg/ml, respectively. Compound 7 showed moderate antifungal activity against Cryptococcus neoformans with IC50 value of 14.8 µg/mL.

Steroidal saponins from the aerial parts of Tribulus alatus Del.

Six steroidal glycosides (1-6) were isolated from the aerial parts of Tribulus alatus Del. (Zygophyllaceae), together with one known cholestane, one spirostane, and six flavonol glycosides. Among them, 1 and 2 possess a furostane-type aglycone, 3 and 6 a cholestane structure, and 4 and 5 a spirostane skeleton. Their structural elucidation was accomplished by extensive spectroscopic methods including 1D ((1)H, (13)C, (13)C DEPT, TOCSY, ROESY) and 2D NMR experiments (DQF-COSY, HSQC, HMBC) as well as ESI-MS analysis.