Bioassays guided isolation of compounds from Chaetomium globosum.

The aim of the present study was to evaluate different biological activities of the fungus Chaetomium globosum (family Chaetomiaceae). The evaluation was done through testing its antimicrobial, antioxidant and anticancer effects. C. globosum was isolated from the Cucumber soil (rhizosphere) and caused inhibition of the mycelial growth of Fusarium solani, Rhizoctonia solani and Sclerotium rolfsii in the biculture test. Petroleum ether and ethyl acetate extracts of the liquid culture of C. globosum showed potent in vitro antioxidant activity. C. globosum proved potent antibacterial activity against Bacillus subtilis, Escherichia coli and Pseudomonas fluorescens. It also recorded significant antifungal activity against Candida albicans, F. solani, Fusarium oxysporum, R. solani and Pythium ultimum. It exerted cytotoxic effect on human hepatocellular carcinoma cell line (HepG2). Unsaponifiable and saponifiable matters of the petroleum ether extract showed the presence of hydrocarbons, sterols and fatty acids. The ethyl acetate extract showed the presence of prenisatin, chrysophanol, chrysazin, chaetoviridin A and B. The isolated secondary metabolites proved significant antioxidant and antimicrobial activity on B. subtilis, E. coli and R. solani. In conclusion, this fungus showed different biological activities. Further studies must be done to apply its use in the agricultural and medicinal field.

Seasonal variation of the lipoidal matters and hypolipidaemic activity of the red alga Corallina officinalis L.

The lipoidal matters of Corallina officinalis L. showed a seasonal nonsignificant quantitative variation. However, the fatty acids revealed a relative increase in the summer and winter, while unsaponifiable matter exhibited a slight increase in the spring. The GC/MS analysis of saponifiable and unsaponifiable matter of the algal samples collected in different seasons revealed that samples collected in the spring contained a low cholesterol content and high steroidal compounds as well as high polyunsaturated fatty acids. The alcohol extract, hexane extract and fatty acid fraction of this algal sample exhibited a significant hypolipidaemic activity. Also, two biologically active fractions of hydrocarbons were isolated by CC technique from the hexane fraction of C. officinalis L. and identified by GC/MS.

Biologically active steroid from the green alga Ulva lactuca.

The marine green alga, Ulva lactuca, was shown to contain 3-O-beta-D glucopyranosyl-stigmasta-5,25-dien. The structure of the compound was established on the basis of its spectroscopic data and it was extracted for the first time from this alga. The topical antiinflammatory activity of this compound was examined using the mouse ear oedema assay as an experimental model of topical inflammation. Also, the antimicrobial activity of the isolated compound was tested against 10 various microorganisms (G+, G-, fungi and yeast strains).