Analysis of molluscan sterols: Colorimetric methods

Isolation and characterization of the bioactive metabolites from the soil derived fungus Trichoderma viride

The aim of the present study was to evaluate different biological activities of Trichoderma viride fungus (Family Hypocreaceae). Trichoderma viride isolated for the first time from the cucumber soil (rhizosphere). It was tested as antimicrobial, antioxidant and anticancer agent. Trichoderma viride from the cucumber soil (rhizosphere) caused inhibition of the mycelial growth of Fusarium solani, Rhizoctonia solani and Sclerotium rolfsii. Also, the alcoholic extract of the fungal mycelia proved a potent antibacterial activity against Bacillus subtilis, Escherichia coli and Pseudomonas fluorescens. In addition, it exhibited a significant antifungal activity against Candida albicans, Fusarium solani, Fusarium oxysporium, Rhizoctonia solani and Pythium ultimum at 100 µg/disc. Study of the antimicrobial and antioxidant activities of the volatile constituents had been done. The in vitro antioxidant, anticancer and antiviral activities of the isolated proteins, and carbohydrates were determined. Furthermore, the volatile constituents were isolated from fresh mycelia of Trichoderma viride and subjected to GC/MS analysis. Total protein (10%), carbohydrate (19.57%), steroidal (13.95%) and triterpenoidal content (38.34%) were determined in the alcoholic extract of Trichoderma viride mycelia. In conclusion, this fungus showed antioxidant, anticancer, antiviral and antibacterial effects. Further studies must be done to identify the molecules responsible for its effect and to consider its application in the pharmacological and medicinal purposes.

Superheated water extraction of cholesterol from solid food

A method based on superheated water extraction has been developed for the removal of cholesterol from solid food thus providing a clean approach by avoiding the use of organic solvents. A preconcentration step was also studied with the aim of solving the problem derived from low-cholesterol-content samples and dilution effect. The research also involved the optimisation of the parameters affecting the extraction process by a central composite experimental design as well as a univariate study of the optimisation of the preconcentration step. The time required for total removal of the target compound was 60 min. The method was validated using a certified reference material (NIST-CRM 1845) and was used to analyse food samples within a wide range of cholesterol concentrations. The efficiency for the CRM was 105%. The precision of the method yielded values less than 6.5% (expressed as relative standard deviation) in all instances.

Sterol and fatty acid composition of the clam, Codakia orbicularis, with chemoautotrophic symbionts

Codakia orbicularis may obtain nutrients from chemoautolithotrophic bacteria. The chemical composition of the C. orbicularis was investigated because of this unusual source of nutrition, and because it is a human food source in the Caribbean. The lipid fraction of these molluscs is discussed in detail. Polyunsaturated fatty acids account for only 11-15% of the total fatty acids, and non-methylene interrupted dienes are present as high as 9.5%. Cholesterol represents about 45% of the total sterols present.