Renée Vanhaelen-Fastré

Direct coupling of high-speed counter-current chromatography to thin-layer chromatography. Application to the separation of asiaticoside and madecassoside from Centella asiatica

Abstract The direct coupling of high-speed counter-current chromatography to thin-layer chromatography is proposed as an efficient method for the on-line monitoring of the column effluent. It requires a simple adaptation of the fittings of a Linomat C device without modification of the software. An application to the separation of asiaticoside and madecassoside from a crude extract of Centella asiatica is presented.

Volatile constituents of Trichothecium roseum

In the course of investigation of Trichothecium roseum (Fungi Imperfecti) for its attractancy against Tyrophagus putrescentiae (cheese mite), the twenty following volatile compounds produced at a very low concentration by the microfungus were identified by gc, gc/ms, gc/c.i.ms and tlc: 3-methyl-1-butanol, 3-octanone, 1-octen-3-one, 3-octanol, octa-1,5-dien-3 one, 1-octen-3-ol, 6-methyl-5-hepten-2-ol, octa-1,5-dien-3 ol, furfural, linalool, linalyl acetate, terpineol (alpha and beta) citronellyl acetate, nerol, citronellol, phenylacetaldehyde, benzyl alcohol geranyl acetate, 1-phenyl ethanol and nerolidol. Octa-1,5-dien-3-ol and octa-1,5-dien-3-one have not been previously isolated from fungi; octa-1,5-dien-3-ol is the most potent attractant amount the volatile compounds detected by gc.

Occurrence in mushrooms (Homobasidiomycetes) of cis- and trans-octa-1,5-dien-3-ol, attractants to the cheese mite Tyrophagus putrescentiae (Schrank) (Acarina, Acaridae)

Cis- and trans-octa-1,5-dien-3-ol were identified in 15 Homobasidiomycetes; these compounds exhibited a significant attraction for the cheese miteTyrophagus putrescentiae (Schrank) (Acarina, Acaridae).

High-performance liquid chromatography determination of potential content of vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol) in resins, oils, dry concentrates and multivitamin formulations

The determination of potential vitamin D concentrations in raw materials and in multivitamin formulations by high-performance liquid chromatography is reported. Simple experimental conditions allow the rapid separation of the vitamins from their respective pro- and pre-vitamins, from their irradiation side-products and from some of their overirradiation products. Vitamin extraction is performed directly from dry concentrates, tablets and capsules, without saponification; all procedures are carried out at room temperature so as to preserve the ratio of vitamin D and pre-vitamin D present in the prepatation. The relative standard deviation is less than 1.5%.