Identification of an acetyl disulfide derivative in the synthesis of thiosialosides.

The first report of the formation of an acetyl disulfide sialoside during the synthesis of thioglycosides is described. This compound is a by-product in the synthesis of the 2-thioacetyl sialoside commonly used in thioglycoside preparation. Our investigations into the identification of this novel disulfide are described.

A facile preparation of trehalose analogues: 1,1-thiodisaccharides.

The synthesis of 1,1-thiodisaccharide trehalose analogues in good to excellent yields by a Lewis acid (BF(3).Et(2)O)-catalysed coupling of sugar per-O-acetate with thiosugar is described. The reactivity of different sugar per-O-acetates and thiosugars is explored.

Strigol: biogenesis and physiological activity.

The role played by molecules of the strigolactone family in stimulating the germination of seeds of parasitic weeds of the genera Striga, Orobanche and Alectra has never been clearly elucidated. The biogenesis of these unusual terpenoid lactones, originally identified in minute quantities in the root exudates of a small number of host plants and two or three "false hosts", also remains obscure. These lactones, as the chemical signals which initiate the life cycle of Striga, are consequently at the forefront of the Striga research effort.

Biological properties of N-acyl and N-haloacetyl neuraminic acids: processing by enzymes of sialic acid metabolism, and interaction with influenza virus.

Several unnatural N-acyl neuraminic acids (N-propionyl, N-hexanoyl, N-benzoyl, N-trifluoroacetyl, N-chloroacetyl, N-difluoroacetyl) were prepared enzymatically using immobilised sialic acid aldolase. N-Trifluoroacetyl-, N-chloroacetyl- and N-difluoroacetyl neuraminic acids were shown to enhance up to 10-fold the rate of association of influenza virus A to a sialoglycolipid neomembrane by surface plasmon resonance, and were found to act as weak inhibitors (K(iapp) 0.45-2.