Mattias U. Roslund

Acyl Group Migration and Cleavage in Selectively Protected β-d-Galactopyranosides as Studied by NMR Spectroscopy and Kinetic Calculations

The migration of acetyl, pivaloyl, and benzoyl protective groups and their relative stabilities at variable pH for a series of beta- d-galactopyranoses were studied by NMR spectroscopy. The clockwise and counterclockwise migration rates for the different ester groups were accurately determined by use of a kinetic model. The results presented provide new insights into the acid and base stabilities of commonly used ester protecting groups and the phenomenon of acyl group migration and may prove useful in the planning of synthesis strategies.

Evaluation of Immunostimulatory Activities of Synthetic Mannose-Containing Structures Mimicking the β-(1→2)-Linked Cell Wall Mannans of Candida albicans

ABSTRACT Immunostimulatory properties of synthetic structures mimicking the β-(1→2)-linked mannans of Candida albicans were evaluated in vitro. Contrary to earlier observations, tumor necrosis factor (TNF) production was not detected after stimulation with mannotetraose in mouse macrophages. Divalent disaccharide 1,4-bis(α-d-mannopyranosyloxy)butane induced TNF and some molecules induced low levels of gamma interferon (IFN-γ) in human peripheral blood mononuclear cells (PBMC).

New nucleoside analogs from 2-amino-9-(β-D-ribofuranosyl)purine

Four novel derivatives of 2-amino-9-(β-D-ribofuranosyl)purine (1) were synthesised and fully characterised. When 1 was reacted with chloroacetaldehyde (a), 2-chloropropanal (b), bromomalonaldehyde (c) and a mixture of chloroacetaldehyde + malonaldehyde (d), 3-(β-D-ribofuranosyl)-imidazo-[1,2a]purine (2), 3-(β-D-ribofuranosyl)-5-methylimidazo-[1,2a]purine (3), 3-(β-D-ribofuranosyl)-5-formylimidazo-[1,2a]purine (4) and 9-(β-D-ribofuranosyl)-2-(3,5-diformyl-4-methyl-1,4-dihydro-1-pyridyl)purine (5) were formed, respectively. The products were isolated, purified by chromatography and characterised by MS, complete NMR assignment as well as fluorescence and UV spectroscopy. The yields of these reactions were moderate (14–20%). The fluorescence properties differed from those of the starting compound and the quantum yields were considerably lower.