Synthesis and evaluation of diastereoisomeric alkylating pseudo-disaccharides as potential affinity reagents for trehalase.

Reaction of (+/-)-(3/4,5,6)-4-bromo-5,6-epoxy-3-hydroxycyclohexene with 2,3,4,6-tetra-O-acetyl-1-thio-alpha-D-glucopyranose, followed by treatment of the resulting isolated diastereoisomeric 4-bromo-3,5-dihydroxycyclohexene 1-thioglycoside derivatives with base under phase-transfer conditions, gave (R)- and (S)-(3,4,6/5)-3,4-epoxy-6-S-(1-thio-alpha-D-glucopyranosyl)-5- hydroxycyclohexene. None of them was substrate or inhibitor for cockchafer trehalase.

Spacer-modified disaccharide and pseudo-trisaccharide methyl glycosides that mimic maltotriose, as competitive inhibitors for pancreatic alpha-amylase: a demonstration of the "clustering effect".

The synthesis is reported of methyl 4,4'-dithio-alpha-maltotrioside (12) and the spacer-modified disaccharide glycosides methyl 4-S-(4-alpha-D-glucopyranosylthio-2-hydroxybutyl)-4-thio-alpha -D-glucopyranoside (20) and methyl 4-S-[(1,5/4,6)- and (4,6/1,5)-4-alpha-D-glucopyranosylthio-5,6-dihydroxy-2- cyclohexen-1-yl]-4-thio-alpha-D-glucopyranoside (29a/b), which are analogues of methyl alpha-maltotrioside. The Ki values for alpha-amylase for these compounds were determined as were those of methyl alpha-maltotrioside and maltose.