Convenient synthesis and evaluation of glycosidase inhibitory activity of alpha- and beta-galactose-type valienamines, and some N-alkyl derivatives.

Valienamine analogues having alpha- and beta-galactose-type structures were synthesized by racemic modification from (1SR,2RS,3SR)-6-methylenecyclohex-4-ene-1,2,3-triol. Four N-alkyl derivatives of the beta-anomer were readily prepared selectively by treatment of key intermediate 2,6-di-O-acetyl-3,4-O-isopropylidene-5a-carba-alpha- and beta-l-arabino-hex-5(5a)-enopyranosyl bromides with alkyl amines. All compounds were assayed for inhibitory activity against six glycosidases, and the N-dodecyl derivative was shown to be a very strong inhibitor of beta-galactosidase (IC(50) 0.01 microM, bovine liver).