Synthesis of N-, S-, and C-glycoside castanospermine analogues with selective neutral alpha-glucosidase inhibitory activity as antitumour agents.

sp(2)-Iminosugar-type castanospermine analogues bearing an alpha-configured N-, S-, or C-linked pseudoanomeric group have been designed as selective inhibitors of the neutral alpha-glucosidases involved in N-glycoprotein processing; evaluation in breast cancer cell growth indicated a significant antiproliferative potential that was dependent on the nature of the pseudoanomeric group.