The reaction of 2,3,4-tri-O-acetyl-b-D-xylopyranosyl isothiocyanate 1 and 2-amino-4/6-substituted benzothiazoles 2a～2e gave xylopyranosylthioureas 3a～3e, which then reacted with alkyl/aryl amine in the presence of HgCl₂ to afford a series of new guanidinoxylopyranosides (4a～4e, 5a～5e, 6a～6e and 7a～7e). The structures of the new compounds were established on the basis of elemental analyses, IR, ¹H NMR and mass spectral data and all compounds took b-configuration. The biological activities of these compounds have been evaluated. Compounds 4c, 5b, 6b～6d and 7b showed anti-HIV-1 PR activity.

Key words: xylopyranosyl isothiocyanate, xylopyranosylthiourea, guanidinoxylopyranoside, anti-HIV-1 PR activity