DIDANOSINE PRECURSOR DRUG AND ITS PREPARATION METHOD

摘要

The present invention provides a didanosine precursor drug which is used as anti-AIDS agent and characterized in that 5'-hydroxyl of didanosine is esterified by L-amino acid. The didanosine precursor drug has structural formula I, in which R is L-amino acid residue, preferably is L-valine, L-isoleucine, L-phenylalanine, L-proline or L-tryptophane. Compared with didanosine, the present compounds possess enhanced Caco-2 membrane permeability and oral bioavailability.