SYNTHESIS OF DIPHENYL PHOSPHONATE ANALOGS OF TYROSINE AND TRYPTOPHAN AND DERIVED PEPTIDES AS CHYMOTRYPSIN INHIBITORS

The synthesis of alpha-aminophosphonate analogues of tyrosine and tryp tophan, e.g. 4 and 5 respectively, and their incorporation into prolin e-containing dipeptides is reported; of the sequences synthesised, the dipeptide Z-Pro-Trp(P)(OPh)(2) is the only derivative that functions as an irreversible inactivator of the serine proteinase chymotrypsin, in contrast, the tyrosine analogue 4 behaves as a competitive reversib le inhibitor of the enzyme and the tryptophan analogue 5 behaves as a slow-binding inhibitor.