1 VSC N-[N'-benzyloxycarbonyl-phenylalaninyl]-3-amino-5-phenyl-pentane-1-sulfonic acid phenyl ester 1.000 2 VS3 3-[N-[benzyloxycarbonyl]-phenylalaninyl-amino]-5-phenyl-pentane-1-sulfonic acid 4-nitro-phenyl ester 0.935 3 VS2 3-[N-[benzyloxycarbonyl]-phenylalaninyl-amino]-5-phenyl-pentane-1-sulfonylmethylbenzene 0.720