157973-91-6 4-((1,1-Dimethylethoxy)carbonyl)-tryptophyl-lysyl(2-tolylaminocarbonyl)amino-1-(benzylcarbamoylmethyl)pyrrolidin-2-one 4-Boc-trp-lys(tac)amino-1-(benzylcarbamoylmethyl)pyrrolidin-2-one Bootlabcap