(S)-Nα-tert-butoxycarbonyl-N1,β,β-trimethyltryptophan

(2S)-2-[(benzothiazole-2-sulfonyl)amino]-3-methyl-3-(1-methylindol-3-yl)butyramide

(2S)-2-amino-3-methyl-3-(1-methylindol-3-yl)butyronitrile

N-[(1'R)-2'-hydroxy-1'-phenylethyl]-(2S)-2-amino-3-methyl-3-(1-methylindol-3-yl)butyramide

(2S)-2-[(benzothiazole-2-sulfonyl)methylamino]-3-methyl-3-(1-methylindol-3-yl)butyramide