(S)-4-{4-[(2,4-Diamino-pteridin-6-ylmethyl)-methyl-amino]-benzoylamino}-4-methylcarbamoyl-butyric acid tert-butyl ester

N--L-glutam-α-ethylamide t-butyl ester

(S)-2-{4-[(2,4-Diamino-pteridin-6-ylmethyl)-methyl-amino]-benzoylamino}-5-oxo-5-piperidin-1-yl-pentanoic acid

(S)-4-{4-[(2,4-Diamino-pteridin-6-ylmethyl)-methyl-amino]-benzoylamino}-4-isopropylcarbamoyl-butyric acid tert-butyl ester

(S)-2-{4-[(2,4-Diamino-pteridin-6-ylmethyl)-methyl-amino]-benzoylamino}-4-propylcarbamoyl-butyric acid tert-butyl ester