N-epsilon-(indole-3-acetyl)-L-Lysine (epsilon-IAA-Lys) and its N-alpha
-acetyl derivative (Ac-epsilon-IAA-Lys), products of the metabolism of
indole-3-acetic acid (IAA) in Pseudomonas syringae subsp. savastanoi,
have been synthesized by a conjugation of IAA with the N-alpha-CBZ-L-
lysine p-nitrophenylester. The same synthetic strategy was used to obt
ain the unnatural conjugate, N-alpha-(indole-3-acetyl)-L-lysine (alpha
-IAA-Lys) and its N-epsilon-acetyl derivative (Ac-alpha-IAA-Lys). Comp
arative bioassay for auxin activity on wheat coleoptiles proved that e
psilon-IAA-Lys and Ac-epsilon-IAA-Lys significantly stimulated their g
rowth, although their activity was considerably less than IAA. No acti
vity was shown by alpha-IAA-Lys and Ac-alpha-IAA-Lys.