M. Katayama et al., SYNTHESIS AND BIOLOGICAL-ACTIVITIES OF 5,6-DIFLUOROINDOLE-3-ACETIC ACID - A NEW FLUOROINDOLE AUXIN, Nippon Noyaku Gakkaishi, 23(3), 1998, pp. 289-295
5,6-Difluoroindole-3-acetic acid (5,6-F-2-IAA, 1), a new fluoroindole
auxin synthesized via Fischer's indolization, has much a stronger elon
gation activity on At ena coleoptile segments than indole-3-acetic aci
d (IAA). Although the optimal concentration of 5,6-F-2-IAA for Avena c
oleoptile elongation was much higher than that of 5,6-Cl-2-IAA, the ex
tent of elongation was much greater. 5,6-F-2-IAA also induces the form
ation and promotes the growth of lateral roots of mung bean seedlings.
Of the synthetic monofluoro- and difluoro-IAAs, it had the strongest
inhibitory activity on hypocotyl growth of Chinese cabbage. It also is
moderately resistant to peroxidase oxidation.