ISOLATION OF AN INHIBITOR OF GROWTH AND ROOT FORMATION FROM PORTULACA GRANDIFLORA LEAVES1

Abstract

1. From leaves of Portulaca grandiflora, a substance which inhibited the IAA-induced elongation of Avena coleoptile sections and the adventitious root formation of Raphanus hypocotyl cuttings was separated by means of thin layer chromatography. It was isolated and crystallized. 2. On paper chromatograms, this substance gave the same R_f values as the inhibitor from leaves of Xanthium strumarium and that from leaves of Helianthus tuberosus (“heliangine”), namely, R_f0.9 in ammoniacal isopropanol, R_f 0.85 in methanol-water and R_f 0.0 in n-hexane-water. On thin layer chromatograms, however, these inhibitors were clearly separated from each other. 3. Infra-red absorption spectrum also indicated that this substance is identical with neither xanthinin nor heliangine.