260963-96-0Relevant academic research and scientific papers
Synthesis and biological activity of 3'-chloro, -bromo, and - iodoabscisic acids, and biological activity of 3'-fluoro-8'-hydroxyabscisic acid
Arai, Sho,Todoroki, Yasushi,Ibaraki, Satomi,Naoe, Yoshikazu,Hirai, Nobuhiro,Ohigashi, Hajime
, p. 1185 - 1193 (1999)
(+)-3'-Chloro, -bromo and -iodoabscisic acids were synthesized, and their biological activities and metabolism were examined, as well as that of (+)-3'-fluoroabscisic acid. This was in order to estimate the effects of altered electron density at the C-2' position of abscisic acid on both biological activity and metabolic stability. The biological activities of (+)-3'-chloro and bromoabscisic acids were similar to, or higher than, those of (+)-abscisic acid in four bioassays, while (+)-3'-iodoabscisic acid was more potent in two bioassays and less potent than (+)-abscisic acid in the other two bioassays. The biological activities of 3'-haloabscisic acids seem to be dependent on the 3'-halogens, but not on the electron density at C-2'. The metabolism of (+)3'-haloabscisic acids to ca. 50% of their original levels in the media of rice cell suspension culture was similar to that of (+)abscisic acid. Metabolites from (+)-3'-chloro, -bromo and -iodoabscisic acids were not found in the culture media and cells, while (+)-3'- fluoroabscisic acid gave (+)-3'-fluoro-8'-hydroxyabscisic acid as a stable metabolite. (+)-3'-fluoro-8'-hydroxyabscisic acid showed biological activities lower than (+)-3'-fluoroabscisic acid, but higher than (-)-3'α- Fluorophaseic acid. These findings suggested that the biological activity of (+)-8'-hydroxyabscisic acid is intermediate between those of (+)abscisic acid and (-)-phaseic acid. Abscisic acid may be inactivated in a stepwise manner by metabolism in plants.
