Brassinolide-like activity of castasterone analogs with varied side chains against rice lamina inclination

Autor: Shinri Horoiwa, Bunta Watanabe, Yoshiaki Nakagawa, Shuji Yamamoto, Hisashi Miyagawa, Airi Sugiura, Takanori Aoki, Taiyo Yokoi
Rok vydání: 2017
Předmět:
Zdroj: Bioorganicmedicinal chemistry. 25(17)
ISSN: 1464-3391
Popis: Brassinolide (BL) and castasterone (CS) are the representative members of brassinosteroid class of plant steroid hormone having plant growth promoting activity. In this study, eleven CS analogs bearing a variety of side chains were synthesized to determine the effect of the side chain structures on the BL-like activity. The plant hormonal activity was evaluated in a dwarf rice lamina inclination assay, and the potency was determined as the reciprocal logarithm of the 50% effective dose (ED50) from each dose-response curve. The reciprocal logarithm of ED50 (pED50) was decreased dramatically upon deletion of the C-28 methyl group of CS. The introduction of oxygen-containing groups such as hydroxy, methoxy, and ethoxycarbonyl was also unfavorable to the activity. The pED50 was influenced by the geometry of carbon-carbon double bond between C-24 and C-25 (cis and trans), but the introduction of a fluorine atom at the C-25 position of the double bond did not significantly change the activity. The binding free energy (ΔG) was calculated for all ligand-receptor binding interactions using molecular dynamics, resulting that ΔG is linearly correlated with the pED50.
Databáze: OpenAIRE