Synthesis and quantative structure-activity relationships on the antifungal activity of 3-phenylisoxazol and 3-phenyl-2,5-dihydro-5-isoxazolone derivatives

3-phenylisoxazole 및 3-phenyl-2,5-dihydroisoxazol-5-one 유도체의 합성과 살균활성에 관한 구조-활성관계

  • Sung, Nack-Do (Division of Applied Biology & Chemistry, College of Agriculture, Chung-nam National University) ;
  • Yu, Seong-Jae (Division of Applied Biology & Chemistry, College of Agriculture, Chung-nam National University) ;
  • Lee, Hee-Chul (Dongbu Fine Chemicals Co., Chungcheong Province Technology Diffusion Center)
  • 성낙도 (충남대학교 농과대학 응용생물화학부) ;
  • 유성재 (충남대학교 농과대학 응용생물화학부) ;
  • 이희철 (동부정밀화학(주) 충청기술보급센타)
  • Published : 2001.12.31

Abstract

A series of new 2-benzoyl-3-phenyl-2,5-dihydroisoxazol-5-one, (A) and 3-phenyl-5-phenylcarbonyl-oxyisoxazole, (B) derivatives as substrates were synthesized and their quantitative structure-activity relationships (QSAR) analyses between the antifungal activities ($pI_{50}$) and physicochemical parameters of substituents onl the benzoyl group against resistant (RPC:95CC7303) and sensitive (SPC:95CC7105) Phytophthora blight (Phytophthora capsici,) were studied. The synthetic yield (%) and antifungal activities of (A) were higher than (B) and selectivities between the fungi were not showed. From the basis on the Hansch-Fujita analyses, the optimum width values ($(B_2)_{opt.}=ca.\;4.00{\AA}$) of the substituents on the benzoyl group were important factor in determining fungicidal activity against the two fungi. Influence of the substituents as electron withdrawing group on the fungicidal activity against RPC, but not for SPC. And tile bromo- and acetyl-substituents were contributed to higher antifungal activity against RPC and SPC from the results of Free-Wilson analyses.

Keywords

2-benzoyl-3-phenyl-2,5-dihydroisoxazol-5-ones;3-phenyl-5-phenylcarbonyloxyisoxazoles;Resistant & sensitive Phytophthora capsici;QSARs