Understanding the Protox Inhibition Activity of Novel 1-(5-methyl-3-phenylisoxazolin-5-yl)methoxy-2-chloro-4-fluorobenzene Derivatives Using Holographic Quantitative Structure-Activity Relationship (HQSAR) Methodology

Holographic quantitative structure activity relationships (HQSAR) as 2D QSAR between the herbicidal activities against root and shoot of rice plant (Orysa sativa L.) and barnyardgrass (Echinochloa crus-galli), and structures of A=3,4,5,6-tetra-hydrophthalimino, B = 3-chloro-4,5,6,7-tetrahydro-2H-indazolyl and C = 3,4-dimethylmaleimino substituents in 1-(5-methyl-3-phenylisoxazolin-5-yl)methoxy-2-chloro-4-fluorobenzene derivatives were studied and discussed. The statistical results of four HQSAR models for the herbicidal activities against root and shoot of the two plants showed the best predictability of the herbicidal activities based on the cross-validated $r^2\;_{cv}\;(q^2=\;0.760{\sim}0.924)$, non cross-validated conventional coefficient $(r^2\;_{ncv}\;=\;0.868{\sim}0.970)$ and PRESS values $(0.123{\sim}0.261)$. The results indicated that the qualities of HQSAR models for barnyardgrass were slightly higher than that of rice plant. And also, the predictability of HQSAR models were higher $(q^2\;=\;HQSAR\;>\;CoMFA)$ than CoMFA but the conventional coefficients of HQSAR models lower $(r^2\;=\;HQSAR\;<\;CoMFA)$ than CoMFA. Moreover, from the contribution maps, it was founded that the selectivity between the two plants depends upon the 2-fluoro-4-chloro-5-alkoxyanilino and $R_3$ substituent on the C-phenyl ring. These features suggest where to modify a molecular structure in order to improve its selective of herbicidal activities against barnyardgrass.

홀로그램(H) QSAR 방법에 따른 1-(5-methyl-3-phenylisoxazolin-5-yl)methoxy-2-chloro-4-fluorobenzene 유도체들의 Protox 저해 활성에 관한 이해

HQSAR 방법으로 일련의 새로운 1-(5-methyl-3-phenylisoxazolin-5-yl)methoxy-2-chloro-4-fluorobenzene 유도체들중 A = 3,4,5,6-tetrahydrophthalimino, B = 3-chloro-4,5,6,7-tetrahydro-2H-indazolyl 및 C = 3,4-dimethylmaleimino 치환체들의 구조 변화에 따른 벼(Orysa sativa L.)와 논피(Echinochloa crus-galli) 뿌리와 줄기부위 사이의 살초활성 관계를 연구하였다. 두 가지 초종의 뿌리와 줄기의 살초활성에 대하여 유도된 4개의 HQSAR 모델들은 예측성, cross-validated $r^2\;_{cv.}$값$(q^2\;=\;0.760{\sim}0.924)$, non-cross-validated 상관계수$(r^2\;_{cv.}\;=\;0.868{\sim}0.970)$ 및 PRESS 값$(0.123{\sim}0.261)$에 근거하여 매우 양호한 통계값들을 나타내었다. 유도된 HQSAR 모델들은 벼 보다는 논피에 대하여 양호한 경향을 나타내었으며 CoMFA 모델에 비하여 예측성은 좋았으나$(q^2\;=\;HQSAR\;>\;CoMFA)$ 저해활성과의 상관성은 약간 낮은$(r^2\;=\;HQSAR\;<\;CoMFA)$ 경향이었다. 또한, HQSAR 기여도로부터 논피에 대한 선택적인 살초활성은 2-fluoro-4-chloro-5-alkoxy anilino 및 C-phenyl 고리상 $R_3-$치환기에 의존적임을 알았다.