일련의 새로운 N-치환-phenyl-3,4,5,6-tetrahydrophthalimide 유도체를 합성하여 $R_2=Sub.X$ 치환기들의 변화에 따르는 발아 전, 벼(Oryza sativa L.)와 논피(Echinochloa crus-galli) 의 줄기와 뿌리에 대한 생장 저해활성 $(pI_{50})$과의 관계 (QSAR)는 물론, 기질 유도체와 protox의 기질인 protogen 분자 사이의 구조적인 분자 유사성을 연구하였다. 두 초종간 및 부위별, 생장 저해활성은 비례관계를 보였으며 벼 보다는 논피에 대하여 약간 강한 저해활성을 나타내었다. QSAR식으로부터 논피의 생장 저해활성은 기질 분자중 음으로 하전된 원자들의 표면적이 클수록 증가하므로 $R_2=Sub.X$ 치환기로서 전자 밀게가 치환되어야 할 것으로 추측되었다. 또한, 기질 유도체와 protogen 분자 사이의 유사성을 검토한 결과, 기질 유도체들의 유사성 지수(S)는 대략 0.8 이상으로 비교적 큰 유사성을 나타내었으나 두 초종의 생장 저해활성과의 상관성은 낮은 편이었다.
To improve the growth inhibitory activity against the shoot and root of rice plant (Oryza sativa L) and barnyard grass (Echinochloa crus-galli), a series of N-substituted phenyl-3,4-dimethylmaleimdes derivatives as substrates were synthesized and then their the inhibitory activities of protoporphyrinogen oxidase (1.3.3.4), protox were measured. The quantitative structure-activity relationships (QSAR) between structures and the inhibitory activities were studied quantitatively using the 2D-QSAR method. And also, molecular sharp similarity between the substrate derivatives and protogen, substrare of protox enzyme were studied. The activities of the two plants indicated that barnyard grass had a higher activity than the rice plant and their correlation relationships have shown in proportion for each. Accordingly, the results of SARs suggest that the electron donating groups as $R_2=Sub.X$ group will bind to phenyl ring because the bigger surface area of negative charged atoms in the substrate molecule derivatives may increase to the higher the activity against barnyard grass. Based on the molecular shape similarity, when the derivatives and protogen, subsbrate of protox enzyme were superimposed by atom fitting, the similarity indices (S) were above 0.8 level but the correlation coefficients (r) between S values and the activities showed not good.
