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성낙도 ( Nack-do Sung ),정훈성 ( Hoon-sung Jung ),김상진 ( Sang-jin Kim ) 대한화장품학회 2004 대한화장품학회지 Vol.30 No.4
일련의 Alkyl-3,4-dihydroxybenzoate (A)와 N-Alkyl-3,4-dihydroxybenzamide (B) 유도체들의 치환기(R<sub>1</sub> 및 R<sub>2</sub>) 변화에 따른 멜라닌생성 저해활성 관계들을 HQSAR 방법으로 분석하였다. 멜라닌생성 저해활성에 관하여 유도된 HQSAR 모델은 매우 양호한 예측성(cross-validated r<sup>2</sup><sub>cv.</sub>, q<sup>2</sup>=0.674)과 적합성(non-cross-validated, r<sup>2</sup><sub>ncv</sub>=0.936)을 나타내었다. 멜라닌생성 저해활성과 가수분해 반응성은 공히, (A)가 (B)보다 컸으며(A>B), R<sub>1</sub>-치환기가 R<sub>2</sub>-치환기보다 저해활성에 의존적인 경향을 나타내었다(R<sub>1</sub>>R<sub>2</sub>). 또한, 경계분자궤도(FMO) 이론에 따라 가수분해 반응은 (A), (B)의 LUMO와 물분자의 HOMO 사이에 강한 상호작용으로 orbital-control 반응인 친핵성 첨가-제거반응(Ad<sub>N-E</sub>)이 주로 일어나는 것을 알 수 있었다. Holographic quantitative structure activity relationships (HQSAR) between the melanogenesis inhibitory activities of alkyl-3,4-dihydroxybenzoate (A) and N-Alkyl-3,4-dihydroxybenzamide (B) derivatives were analyzed and discussed. The statistical results of HQSAR model for the activities showed the best predictability of the activities based on the cross-validated r<sup>2</sup><sub>cv</sub>(q<sup>2</sup>=0.674), non-cross-validated, conventional coefficient (r<sup>2</sup><sub>ncv</sub>=0.936). The melanogenesis inhibitory activities and hydrolytic reactivity of (A) were slightly higher than that of (B) (A>B) and the activities depends upon the R<sub>1</sub>-substituents (R<sub>1</sub>>R<sub>2</sub>). It has been found using frontier molecular orbital (FMO) theory that the hydrolysis reactions of (A) and (B) proceeded to an orbital-controlled reactions, while the nucleophillc addition-elimination reactions (Ad<sub>N-E</sub>) between LUMO energy of (A) and (B) and HOMO energy of water molecule are occurred.
성낙도(Nack-Do Sung),송종환(Jong-Whan Song) 한국농약과학회 2000 농약과학회지 Vol.4 No.2
The herbicidal activities (pI??) with alkoxy (RO-) groups on the azomethine nitrogen atom in 5-(2,3-dihydro-2,2-dimethylbenzothiophene-7-y1)-2-(1-(alkoxyimino)-butyl)-3-hydroxy-2-cyclohexene-1-one derivatives against various weeds were measured in the flooded and in the paddy conditions. Particularly, i-propoxy substituent, 5 of them showed excellent herbicidal activity at a rate of 4㎏/㏊ with pre-emergence against barnyard grass (Echinochlora crus-galli) with good selectivity on rice plant (Oryza sativa). The results of the structure-activity relationships (SAR) analyses are shown that the alkyl subsituents with higher hydrophobicity (logP>0) and electron donating (σ*<0) group as a new substrate rather than alkoxy substituents seems to be contribute to the herbicidal activity with pre-emergence.