Theoretical elucidation on structure–Antioxidant activity relationships for indolinonic hydroxylamines

• Published in: Bioorganic & medicinal chemistry letters Vol. 12; no. 2; pp. 225 - 227
• Main Authors: Zhang, Hong-Yu, Wang, Lan-Fen
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 21.01.2002; Elsevier
• Subjects: Antioxidants - chemistry; Antioxidants - pharmacology; Biological and medical sciences; Free Radical Scavengers - chemistry; Free Radical Scavengers - pharmacology; General and cellular metabolism. Vitamins; Hydroxylamines - chemistry; Hydroxylamines - pharmacology; Indoles - chemistry; Medical sciences; Pharmacology. Drug treatments; Structure-Activity Relationship; Enthalpy; Chain length; Imine; Antioxidant; Radical scavenger; Modeling; Free radical; Side chain; Synthetic product; Structure activity relation; Molecular model; Ketimine; Density functional method; Indole derivatives; Thermodynamic properties; Organic hydroxylamine
• ISSN: 0960-894X; 1464-3405
• DOI: 10.1016/S0960-894X(01)00724-7

Indolinonic hydroxylamines (IH), representing a new type of antioxidants, are comparative to α-tocopherol to protect lipids from oxidation. To elucidate the structure–activity relationship for IH, B3LYP/6-31G(d, p) method was employed to calculate the O–H bond dissociation enthalpy (BDE), a theoretical parameter to characterize the free radical scavenging activity. By constructing several model molecules, it was revealed that hydroxylamine was the key structural factor for this type of antioxidants, and substituents had little effect on the O–H BDE. If the NR of IH was substituted by O, its activity got lower. Structure–antioxidant activity relationships for indolinonic hydroxylamines were elucidated by B3LYP/6-31G(d, p) calculations.