title: Synthesis and antioxidant activity of thymol and carvacrol based Schiff bases.
abstract: Thymol and carvacrol are well known antioxidants found in the extract of the plants of thyme species. The Schiff bases of 2-iso-propyl-5-methyl-phenol (thymol/1a), 2-tert-butyl-5-methyl-phenol (1b) and 5-iso-propyl-2-methyl-phenol (carvacrol/1c) exhibited much better antioxidant activity than thymol and carvacrol in DPPH assay. Ten compounds (4k, 4l, 4r, 5k, 5l, 5q, 5r, 6k, 6l and 6r) showed better or similar activity as compared to the reference compound ascorbic acid. Twenty-four most active compounds were also screened by ABTS method and showed 60-90% inhibition at 5 μg/mL concentration.
authors.affiliation: Department of Chemistry, University of Delhi, Delhi 110007, India.
authors.lastname: Beena
authors.forename: Deepak
authors.initials: D
authors.lastname: Kumar
authors.forename: Diwan S
authors.initials: DS
authors.lastname: Rawat
mesh_terms: D000975:Antioxidants / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D001205:Ascorbic Acid / Q000494:pharmacology; D000081007:Cymenes; D020128:Inhibitory Concentration 50; D039821:Monoterpenes / Q000737:chemistry*; D012545:Schiff Bases / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D013943:Thymol / Q000737:chemistry*; D046930:Thymus Plant / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D000081007:Cymenes; D039821:Monoterpenes; D012545:Schiff Bases; D013943:Thymol; C073316:carvacrol; D001205:Ascorbic Acid