Enantioselective synthesis and antioxidant activity of 3-(3,4-dihydroxyphenyl)-glyceric acid--basic monomeric moiety of a biologically active polyether from Symphytum asperum and S. caucasicum.
The racemic and enantioselective synthesis of a novel glyceric acid derivative, namely, 2,3-dihydroxy-3-(3,4-dihydroxyphenyl)-propionic acid as well as the antioxidant activities is described. The virtually pure enantiomers, (+)-(2R,3S)-2,3-dihydroxy-3-(3,4-dihydroxyphenyl)-propionic acid and (-)-(2S,3R)-2,3-dihydroxy-3-(3,4-dihydroxyphenyl)-propionic acid were synthesized for the first time via Sharpless asymmetric dihydroxylation of trans-caffeic acid derivatives using the enantiocomplementary catalysts, (DHQD)(2)-PHAL and (DHQ)(2)-PHAL. The determination of enantiomeric purity of the novel chiral glyceric acid derivatives was performed by high-performance liquid chromatographic techniques on the stage of their alkylated precursors. The novel glyceric acid derivatives show strong antioxidant activity against hypochlorite and N,N-diphenyl-N-picryl-hydrazyl free radical. Their antioxidant activity is about 40-fold higher than that of the corresponding natural polyether and three-fold higher of trans-caffeic acid itself.
Kutateladze Institute of Pharmacochemistry, Laboratory of Plant Biopolymers, 0159 Tbilisi, Georgia. maiamer@hotmail.com
Maia
M
Merlani
Vakhtang
V
Barbakadze
Lela
L
Amiranashvili
Lali
L
Gogilashvili
Elina
E
Yannakopoulou
Kyriakos
K
Papadopoulos
Bezhan
B
Chankvetadze
D001713:Biphenyl Compounds / Q000737:chemistry; D028082:Boraginaceae / Q000737:chemistry*; D002109:Caffeic Acids / Q000737:chemistry; D002851:Chromatography, High Pressure Liquid; D016166:Free Radical Scavengers / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D005988:Glyceric Acids / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D006900:Hydroxylation; D006997:Hypochlorous Acid / Q000737:chemistry; D010851:Picrates / Q000737:chemistry; D013057:Spectrum Analysis; D013237:Stereoisomerism; D013379:Substrate Specificity
D001713:Biphenyl Compounds; D002109:Caffeic Acids; D016166:Free Radical Scavengers; D005988:Glyceric Acids; D010851:Picrates; C525096:poly(3-(3,4-dihydroxyphenyl)glyceric acid); D006997:Hypochlorous Acid; C004931:1,1-diphenyl-2-picrylhydrazyl; C040048:caffeic acid