title: Separation and evaluation of free radical-scavenging activity of phenol components of Emblica officinalis extract by using an HPTLC-DPPH* method.
abstract: A new procedure has been developed to separate and quantify the free radical-scavenging activity of individual compounds from an Emblica officinalis extract based on the combination of HPTLC with a diode array detector (DAD) and postchromatographic DPPH* radical derivatization. Free gallic and ellagic acids and emblicanins A and B in the E. officinalis extract were separated by TLC and identified. All the compounds of the extract were capable of scavenging of DPPH* radicals. It was established that the DPPH* scavenging activity of emblicanins A and B was 7.86 and 11.20 times more than that of ascorbic acid and 1.25 and 1.78 times more than gallic acid, respectively. From the estimated ID50 values, it can be seen that the increasing order of activity was emblicanin B > emblicanin A > gallic acid > ellagic acid > ascorbic acid. Probably, the antioxidant activity of E. officinalis extract is associated with the presence of hydrolyzable tannins having ascorbic acid-like action.
authors.affiliation: Interregional Center, "Adaptogen", Piskarevsky prosp., St.-Petersburg, Russia.
authors.forename: Olga N
authors.initials: ON
authors.lastname: Pozharitskaya
authors.forename: Svetlana A
authors.initials: SA
authors.lastname: Ivanova
authors.forename: Alexander N
authors.initials: AN
authors.lastname: Shikov
authors.forename: Valery G
authors.initials: VG
authors.lastname: Makarov
mesh_terms: D001713:Biphenyl Compounds; D002855:Chromatography, Thin Layer / Q000379:methods; D016166:Free Radical Scavengers / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D006834:Hydrazines; D010636:Phenols / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D029842:Phyllanthus emblica / Q000737:chemistry* / Q000378:metabolism; D010851:Picrates; D010936:Plant Extracts / Q000032:analysis / Q000737:chemistry
chemical_list: D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D006834:Hydrazines; D010636:Phenols; D010851:Picrates; D010936:Plant Extracts; C004931:1,1-diphenyl-2-picrylhydrazyl