title: Effect of polymerization on antioxidant and xanthine oxidase inhibitory potential of sea buckthorn (H. rhamnoides) proanthocyanidins.
abstract: Inhibitory potential of sea buckthorn (Hippophae rhamnoides L) seed proanthocyanidins against oxidative stress and xanthine oxidase activity was evaluated. Composition of antioxidant proanthocyanidins was profiled by analyzing the cleavage products obtained by the acid catalyzed hydrolysis in the presence of phloroglucinol. Catechin, epicatechin, gallocatechin, and epigallocatechin were found as the extension and terminal subunits of proanthocyanidins with an average degree of polymerization (ADP) of 14.7. Seed proanthocyanidins showed considerably high antioxidant and xanthine oxidase inhibitory potentials. Antioxidant and xanthine oxidase inhibitory capacity evaluation of proanthocyanidin fractions with varying ADP showed that proanthocyanidins with lower molecular size were more effective as superoxide anion (ADP ≤ 4.2) and hydroxyl radical (ADP ≤ 5.9) scavengers and xanthine oxidase (ADP ≤ 3.1) inhibitors. ADP of the studied proanthocyanidin fractions did not show significant influence on their DPPH and ABTS radical scavenging and ferric reduction capacities.
authors.affiliation: Agroprocessing and Natural Products Division Natural Institute for Interdisciplinary Science Technology (CSIR), Trivandrum 695019, Kerala, India. ranjith.arbr@gmail.com
authors.forename: Ranjith
authors.initials: R
authors.lastname: Arimboor
authors.forename: C
authors.initials: C
authors.lastname: Arumughan
mesh_terms: D000975:Antioxidants / Q000032:analysis / Q000494:pharmacology*; D052160:Benzothiazoles / Q000032:analysis; D002392:Catechin / Q000031:analogs & derivatives / Q000032:analysis / Q000494:pharmacology; D002614:Chelating Agents / Q000378:metabolism; D016166:Free Radical Scavengers / Q000032:analysis; D031281:Hippophae / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000032:analysis; D007501:Iron / Q000378:metabolism; D058105:Polymerization; D044945:Proanthocyanidins / Q000032:analysis / Q000494:pharmacology*; D012639:Seeds / Q000737:chemistry; D013451:Sulfonic Acids / Q000032:analysis; D013481:Superoxides / Q000032:analysis; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D052160:Benzothiazoles; D002614:Chelating Agents; D016166:Free Radical Scavengers; D044945:Proanthocyanidins; D013451:Sulfonic Acids; D013481:Superoxides; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; D017665:Hydroxyl Radical; D002392:Catechin; D007501:Iron; D014969:Xanthine Oxidase; C057580:gallocatechol