HOMEPRODUCTSCOMPANYCONTACTFAQResearchDictionaryPharmaSign Up FREE or Login

Preparation of A-type proanthocyanidin dimers from peanut skins and persimmon pulp and comparison of the antioxidant activity of A-type and B-type dimers.

Abstract
We have established a simple method for preparing large quantities of A-type dimers from peanut skin and persimmon for further structure-activity relationship study. Peanut skins were defatted with hexane and oligomeric proanthocyanidins were extracted from it with 20% of methanol, and the extract was fractionated with ethyl acetate. Persimmon tannin was extracted from persimmon with methanol acidified with 1% hydrochloric acid, after removing the sugar and small phenols, the high molecular weight persimmon tannin was partially cleaved with 6.25% hydrochloric acid in methanol. The ethyl acetate fraction from peanut skins and persimmon tannin cleaved products was chromatographed on AB-8 macroporous resin followed by Toyopearl HW-50F resin to yield about 378.3mg of A-type (epi)catechin (EC) dimer from 1 kg dry peanut skins and 34.3mg of A-type (epi)catechin-3-O-gallate (ECG) dimer and 37.7 mg of A-type (epi)gallocatechin-3-O-gallate (EGCG) dimer from 1 kg fresh persimmon fruit. The antioxidant properties of the A-type and B-type dimers were compared in five different assays, namely, 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, 2,2-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical, hydroxyl radical, lipid peroxidation in mice liver homogenate and erythrocyte hemolysis in rat blood. Our results showed that both A-type and B-type dimers showed high antioxidant potency in a dose-dependent manner. In general, B-type dimers showed higher radical scavenging potency than A-type ones with the same subunits in aqueous systems. But in tissue or lipid systems, A-type dimers showed similar or even higher antioxidant potency than B-type ones.
AuthorsXiao-Qian Dong, Bo Zou, Ying Zhang, Zhen-Zhen Ge, Jing Du, Chun-Mei Li
JournalFitoterapia (Fitoterapia) Vol. 91 Pg. 128-139 (Dec 2013) ISSN: 1873-6971 [Electronic] Netherlands
PMID24001713 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)
Copyright© 2013.
Chemical References
  • Antioxidants
  • Plant Extracts
  • Proanthocyanidins
  • Tannins
  • proanthocyanidin
  • Hydroxyl Radical
  • Catechin
Topics
  • Animals
  • Antioxidants (chemistry, pharmacology)
  • Arachis (chemistry)
  • Catechin (analogs & derivatives, chemistry, pharmacology)
  • Dimerization
  • Diospyros (chemistry)
  • Dose-Response Relationship, Drug
  • Erythrocytes (drug effects, metabolism)
  • Fruit (chemistry)
  • Hydroxyl Radical (metabolism)
  • Lipid Peroxidation (drug effects)
  • Liver (drug effects, metabolism)
  • Mice
  • Plant Extracts (chemistry, pharmacology)
  • Proanthocyanidins (chemistry, pharmacology)
  • Rats
  • Seeds (chemistry)
  • Structure-Activity Relationship
  • Tannins (chemistry)

Join CureHunter, for free Research Interface BASIC access!

Take advantage of free CureHunter research engine access to explore the best drug and treatment options for any disease. Find out why thousands of doctors, pharma researchers and patient activists around the world use CureHunter every day.
Realize the full power of the drug-disease research graph!


Choose Username:
Email:
Password:
Verify Password:
Enter Code Shown: