Related Experiment Video
Updated: Jul 11, 2026

Valorization of the Red Seaweed Gracilaria gracilis Through a Biorefinery Approach
Published on: November 21, 2023
Flavanol derivatives from Rhizophora stylosa and their DPPH radical scavenging activity
Dong-Li Li1, Xiao-Ming Li, Ze-Yu Peng
1Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Nanhai Road 7, Qingdao, 266071, PR China.
Abstract:
A new acetylated flavanol, 3,7-O-diacetyl (-)-epicatechin (3), and seven known flavanol derivatives, (-)-epicatechin (1), 3-O-acetyl (-)-epicatechin (2), 3,3',4',5,7-O-pentaacetyl (-)-epicatechin (4), (+)-afzelechin (5), (+)-catechin (6), cinchonain Ib (7), and proanthocyanidin B2 (8), were isolated from the stems and twigs of the mangrove plant Rhizophora stylosa and identified. The crude extract, the different fractions and all of the purified compounds were evaluated for DPPH radical scavenging activity.
Related Concept Videos
Oxidation of Phenols to Quinones
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox property is crucial in...
Radical Reactivity: Steric Effects
Along with electronic factors, steric factors also account...
Radical Autoxidation
Preparation of Diols and Pinacol Rearrangement
The reaction begins with transferring a proton from the acid catalyst to one of the hydroxyl groups, producing an oxonium ion.
