(-)-Epiafzelechin 3-O-gallate

Molecules. 2012 Nov 27;17(12):14037-45.

Antioxidant phenolic compounds from Pu-erh tea.[Pubmed: 23187287 ]

METHODS AND RESULTS:
Eight compounds were isolated from the water extract of Pu-erh tea and their structures were elucidated by NMR and MS as gallic acid (1), (+)-catechin (2), (−)-epicatechin (3), (−)-epicatechin-3-O-gallate (4), (−)-epigallocatechin-3-O-gallate (5), (-)-Epiafzelechin 3-O-gallate (6), kaempferol (7), and quercetin (8). Their in vitro antioxidant activities were assessed by the DPPH and ABTS scavenging methods with microplate assays. The relative order of DPPH scavenging capacity for these compounds was compound 8 > compound 7 > compound 1 > compound 6 > compound 4 ≈ compound 5 > compound 2 > VC (reference) > compound 3, and that of ABTS scavenging capacity was compound 1 > compound 2 > compound 7 ≈ compound 8 > compound 6 > compound 5 > compound 4 > VC (reference) > compound 3.
CONCLUSIONS:
The results showed that these phenolic compounds contributed to the antioxidant activity of Pu-erh tea.

Zhongguo Zhong Yao Za Zhi. 2013 May;38(9):1386-9.

Chemical constituents of Camellia sinensis var. assamica.[Pubmed: 23944074]

To study the chemical constituents of Camellia sinensis var. assamica.
METHODS AND RESULTS:
The compounds were isolated by NKA Macroporous resin silica gel, Sephadex LH-20, RP-C18 column chromatographies and semi-preparative HPLC,and their structures were elucidated by physicochemical properties and spectral analysis. Thirteen compounds were isolated and identified as caffeine (1), theobromine (2), gallic acid (3), (+)-catechin (4), ampelopsin (5), (-)-epicatechin (6), (-)-epiafzelechin (7), (-)-epicatechin-3-O-gallate (8), (-)-Epiafzelechin 3-O-gallate(9) , (+)-catechin-3-O-gallate (10) , (+)-afzelechin-3-O-gallate (11), quemefin-3-O-alpha-L-arabinopyranosid (12), and (-)-epicatechin-3-O-p-hydroxybenzoate (13).
CONCLUSIONS:
Compounds 2, 5, 10-13 were isolated from this plant for the first time, and compound 11 is a new natural product.