The Isolation and Properties of Catechol From White Fir Bark

Hergert, H. L.; Kurth, E. F.

doi:10.1021/jo01133a008

Cited by 24 publications

(20 citation statements)

References 9 publications

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“…However, part of an intense band near 1600cm-' was probably due to water of hydration (Hergert and Kurth 1953). The spectrum was most different from Foo's (198 1) spectra of proanthocyanidin polymers in the aromatic out-of-plane C-H bending region (90CL700 cm-').…”

Section: -R G Bailey H E Nursten I Mcdowenmentioning

confidence: 62%

Isolation and analysis of a polymeric thearubigin fraction from tea

1992

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A brown thearubigin fraction was isolated from a black tea liquor, using chromatography on a column of Solka-Floc cellulose. The paper chromatograms of the fraction resembled the chromatograms of thearubigin fractions produced in the past. The substance contained no protein or caffeine, and was free of flavonol glycosides. Reversed phase HPLC showed the fraction to be a mixture of polymers, the chromatograms showing a convex broad band. Infra-red spectroscopy showed the substance to be phenolic, and lac NMR showed it was a flavanol polymer with various linkages to the proanthocyanidin polymers. The NMR spectra in this paper are the first NMR spectra of polymeric thearubigins. The brown fraction was designated the theafulvin fraction.

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Section: -R G Bailey H E Nursten I Mcdowenmentioning

confidence: 62%

Isolation and analysis of a polymeric thearubigin fraction from tea

1992

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“…From the above evidence, the structure of compound 3 was determined to be 3,7-O-diacetyl (-)-epicatechin. The known compounds 1, 2, 4-8 were characterized as (-)-epicatechin (1) [12], 3-O-acetyl (-)-epicatechin (2) [13], 3,3′,4′,5,7-O-pentaacetyl (-)-epicatechin (4) [14], (+)-afzelechin (5) [15], (+)-catechin (6) [12], cinchonain Ib (7) [16], and proanthocyanidin B2 (8) [12], respectively, based on the detailed comparison of the 1 H-and 13 C-NMR spectral data with those of the literature reports. To the best of our knowledge, this is the first report of the isolation of compound 2 as a natural substance, as previously 2 had been obtained after hydrolysis of compound 4.…”

Section: Resultsmentioning

confidence: 99%

Flavanol Derivatives from Rhizophora stylosa and Their DPPH Radical Scavenging Activity

Peng

et al. 2007

Molecules

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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-Opentaacetyl (-)-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.

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“…Suberin corresponds to 50-85 wt.% of extractive-free cork material [2][3][4]. Suberin is viewed as a complex heteropolymer composed of a polyphenolic and polyaliphatic domains [5,6].…”

Section: Introductionmentioning

confidence: 99%

“…Transesterification of the material prior to lignin isolation is one of the keys to success. Furthermore, lignin determination by total hydrolysis with sulfuric acid (Klason method) should begin implicitly with saponification of the cork tissue [4,24].…”

Section: Introductionmentioning

confidence: 99%