Heterogeneity of interflavanoid bond location in loblolly pine bark procyanidins

Hemingway, Richard W.; Karchesy, Joseph J.; McGraw, Gerald W.; Wielesek, R.A.

doi:10.1016/s0031-9422(00)80105-3

Cited by 44 publications

(10 citation statements)

References 14 publications

(16 reference statements)

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“…After purification, NMR data were obtained for the six most abundant procyanidin oligomers. The structures of four dimers (m/z 577; B1, B2, B3 and B7), an A-type trimer [m/z 863; epicatechin-(4β→8, 2β→O→7)-epicatechin-(4β→8)-epicatechin] and B2-3,3′-di-O-gallate [m/z 881; epicatechin gallate-(4β→8)-epicatechin gallate] were confirmed by comparison of the NMR data with literature values (Nonaka et al, 1981;Hemingway et al, 1983;Ohara and Yanagi, 1995;Foo et al, 2000a;Shoji et al, 2003).…”

Section: Elucidation Of the Structures Of The Procyanidinsmentioning

confidence: 91%

Isolation and Characterisation of Procyanidins from Rumex obtusifolius

Spencer

Sivakumaran

Fraser

et al. 2007

Phytochemical Analysis

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An acetone:water (7:3) extract obtained from the leaves of Rumex obtusifolius was fractionated into procyanidin oligomer and polymer fractions using a linear gradient and a simple step method on Sephadex LH-20. The chemical characteristics of the procyanidin fractions were studied by 13C-NMR spectroscopy, acid-catalysed degradation in the presence of benzyl mercaptan, matrix-assisted laser desorption/ionisation time-of-flight (MALDI-TOF) MS and electrospray ionisation (ESI) MS. The 13C-NMR showed that the polymer fraction consisted predominantly of procyanidin polymers, some with galloyl groups attached. The thiolysis reaction products indicated a mean degree of polymerisation (DP) of 4.3 for the step method, and a range of 2.3-8.2 mean DP for the gradient fractionation, with epicatechin as the most abundant flavan-3-ol extension unit, while the terminal units consisted of equal proportions of catechin, epicatechin and epicatechin gallate. Singly charged ions observed in MALDI-TOF/MS showed a range of oligomeric procyanidins and their polygalloyl derivatives. These species (in the range DP 2-7) were also observed by ESI/MS but the spectra were more complex due to overlapping multiply charged ions. Isolation of oligomers from the Sephadex LH-20 fraction by chromatography on polyamide and C18 yielded B1, B2, B3 and B7 dimers, an A-type trimer and a B2 3,3'-O-digallate.

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Section: Elucidation Of the Structures Of The Procyanidinsmentioning

confidence: 91%

Isolation and Characterisation of Procyanidins from Rumex obtusifolius

Spencer

Sivakumaran

Fraser

et al. 2007

Phytochemical Analysis

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“…?-+8)-epicatechin (10) as acetate and methyl ether acetate derivatives where coupling constants were J2,3 =9.6; Js,,=6. 5 and Jz,,= 9.5; J3,4 = 5.5 Hz, respectively. The 2,3-trans-3,4-trans stereochemistry of 8 is of interest in comparison to coupling constants observed in 9 and 10.…”

mentioning

confidence: 88%

Flavan and procyanidin glycosides from the bark of blackjack oak

Bae¹,

Burger²,

Steynberg³

et al. 1994

Phytochemistry

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The bark of blackjack oak contains (+)-catechin, (-)-epicatechin, (+)-3-O-[beta-D-glucopyranosyl]-catechin, catechin-(4 alpha-->8)-catechin, epicatechin-(4 beta-->8)-catechin as well as the novel 3-O-[beta-D-glucopyranosyl]-catechin-(4 alpha-->8)-catechin and 3-O-[alpha-L-rhamnopyranosyl-(1-->6)-beta-D-glucopyranosyl]-catechin, as major components. The latter rutinoside of catechin is especially interesting because of the exceptionally small J2,3 C-ring coupling. The glucoside of catechin-(4 alpha-->8)-catechin is only the second proanthocyanidin found in nature in which a 3-O-glycoside is present in the upper 'extender unit' of a dimer.

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“…From the 70% acetone extract of the inner bark of loblolly pine (Pinus taeda), four procyanidin trimers were isolated by Hemingway et al [63] and their chemical structures were elucidated as epicatechin-(4β-8)epicatechin-(4β-8)-epicatechin, epicatechin-(4β-6)-epicatechin-(4β-8)-catechin, epicatechin-(4β-8)-epicatechin-(4β-6)-catechin and epicatechin-(4β-8)-epicatechin-(4β-8)-epicatechin. Further work by Hemingway et al [64] gave an average yield of the 70% acetone extract from loblolly pine inner bark as 36% of the weight of the dried inner bark. However, the ethyl acetate soluble portion of the extract was only 21% and three procyanidin dimers; B-1 (0.076%), B-3 (0.021%), and B-7 (0.034%) were isolated with a total yield of only 0.12% of the weight of the dried inner bark.…”

Section: Flavonoids In the Bark Of Radiata Pine And Southern Pinementioning

confidence: 99%

Wood Colors and their Coloring Matters: A Review

Yazaki

2015

Natural Product Communications

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A number of colored specialty woods, such as ebony, rosewood, mahogany and amboyna, and commercially important woods, such as morus, logwood, Brazilwood, Japanese yellowwood, blackwood, kwila, red beech and myrtle beech, exhibit a wide range of colors from black, violet, dark red, reddish brown, to pale yellow. These colors are not only due to colored pigments contained in extractives from those woods but also to insoluble polymers. Wood and bark from many species of both hardwood and softwood trees contain many types of flavonoid compounds. Research on flavonoids has been conducted mainly from two points of view. The first is chemotaxonomy with flavonoid compounds as taxonomic markers, and the second relates to the utilization of woods for pulp and paper and the use of tannins from bark for wood adhesives. Most chemotaxonomic studies have been conducted on flavonoids in the extracts from softwoods such as Podocarpus,

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Heterogeneity of interflavanoid bond location in loblolly pine bark procyanidins

Cited by 44 publications

References 14 publications

Isolation and Characterisation of Procyanidins from Rumex obtusifolius

Isolation and Characterisation of Procyanidins from Rumex obtusifolius

Flavan and procyanidin glycosides from the bark of blackjack oak

Wood Colors and their Coloring Matters: A Review

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