Color development of proanthocyanidins in vanillin-hydrochloric acid reaction

Mitsunaga, Tohru; Doi, Toshiya; Kondo, Yasuhito; Abe, Isao

doi:10.1007/bf00526257

Cited by 38 publications

(23 citation statements)

References 7 publications

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“…This test poorly detects acacia and quebracho-type proanthocyanidins. 18,22,23 Proanthocyanidins are common in Acacia spp. wood and bark material 10 but Lange and Hashim 24 did not detect their presence in the polar extractive fractions of A. mangium wood using ethanol-hydrochloric acid.…”

Section: Resultsmentioning

confidence: 99%

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Polyphenols in Acacia mangium and Acacia auriculiformis heartwood with reference to heart rot susceptibility

et al. 2005

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The heartwood of Acacia mangium is vulnerable to heart rot and this is the first study to investigate the role of heartwood extractives in its susceptibility. Acacia auriculiformis was compared with A. mangium because it is rarely associated with heart rot. The heartwood extracts of both species were dominated by three flavonoids (2,3-trans-3,4¢,7,8-tetrahydroxyflavanone, teracacidin, and 4¢,7,8,-trihydroxyflavanone), which were purified and identified by nuclear magnetic resonance spectroscopy. The latter compound has not been previously reported in A. mangium and evidence for melacacidin is also newly reported. The mass spectrometric (MS) behavior of these compounds is given, for example teracacidin does not form molecular ions by either electrospray ionization or atmospheric-pressure chemical ionization. The nature of Acacia tannins was compared to quebracho tannin (composed of profisetinidins) using oxidative cleavage to enable MS detection but a negative reaction was obtained for both, which suggests the Acacia tannins may also be of the 5-deoxy proanthocyanidin type. The concentration of flavanones was less when A. mangium heartwood was decayed but the amount of proanthocyanidins was only slightly reduced and therefore these compounds may be more resistant to degradation by heart rot fungi. We found that the total phenol content of A. auriculiformis was about fivefold that of A. mangium, and, while preliminary, this provides evidence for a role played by phenolic extractives in heart rot resistance of these Acacia species.

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Section: Resultsmentioning

confidence: 99%

“…18 To determine tannins, a protein precipitation method using bovine serum albumin (BSA, Wako, Japan) was used. This method was adapted from Kawamoto et al, 19 and analyzed the BSA content of the supernatant liquid rather than the BSA content of precipitation.…”

Section: Fractionation and Isolationmentioning

confidence: 99%

Polyphenols in Acacia mangium and Acacia auriculiformis heartwood with reference to heart rot susceptibility

et al. 2005

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“…Aromatic substances such as lignin and many polyphenolics contain aromatic ring structures. The UV absorption spectra of flavonoids, as an example of typical Sapelli extractives (Hegnauer 1990), and lignin show similar maxima and curve shapes, often preventing clear differentiation between them (Scheidemann and Wetzel 1997;Mitsunaga et al 1998;Rice-Evans and Packer 1998). The UV absorption spectra of flavonoids, as an example of typical Sapelli extractives (Hegnauer 1990), and lignin show similar maxima and curve shapes, often preventing clear differentiation between them (Scheidemann and Wetzel 1997;Mitsunaga et al 1998;Rice-Evans and Packer 1998).…”

Section: Subcellular Localisation Of Extractives In the Cell Wallsmentioning

confidence: 99%

Cellular UV Microspectrophotometric Investigation of Sapelli Heartwood (Entandrophragma cylindricum Sprague) from Natural Provenances in Africa

Kleist¹,

Bauch²

2001

Holzforschung

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Summary The colour of Sapelli heartwood (Entandrophragma cylindricum Sprague) is variable depending on habitat. In recent years an unusual pinkish-brown colour has been observed in commercial sawn timber of this species from Central Africa. Initial studies of Sapelli heartwood samples from various provenances have furthermore demonstrated pronounced differences in its decay resistance. Heartwood extractive composition varies considerably between provenances. Samples of Sapelli heartwood from the Central African Republic (RCA) contained 6.4% by weight of extractives compared with 12.5% for those from Cameroon and four other provenances investigated. UV microspectrophotometric analysis of heartwood extractives was used to localise phenolic extractives within wood cell walls and to identify their distribution at tissue level. The S2 and S3 wall layers of vessels and fibres in the heartwood were discriminated from sapwood by their high concentration of non-lignin phenolic extractives. These extractives in the cell walls were also found to be variable. As UV absorption properties show, the vessel and fibre secondary walls of Cameroon heartwood had a considerably higher concentration of extractives in comparison with samples from the RCA. In sapwood, the UV absorption levels for the fibre S2 layer and the vessel S3 layer were independent of the extraction procedure, suggesting the phenolic extractives in this part of the trunk were in low concentrations. Furthermore it is suggested that polyphenols constitute part of the cell wall matrix. The non-extractable phenolic content was found to be independent of provenances as demonstrated by wood from Cameroon and the RCA. The natural durability of Sapelli heartwood against fungal decay appears to be dependent on the extractive composition and on their concentration in the fibre tissue.

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“…2) in order to control the reactivity of phenol with formaldehyde in the presence of a basic medium, 15 as well as on several mechanisms of several acid-catalyzed dissolution of catechin. 22,23 More recently, Mutlu et al reacted phenolmodified condensed tannin with formaldehyde to make polymer matrix for brake linings. 24 In the mean time, it was shown that lignocellulosic biomass such as wood and wheat straw could be dissolved with phenol by using acidic catalysts in order to make phenol-formaldehyde-type resin.…”

Section: Introductionmentioning

confidence: 99%

Dissolution of condensed tannin with phenol: Optimum reaction parameters and some flow properties

Samil

Alma

Acemioğlu

2005

J of Applied Polymer Sci

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Condensed tannins from the bark of black wattle (Acacia mearnsii L.) were solubilized with phenol using HCl as a catalyst. The optimum reaction parameters (temperature, time, and acid concentration) of the dissolution were determined. The results showed a clear effect on the percentage of reacted phenol and residue tannin by temperature, time and, particularly, acid concentration. It was found that almost 77% of the phenol used could be reacted with the tannin, and about 90% of the tannin could be solubilized into phenol in the presence of HCl (as a catalyst) having a concentration of 5%. The optimum temperature, time, and acid concentration were 160°C, 90 min, and 4%-5%, respectively.

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Color development of proanthocyanidins in vanillin-hydrochloric acid reaction

Cited by 38 publications

References 7 publications

Polyphenols in Acacia mangium and Acacia auriculiformis heartwood with reference to heart rot susceptibility

Polyphenols in Acacia mangium and Acacia auriculiformis heartwood with reference to heart rot susceptibility

Cellular UV Microspectrophotometric Investigation of Sapelli Heartwood (Entandrophragma cylindricum Sprague) from Natural Provenances in Africa

Dissolution of condensed tannin with phenol: Optimum reaction parameters and some flow properties

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