Anthocyanidins from leucoanthocyanidins

Govindarajan, V. S.; Mathew, A. G.

doi:10.1016/s0031-9422(00)86280-9

Cited by 44 publications

(20 citation statements)

References 15 publications

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“…Briefly, samples were extracted with methanol-water-mixture (4:1) and soluble matter was fractionated into two parts as diethyl ethersoluble and water-soluble extractives. Total phenols were estimated in both fractions by the Folin-Ciocalteu method, and water extracts were analyzed for proanthocyanidins by the acid-butanol assay with catechin as a standard, and for ellagitannins by the nitrous acid method [13,[20][21][22].…”

Section: Methodsmentioning

confidence: 99%

Characterization of methanol extracts from Quercus hartwissiana wood and bark

Uçar

2011

Chem Nat Compd

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547.915 + 547.972 The MeOH extracts of wood and bark from Quercus hartwissiana have been investigated by GC-MS after derivatization, as well as by classical spectroscopic methods. The results for the free compounds revealed that ellagic acid, catechin, gallic acid, quercitol, and also long chain fatty acids, sugars, and sitosterol were the essential compounds in wood and bark, most of them being present in differing amounts. Quercitol, a characteristic compound for the oak wood tannin, was also recognized and determined in oak bark extracts in this study. Amounting to 1/4 th to 1/3 rd of the free compounds, the bark had the highest catechin content. While the content of sugars, such as fructose and glucose, increased in sapwood and bark extracts remarkably, the amounts of these compounds decreased in extracts of heartwood. The profile of the bound compounds contained sugars (i.e., arabinose, xylose, and, above all, glucose), ellagic and gallic acids, quercitols, and inositols. Compared with the composition of free compounds, the hydrolyzed extracts showed relatively higher amounts of sugars, especially glucose, gallic acid and quercitol.

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Section: Methodsmentioning

confidence: 99%

Characterization of methanol extracts from Quercus hartwissiana wood and bark

Uçar

2011

Chem Nat Compd

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“…The concentration of total phenolics (expressed as tannic acid equivalents) was determined using the Folin-Denis assay (Swain and Hillis 1959). Condensed tannin concentrations (quebracho-tannin equivalents) were measured following the procedure of Govindarajan and Mathew (1965). A BSA (bovine serum albumin) precipitation assay (Martin and Martin 1982) was used to determine the protein precipitating capacity of the needle extracts.…”

Section: Needle Qualitymentioning

confidence: 99%

Opposing effects of elevated CO 2 and N deposition on Lymantria monacha larvae feeding on spruce trees

Hättenschwiler

Schafellner²

1999

Oecologia

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The effects of elevated atmospheric CO and increased wet N deposition on leaf quality and insect herbivory were evaluated in nine model ecosystems composed of 7-year-old spruce trees (Picea abies) and three understorey species established on natural forest soil. Each model ecosystem was grown in a simulated montane climate, and was exposed to one of three CO concentrations (280, 420, and 560 μl l), and to one of three levels of N deposition (0, 30, and 90 kg ha year) for 3 years. In the 3rd year of the experiment second to third instars of the nun moth (Lymantria monacha) were allowed to feed directly on current-year needles of top canopy branches of each tree for 12 days. Specific leaf area (SLA), water content, and N concentration decreased in needles exposed to elevated CO, whereas the concentrations of starch, condensed tannins, and total phenolics increased. Increased N deposition had no significant effect on SLA, and water content, but the concentrations of starch, condensed tannins, and total phenolics decreased, and sugar and N concentrations increased. Despite higher relative consumption rates (RCRs) larvae consumed 33% less N per unit larval biomass and per day at the two high CO treatments, compared to those feeding on 280 μl l-needles, but they maintained similar N accumulation rates due to increased N utilization efficiencies (NUE). However, over the 12-day experimental period larvae gained less N overall and reached a 35% lower biomass in the two high-CO treatments compared to those at 280 μl l. The effects of increased N deposition on needle quality and insect performance were generally opposite to those of CO enrichment, but were lower in magnitude. We conclude that altered needle quality in response to elevated CO will impair the growth and development of L. monacha larvae. Increasing N deposition may mitigate these effects, which could lead to altered insect herbivore distributions depending on regional patterns of N deposition.

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“…The extracted tannins were then characterized and expressed in total polyphenols, proanthocyanidins, ellagitannins, and gallotannins. The unextracted tannins were estimated in the extraction residue after their transformation to anthocyanidins obtained by acid catalysis in butanol with addition of ferrous ions (Govindarajan et al, 1965).…”

Section: Introductionmentioning

confidence: 99%