High-Performance Liquid Chromatography Separation and Purification of Cacao (<i>Theobroma cacao </i>L<i>.</i>) Procyanidins According to Degree of Polymerization Using a Diol Stationary Phase

Kelm, Mark A.; Johnson, J Chris; Robbins, Rebecca J.; Hammerstone, John F.; Schmitz, Harold H.

doi:10.1021/jf0525941

Cited by 208 publications

(194 citation statements)

References 19 publications

Supporting

Mentioning

179

Contrasting

Order By: Relevance

“…PAs were separated on a LiChrosphere diol column with dimensions of 250 3 4 mm and a particle size of 5 mm (Merck Chemicals) using an Agilent 1100 series HPLC device employing a modified method described previously by Kelm et al (2006) and Hammerbacher et al (2014). Briefly, the total mobile phase flow rate for chromatographic separation was 1.2 mL min 21 .…”

Section: Quantification Of Pas By Hplc-fldmentioning

confidence: 99%

Flavan-3-ols Are an Effective Chemical Defense against Rust Infection

et al. 2017

View full text Add to dashboard Cite

Phenolic secondary metabolites are often thought to protect plants against attack by microbes, but their role in defense against pathogen infection in woody plants has not been investigated comprehensively. We studied the biosynthesis, occurrence, and antifungal activity of flavan-3-ols in black poplar (Populus nigra), which include both monomers, such as catechin, and oligomers, known as proanthocyanidins (PAs). We identified and biochemically characterized three leucoanthocyanidin reductases and two anthocyanidin reductases from P. nigra involved in catalyzing the last steps of flavan-3-ol biosynthesis, leading to the formation of catechin [2,3-trans-(+)-flavan-3-ol] and epicatechin [2,3-cis-(2)-flavan-3-ol], respectively. Poplar trees that were inoculated with the biotrophic rust fungus (Melampsora larici-populina) accumulated higher amounts of catechin and PAs than uninfected trees. The de novo-synthesized catechin and PAs in the rust-infected poplar leaves accumulated significantly at the site of fungal infection in the lower epidermis. In planta concentrations of these compounds strongly inhibited rust spore germination and reduced hyphal growth. Poplar genotypes with constitutively higher levels of catechin and PAs as well as hybrid aspen (Populus tremula 3 Populus alba) overexpressing the MYB134 transcription factor were more resistant to rust infection. Silencing PnMYB134, on the other hand, decreased flavan-3-ol biosynthesis and increased susceptibility to rust infection. Taken together, our data indicate that catechin and PAs are effective antifungal defenses in poplar against foliar rust infection.

show abstract

Section: Quantification Of Pas By Hplc-fldmentioning

confidence: 99%

Flavan-3-ols Are an Effective Chemical Defense against Rust Infection

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Both anthocyanin and flavanol diets were prepared by incorporating either the anthocyanin extract or pure flavanols, (+)-catechin and (2)-epicatechin (Sigma, UK), into the standard rodent feed at a level equivalent to that found in the blueberry diet (2% w/w). The blueberry powder and the anthocyanin extract were analysed for their flavonoid content prior to incorporation into the diets as described previously [52][53][54]. The flavanol diet contained 14.8 mg of pure (2)-epicatechin and 59.3 mg of (+)-catechin.…”

Section: Intervention Dietsmentioning

confidence: 99%

Association Between Psychiatric Disorders and Iron Defi ciency Anemia Among Children And Adolescents: A Nationwide Population-Based Study

Croft¹

2015

Prenatal and Childhood Nutrition

View full text Add to dashboard Cite

Evidence suggests that flavonoid-rich foods are capable of inducing improvements in memory and cognition in animals and humans. However, there is a lack of clarity concerning whether flavonoids are the causal agents in inducing such behavioral responses. Here we show that supplementation with pure anthocyanins or pure flavanols for 6 weeks, at levels similar to that found in blueberry (2% w/w), results in an enhancement of spatial memory in 18 month old rats. Pure flavanols and pure anthocyanins were observed to induce significant improvements in spatial working memory (p = 0.002 and p = 0.006 respectively), to a similar extent to that following blueberry supplementation (p = 0.002). These behavioral changes were paralleled by increases in hippocampal brain-derived neurotrophic factor (R = 0.46, p,0.01), suggesting a common mechanism for the enhancement of memory. However, unlike protein levels of BDNF, the regional enhancement of BDNF mRNA expression in the hippocampus appeared to be predominantly enhanced by anthocyanins. Our data support the claim that flavonoids are likely causal agents in mediating the cognitive effects of flavonoid-rich foods.

show abstract

“…A number of extraction solvents have been trialled, including ethanol, methanol, acetone, n-butanol, diethyl ether, ethyl acetate and aqueous and/or acidified mixtures (Hagerman, 1988;Kantz & Singleton, 1990;Alonso et al, 1991;Kallithraka et al, 1995;Pekic et al, 1998;Kelm et al, 2006). Numerous reports comparing a range of different extraction solvents populate the published literature (Alonso et al, 1991;Kallithraka et al, 1995;Pekic et al, 1998).…”

Section: Introductionmentioning

confidence: 99%

Comparison of Ethanol and Acetone Mixtures for Extraction of Condensed Tannin from Grape Skin

Downey¹,

Hanlin²

2016

SAJEV

View full text Add to dashboard Cite

Discrepancies in condensed tannin concentrations in grape skin determined by different analytical methods prompted the closer examination of aspects of the methodologies. One of these was the choice of extraction solvent. Condensed tannins were extracted from Shiraz grape skins using a range of aqueous solvent mixtures ranging from zero to 100% acetone and ethanol to examine the relative effectiveness of each solvent mixture and to determine whether different solvent mixtures extracted similar condensed tannin components. Acetone extracted more condensed tannin than ethanol. Mixtures of 50 to 70% acetone were equally effective. The most effective ethanol concentration was 50%. Epicatechin-gallate terminal subunits were not detected by HPLC following acid-catalysed cleavage in any of the extraction solvents. Extension subunit composition was similar between solvents across most mixtures. Polymers were generally shorter in the ethanol extracts than in the acetone extracts. Despite differences in tannin concentration and polymer length, the subunit composition was similar in 50% ethanol and 70% acetone. More tannin and tannins with longer polymer lengths were extracted with 70% acetone than with 50% ethanol. This suggests that all grape skin tannins are similar in composition, varying only in length. Thus, 50% ethanol and 70% acetone would give a fair indication of the grape skin tannin composition extracted into wine. However, both 50% ethanol and 70% acetone may overestimate the amount of tannin that is extracted into wine, as wine typically has a much lower solvent concentration, ranging between 10 and 15% ethanol.

show abstract

High-Performance Liquid Chromatography Separation and Purification of Cacao (Theobroma cacao L.) Procyanidins According to Degree of Polymerization Using a Diol Stationary Phase

Cited by 208 publications

References 19 publications

Flavan-3-ols Are an Effective Chemical Defense against Rust Infection

Flavan-3-ols Are an Effective Chemical Defense against Rust Infection

Association Between Psychiatric Disorders and Iron Defi ciency Anemia Among Children And Adolescents: A Nationwide Population-Based Study

Comparison of Ethanol and Acetone Mixtures for Extraction of Condensed Tannin from Grape Skin

Contact Info

Product

Resources

About