Neutral sugar side chains of pectins limit interactions with procyanidins

Abstract

Interactions between seven hairy regions of pectins, rhamnogalacturonans II and arabinogalactan-proteins and procyanidins with different average degrees of polymerization, low (DP9) and high (DP30), were investigated by isothermal titration calorimetry and absorption analysis to study the impact of neutral sugar side chains of pectins on these associations. Associations between pectic fractions and procyanidins involved hydrophobic interactions and hydrogen bonds. No difference in association constants between various hairy regions and procyanidins DP9 was found. Nevertheless, arabinan chains showed lower association constants, and hairy regions of pectins with only monomeric side chains showed higher association with procyanidin DP30. Only very low affinities were obtained with rhamnogalacturonans II and arabinogalactan-proteins. Aggregation could be observed only with the procyanidins of DP30 and the protein-rich arabinogalactan-protein. Associations were obtained at both degrees of polymerization of the procyanidins, but differed depending on neutral sugar composition and the structure of pectic fractions.

Effect of maturity on the phenolic compositions of pear juice and cell wall effects on procyanidins transfer

“…First, the loss of arabinose and galactose indicated a loss of pectin side chains. Watrelot et al (2014) show that these pectin side chains have low affinity for procyanidins, hence their elimination and better access to pectin's rhamnogalacturonic backbone can contribute to increase affinity. Second, during overripening solubilization and loss of polysaccharides from cell wall might increase its porosity (Bindon, Madani, Pendleton, Smith, & Kennedy, 2014) so that more surface become available for binding of procyanidins.…”

“…Associations differ depending on neutral sugar composition and the structure of pectic fractions. Arabinogalactan had the lowest affinity for procyanidins (Watrelot, Le Bourvellec, Imberty, & Renard, 2014). Watrelot, Le Bourvellec, Imberty, and Renard (2013) showed also that the strongest association was obtained with highly polymerized procyanidins and highly methylated pectins.…”

Soluble polysaccharides reduce binding and inhibitory activity of tea polyphenols against porcine pancreatic α-amylase

“…The neutral sugar side chains (especially arabinan) have mobile properties in solution, which may limit the association of the main chain with polyphenols (Ha, Vi€ etor, Jardine, Apperley, & Jarvis, 2005). As a result, the presence of less sugar branches on the polysaccharide backbone could allow a linear structure to more easily bind/stack with polyphenols (Ha et al, 2005;Watrelot, Le Bourvellec, Imberty, & Renard, 2014). Therefore, OBG is proposed to more likely bind with tea polyphenols than WAX (which contains only monosaccharide branches), which in turn is more likely to bind than CP (which contains longer branches and a charged backbone both of which would limit binding), and thus showed the largest reducing effect on the binding of tea polyphenols with PPA due to the competitive mechanism.…”

Fenolik Bileşiklerin Bağlı Formları ve Biyoyararlılığı

“…Karbonhidratların fenolik bileşiklerle arasındaki ilişki hücre duvarındaki karbonhidratın hidroksil grupları ve glikozidik oksijen atomlarıyla proantosiyanidinlerin hidroksil ve aromatik halkaları arasında oluşan hidrojen bağları ve hidrofobik etkileşimlere bağlıdır [59]. Fenolikler ile karbonhidratlar arasındaki ilişkide proteinlere benzer şekilde kovalent olmayan hidrojen, van der Waals ve hidrofobik bağlar etkilidir [60]. Araştırmalar sonucunda bu etkileşimlerin meydana gelmesinde önem taşıyan bir çok faktör tanımlanmıştır [59].…”