Feruloylated Wheat Bran Arabinoxylans: Isolation and Characterization of Acetylated and O–2‐Monosubstituted Structures

Abstract

1Arabinoxylan structures vary based on the degree and pattern of substitution of the 2 β-(1→4)-linked D-xylopyranose backbone with α-L-arabinofuranose units, acetyl groups, 3 uronic acids, and feruloylated side chains. Substitution differences affect arabinoxylans' 4 physicochemical and physiological characteristics. Wheat bran arabinoxylans were 5 hydrolyzed with GH10 and GH11 endo-1,4-β-xylanases, and feruloylated oligosaccharides 6 were isolated and purified (Amberlite XAD-2, Sephadex LH-20, and preparative RP-HPLC). 7 The pure, isolated compounds were structurally characterized via LC-ESI-MS and 1D-and 8 2D-NMR analyses. In addition to the well-known products of endo-xylanase hydrolysis 9 (xylotriose and xylobiose O-3-substituted with a 5-O-trans-feruloyl-α-arabinofuranosyl unit 10 on the middle and non-reducing xylose residue, respectively), novel structural features, 11 including O-2-monosubstitution of xylose adjacent to a xylose carrying feruloylated 12 arabinose, were observed. Additionally, a simultaneously acetylated and feruloylated 13 oligosaccharide has been isolated and tentatively characterized. Oligosaccharides esterified 14with caffeic acid were also isolated, but these were proven to result, at least in part, as 15 artefacts of the enzymatic hydrolysis.

Extraction, Identification, and In Vitro Anti-Inflammatory Activity of Feruloylated Oligosaccharides from Baijiu Distillers’ Grains

“…Consequently, it can be inferred that the phenolic compounds in BDG are predominantly feruloyl polysaccharides. In accordance with a prior study [25], the presence of ferulic acid in plant cell walls is mainly attributed to FOs. Therefore, the decision was made to employ xylan xylanase hydrolysis to extract the FOs in BDGs.…”

Functional Validation of Two Fungal Subfamilies in Carbohydrate Esterase Family 1 by Biochemical Characterization of Esterases From Uncharacterized Branches

“…anserina FaeD could release ferulic acid from the feruloylated substrates ( Figure 5). As mentioned before, feruloylation in commelinid monocots mainly occurs at the O-5 position on arabinosyl residues of xylan (Smith and Hartley, 1983;Saulnier et al, 1995;Wende and Fry, 1997;Schendel et al, 2016), while in pectin it mainly occurs at the O-2 and/or O-5 positions of arabinan side chains and at the O-6 position of D-galactosyl residues in (arabino-)galactan of rhamnogalacturonan I (Carpita, 1996;Levigne et al, 2004;Harris, 2005;Harris and Trethewey, 2010). Po.…”

“…Xylan composes of a β-1,4-xylosyl backbone with different substituents, e.g., L-arabinose, D-galactose, D-(methyl)glucuronic acid, ferulic acid, and acetic acid. The acetyl groups are linked to the O -2 and/or O -3 position of the xylosyl units in commelinid monocots (cereals and grasses) ( Puls, 1997 ; Appeldoorn et al, 2010 , 2013 ), whereas feruloyl and to a lesser degree p -coumaryl groups are esterified mainly at the O -5 position on arabinosyl residues of xylan of commelinid monocots ( Smith and Hartley, 1983 ; Saulnier et al, 1995 ; Wende and Fry, 1997 ; Schendel et al, 2016 ). Feruloyl groups are also present in pectin, which esterified to the O -2 and/or O -5 positions of arabinan side chains and to the O -6 position of D-galactosyl residues in (arabino-)galactan of rhamnogalacturonan I ( Carpita, 1996 ; Levigne et al, 2004 ; Harris, 2005 ; Harris and Trethewey, 2010 ).…”

Bioactive Components and Health Beneficial Properties of Whole Wheat Foods

“…49,50 Schendel et al isolated the feruloylated arabinoxylans from the insoluble fiber of wheat bran following GH10 and GH11 endo-1,4-b-xylanase hydrolysis. 51 In summary, feruloylated oligosaccharides in wheat grain may differ in their number and composition of glycosylated monosaccharides, ferulic acid contents, types of sugar residues linked by ferulic acid, and linking positions.…”

“…Feruloylated arabinoxylans (Figure ) are the major feruloylated oligosaccharides. Wheat flour may have low-molecular-weight and highly feruloylated arabinoxylans with a high arabinose/xylose ratio (nearly 1:1). , Schendel et al isolated the feruloylated arabinoxylans from the insoluble fiber of wheat bran following GH10 and GH11 endo-1,4- b -xylanase hydrolysis . In summary, feruloylated oligosaccharides in wheat grain may differ in their number and composition of glycosylated monosaccharides, ferulic acid contents, types of sugar residues linked by ferulic acid, and linking positions.…”