Bunzel Mirko, Ralph John, Steinhart Hans
University of Hamburg, Department of Food Chemistry, Hamburg, Germany.
Mol Nutr Food Res. 2005 Jun;49(6):551-9. doi: 10.1002/mnfr.200500030.
The association of ferulic acid, an alkali-extractable phenolic acid in amaranth (Amaranthus caudatus L., Amaranthaceae) insoluble fiber (trans-ferulic acid: 620 microg.g-1, cis-ferulic acid: 203 microg.g-1), and non-starch polysaccharides was investigated. Enzymatic hydrolysis of insoluble amaranth fiber released several feruloylated oligosaccharides that were separated using Sephadex LH-20-chromatography and reversed phase-high performance liquid chromatography (RP-HPLC). Three compounds were unambiguously identified: O-(6-O-trans-feruloyl-beta-D-galactopyranosyl)-(1-->4)-D-galactopyranose, O-(2-O-trans-feruloyl-alpha-L-arabinofuranosyl)-(1-->5)-L-arabinofuranose, and O-alpha-L-arabinofuranosyl-(1-->3)-O-(2-O-trans-feruloyl-alpha-L-arabinofuranosyl)-(1-->5)-L-arabinofuranose. These feruloylated oligosaccharides show that ferulic acid is predominantly bound to pectic arabinans and galactans in amaranth insoluble fiber. 5-O-trans-Feruloyl-L-arabinofuranose was the only compound isolated in pure form from an acid hydrolyzate. This compound may have its origin from pectic arabinans but also from arabinoxylans.
研究了苋菜（苋科尾穗苋）不溶性纤维中一种碱可提取酚酸阿魏酸（反式阿魏酸：620微克·克⁻¹，顺式阿魏酸：203微克·克⁻¹）与非淀粉多糖之间的关联。苋菜不溶性纤维的酶促水解释放出几种阿魏酰化低聚糖，这些低聚糖通过葡聚糖LH - 20色谱和反相高效液相色谱（RP - HPLC）进行分离。明确鉴定出三种化合物：O -（6 - O - 反式阿魏酰基 - β - D - 吡喃半乳糖基）-（1→4）- D - 吡喃半乳糖、O -（2 - O - 反式阿魏酰基 - α - L - 阿拉伯呋喃糖基）-（1→5）- L - 阿拉伯呋喃糖以及O - α - L - 阿拉伯呋喃糖基 -（1→3）- O -（2 - O - 反式阿魏酰基 - α - L - 阿拉伯呋喃糖基）-（1→5）- L - 阿拉伯呋喃糖。这些阿魏酰化低聚糖表明阿魏酸主要与苋菜不溶性纤维中的果胶阿拉伯聚糖和半乳聚糖结合。5 - O - 反式阿魏酰基 - L - 阿拉伯呋喃糖是从酸水解产物中以纯形式分离出的唯一化合物。该化合物可能来源于果胶阿拉伯聚糖，也可能来源于阿拉伯木聚糖。
