Identification of the connecting linkage between homo- or xylogalacturonan and rhamnogalacturonan type I
Identification of the connecting linkage between homo- or xylogalacturonan and rhamnogalacturonan type I
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DOI：
10.1016/j.carbpol.2007.04.007
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发表时间：
2007-09-20
影响因子：
11.2
通讯作者：
Voragen, A. G. J.
中科院分区：
文献类型：
--
作者：
Coenen, G. J.;Bakx, E. J.;Voragen, A. G. J.
果胶作为细胞壁组分和作为食品添加剂都是令人感兴趣的。果胶的精确化学结构仍在争论中，尽管果胶的结构元素被相当好地描述。为了更深入地了解各种结构元件之间的相互连接，通过控制酸水解来降解苹果果胶修饰的毛状区域。从降解产物中选择能够代表互连点的寡聚体片段，并使用LCMS和NMR方法对这些寡聚体进行表征，结果表明，寡聚体GalA（3）Rha（1）、GalA（4）Rha（2）和GalA（5）Rha（3）由通过GalAp α-（1 -> 2）Rhap键连接的同型半乳糖醛酸聚糖和鼠李糖半乳糖醛酸聚糖I型片段组成。此外，还鉴定了GalA（6）Rha（3）Xyl（1）寡聚体，其由木半乳糖醛酸和鼠李半乳糖醛酸I型片段组成。这些低聚物表明，在苹果果胶中，高半乳糖醛酸聚糖和木半乳糖醛酸聚糖都共价连接到I型鼠李糖半乳糖醛酸聚糖。有了这些新的见解，目前使用的果胶模型进行了改进。(c)2007爱思唯尔有限公司版权所有。
Pectin is of interest both as cell wall component and as food additive. The precise chemical structure of pectin remains under debate, although the structural elements of pectin are rather well described. In order to get more insight in the inter linkage between the various structural elements, apple pectin modified hairy regions were degraded by controlled acid hydrolysis. From the degradation products oligomeric fragments were selected which could represent interconnection points, and these oligomers were characterized using LCMS and NMR approaches.It was shown that the oligomers GalA(3)Rha(1), GalA(4)Rha(2) and GalA(5)Rha(3) consisted out of a homogalacturonan and a rhamnogalacturonan type I segment connected via a GalAp alpha-(1 -> 2) Rhap linkage. In addition, a GalA(6)Rha(3)Xyl(1) oligomer was identified, which consisted out of a xylogalacturonan and a rhamnogalacturonan type I segment. These oligomers indicated that in apple pectin both homogalacturonan and xylogalacturonan were covalently linked to rhamnogalacturonan type I. With these new insights, currently used pectin models were refined. (c) 2007 Elsevier Ltd. All rights reserved.