Institute of Chemistry named after V.I Nikitin of the Tajikistan National Academy of Sciences, Dushanbe 734063, Tajikistan.
Institute of Chemistry named after V.I Nikitin of the Tajikistan National Academy of Sciences, Dushanbe 734063, Tajikistan.
Int J Biol Macromol. 2024 Nov;279(Pt 4):135544. doi: 10.1016/j.ijbiomac.2024.135544. Epub 2024 Sep 13.
Apricot pectin polysaccharides' fine structure was performed using HPSEC, HPAEC-PAD, GC-MS, NMR and FTIR spectroscopies. Purified pectin fraction (F1AP) was composed of D-galacturonic acid, L-rhamnose, D-arabinose and D-galactose, Mw ∼ 1588 kDa. F1AP was eluted by water and with 0.2 M NaCl from DEAE Sepharose fraction resulting in two distinct fractions, F1AP1 and F1AP6, with different structures, molecular weights, and conformations, providing insights into their structural diversity. F1AP1 neutral properties were related to its association with protein. F1AP1 had a backbone of (1 → 4)-linked-D-galacturonic acid and (1 → 2)-linked-L-rhamnopyranosyl residues branched with arabinogalactan including multiple glycosidic linkages of T-α-Araf, 3-α-Araf, 5-α-Araf, T-α-Arap, 2-α-Arap, t-Galp, 2-Galp, 3-Galp, 4-Galp, 6-Galp, 2,4-Galp, 3,4-Galp, 3,6-Galp and 4,6-Galp side chains, having methyl and acetylated groups, and a high molecular weight (1945 kDa). The Mark-Houwink exponent was 0.276, indicating a compact spherical conformation. While the other F1AP6 fraction consists predominately of less methylated HG regions of pectin polysaccharides. The molar mass of this fraction was 117.5 kDa, which adopted a stiffer and random coil conformation. This knowledge allows us to evaluate how the balance of chemical structure and physical properties of the two pectin domains may manifest itself in the isolated structure of apricot pectin and its applications.
采用 HPSEC、HPAEC-PAD、GC-MS、NMR 和 FTIR 光谱法研究了杏果胶多糖的精细结构。纯化的果胶级分（F1AP）由 D-半乳糖醛酸、L-鼠李糖、D-阿拉伯糖和 D-半乳糖组成，Mw∼1588 kDa。F1AP 用水和 0.2 M NaCl 从 DEAE 琼脂糖柱洗脱，得到两个不同的级分 F1AP1 和 F1AP6，它们具有不同的结构、分子量和构象，为了解其结构多样性提供了线索。F1AP1 的中性性质与其与蛋白质的结合有关。F1AP1 的骨架由（1→4）-连接的-D-半乳糖醛酸和（1→2）-连接的-L-鼠李吡喃糖残基组成，支链为阿拉伯半乳聚糖，包括多个糖苷键 T-α-Araf、3-α-Araf、5-α-Araf、T-α-Arap、2-α-Arap、t-Galp、2-Galp、3-Galp、4-Galp、6-Galp、2,4-Galp、3,4-Galp、3,6-Galp 和 4,6-Galp 侧链，具有甲基和乙酰化基团，分子量较高（1945 kDa）。Mark-Houwink 指数为 0.276，表明为紧凑的球形构象。而另一个 F1AP6 级分主要由果胶多糖中甲基化程度较低的 HG 区组成。该级分的摩尔质量为 117.5 kDa，采用较硬的无规卷曲构象。这一知识使我们能够评估两种果胶结构域的化学结构和物理性质之间的平衡如何在杏果胶的分离结构及其应用中表现出来。
