Natural Products Laboratory, Department of Chemistry, The University of Burdwan , West Bengal 713 104, India.
Biomacromolecules. 2013 Jun 10;14(6):1761-8. doi: 10.1021/bm4001316. Epub 2013 May 16.
Enhydra fluctuans leaves are traditionally sold on Indian markets for various health benefits. However, no phytochemical study on its high molecular weight compound has so far been performed. Chemical, chromatographic, ESI-TOF-MS, and NMR analyses of the water extracted carbohydrate polymer (CP) of E. fluctuans leaves showed the presence of a 24 kDa arabinogalactan having a (1,3)-linked β-d-Galp main chain, substituted at O-6 by (1,6)-linked β-d-Galp side chains. The latter residues were substituted at O-3 by (1,3)-, (1,5)-, and (1,3,5)-linked α-l-Araf chains, and nonreducing end-units of α-l-Araf and β-d-Galp. This polymer contained esterified phenolic acids. Biochemical analysis revealed similarity in antioxidative potential between the identified carbohydrate polymer and known standard antioxidants. The highly branched side chains and the phenolic acid residues of the arabinogalactan might be the functional sites. Fluorimetric and ultraviolet spectrometric analyses showed that the studied carbohydrate polymer can form complex with bovine serum albumin having binding constant K = 2.42 × 10(6)/M and changes its microenvironment. Thus, traditional aqueous extraction method provides a carbohydrate polymer, which stimulates a fair biological response: this could represent an interesting approach in phytotherapeutic treatments.
水龙木叶在印度市场上一直被用于各种健康益处。然而，目前尚未对其高分子化合物进行过植物化学研究。对水提取的碳水化合物聚合物（CP）的化学、色谱、ESI-TOF-MS 和 NMR 分析表明，水龙木叶中的阿拉伯半乳聚糖具有 24 kDa 的分子量，其主链由（1,3）连接的β-d-Galp 组成，在 O-6 位置被（1,6）连接的β-d-Galp 侧链取代。后者残基在 O-3 位置被（1,3）、（1,5）和（1,3,5）连接的α-l-Araf 链以及α-l-Araf 和β-d-Galp 的非还原端单元取代。这种聚合物含有酯化的酚酸。生化分析表明，鉴定出的碳水化合物聚合物与已知的标准抗氧化剂在抗氧化潜力方面具有相似性。阿拉伯半乳聚糖的高度支化侧链和酚酸残基可能是功能位点。荧光和紫外光谱分析表明，所研究的碳水化合物聚合物可以与牛血清白蛋白形成复合物，结合常数 K = 2.42×10(6)/M，并改变其微环境。因此，传统的水提取方法提供了一种具有生物刺激作用的碳水化合物聚合物：这可能是植物治疗方法中的一个有趣途径。
