Abstract Aloe barbadensis Miller (Aloe vera) has long been used in food, cosmetic and pharmaceutical industries. The solid wastes such as the spikes and the outer green skins are usually separated from the inner gel and discarded during the process of Aloe vera leaves. Three kinds of polysaccharides (designated as ASP-4N, ASP-6N and ASP-8N) were successfully purified from the leaf skin of Aloe vera in our previous work. The present study aimed to analyze the structural and molecular features of ASP-6N and ASP-8N using methylation and GC-MS, NMR, high performance size-exclusion chromatography coupled with multi-angle laser light scattering (HPSEC-MALLS) and scanning electron microscopy (SEM) techniques. Results showed that ASP-6N and ASP-8N were β-(1→4)-glucomannans with acetyl groups, which may attach to O-2, O-3 or O-6 of mannopyranosyl residues in the backbone as mono-, di-, or tri-acetylated forms. HPSEC-MALLS analysis indicated that the polysaccharide fractions from Aloe leaf skin adopted various conformations in the aqueous solution depending on their molecular mass. The polysaccharides had fibrous, ribbon-like and spherical morphology by SEM observation.

中文翻译：

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芦荟叶皮多糖的研究：第二部分。两种低分子量级分的结构特征和分子性质

摘要 库拉索芦荟（Aloe vera）长期以来被用于食品、化妆品和制药行业。在芦荟叶子的加工过程中，通常将穗状花序和外绿皮等固体废物与内凝胶分离并丢弃。我们之前的工作成功地从芦荟叶皮中纯化出三种多糖（指定为 ASP-4N、ASP-6N 和 ASP-8N）。本研究旨在使用甲基化和 GC-MS、NMR、高效尺寸排阻色谱结合多角度激光散射 (HPSEC-MALLS) 和扫描电子分析 ASP-6N 和 ASP-8N 的结构和分子特征。显微镜 (SEM) 技术。结果表明，ASP-6N 和 ASP-8N 是带有乙酰基的 β-(1→4)-葡甘露聚糖，可能与 O-2 相连，主链中吡喃甘露糖残基的 O-3 或 O-6，呈单乙酰化、二乙酰化或三乙酰化形式。HPSEC-MALLS 分析表明，芦荟叶皮中的多糖组分根据其分子量在水溶液中采用各种构象。扫描电镜观察发现多糖呈纤维状、带状和球形。