Edible snails have been widely used as a health food and medicine in many countries. A unique glycosaminoglycan (AF-GAG) was purified from Achatina fulica. Its structure was analyzed and characterized by chemical and instrumental methods, such as Fourier transform infrared spectroscopy, analysis of monosaccharide composition, and 1D/2D nuclear magnetic resonance spectroscopy. Chemical composition analysis indicated that AF-GAG is composed of iduronic acid (IdoA) and N-acetyl-glucosamine (GlcNAc) and its average molecular weight is 118 kDa. Structural analysis clarified that the uronic acid unit in glycosaminoglycan (GAG) is the fully epimerized and the sequence of AF-GAG is →4)-α-GlcNAc (1 → 4)-α-IdoA2S(1→. Although its structure with a uniform repeating disaccharide is similar to those of heparin and heparan sulfate, this GAG is structurally highly regular and homogeneous. Anticoagulant activity assays indicated that AF-GAG exhibits no anticoagulant activities, but considering its structural characteristic, other bioactivities such as heparanase inhibition may be worthy of further study.

中文翻译：

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褐壳菜高度规则的糖胺聚糖的结构分析和生物活性

食用蜗牛在许多国家被广泛用作健康食品和药品。从Achatina fulica中纯化出独特的糖胺聚糖（AF-GAG）。通过化学和仪器方法，例如傅里叶变换红外光谱法，单糖成分分析和一维/二维核磁共振光谱法，对其结构进行了分析和表征。化学成分分析表明，AF-GAG由艾杜糖醛酸（IdoA）和N组成-乙酰基葡糖胺（GlcNAc），其平均分子量为118 kDa。结构分析表明，糖胺聚糖（GAG）中的糖醛酸单元是完全差向异构体，AF-GAG的序列为→4）-α-GlcNAc（1→4）-α-IdoA2S（1→）。均匀重复的二糖类似于肝素和硫酸乙酰肝素，这种GAG在结构上是高度规则且均质的；抗凝活性测定表明AF-GAG不显示抗凝活性，但考虑到其结构特征，其他生物活性（如乙酰肝素酶抑制）可能值得有待进一步研究。