Agarose sulfates are bioactive modified polysaccharides important for application. To obtain the bioactive agarose derivatives and expand the range of their potential use, the modification with some functional groups is needed. Agarose sulfates exhibit the anticoagulant, hypolipidemic, and other-type bioactivity. In this study, different methods for preparation of agarose sulfates using nontoxic ammonium sulfamate are investigated. Several activators and catalysts of the process of sulfation with ammonium sulfamate are examined. It is shown that urea does not significantly activate ammonium sulfamate in the sulfation reaction, while potassium permanganate ensures a sulfur content of up to 13.2 wt% in the synthesized agarose sulfate. When Lewis acids (titanium and aluminum oxides) are used, the sulfur content in agarose sulfates can only reach 7.3 wt%. The catalysts with the Brønsted acid sites used in the synthesis of sulfated agarose can provide sulfur contents of up to 14.6 wt% in it. The incorporation of a sulfate group into the agarose molecule has been confirmed by elemental analysis and Fourier-transform infrared spectroscopy: the absorption bands at 1249 cm^‒1 have been observed in the spectra. The X-ray diffraction and atomic force microscopy studies have revealed no ammonium sulfamate inclusions. According to the X-ray diffraction patterns, sulfation of agarose enhances its X-ray amorphism. It has been established from the atomic force microscopy images that the incorporation of a sulfate group into the agarose molecule changes the size of particles on the film surface from 42 to 80 nm. The theoretical examination of initial and sulfated agarose has been carried out within the density functional theory. The molecular geometry, vibration assignments, HOMO‒LUMO, molecular electrostatic potential maps, and electronic properties of the substances have been established by the quantum-chemical calculations in the framework of the density functional theory.

硫酸琼脂糖是具有重要应用价值的生物活性修饰多糖。为了获得具有生物活性的琼脂糖衍生物并扩大其潜在用途范围，需要对一些官能团进行修饰。硫酸琼脂糖具有抗凝血、降血脂等生物活性。在本研究中，研究了使用无毒氨基磺酸铵制备琼脂糖硫酸盐的不同方法研究了氨基磺酸铵硫酸化过程中的几种活化剂和催化剂结果表明，尿素不会显着激活氨基磺酸铵的硫酸化反应，而钾高锰酸盐确保合成的硫酸琼脂糖的硫含量高达 13.2 wt%。当使用路易斯酸（钛和铝的氧化物）时，硫酸琼脂糖中的硫含量只能达到7.3wt%。用于合成硫酸化琼脂糖的具有布朗斯台德酸性位点的催化剂可以提供高达14.6 wt%的硫含量。元素分析和傅里叶变换红外光谱证实了琼脂糖分子中掺入了硫酸基团：在光谱中观察到了^{1249 cm -1}X射线衍射和原子力显微镜研究表明不存在氨基磺酸铵夹杂物。根据X射线衍射图，琼脂糖的硫酸化增强了其X射线无定形性。从原子力显微镜图像可以看出，将硫酸基团掺入琼脂糖分子中，膜表面颗粒的尺寸从 42 nm 变为 80 nm。初始琼脂糖和硫酸化琼脂糖的理论检验是在密度泛函理论中进行的。通过密度泛函理论框架下的量子化学计算，建立了物质的分子几何形状、振动分配、HOMO-LUMO、分子静电势图和电子特性。