School of Pharmaceutical Sciences, South-Central University for Nationalities, Wuhan 430074, China.
National Demonstration Center for Experimental Ethnopharmacology Education, South-Central University for Nationalities, Wuhan 430074, China.
Int J Mol Sci. 2022 Apr 19;23(9):4488. doi: 10.3390/ijms23094488.
Fucan sulfate I (FSI) from the sea cucumber was purified and its structure was clarified based on a bottom-up strategy. The unambiguous structures of a series of oligosaccharides including disaccharides, trisaccharides, and tetrasaccharides, which were released from mild acid hydrolysis of FSI, were identified by one-dimensional (1D)/two-dimensional (2D) nuclear magnetic resonance (NMR) and mass spectrometry (MS) analysis. All the glycosidic bonds in these oligosaccharides were presented as α1,3 linkages confirmed by correlated signals from their H-H ROESY and H-C HMBC spectra. The structural sequence of these oligosaccharides formed by Fuc, Fuc, and non-sulfated ones (Fuc), along with the general structural information of FSI, indicated that the structure of FSI could be elucidated as: [-L-Fuc-α1,3-L-Fuc-α1,3-L-Fuc-α1,3-L-Fuc-α1,3-1-]. Moreover, the L-Fucα1,3-L-Fuc linkage in FSI was susceptible to be cleaved by mild acid hydrolysis. The antioxidant activity assays in vitro showed that FSI and the depolymerized product (dFSI') had potent activities for superoxide radical scavenging activity with IC of 65.71 and 83.72 μg/mL, respectively, while there was no scavenging effect on DPPH, hydroxyl and ABTS radicals.
从海参中提取的硫酸软骨素 I（FSI），基于自下而上的策略进行了纯化和结构阐明。通过对 FSI 进行温和酸水解，释放出一系列寡糖，包括二糖、三糖和四糖。通过一维（1D）/二维（2D）核磁共振（NMR）和质谱（MS）分析，确定了这些寡糖的明确结构。所有这些寡糖中的糖苷键均通过它们的 H-H ROESY 和 H-C HMBC 光谱中的相关信号确定为α1,3 键。这些寡糖由 Fuc、Fuc 和非硫酸化的（Fuc）组成，其结构序列以及 FSI 的一般结构信息表明，FSI 的结构可以被阐明为：[-L-Fuc-α1,3-L-Fuc-α1,3-L-Fuc-α1,3-L-Fuc-α1,3-1-]。此外，FSI 中的 L-Fucα1,3-L-Fuc 键对温和酸水解敏感。体外抗氧化活性测定表明，FSI 和部分解聚产物（dFSI'）对超氧自由基具有很强的清除活性，IC 分别为 65.71 和 83.72 μg/mL，而对 DPPH、羟基和 ABTS 自由基没有清除作用。
