Zhejiang Key Laboratory for Agro-Food Processing, Department of Food Science and Nutrition, Fuli Institute of Food Science, Zhejiang University, Hangzhou 310058, China.
Center for Molecular Medicine, Zhejiang Academy of Medical Sciences, Hangzhou 310013, China.
Carbohydr Polym. 2019 Apr 1;209:82-91. doi: 10.1016/j.carbpol.2018.12.061. Epub 2018 Dec 21.
Fucosylated chondroitin sulfate from sea cucumber Isostichopus badionotus (fCS-Ib) was depolymerized with an ultrasound-accelerated, metal-free Fenton chemistry, relying on HO/ascorbic acid redox system. Fragments of different molecular weights were obtained at different reaction temperatures, ascorbic acid concentrations and ultrasonic intensities. The structures of two typical depolymerized fragments were evaluated using high-performance liquid chromatography (HPLC), infrared spectroscopy (IR), and nuclear magnetic resonance spectroscopy (NMR). The results showed that ultrasound enhanced the degradation efficiency of HO/ascorbic acid system mainly by disaggregating sulfated polysaccharide clusters and that free radicals induced depolymerization with no significant chemical changes in the backbone of fCS-Ib and with no obvious loss of fucose branches. The antitumor activity, using A549 lung cancer cells, showed that the ultrasound treated low molecular weight sulfated fragment enhanced proliferation-inhibitory and anti-migration effects, compared to native fCS-Ib. This was different from the anticoagulant activity of fCS-Ib, suggesting that the molecular weight change may cause a conformational transition and affect biological activity. We propose that combining ultrasound with non-metal Fenton chemistry as an effective method to prepare low molecular weight fCS fragments with potential applications as functional foods, antitumor drugs, and that these fCS fragments display negligible bleeding risk.
海参岩沙海胆来源的岩藻糖基硫酸软骨素（fCS-Ib）经超声加速、无金属芬顿化学法，依赖 HO/抗坏血酸氧化还原体系解聚，在不同反应温度、抗坏血酸浓度和超声强度下得到不同分子量的片段。采用高效液相色谱（HPLC）、红外光谱（IR）和核磁共振光谱（NMR）对两种典型的解聚片段的结构进行了评价。结果表明，超声主要通过解聚硫酸多糖簇来增强 HO/抗坏血酸体系的降解效率，自由基诱导的解聚对 fCS-Ib 的骨架没有明显的化学变化，且岩藻糖支链没有明显丢失。以 A549 肺癌细胞为模型的抗肿瘤活性研究表明，与天然 fCS-Ib 相比，超声处理的低分子量硫酸化片段增强了增殖抑制和抗迁移作用。这与 fCS-Ib 的抗凝活性不同，表明分子量的变化可能导致构象转变并影响生物活性。我们提出将超声与无金属芬顿化学相结合，作为一种有效制备具有潜在应用价值的低分子量 fCS 片段的方法，可作为功能性食品、抗肿瘤药物，且这些 fCS 片段显示出可忽略的出血风险。
