Levan is an exopolysaccharide produced by Bacillus licheniformis (strain FRI MY-55) that shows promising pharmacological activity. Phosphorylation is a chemical modification that can increase the biological and antioxidant properties of levan. In this study, levan was phosphorylated by microwave-assisted synthesis to achieve a degree of substitution of 0.29. The hydroxyl radical scavenging activity of microwave-assisted phosphorylated levan (microwave P) increased significantly (6-fold) over native levan; this activity was only slightly lower than vitamin C. Other free radical scavenging and reducing power tests revealed that Microwave P activity was increased by 30–40%. Microwave P inhibited the proliferation of HCT-116 and A549 cancer cell lines more readily than native levan with an IC₅₀ of 1.03 mg/mL and 1.38 mg/mL for HCT-116 and A549 cells, respectively. Cells treated with native levan and its derivatives remained in the sub-G1 phase according to cell cycle analysis, whereas Microwave P treatment increased the proportion of cells undergoing apoptosis. Furthermore, Microwave P effectively upregulated pro-apoptosis marker Bax and downregulated anti-apoptosis marker Bcl-2, in addition to inducing the expression of caspase-9 and caspase-3. These findings show that levan phosphorylated via microwave-assisted synthesis showed increased antioxidant and antitumor activity over native levan or levan phosphorylated via traditional long-term heating. In particular, Microwave P possesses antiproliferative activity and can induce apoptosis through mitochondrial pathways in cancerous cells.

莱万是地衣芽孢杆菌产生的胞外多糖（菌株FRI MY-55），具有良好的药理活性。磷酸化是一种化学修饰，可以增加levan的生物学和抗氧化性能。在这项研究中，levan通过微波辅助合成被磷酸化，以达到0.29的取代度。微波辅助磷酸化莱文（微波P）的羟自由基清除活性比天然莱文明显提高（6倍）。这种活性仅略低于维生素C。其他清除自由基和降低功率的实验表明，微波P的活性提高了30％至40％。微波P比具有IC _50的天然levan更容易抑制HCT-116和A549癌细胞系的增殖对于HCT-116和A549细胞，分别为1.03 mg / mL和1.38 mg / mL。根据细胞周期分析，用天然左聚糖及其衍生物处理的细胞保留在亚G1期，而微波P处理则增加了细胞凋亡的比例。此外，微波P除了诱导caspase-9和caspase-3的表达外，还有效地上调了促凋亡标记Bax和下调了抗凋亡标记Bcl-2。这些发现表明，通过微波辅助合成磷酸化的莱万显示出比天然莱万或通过传统长期加热磷酸化的莱万提高的抗氧化剂和抗肿瘤活性。特别是，微波P具有抗增殖活性，并且可以通过癌细胞中的线粒体途径诱导凋亡。