Bacillus natto TK-1 产脂肽的结构鉴定及其诱导MCF-7细胞凋亡的研究

利用酸沉、醇提和薄层层析等方法从Bacillus natto TK-1发酵液中分离脂肽，经过HPLC、ESI MS和IR分析可知分离物是分子量为1036Da的脂肪酸链上有15个碳的环状脂肽surfactin。细胞增殖抑制实验显示surfactin在体外能抑制肿瘤细胞MCF-7的增殖，并且呈现出浓度和时间依赖关系，其中细胞被处理48 h时的IC50是38.77mg/L。通过HE染色观察和TUNEL实验发现surfactin可诱导MCF-7细胞凋亡，而且这种抑制作用呈现明显的时间依赖性。

The Structural Identification and Antitumor Activity on MCF-7 Cells of Surfactin from Bacillus subtilis TK-1

This thesis aimed at the Bacillus natto TK-1 screened out from Natto. The authors purified the lipopeptide using Thin-Layer Chromatography (TLC), and investigated its anti-tumor activity. After acid precipitation and methanol extraction, the lipopeptide was separated on TLC. Then the authors get the monomer surfactin which molecular weight is 1036D through the High performance liquid chromatography (HPLC), electro spray ionization-mass spectrometry (ESI-MS) and infrared (IR). MTT method was implied to testify the anti-tumor activity of the purified sample from TLC. The results indicated a concentration and time-dependent relationships. After 48h, their IC50 were 40 mg/L. The detection with inverted microscope fluorescence microscope displays that the surfactin will cause a series of Morphological changes to the cells. In TUNEL experiment, the authors noticed that surfactin has the ability to induce apoptosis, besides this inhibition shows an obvious time-dependent relationship.