三株深海微生物中抗食物过敏活性的物质基础及其作用机制研究

Food allergy is a potentially life-threatening condition with increasing incidence in the last few decades. However, there are no approved treatments currently. Therefore, it is urgent to search for anti-food allergic lead compounds. As the largest preservation center of the marine microbes, the Marine Culture Collection of China (MCCC) owns over 20,000 strains at the present. Previously, we conducted anti-food allergic tests on 2923 crude extracts produced by 315 deep-sea-derived microorganisms of MCCC. As a result, three strains showed potent effect under the concentration of 10 μg/mL with inhibition rates of 100, 90, and 76 %, respectively, compared to 41% of the positive control, loratadine, in the same concentration. Moreover, they were characteristics of large output and rich secondary metabolites. Therefore, they were selected in this project to search for anti-food allergic secondary metabolites using bio-guided isolation. The most potent bioactive compounds will be accumulated by large-scale fermentation under optimized conditions. Then it will be subjected to further bioactive mechanism studies. In general, the project will provide the anti-food allergic lead compounds from marine microorganisms with the self-property right completely owned by our country.

食物过敏性疾病多发难治，严重影响患者的生活质量，严重时可危及生命。然而，至今临床上尚无真正意义上的抗食物过敏药物，因此抗食物过敏药物的研发迫在眉睫。中国海洋微生物菌种保藏管理中心是国际上最大的海洋微生物库，目前库藏菌株2万多株。前期我们对其中315株深海微生物的2923个粗提物进行了抗食物过敏活性筛选，发现3株深海微生物具有很强的活性，在10μg/mL的浓度下，抑制率分别达到了100、90、76%（相同浓度下，阳性对照药氯雷他定的抑制率为41%）。且产量大、代谢产物丰富。因此，本项目拟以该3株深海微生物为研究对象，以活性为导向，从中寻找发现抗食物过敏活性次级代谢产物，对强活性的目标化合物进行优化发酵和大量富集，深入研究其作用机制，以期发现抗食物过敏先导化合物。通过本项目的研究，最终有望获得具有我国完全自主知识产权的海洋微生物创新药物。

海洋微生物是新药研发过程中，活性先导化合物发现的重要来源，已逐渐成为天然产物研究的重点。本项目在前期研究的基础上，以具有抗食物过敏活性的三株深海微生物为研究对象，通过微生物发酵、次级代谢物提取、分离、结构鉴定、活性测试等工作，从中寻找发现抗食物过敏的活性化合物。项目执行四年来，我们完成了三株深海微生物Penicillium griseofulvum MCCC 3A00225、Botryotinia fuckeliana MCCC 3A00494和Penicillium allii-sativi MCCC 3A00580系统的化学成分研究，从中一共分离得到78个化合物，其中新化合物31个，极大丰富了天然产物的结构类型。经体外抗食物过敏活性测试（IgE介导的RBL-2H3细胞脱颗粒试验），发现3个强活性化合物：3-deacetylcitreohybridonol、3,4-dihydro-3,4,8-trihydroxy-1(2H)-naphthalenone、viridicatol，其抑制肥大细胞脱颗粒的IC50值分别为：14.8 μM、27.9 μM和37.4 μM，是阳性对照药氯雷他定（IC50 = 91.6 μM）的3～6倍。我们选择活性最强的3-deacetylcitreohybridonol进行初步的机制研究，发现其可显著减少肥大细胞的脱颗粒效应，其机制可能是通过抑制细胞内Ca2+的聚集，减少组胺和TNFα的释放，提示3-deacetylcitreohybridonol为抗食物过敏活性先导化合物。研究至今，本项目一共发表SCI论文13篇，申请专利3项，为从深海微生物来源的抗食物过敏药物的研发提供了模式结构和药物前体，同时也为具有我国完全自主知识产权的海洋药物研发奠定了坚实的物质基础。