特境新Amicoumacin类抗生素的定向资源勘探和高效发现

Antibiotic-resistant bacteria and malignant tumors occurred more and more seriously in the world and already became a global challenge to public health. Antibiotics were one of main sources for anti-cancer and anti-bacterial drugs，but after excavation of antibiotics for many decades, discovery of new antibiotics suffered from a lack of high throughput analytical techniques capable of identifying structural novelty in face of a high degree of rediscoveries of known antibiotics. To solve this problem, a technique platform based on identification of UV absorbance and molecular weight of all known amicoumacin antibiotics was developed in our previous research for directly bioprospecting of amicoumacin-producing microorganisms and high-efficient discovery of new amicoumacin antibiotics. Integration of miniaturized liquid culture of microorganisms, high-efficient sample preparation and high-throughput activity screening with “HPTLC Profile/UPLC-DAD-MS” as key and core analytical technique of the platform. Two strains, which produce five new amicoumacins, were precisely found from five melanin-producing bacillus for the first time. Because some amicoumacin antibiotics possess different anti-MRSA mechanism and remarkable inhibitory activities against MRSA and cancer cell, and all known amicoumacin-producing strains can secrete melanin, our proposal will focus on discovery of new members of amicoumacins with excellent bioactivities as leading compound from melanin-producing bacillus strains collected from different special environment with strong ultraviolet radiation in china. The micro-, rapid, precise, and high-efficient discovery platform will play a pivotal role in expanding the achievement, which will encourage and enlighten the discovery of other group antibiotics.

耐药菌日益猖獗和恶性肿瘤频繁高发，对人类健康构成严重威胁。抗生素是抗菌、抗肿瘤药物重要来源，经过几十年对新抗生素的发掘，采用传统缺乏早期高效排重的研究模式使发现新抗生素效率很低。针对这一问题，申请者以HPTLC Profile/UPLC-DAD-MS为核心分析技术，集成小规模发酵、高效样品制备和高通量活性筛选，已建立一个以“紫外特征-分子量”为指针的新Amicoumacin抗生素定向资源勘探和高效发现平台，并首次以黑色素分泌为线索，从2株芽孢杆菌中获得5个新Amicoumacin抗生素。鉴于Amicoumacin抗生素具有不同机制的强抗MRSA、抗肿瘤活性，本课题拟在前期工作基础上，利用我国丰富的强辐射生态资源，从不同特境分离产黑色素芽孢杆菌，早期、微量、快速、准确地获得新Amicoumacin抗生素，为新型抗耐药菌、抗肿瘤等先导化合物发现奠定基础，也为新抗生素高效研发起到示范和启示作用。

本研究采集5个省份、4种特境的土壤及植物样品，开展了产黑色素芽孢杆菌的定向分离筛选，经抗细菌活性筛选，获得73株芽孢杆菌目标菌株，通过HPTLC Profile和UPLC-DAD-MS分析，获得8株产Amicoumacin的阳性菌株，1株新Amicoumacin产生菌株；从西藏当雄土壤来源产黑色素芽孢杆菌XZ-7发酵液中获得当雄霉素系列4个新Amicoumacin类抗生素，其中当雄霉素A对肿瘤细胞具有中等抑制活性；完成塔克拉玛干沙漠来源芽孢杆菌PJS发酵产物中新Amicoumacin类抗生素：和田霉素B-D的纯品积累、结构确定、活性评价等工作，并与北京儿童医院合作完成了和田霉素B对157株MRSA临床分离菌株体外抗菌活性研究，结果显示和田霉素B对不同来源的临床MRSA菌株显示出较好的体外抗菌活性，MIC范围为1-8μg/mL，且其与利奈唑胺联用显示出较好的协同效果；完成和田霉素A的全合成研究工作，为下一步开展动物体内活性及毒性评价奠定基础；另外，从广东省湛江红树林来源产黑色素芽孢杆菌MMB-016中发现一新型铁载体类似物，命名为tribenglthin A；从海南东寨港红树林植物样品中，发现并鉴定了一株小单孢菌科新属新种（Mangrovihabitans endophyticus gen. nov., sp. nov.）菌株。综上，本研究建立了含20个天然来源Amicoumacin化合物的实物库1个，发现新Amicoumacin化合物9个，获得抗菌新先导化合物1组（和田霉素A-D系列），完成和田霉素A的全合成工作。发表SCI论文4篇，中文核心期刊1篇，获得及申请专利各1项；参加学术会议2次，培养博士研究生4名，硕士研究生1名。Amicoumacin类抗生素具有不同于目前所有抗MRSA药物的化学结构和抗菌靶点，是潜在抗MRSA药物新的重要来源；和田霉素系列抗生素具有较好的成药潜力，为有效抗MRSA感染治疗提供了新的可能，值得进一步研究。