Biomimetic synthesis, biosynthetic pathway engineering and structure activities studies of unique glycosolyated macrolactams

微生物共生体的化学分析产生了更深入的了解共生系统的演变，并在同一时间赠款访问本质上具有生物活性的天然产品。直到现在，这些天然产物对发现具有潜在应用于人类健康的新型抗生素的影响才被认识到。然而，需要新的抗生素来源，因为抗生素的使用不可避免地选择耐药病原体。在多重耐药菌株如耐甲氧西林金黄色葡萄球菌（MRSA）和耐万古霉素肠球菌（VRE）的时代，对新类别抗生素和新靶标的发现的需求很高。从广义上讲，该项目旨在阐明真菌生长白蚁的细菌共生体Amycolatopsis M39的化学组成。这种方法的吸引人的特征和目标包括：（1）化学研究不足的共生细菌及其各自的次级代谢产物的基因组驱动分析;（2）现代半合成和全合成，以评估有趣的目标结构和生物合成中间体的绝对结构;和（3）生成内在生物活性次级代谢产物的底物库。我们打算利用有机合成，DNA测序和基因组挖掘方法以及合成生物学的最新进展。我们的目标是将天然产物与其基因组基础联系起来，了解其生物合成的基础，并利用产生的信息建立一个更属的发现和评估平台。该项目得益于与其他在化学生态学和生物合成方面具有强大专业知识的学术合作伙伴的合作，以及内部药理学和临床前评估平台的存在。该提案的关键要素是学科之间的协同互动，因为合作研究联盟在天然产物化学，化学分析和有机合成化学领域提供了广泛的专业知识，这是解决所概述的雄心勃勃的任务所必需的。本项目的具体目标如下：（1）我们将通过使用有效的模块化策略来确定大白蚁霉素A的绝对结构及其核心结构，该策略同时为生物合成途径研究提供硫酯前体。将（生物）合成结构简化的macrotermycins，以进行结构-活性研究。(2)我们的目标是了解和随后操纵的推定的macrotermycins的生物合成途径，使用异源表达系统，可以转移到其他尚未完全表征的基因簇内M39的分析，以充分收获的化学潜力。(3)我们的目的是阐明其他编码的生物合成基因簇诱导的手段，并确定各自的次级代谢产物。

The chemical analysis of microbial symbionts yields a deeper understanding of the evolution of symbiotic systems, and at the same time grants access to intrinsically bioactive natural products. It is only now that the impact of these natural products on the discovery of novel antibiotics with potential applications for human health is being realized. Yet, novel sources of antibiotics are needed since the use of antibiotics inevitably selects for resistant pathogens. In times of multiresistant strains such as methicillin resistant Staphylococcus aureus (MRSA) and vancomycin resistant Enterococci (VRE), the demand for new classes of antibiotics and the discovery of new targets, is high. Broadly, the project aims to elucidate the chemical repertoire of a bacterial symbiont, Amycolatopsis M39, of fungus-growing termites. Attractive features and goals of this approach include: (1) the genome-driven analysis of chemically poorly studied symbiotic bacteria and their respective secondary metabolites; (2) modern semi and total synthesis to evaluate the absolute structure of pharmacologically interesting target structures and biosynthetic intermediates; and (3) the generation of a substrate library of intrinsically bioactive secondary metabolites. We intend to capitalize on recent advances in organic synthesis, DNA sequencing and genome mining approaches, as well as synthetic biology. We aim to link natural products to their genomic basis to understand the underpinnings of their biosynthesis, and we will use the generated information to build up a more genera discovery and evaluation platform.This project benefits from collaborations with other academic partners having strong expertise in chemical ecology and biosynthesis, and the presence of an in-house pharmacological and pre-clinical evaluation platform. Key element of this proposal is the synergistic interaction between the disciplines as the collaborative research consortium offers a broad range of expertise in the fields of natural product chemistry, chemical analytics and organic synthetic chemistry, which is necessary to tackle the outlined ambitious tasks. The following three specific aims will be addressed within this project: (1) We will determine the absolute structure of macrotermycin A and its core structure by using an efficient and modular strategy, a strategy which provides at the same time thioester precursors for biosynthetic pathway studies. Structurally simplified macrotermycins will be (bio)synthesized to enable structure-activity studies. (2) We aim to understand and subsequently manipulate the putative biosynthetic pathway of macrotermycins using a heterologous expression system that can be transferred to the analysis of other not yet fully characterized gene clusters within M39 to fully harvest the chemical potential. (3) We aim to elucidate the means by which other encoded biosynthetic gene clusters are induced and identify the respective secondary metabolites.