Diverse Molecular Libraries from Unique Endosymbiotic Fungi

描述（由申请人提供）：真菌，特别是那些与其他生物共生的真菌，是代表新结构和引发多种生物反应的小分子天然产物的丰富来源，但迄今为止，它们仍未得到充分开发。该项目的目标是生成来自四个不同的美国生态区的精心鉴定和策划的内生真菌和内生地衣真菌菌株的独特集合的分子库。具体目标1、 将以前从未研究过其次级代谢产物的真菌物种的选定菌株以小规模培养，并进行HPLC分析、LC-MS和13 C-NMR去复制，以选择产生新的、稀有的和/或含羰基化合物的高产菌株。在目标2中，将大规模培养有前途的真菌菌株，并对其进行处理，以分离NIH分子库小分子储存库（MLSMR）新的天然产物。目标3将侧重于一种创新的方法，在与二胺试剂肼的高产率反应中，使真菌次级代谢产物中普遍存在的含CO天然产物化学多样化。这将导致含有N-N部分的类似物在自然界中非常罕见，但在“药物样”组合和合成分子中很常见。在本项目实施过程中，将产生具有独特结构特征并占据MLSMR中迄今未代表的生物相关化学空间的化合物，并提交给MLSMR，这构成了本提案的目标4。该应用的主要优势是：（i）以前未对其次级代谢产物进行研究的独特的基因型内共生真菌菌株集合的可用性;（ii）待生成的结构的生物相关性，这些结构在MLSMR中表现不佳;（iii）小组在微生物学及天然产品化学方面的往绩，以及（iv）该小组在将含羰基的真菌代谢物转化成其含N-N键的类似物方面取得的成功，其中许多具有前所未有的结构和潜在的生物活性。因此，由于其天然产物来源和/或“药物样”结构，在这些文库中发现与人类疾病相关的活性和/或影响基因功能、信号传导途径和疾病相关生物过程的可能性将更大。 公共卫生相关性：微生物天然产物作为鉴定人类疾病的新治疗靶点的工具和作为药物开发的先导结构具有丰富的历史。该项目提出从内共生真菌中产生多样化的分子库，这些分子库具有与细胞靶点相互作用的潜力，并作为药物开发的先导分子，因此将对公共卫生产生重大影响。

DESCRIPTION (provided by applicant): Fungi, especially those which live in symbiotic association with other organisms, are rich sources of small-molecule natural products representing novel structures and eliciting diverse biological responses, but to date they remain underexplored. The goal of this project is to generate molecular libraries derived from a unique collection of carefully identified and curated endophytic and endolichenic fungal strains from four diverse U.S. eco-zones. In Specific Aim 1, selected strains of fungal species which have never been investigated previously for their secondary metabolites will be cultured in small-scale and subjected to HPLC analysis, LC-MS and 13C-NMR dereplication to select high-yielding strains producing new, rare, and/or carbonyl-containing compounds. In Aim 2, promising fungal strains will be cultured on large-scale and processed to isolate natural products new to the NIH Molecular Libraries Small-Molecule Repository (MLSMR). Aim 3 will focus on an innovative approach of chemically diversifying CO-containing natural products prevalent among fungal secondary metabolites in a high-yielding reaction with the diamine reagent, hydrazine. This will result in analogs containing N-N moieties very rare in nature but common among "drug-like" combinatorial and synthetic molecules. During the course of this project compounds possessing unique structural features and occupying biologically-relevant chemical space hitherto not represented in the MLSMR will be generated and submitted to the MLSMR, which constitutes Aim 4 of this proposal. The major strengths of this application are: (i) availability of a collection of a unique, geno-typed endosymbiotic fungal strains not previously investigated for their secondary metabolites; (ii) biological relevance of structures to be generated that are poorly represented in the MLSMR; (iii) the track record of the group in microbiology and natural products chemistry, as well as (iv) the success the group has had in converting carbonyl-containing fungal metabolites into their N-N bond-containing analogs, many with unprecedented structures and potential bioactivities. Thus, the likelihood of discovering activities relevant to human diseases and/or affecting the functions of genes, signaling pathways, and disease-related biological processes will be greater within these libraries due to their natural product origin and/or "drug-like" structures. PUBLIC HEALTH RELEVANCE: Microbial natural products have a rich history for their utility as tools for identification of novel therapeutic targets for human diseases and as lead structures for drug development. This project proposes to generate diverse molecular libraries from endosymbiotic fungi with potential to interact with cellular targets and serve as lead molecules for drug development and therefore will have a great impact on public health.