Pilot-Scale Libraries of Marine Cyanobacterial Natural Products

描述（由申请人提供）：蓝藻是地球上最古老的生物之一，它们在陆地、淡水和海洋环境中无处不在，这表明它们在竞争环境中取得了成功。许多蓝藻产生一系列不同的次生代谢产物，据估计，其中一些生命形式将高达10%的基因组用于次生代谢，可能是为了防御目的，以获得竞争优势。迄今为止，分离出的蓝藻次级代谢物（天然产物）仅在很少的分析中进行了测试，但在细胞毒性或靶向性分析中发现抗癌药物的命中率相当高。然而，相对较少的探索，海洋蓝藻产生的次生代谢物是特权结构，已经很好地优化与生物靶标相互作用。本研究的总体目标是从底栖海洋蓝藻中分离出已知的和发现新的天然产物，这些产物将具有独特的结构特征，并将占据MLSMR中尚未表示的生物学相关化学空间。此外，将努力确定培养海洋底栖蓝藻的最佳方法，以优化目标化合物的生产，并提供可持续的化合物供应。首先，将从美国太平洋和佛罗里达水域的几个地点重新收集具有丰富次级代谢物含量的“超级”蓝藻，并重新分离和充分表征结构多样的代谢物。其次，我们将确定培养海洋底栖蓝藻的最佳方法，以优化目标化合物的生产，并提供可持续的化合物供应。第三，将从西太平洋关岛周围和佛罗里达州的几个地点收集尚未表征的蓝藻。提取物将被层析分离，并通过核磁共振分析次级代谢物，即肽和肽-聚酮复合物的存在。化合物通过高效液相色谱法纯化，结构通过光谱技术，特别是核磁共振和质谱分析来阐明。公共卫生相关性：海洋蓝藻产生的天然产物结构独特，具有生物活性，并且尚未对其对抗疾病相关目标的活性进行广泛测试。这些天然产物将显著丰富MLSMR的多样性。

DESCRIPTION (provided by applicant): Cyanobacteria are among the most ancient organisms on Earth and their ubiquitous presence to this day in terrestrial, freshwater and marine environments is indication for their success in competitive situations. Many cyanobacteria produce an array of different secondary metabolites, and it is estimated that some of these life forms devote up to 10% of their genome to secondary metabolism, presumably for defense purposes to gain competitive advantages. Cyanobacterial secondary metabolites (natural products) isolated so far have only been tested in very few assays, yet hit rates in cytotoxicity or target-based assays towards anticancer drug discovery have been quite high. Yet relatively little explored, secondary metabolites produced by marine cyanobacteria are privileged structures that are already well-optimized to interact with biological targets. The overall goal of this proposed research is to isolate known and to discover new natural products from benthic marine cyanobacteria that will possess unique structural features and will occupy biologically relevant chemical space not yet represented in the MLSMR. Furthermore, efforts will be undertaken to determine the best methods for culturing marine benthic cyanobacteria that optimize production of targeted compounds and also provide sustainable compound supply. First, "superproducing" cyanobacteria with proven rich secondary metabolite content will be re-collected from several locations in US waters in the Pacific and Florida and structurally diverse metabolites re-isolated and fully characterized. Second, we will determine the best methods for culturing marine benthic cyanobacteria that optimize production of targeted compounds, which also provides sustainable compound supply. Third, yet uncharacterized cyanobacteria will be collected from several locations in the western Pacific around Guam and in Florida. Extracts will be chromatographically fractionated and analyzed by NMR for the presence of secondary metabolites, i.e., peptides and peptide-polyketide hybrids. Compounds are purified by HPLC and structures elucidated by spectroscopic techniques, particularly NMR and mass spectrometry. PUBLIC HEALTH RELEVANCE: Marine cyanobacteria produce natural products which are structurally unique, biologically active, and have not been extensively tested for their activities against disease-relevant targets. These natural products will significantly enrich the diversity of the MLSMR.