Pilot-Scale Libraries of Marine Cyanobacterial Natural Products

描述(申请人提供)：蓝藻是地球上最古老的生物之一，它们至今在陆地、淡水和海洋环境中无处不在，这表明它们在竞争中取得了成功。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其基因组的10%用于次生代谢，想必是为了防御目的，以获得竞争优势。到目前为止分离的蓝藻次生代谢物(天然产物)只在很少的测试中进行了测试，但在细胞毒性或基于靶点的抗癌药物发现测试中的命中率相当高。然而，由海洋蓝藻产生的相对较少探索的次生代谢物是特权结构，已经很好地优化了与生物靶标的相互作用。这项拟议研究的总体目标是从底栖海洋蓝藻中分离已知的并发现新的天然产物，这些产物将具有独特的结构特征，并将占据MLSMR中尚未出现的生物相关化学空间。此外，将努力确定培养海洋底栖蓝细菌的最佳方法，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已证实具有丰富次生代谢物含量的“超级生产”蓝藻，并重新分离和充分鉴定结构多样的代谢物。其次，我们将确定培养海洋底栖蓝细菌的最佳方法，以优化目标化合物的生产，从而提供可持续的化合物供应。第三，将从关岛和佛罗里达附近西太平洋的几个地点收集尚未鉴定的蓝藻。萃取物将被层析分离，并通过核磁共振分析次级代谢物的存在，即多肽和多肽-聚酮杂交物。化合物通过高效液相色谱进行纯化，并通过波谱技术，特别是核磁共振和质谱学来确定结构。与公共健康相关：海洋蓝藻产生的天然产物结构独特，具有生物活性，并且没有针对与疾病相关的目标进行广泛的活性测试。这些天然产品将极大地丰富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.