Natural Products Discovery and Characterization Through Network Collaborations

通过网络合作发现和表征天然产品

基本信息

批准号：
9556636
负责人：
james mcmahon
金额：
$ 128.55万
依托单位：
DIVISION OF BASIC SCIENCES - NCI
依托单位国家：
美国
项目类别：
财政年份：
资助国家：
美国
起止时间：
至
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/9556636
关键词：
Advanced Development Alkaloids Amidines Architecture Biochemical Biochemistry Biocompatible Materials Bioinformatics Biological Biological Assay Biology Cancer Biology Carbon Cell Line Cell physiology Cells Cellular biology Chemicals Chemistry Clinical Collaborations Collection Cyclodepsipeptides Data Data Analyses Development Disease EP300 gene Ecuadorian Evaluation Exhibits Fractionation Guanidines HIF1A gene HIV Imidazole Individual Industrialization Laboratories Lead Malignant Neoplasms Manuscripts Marines Microbe Molecular Molecular Probes Molecular Target Mutate Names Natural Products Natural Products Chemistry New Agents Nitrogen One-Step dentin bonding system Oxygen Pain Pharmaceutical Preparations Pharmacology Phosphotransferases Plants Play Porifera Portugal Preparation Process Proteins Publications Pyrimidine Reaction Reagent Resources Role Scientist Series Sesquiterpenes Skeleton Source Specificity Structure Synthesis Chemistry Technology Testing Therapeutic Transcription Coactivator Triterpenes United States National Institutes of Health Universities cancer cell colon cancer cell line cytotoxic experience experimental study high throughput screening inhibitor/antagonist interdisciplinary approach marine organism melanoma novel polyol preclinical development professor response scaffold screening skills spectroscopic data structural biology tumor

项目摘要

We utilized high throughput screening technologies to help identify compounds and extracts that can specifically interact with or modulate the function of selected biochemical targets or processes. Bioassay-guided chemical fractionation of natural products extracts is employed to isolate and purify the individual bioactive compounds. Identification and structural characterization of these compounds provides new structural classes or molecular scaffolds for the development of potential drug leads or biological probes that can interact with the desired molecular target. In addition to extensive NMR and mass spectroscopic analyses, our efforts include rigorous evaluation of a new compound's potency, molecular target specificity, and mode of action. A new class of marine alkaloids named the eudistidines was identified and these metabolites were shown to disrupt interactions between the transcriptional co-activator p300 and HIF-1 alpha. These compounds have an unprecedented fused tetracyclic core skeleton, comprised of two pyrimidine rings fused with an imidazole ring that also contains embedded guanidine and amidine functionalities. The novel molecular architecture of eudistidine C was initially assigned from a comprehensive analysis of spectroscopic data (primarily NMR and MS). Elucidation of the structure presented some very significant challenges due to a lack of protonated carbon and nitrogen atoms in the core of the molecule. Application of sophisticated NMR experiments and pains-taking data analysis finally allowed assignment of the novel structures. A synthetic effort to verify the structure and provide additional material for biological evaluates was accomplished in conjunction with staff in the Chemical Biology Laboratory. The novel heterocyclic architecture of eudistidine C was confirmed by a one-step synthesis that involved reaction of eudistidine A with a methoxyphenyl-aminoimidazole reagent to generate a synthetic product that was identical in all respects with the natural product. The eudistidine C scaffold, which can now be synthesized in a straightforward and scalable manner, may provide potential therapeutic lead compounds or molecular probes to study p300/HIF-1 alpha interactions and the role these proteins play in tumor response to low oxygen conditions. An EIR was filed to cover the discovery and synthesis of the eudistidines and a high impact publication that describes their isolation, structural elucidation, and synthesis has been prepared. A series of semisynthetic plant triterpene derivatives were obtained from Professor Jorge Salvador at the University of Coimbra, Portugal and tested in all of the MTL and DTP assays. One of these compounds showed selective cytotoxic activity against melanoma and colon cancer cell lines and Cell Miner bioinformatic analysis of the NCI 60-cell data showed a strong correlation with clinically used B-Raf inhibitors. All of the sensitive cell lines have V600E mutated B-Raf (constitutive active B-Raf). The clinical agents inhibit the kinase activity of B-Raf. The compound we investigated did not inhibit the kinase activity of B-Raf or C-Raf, but it did result in significant reductions in cellular levels of B-Raf and C-Raf. An EIR and a manuscript describing these findings is in preparation. Other notable discoveries included stellettapeptins A and B, novel HIV-inhibitory cyclic depsipeptides from the sponge Stelletta sp., and stelliosphaerol A and B, sesquiterpene-polyol conjugates from an Ecuadorian fungal endophyte. The latter project was done in conjunction with Professor Scott Strobel at Yale University.

我们利用高吞吐量筛选技术来帮助识别可以与所选生化目标或过程的功能特别相互作用或调节功能的化合物和提取物。天然产物提取物的生物测定指导化学分级用于分离和纯化单个生物活性化合物。这些化合物的鉴定和结构表征为可能与所需的分子靶标相互作用的潜在药物铅或生物学探针提供了新的结构类别或分子支架。除了广泛的NMR和质谱分析外，我们的努力还包括对新化合物的效力，分子目标特异性和作用方式的严格评估。确定了一类新的名为Eudistidines的海洋生物碱，这些代谢产物被证明会破坏转录共激活器P300和HIF-1 Alpha之间的相互作用。这些化合物具有前所未有的融合四环素核心骨骼，由两个与咪唑环融合的嘧啶环组成，其中还含有嵌入式鸟根和胺功能。 Eudistidine C的新型分子结构最初是从光谱数据的全面分析（主要是NMR和MS）中分配的。由于分子核心缺乏质子化的碳和氮原子，因此对结构的阐明提出了一些非常重大的挑战。复杂的NMR实验和疼痛数据分析的应用最终允许分配新结构。与化学生物学实验室的员工一起完成了验证结构并为生物评估提供其他材料的合成努力。一步合成的新型eudistidine C的新型杂环结构证实，eudistidine A与甲氧基苯基 - 氨基咪唑试剂的反应，以产生与自然产物相同的合成产物。现在可以直接且可扩展的方式合成的Eudistidine C支架可以提供潜在的治疗性铅化合物或分子探针来研究p300/HIF-1αα相互作用，并且这些蛋白质在肿瘤对低氧条件的反应中起着作用。提出了一个EIR，以涵盖eudistidines的发现和合成，并为描述其隔离，结构阐明和综合的高影响出版物进行了高影响。从Coimbra大学的Jorge Salvador教授那里获得了一系列的半合成植物三萜衍生物，并在所有MTL和DTP分析中进行了测试。其中一种化合物显示了针对黑色素瘤和结肠癌细胞系的选择性细胞毒性活性，对NCI 60细胞数据的细胞矿物生物信息学分析显示，与临床使用的B-RAF抑制剂有很强的相关性。所有敏感的细胞系都有V600E突变的B-RAF（组成型活性B-RAF）。临床剂抑制B-RAF的激酶活性。我们研究的化合物没有抑制B-RAF或C-RAF的激酶活性，但确实导致B-RAF和C-RAF的细胞水平显着降低。描述这些发现的EIR和手稿正在准备。其他值得注意的发现包括星状肽A和B，来自海绵星菌Sp。的新型HIV抑制性循环抑制剂，以及恒星磷脂A和B，倍苯二酚 - 苯乙烯 - 苯酚偶联物，来自eCuadorian fungal endophyte。后一个项目与耶鲁大学的斯科特·斯特罗贝尔（Scott Strobel）教授一起完成。