The Natural Products Atlas : an open access knowledge base for microbial natural products discovery

Despite rapid evolution in the area of microbial natural products chemistry, there is currently no open access database containing all microbially produced natural product structures. Lack of availability of these data is preventing the implementation of new technologies in natural products science. Specifically, development of new computational strategies for compound characterization and identification are being hampered by the lack of a comprehensive database of known compounds against which to compare experimental data. The creation of an open access, community-maintained database of microbial natural product structures would enable the development of new technologies in natural products discovery and improve the interoperability of existing natural products data resources. However, these data are spread unevenly throughout the historical scientific literature, including both journal articles and international patents. These documents have no standard format, are often not digitized as machine readable text, and are not publicly available. Further, none of these documents have associated structure files (e.g., MOL, InChI, or SMILES), instead containing images of structures. This makes extraction and formatting of relevant natural products data a formidable challenge. Using a combination of manual curation and automated data mining approaches we have created a database of microbial natural products (The Natural Products Atlas, www.npatlas.org) that includes 24 594 compounds and contains referenced data for structure, compound names, source organisms, isolation references, total syntheses, and instances of structural reassignment. This database is accompanied by an interactive web portal that permits searching by structure, substructure, and physical properties. The Web site also provides mechanisms for visualizing natural products chemical space and dashboards for displaying author and discovery timeline data. These interactive tools offer a powerful knowledge base for natural products discovery with a central interface for structure and property-based searching and presents new viewpoints on structural diversity in natural products. The Natural Products Atlas has been developed under FAIR principles (Findable, Accessible, Interoperable, and Reusable) and is integrated with other emerging natural product databases, including the Minimum Information About a Biosynthetic Gene Cluster (MIBiG) repository, and the Global Natural Products Social Molecular Networking (GNPS) platform. It is designed as a community-supported resource to provide a central repository for known natural product structures from microorganisms and is the first comprehensive, open access resource of this type. It is expected that the Natural Products Atlas will enable the development of new natural products discovery modalities and accelerate the process of structural characterization for complex natural products libraries

Total Synthesis and NMR-Based Mechanistic Elucidation of Non-Enzymatic Natural Products

Natural products have been a source of inspiration for modern medicine, novel chemistries, and understanding the ecological systems with which organisms inhabit. Natural products are traditionally biosynthesized via enzymes and other chemistry catalyzing proteins. But within that framework there exists natural products that contain one or more non-enzymatic steps in their biosynthesis. In the context of this thesis, we have synthesized two natural products that contain one or more non-enzymatic steps in their biosynthesis: oxazinin A and the pyonitrins. To further elucidate these rare biosynthetic mechanisms, we have utilized 1H-15N NMR with isotopically labeled substrates to study the formation of these natural products and gain further insight into how these molecules form. This information allows us to not only see trends in terms of what kinds of natural products may form non-enzymatically but to exploit that non-enzymatic chemistry to get to natural products and natural product analogs in higher yields and faster times than traditional isolation. Furthermore, these natural products can be combined to form novel unnatural products that are not found in nature but may have ameliorated or altered bioactivity

Synthesis and Investigation of the Abiotic Formation of Pyonitrins A-D.

Pyonitrins A-D are recently isolated natural products from the insect-associated Pseudomonas protegens strain, which were isolated from complex fractions that exhibited antifungal activity via an in vivo murine candidiasis assay. Genomic studies of Pseudomonas protegens suggested that pyonitrins A-D are formed via a spontaneous nonenzymatic reaction between biosynthetic intermediates of two well-known natural products pyochelin and pyrrolnitrin. Herein we have accomplished the first biomimetic total synthesis of pyonitrins A-D in three steps and studied the nonenzymatic formation of the pyonitrins using 15N NMR spectroscopy

Biomimetic Total Synthesis and Investigation of the Non-Enzymatic Chemistry of Oxazinin A.

We report the first total synthesis of an antimycobacterial natural product oxazinin A that takes advantage of a multi-component cascade reaction of anthranilic acid and a precursor polyketide containing an aldehyde. The route utilized for the synthesis of the pseudodimeric oxazinin A validates a previously proposed biosynthetic mechanism, invoking a non-enzymatic pathway to the complex molecule. We found a 76 : 10 : 9 : 5 ratio of oxazinin diastereomers from the synthetic cascade, which is an identical match to that found in the fermentation media from the fungus Eurotiomycetes 110162. Further investigation of the non-enzymatic formation of oxazinin A using 1 H-15 N HMBC NMR spectroscopy allowed for a plausible determination of the stepwise mechanism. The developed route is highly amenable for the synthesis of diverse sets of analogs around the oxazinin scaffold to study structure-activity relationships (SAR)

The Natural Products Atlas - data download

Download files from the Natural Products Atlas (npatlas.org). van Santen, J. A.; Jacob, G.; Leen Singh, A.; Aniebok, V.; Balunas, M. J.; Bunsko, D.; Carnevale Neto, F.; Castaño-Espriu, L.; Chang, C.; Clark, T. N.; Cleary Little, J. L.; Delgadillo, D. A.; Dorrestein, P. C.; Duncan, K. R.; Egan, J. M.; Galey, M. M.; Haeckl, F. P. J.; Hua, A.; Hughes, A. H.; Iskakova, D.; Khadilkar, A.; Lee, J.-H.; Lee, S.; LeGrow, N.; Liu, D. Y.; Macho, J. M.; McCaughey, C. S.; Medema, M. H.; Neupane, R. P.; O’Donnell, T. J.; Paula, J. S.; Sanchez, L. M.; Shaikh, A. F.; Soldatou, S.; Terlouw, B. R.; Tran, T. A.; Valentine, M.; van der Hooft, J. J. J.; Vo, D. A.; Wang, M.; Wilson, D.; Zink, K. E.; Linington, R. G.* "The Natural Products Atlas: An Open Access Knowledge Base for Microbial Natural Products Discovery”, ACS Central Science, 2019, 5, 11, 1824-1833. 10.1021/acscentsci.9b00806 Now includes ontological data from: NP Classifier - https://npclassifier.ucsd.edu/ ClassyFire - http://classyfire.wishartlab.com/ Including archived versions, extra data download types, and new MIBiG and GNPS IDs Includes dump of compounds deemed out of scope and removed from DB on May 19, 2021. The latest versions (v2021_08 onward) include the ontological data in the full JSON download

The Natural Products Atlas - data download

Download files from the Natural Products Atlas (npatlas.org). van Santen, J. A.; Jacob, G.; Leen Singh, A.; Aniebok, V.; Balunas, M. J.; Bunsko, D.; Carnevale Neto, F.; Castaño-Espriu, L.; Chang, C.; Clark, T. N.; Cleary Little, J. L.; Delgadillo, D. A.; Dorrestein, P. C.; Duncan, K. R.; Egan, J. M.; Galey, M. M.; Haeckl, F. P. J.; Hua, A.; Hughes, A. H.; Iskakova, D.; Khadilkar, A.; Lee, J.-H.; Lee, S.; LeGrow, N.; Liu, D. Y.; Macho, J. M.; McCaughey, C. S.; Medema, M. H.; Neupane, R. P.; O’Donnell, T. J.; Paula, J. S.; Sanchez, L. M.; Shaikh, A. F.; Soldatou, S.; Terlouw, B. R.; Tran, T. A.; Valentine, M.; van der Hooft, J. J. J.; Vo, D. A.; Wang, M.; Wilson, D.; Zink, K. E.; Linington, R. G.* "The Natural Products Atlas: An Open Access Knowledge Base for Microbial Natural Products Discovery”, ACS Central Science, 2019, 5, 11, 1824-1833. 10.1021/acscentsci.9b00806 Now includes ontological data from: NP Classifier - https://npclassifier.ucsd.edu/ ClassyFire - http://classyfire.wishartlab.com/ Including archived versions, extra data download types, and new MIBiG and GNPS IDs Includes dump of compounds deemed out of scope and removed from DB on May 19, 2021. The latest versions (v2021_08 onward) include the ontological data in the full JSON download