Extracting Value from Marine and Microbial Natural Product Artifacts and Chemical Reactivity

Natural products have and continue to be a remarkable resource, rich in structural di-versity, and endowed with valuable chemical and biological properties that have ad-vanced both science and society. Some natural products, especially those from marine organisms, are chemically reactive, and during extraction and handling can partially or totally transform into artifacts. All too often overlooked or mischaracterised as natural products, artifacts can be invaluable indicators of a uniquely evolved and primed chemical space, with enhanced chemical and biological properties highly prized for drug discovery. To demonstrate this potential, we review a wide selection of marine and mi-crobial case studies, revealing the factors that initiate artifact formation (e.g. solvents, heat, pH, light and air oxidation) and commenting on the mechanisms behind artifact for-mation. We conclude with reflections on how to recognise and control artifact formation, and how to exploit knowledge of artifacts as a window into unique regions of natural product chemical space — to better inform the development of future marine bioproducts.