Environmental Processing of Lipids Driven by Aqueous Photochemistry of α‑Keto Acids

• Published in: ACS central science Vol. 4; no. 5; pp. 624 - 630
• Main Authors: Rapf, Rebecca J, Perkins, Russell J, Dooley, Michael R, Kroll, Jay A, Carpenter, Barry K, Vaida, Veronica
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 23-05-2018; American Chemical Society (ACS)
• Subjects: INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
• ISSN: 2374-7943; 2374-7951
• DOI: 10.1021/acscentsci.8b00124

Sunlight can initiate photochemical reactions of organic molecules though direct photolysis, photosensitization, and indirect processes, often leading to complex radical chemistry that can increase molecular complexity in the environment. α-Keto acids act as photoinitiators for organic species that are not themselves photoactive. Here, we demonstrate this capability through the reaction of two α-keto acids, pyruvic acid and 2-oxooctanoic acid, with a series of fatty acids and fatty alcohols. We show for five different cases that a cross-product between the photoinitiated α-keto acid and non-photoactive species is formed during photolysis in aqueous solution. Fatty acids and alcohols are relatively unreactive species, which suggests that α-keto acids are able to act as radical initiators for many atmospherically relevant molecules found in the sea surface microlayer and on atmospheric aerosol particles.