3oxooctanoylhomoserine

3-oxooctanoylhomoserine, more commonly referred to as 3-oxo-C8-homoserine lactone (3-oxo-C8-HSL), is a member of the N-acyl homoserine lactone (AHL) family of quorum-sensing signaling molecules produced by many Gram-negative bacteria. It comprises a homoserine lactone ring linked to an eight-carbon acyl side chain with a keto group at the third carbon.

In bacterial communication systems, 3-oxo-C8-HSL acts as an autoinducer. It is synthesized by LuxI-family enzymes and released into the environment. As the bacterial population grows, the molecule accumulates and diffuses back into cells, where it binds to LuxR-type transcription factors. This interaction alters gene expression in a density-dependent manner, coordinating collective behaviors such as biofilm formation, virulence factor production, or bioluminescence in some species. The exact regulon and physiological outcomes are species-specific and can vary.

Synthesis and occurrence: The LuxI-type synthases use S-adenosylmethionine and acyl carrier protein-linked substrates to produce AHLs, including 3-oxo-C8-HSL. The compound has been identified in various genera of Proteobacteria, reflecting the widespread role of AHL-mediated quorum sensing in microbial communities.

Functional significance and research: 3-oxo-C8-HSL is often studied as part of broader efforts to understand intercellular signaling in bacteria and to explore anti-virulence strategies. Analytical detection commonly employs AHL biosensors or mass spectrometry. Research aims include mapping species-specific signaling networks, understanding cross-talk among AHLs, and developing quorum-sensing modulators for medical or agricultural applications.