:4-Hydroxy-2-alkylquinoline

{{Short description|Class of chemical compounds}}

File:4-Hydroxy-2-heptylquinoline.svg

4-Hydroxy-2-alkylquinolines (HAQs) are a class of intracellular signaling molecules associated with iron chelation. HAQs are produced by various types of bacteria, such as Pseudomonas aeruginosa,{{cite journal | author = Luckner, M. | author2 = Ritter, C. | title = Biosynthesis of the 2-n-alkyl-4-hydroxyquinolines by Pseudomonas aeruginosa | journal = Tetrahedron Letters | year = 1965 | volume = 12 | pages = 741–744 | doi = 10.1016/s0040-4039(01)83977-0 | pmid = 14291872 }} and are involved in quorum sensing.

The overproduction of these molecules, with their pro-oxidative effects, leads to antibiotic properties.