... ChemBioChem, 12: 850–853. ... Volume: Issue: Page ... precursor 2-heptyl-4(1H)-quinolone (HHQ) are used (see Scheme 1).4 The pqs system is involved in the regulation of P. aeruginosa virulence such as pyocyanin biosynthesis,5 biofilm formation and maturation,6 the production ...