(a) Native AHLs
(b) AHLs analogues
(c) Compounds with lactone ring analogues
Figure 3: Structure of natural and synthetic AHL-based compounds which inhibit biofilm formation by P. aeruginosa. (a) Native N-acyl-l-homoserine lactone, signal molecules of P. aeruginosa (C4-HSL and 3-oxo-C12-HSL), (b) synthetic analogue of AHLs with side aromatics and synthetic analogues of AHLs with modified lactone rings, and (c) natural (manoalide, penicillic acid, and patulin), and synthetic (furanones) compounds with lactone ring analogues.