Lux type systems work with acyl-homoserine lactone molecules like AI's. These molecules are composed of a lactonic ring and a carbonate chain of variable size connected by an amide. N-3-oxo-dodecanoyl homoserine lactone (3OC12-HSL) is the autoinducer of the Las system, while butyryl homoserine lactone (C4-HSL) is an autoinducer of the Rhl system (Figure ). 2-heptyl-3-hydroxy-4-quinolone (PQS) is the associated autoinducer to PQS system. PQS is recognized by PqsR and synthesized by multiple proteins, as PqsB, PqsC, PqsD, and others . 2-(2hydroxyphenyl)-thiazole-4-carbaldehyde (IQS) is an autoinducer for IQS system. Previous studies established the activation of QS by IQS in deficiency of Las system, generating interest for its study .