TABLE 2.

Published data of halogenated indole analogues and their impact on pathogens

Name	Structure	Phenotypic changes affected by indoles	Target pathogen	Reference
4-Fluoroindole		Inhibited biofilm formation	Candida albicans	47
5-Fluoroindole		Inhibited QS of Chromobacterium violaceum CV026; inhibited prodigiosin production, biofilm formation, swimming motility, and swarming motility	Serratia marcescens	33
6-Fluoroindole		Inhibited QS of Chromobacterium violaceum CV026; inhibited prodigiosin production, biofilm formation, swimming motility, swarming motility, protease activity, and lipase activity	Serratia marcescens	33
7-Fluoroindole		Inhibited biofilm formation, blood hemolysis of Pseudomonas aeruginosa; inhibited QS of Chromobacterium violaceum CV026; inhibited prodigiosin production, biofilm formation, swimming motility, and swarming motility of Serratia marcescens	Pseudomonas aeruginosa, Serratia marcescens	30, 33
4-Iodoindole		Inhibited biofilm formation, bacterial motility, fimbrial activity, hydrophobicity, protease activity, and indole production	Vibrio parahaemolyticus	29
5-Iodoindole		Inhibited biofilm formation of Candida albicans; inhibited prodigiosin production, biofilm formation, swimming motility, and swarming motility of Serratia marcescens; inhibited swimming motility, biofilm formation of Acinetobacter baumannii	Candida albicans, Serratia marcescens, Acinetobacter baumannii	47, 33, 50
6-Iodoindole		Inhibited biofilm formation, swimming motility, protease activity	Agrobacterium tumefaciens	48
7-Iodoindole		Inhibited biofilm formation, bacterial motility, fimbrial activity, hydrophobicity, protease activity, and indole production	Vibrio parahaemolyticus	29
4-Chloroindole		Inhibited biofilm formation, bacterial motility, fimbrial activity, hydrophobicity, protease activity, and indole production of V. parahaemolyticus; inhibited biofilm formation, swimming motility, protease activity of Agrobacterium tumefaciens; inhibited swarming and swimming motility and downregulated the expressions of virulence genes of Escherichia coli	Vibrio parahaemolyticus, Agrobacterium tumefaciens, Escherichia coli	29, 48, 49
5-Chloroindole		Inhibited swarming and swimming motility and downregulated the expressions of virulence genes of Escherichia coli	Escherichia coli	49
7-Chloroindole		Inhibited biofilm formation, bacterial motility, fimbrial activity, hydrophobicity, protease activity, and indole production	Vibrio parahaemolyticus	29