7 iodoindole

All moisture-sensitive reagents were manipulated under a nitrogen atmosphere using Schlenk and syringe techniques. Glassware was dried in an oven at 200°C and cooled under a nitrogen atmosphere. Palladium(II) acetate, triphenylphosphine, the diamines and the iodoindole substrates (7-iodoindole and 5-iodoindole) were purchased from Sigma-Aldrich and were used without further purification. Nuclear magnetic resonance (NMR) spectra were recorded on a Bruker Avance 400 spectrometer, operating at 400.13 MHz for ¹H NMR and 100.62 MHz for ¹³C NMR. Chemical shifts (δ) are reported in ppm relative to CDCl₃ (7.26 and 77.16 ppm for ¹H and ¹³C, respectively) or tetramethylsilane (TMS). High-resolution mass spectrometry (HRMS) analysis was carried out on a Bruker Microtof apparatus, equipped with a selective electrospray ionization (ESI) detector. The specific rotation [α] was measured using an electrical polarimeter (Optical Activity AA-5). Melting points, with uncorrected values, were determined with a capillary microscope electrothermal melting point apparatus. The Fourier transform infrared (FT-IR) spectra were measured in KBr pellets using a Thermo Scientific Nicolet 380 spectrometer.

V. parahaemolyticus strain ATCC 17802 and V. harveyi ATCC 14126 (American Type Culture Collection, Manassas, United States) were used in this study. Marine Luria-Bertani (mLB) broth containing 3% (w/v) NaCl was purchased from Becton Dickinson (Franklin Lakes, NJ, United States). V. parahaemolyticus was streaked from a glycerol stock −80°C onto mLB agar plates and incubated overnight at 30°C. For biofilm and other assays, a single colony from each plate was inoculated into 2 mL of an mLB broth and incubated overnight at 30°C in a shaking incubator at 250 rpm (Ashrafudoulla et al., 2020 (link)). Sixteen halogenated indole derivatives (4-bromoindole, 5-bromoindole, 6-bromoindole, 7-bromoindole, 4-chloroindole, 5-chloroindole, 6-chloroindole, 7-chloroindole, 4-fluoroindole, 5-fluoroindole, 6-fluoroindole, 7-fluoroindole, 4-iodoindole, 5-iodoindole, 6-iodoindole, 7-iodoindole, and indole) and other chemicals were purchased from Sigma-Aldrich (St. Louis, MO, United States) and Combi-Blocks, Inc. (San Diego, CA, United States). The compounds were dissolved in dimethyl sulfoxide (DMSO). Kanamycin, tetracycline, and crystal violet were obtained from Sigma-Aldrich. Dimethyl sulfoxide (DMSO) was also used as a negative control in all experiments at a concentration of 0.1% (v/v) in media; it did not affect cell growth or the biofilm formation.