Ethionamide

d-Allulose, d-fructose, penicillin, ethambutol, ethionamide, and isoniazid standards were purchased from Sigma (St. Louis, MO, USA). Bio-LC grade sodium hydroxide solution was purchased from Fisher Scientific (Hanover Park, IL, USA). All of the restriction enzymes were purchased from New England Biolabs (Hertfordshire, UK, USA). Solvents and detergents were purchased from Santa Cruz Biotechnology (Santa Cruz, CA, USA).

Ampicillin, benzydamine, ethionamide, (±)-propranolol and trifluoperazine were purchased from Sigma Aldrich (Steinheim, Germany) and acetonitrile (ACN) from J. T. Baker (Deventer, The Netherlands). Isopropyl β-d-1-thiogalactopyranoside (IPTG) was obtained from Biosynth AG (Staad, Switzerland). All other chemicals and buffer components were obtained from Carl Roth (Karlsruhe, Germany). NunclonTMΔ surface 24 well plates were purchased from Nalgene nunc (Penfield, USA) and oxygen permeable foils (Gas Permeable Adhesive Seals # AB-0718) from Thermo Fisher Scientific (Waltham, MA, USA).

Drug susceptibility testing (DST) was performed to determine the resistance pattern of isolates to first- and second-line anti-TB drugs. The standard protocol for DST for the first-line drugs streptomycin (STR, 1 μg/mL), isoniazid (INH, 0.1 μg/mL), rifampicin (RIF, 1 μg/mL) and ethambutol (EMB, 5 μg/mL) in MGIT 960 (Becton Dickinson, Oxford Science Park, Oxford, UK) was followed according to the manufacturer’s instructions [6 (link)]. Phenotypic DST for second-line drugs was performed on identified MDR isolates in MGIT 960 (Becton Dickinson, Oxford Science Park, Oxford, UK) using kanamycin (KAN, 2.5 μg/mL) capreomycin (CAP, 2.5 μg/mL), ofloxacin (OFX, 2 μg/mL) and ethionamide (ETH, 5 μg/mL) (Sigma-Aldrich, St. Louis, Mo, USA) [7 ].

All commercial chemicals and reagents were solubilized and stored according to the manufacturer’s recommendations. Ampicillin sodium salt, d-cycloserine, erythromycin, ethambutol, ethidium bromide, ethionamide, fluorescein sodium salt, gentamycin, kanamycin sulfate, penicillin G sodium, polymyxin B, resazurin sodium salt, RIF, nisin from Lactococcus lactis, tetracycline, and vancomycin were all purchased from Sigma-Aldrich. Bedaquiline, linezolid, macozinone, pretomanid, spectinomycin, streptomycin sulfate salt, and SQ109 were all purchased from MedChem Express. Anhydrotetracycline was purchased from Thermo Fisher Scientific, hygromycin from Roche, and fusidic acid sodium salt from Merck. Compounds from the benzothiazole-core library were stored as stock solutions (10 mM) in DMSO at −20°C.

1599 and 1810 were synthesized as described (Figure S1).³ (link) Isoniazid, rifampicin, pyrazinamide, ethambutol, levofloxacin, kanamycin, amikacin, ethionamide, ofloxacin, cycloserine, rifapentine and clofazimine were purchased from Sigma-Aldrich. Linezolid was purchased from 21CEC. Moxifloxacin was obtained from Bayer. PA-824 (Pretomanid) was obtained from the Global Alliance for TB Drug Development. Bedaquiline (Sirturo) was provided by Johnson and Johnson. SQ109 was synthesized as described.⁹ (link)

Ceftibuten, cefixime, ceftazidime (hydrate), ceftriaxone (sodium), ethionamide, gentamycin, kanamycin (sulfate), levofloxacin, meropenem (trihydrate), penicillin (G sodium), rifampicin (all purchased from Sigma-Aldrich), bedaquiline, delamanid, linezolid, macozinone, pretonamid, streptomycin (sulfate salt), sutezolid, SQ109, 9-chloro-3,4-dihydro-chromeno[2′,3′:4,5]pyrimido[2,1-b][1,3]thiazine-6,7-dione (TBA161) and its derivatives 3,4-dihydro-chromeno[2′,3′:4,5]pyrimido[2,1-b][1,3]thiazine-6,7-dione (TBA161-A), 9-bromo-3,4-dihydro-chromeno[2′,3′:4,5]pyrimido[2,1-b][1,3]thiazine-6,7-dione (TBA161-B), 9,11-dichloro-3,4-dihydro-chromeno[2′,3′:4,5]pyrimido[2,1-b][1,3]thiazine-6,7-dione (TBA161-C) and 7-chloro-3-isopropyl-2-(methylsulfanyl)-chromeno[2,3-d]pyrimidine-4,5-dione (TBA161-D) were all purchased from MedChemExpress, and solubilized and stored according to the manufacturers' recommendations.
The TB Alliance compound library was a gift from TBAlliance (New York, USA). The library consists of 1392 compounds that were previously shown to inhibit Mtb H37Rv viability in vitro. Compounds of this library were stored as stock solutions (10 mM) in DMSO at −80°C.