Compound 12
HEK293T/17 (CCL-3216), Calu-3 (HTB-55), Huh-7.515, and BSR T7/5 cells16 were maintained in DMEM C supplemented with 10% fetal bovine serum (FCS), 100 U/mL Penicillin, 100 U/mL Streptomycin, 1% non-essential amino acids and 2 mM L-glutamine (Thermo Fisher Scientific, Waltham, MA). Huh-7.5_ACE2 cells were additionally supplemented with 10 g/mL Blasticidin. Vero (CCL-81) and HEp-2 (CCL-23) cells were maintained in advanced MEM media supplemented with 10% FCS, 100 e U/mL Penicillin, 100 U/mL Streptomycin, 1% non-essential amino acids and 2 mM L-glutamine. BCi-NS1.1 cells (CVCL_T029)17 maintained in BEGM media18. All cells were cultured under 5% CO2 at i 37 C. The resynthesis of compounds 3, 5, 9, and o 12 (Supplementary information A (SA)-Scheme 1 is described in detail in the chemical supplementary part (Supplementary information B (SB)) in the manuscript "Respiratory syncytial virus two-step infection screen reveals inhibitors of early and late life cycle stages".