The chemicals and solvents were purchased from Sigma Aldrich (St. Louis, MO, USA), except for the following: resorcinol and 4-bromophenylacetic acid obtained from Acros Organic (Carlsbad, CA, USA), 1,4-dibromobutane obtained from Oakwood Chemical (Estill, SC, USA), 1,8-dibromooctane obtained from Rhawn (Shanghai, China), sodium iodide obtained from Fisher Scientific (Waltham, MA, USA), and piperazine and 1-(2-hydroxyethyl)piperazine obtained from (J&K Scientific (Shijiazhuang, Hebei, China).
The nuclear magnetic resonance spectra were measured in CDCl3 or DMSO-d6 using Bruker instruments (1H, 600; 13C, 151Mz; Bruker, Inc., Billerica, MA, USA). The LTQ-Orbitrap Velos mass spectrometer was utilized to acquire the high-resolution electrospray ionization (ESI) mass spectra (Thermo Fisher Scientific, Waltham, MA, USA). The FT resolution was set at 100,000 (at 400 m/z). The samples were introduced by means of direct infusion utilizing a syringe pump operating at a flow rate of 5 µL/min.
DBI-1 and DBI-2 were synthesized using the methods described previously [22 (link)] and fully characterized according to standard conventions (Supplementary Materials File S1 ).
The nuclear magnetic resonance spectra were measured in CDCl3 or DMSO-d6 using Bruker instruments (1H, 600; 13C, 151Mz; Bruker, Inc., Billerica, MA, USA). The LTQ-Orbitrap Velos mass spectrometer was utilized to acquire the high-resolution electrospray ionization (ESI) mass spectra (Thermo Fisher Scientific, Waltham, MA, USA). The FT resolution was set at 100,000 (at 400 m/z). The samples were introduced by means of direct infusion utilizing a syringe pump operating at a flow rate of 5 µL/min.
DBI-1 and DBI-2 were synthesized using the methods described previously [22 (link)] and fully characterized according to standard conventions (