The Colistin b is an organic compound with the formula C₁₈H₁₂Br₂O₆S₂. The IUPAC name of this chemical is 6-(4-bromophenyl)sulfonyloxyhexa-2,4-diynyl 4-bromobenzenesulfonate. With the CAS registry number 7239-48-7, it is also named as hexa-2,4-diyne-1,6-diyl bis(4-bromobenzenesulfonate).

Physical properties about Colistin b are: (1)ACD/LogP: 5.83; (2)# of Rule of 5 Violations: 2; (3)ACD/LogD (pH 5.5): 5.83; (4)ACD/LogD (pH 7.4): 5.83; (5)ACD/BCF (pH 5.5): 15892.04; (6)ACD/BCF (pH 7.4): 15892.04; (7)ACD/KOC (pH 5.5): 35382.77; (8)ACD/KOC (pH 7.4): 35382.77; (9)#H bond acceptors: 6; (10)#Freely Rotating Bonds: 7; (11)Polar Surface Area: 103.5 Å²; (12)Index of Refraction: 1.636; (13)Molar Refractivity: 111.83 cm³; (14)Molar Volume: 311.6 cm³; (15)Polarizability: 44.33×10^-24cm³; (16)Surface Tension: 62 dyne/cm; (17)Density: 1.759 g/cm³; (18)Flash Point: 344.6 °C; (19)Enthalpy of Vaporization: 91.85 kJ/mol; (20)Boiling Point: 646.2 °C at 760 mmHg; (21)Vapour Pressure: 7.07E-16 mmHg at 25°C.

You can still convert the following datas into molecular structure:
(1)SMILES: Brc1ccc(cc1)S(=O)(=O)OCC#CC#CCOS(=O)(=O)c2ccc(Br)cc2
(2)InChI: InChI=1/C18H12Br2O6S2/c19-15-5-9-17(10-6-15)27(21,22)25-13-3-1-2-4-14-26-28(23,24)18-11-7-16(20)8-12-18/h5-12H,13-14H2
(3)InChIKey: ALFATABMZGZQEK-UHFFFAOYAT
(4)Std. InChI: InChI=1S/C18H12Br2O6S2/c19-15-5-9-17(10-6-15)27(21,22)25-13-3-1-2-4-14-26-28(23,24)18-11-7-16(20)8-12-18/h5-12H,13-14H2
(5)Std. InChIKey: ALFATABMZGZQEK-UHFFFAOYSA-N