Table 2.

Molecular interactions of fluoroquinolines with human DNA topoisomerase II b (3QX3)

Ligand	Run no.	Interacting residue in human Topo II b	Interacting atoms (amino acid……ligand)	H bonds formed	Binding energy	Electrostatic energy
Ciprofloxacin	54	ASP479	HN……O1	1	−9.62	0.11
Enoxacin	32	ASP479	HN……O1	2	−9.96	0.1
		SER480	HN……O2
Finafloxacin	44	ARG 820	HE……O4	1	−8.92	−0.15
Flumequine	41	ARG820	HH12……O3	2	−8.79	−0.76
		ARG820	HH22……O3
Gatifloxacin	15	ARG503	HH12……O3	1	−10.73	−0.3
Levofloxacin	59	ASP479	HN……O2	2	−11.78	−0.18
		SER480	HN……O3
Lomefloxacin	54	ASP479	HN……O1	1	−10.35	−0.1
		SER80	HN……O2	1
Moxifloxacin	17	LYS456	HZ1……O2	1	−9.95	−0.24
Norfloxacin	29	ASP479	HN……O1	2	−10.43	−0.16
		SER480	HN……O2
Ofloxacin	16	ASP479	HN……O2	2	−11.8	0.18
		SER480	HN……O3
Prulifloxacin	47	SER480	HN……O6	1	−10.77	0.07
Sarafloxacin	56	ASP479	HN……O2	1	−10.78	0.01
Sparafloxacin	39	GLN778	HE22……O3	2	−11.43	−0.83
		ARG820	HH12……O2
Etoposide	37	DG10	H19……OP2		−9.38	−0.51
		DA12	H12……O11
		DG10	H10……O5
		DC11	H11……O5,O2