Physicochemical Analysis and Molecular Modeling of the Fosinopril β-Cyclodextrin Inclusion Complex

Table 2

The interaction, , deformation, (host, -cyclodextrin), (guest, fosinopril), binding energies (kJ/mol), and the charge on the β-CD molecule calculated for the three possible optimal geometries of the FOS/β-CD complex, using PM3 calculation results for the two possible forms (salt and ionic) of fosinopril and the three conformations taken to account for free FOS: (a) the nearest stable conformation to the crystal structure; (b) the global minimum energy conformation; (c) the nearest stable conformation to the FOS geometry in the complex; 1, 2, and 3 correspond to the three energy minima obtained by MM+ optimization.

Min	Form									Charge β-CD
				(a)	(b)	(c)	(a)	(b)	(c)	( units)
1	COONa	−86.38	1.44	15.12	81.18	12.05	−69.83	−3.76	−72.90	−0.0216
2	COONa	−83.10	16.51	12.57	78.63	5.65	−54.02	12.05	−60.94	−0.0426
3	COONa	−334.64	39.64	75.60	141.67	110.37	−219.40	−153.34	−184.63	+0.0670
1	COO^−	−110.77	4.32	−3.20	51.27	4.06	−109.65	−55.17	−102.39	−0.0359
2	COO^−	−165.37	24.05	0.56	55.04	11.16	−140.77	−86.29	−130.17	−0.0535
3	COO^−	−330.57	53.29	40.42	94.90	49.48	−236.86	−182.38	−227.80	−0.1593