Table 1.

Calculated molecular parameters of naringenin, quercetin, and catechin

Parameters		Naringenin	Quercetin	(+)-Catechin
AM1 UHF
Number of electrons		102	112	110
Number of doubly occupied levels		51/51	56/56	55/55
Number of total orbitals		92	98	98
Total energy, kcal/mol		− 85,033.7341	− 99,164.7732	− 93,070.1819
Binding energy, kcal/mol		− 3640.1191	− 3717.6003	− 3861.3785
Isolated atomic energy, kcal/mol		− 81,393.6150	− 95,447.1729	− 89,208.8034
Electronic energy, kcal/mol		− 513,116.2131	− 601,021.9335	− 597,927.1805
Core–core interaction kcal/mol		428,082.4789	501,857.1603	504,856.9985
Heat of formation, kcal/mol		− 153.7501	− 216.3173	− 211.2465
E (HOMO) α, eV		− 9.310636	− 8.827891	− 9.042646
E (HOMO) β, eV		− 9.296082	− 8.997514	− 9.061333
E (LUMO) α, eV		− 0.591512	− 1.085702	0.012489
E (LUMO) β, eV		− 0.597053	− 0.852294	0.089334
∆E = E (HOMO) α − E (LUMO) α, eV		− 9.902148	− 7.742189	− 9.055135
∆E = E (HOMO) β − E (LUMO) β, eV		− 9,893,135	− 8.14522	− 9.150667
Lowest level energy α, eV		− 42.063153	− 42.440206	− 42.205243
Lowest level energy β, eV		− 42.057281	− 42.444943	− 42.165635
Highest level energy α, eV		6.299569	6.340062	6.296683
Highest level energy β, eV		6.299778	− 8.997514	6.303410
Dipole moment, D		1.602	0.986	2.107
QSAR properties
Surface area (grid), Å2		453.58	453.62	470.21
Volume, Å3		736.63	753.52	764.33
Hydration energy, kcal/mol		− 22.97	− 32.53	− 31.12
Ab initio UHF (6-31G)
Total energy, kcal/mol		− 595,475.5297	− 688,649.2008	− 643,136.5287
Electronic kinetic energy, kcal/mol		595,905.9009	689,036.7450	643,608.5332
eK, ee & eN energy, kcal/mol		− 1,516,527.37	− 1,770,727.35	− 1,704,258.65
Nuclear repulsion energy, kcal/mol		921,051.8416	1,082,078.1516	1,061,122.1226
Torsion angles (C3-C2-C1′-C2′)		86.4	180	117.9
The total net excess charge of the ring
A		0.437	0.54	0.351
B		0.069	0.128	0.018
C		− 0.26	− 0.352	− 0.049