QSAR study of steroid benchmark and dipeptides based on MEDV-13

A molecular electronegativity distance vector based on 13 atomic types, cal led MEDV-13, is a descriptor for predicting the biological activities of mo lecules based on the quantitative structure-activity relations (QSAR). The MEDV-13 uses a modified electrotopological state (E-state) index to substit ute for the relative eletronegativity (q) of non-hydrogen atoms in the mole cule of interest in the MEDV and a topological distance for the relative di stance (d) in the MEDV. For an organic molecule containing several chemical elements such as C, H, O, N, S, F, Cl, Br, I, and P, the MEDV-13 includes at best 91 descriptors. Then it is essential to employ a principal componen t regression (PCR) technique to derive a QSAR model relating the biological activities to the MEDV-13. The MEDV-13 is used to study the QSAR of the co rticosteroid-binding globulin (CBG) binding affinity of the steroids and th e activity inhibiting angiotensin-converting enzyme (ACE) of dipeptides, an d resulting models have a comparable quality to the current three-dimension al (3D) methods such as CoMFA though the MEDV-13 is a descriptor based on t wo-dimensional topological information.