Pyridones as NNRTIs against HIV-1 mutants: 3D-QSAR and protein informatics.

CoMFA and CoMSIA based 3D-QSAR of HIV-1 RT wild and mutant (K103, Y181C, and Y188L) inhibitory activities of 4-benzyl/benzoyl pyridin-2-ones followed by protein informatics of corresponding non-nucleoside inhibitors' binding pockets from pdbs 2BAN, 3MED, 1JKH, and 2YNF were analysed to discover consensus features of the compounds for broad-spectrum activity. The CoMFA/CoMSIA models indicated that compounds with groups which lend steric-cum-electropositive fields in the vicinity of C5, hydrophobic field in the vicinity of C3 of pyridone region and steric field in aryl region produce broad-spectrum anti-HIV-1 RT activity. Also, a linker rendering electronegative field between pyridone and aryl moieties is common requirement for the activities. The protein informatics showed considerable alteration in residues 181 and 188 characteristics on mutation. Also, mutants' isoelectric points shifted in acidic direction. The study offered fresh avenues for broad-spectrum anti-HIV-1 agents through designing new molecules seeded with groups satisfying common molecular fields and concerns of mutating residues.

Topological descriptors in modelling antimalarial activity: N(1)-(7-chloro-4-quinolyl)-1,4-bis(3-aminopropyl)piperazine as prototype.

The QSAR of antimalarial activity of two distinct series of N(1)-(7-chloro-4-quinolyl)-1,4-bis(3-aminopropyl) piperazine analogues are investigated with DRAGON descriptors in order to rationalize their activity. Of these two series of compounds, one has amide characteristics and the other has amine characteristics. Both the analogues have shared radial centric information (ICR) as common modelling descriptor with increased centricity in the molecules as preferred feature for antimalarial activity. Apart from this, the models of amide analogues suggested in favor of distantly placed nitrogen(s) and unfavorable nature of carbonyl moieties adjacent to nitrogen in the varying portion of the molecule for the activity. Moreover, for these analogues, the regression models have preferred the lone pair electrons on heteroatoms (N and O) for purposes other than H-bonds for better activity. In case of amine analogues, the models suggested in favor of compact structural moieties in the varying parts of the molecule for improved activity. Also, for these analogues, hydrophobicity of the compound is an important factor for influencing activity. The variations in the models of amide and amine analogues are attributed to the characteristic functional differences of these analogues.

Molecular docking studies on 4-thiazolidinones as HIV-1 RT inhibitors.

Flexible docking simulations were performed on two series of 4-thiazolidinones as HIV-1 reverse transcriptase (HIV-1 RT) inhibitors. This was done by analyzing the interaction of these compounds with the allosteric site of the HIV-1 reverse transcriptase enzyme. The binding scores for these compounds were also congruent with their anti-HIV activity. A good correlation between the predicted binding free energies and the experimentally observed inhibitory activities (EC(50)) suggest that the identified binding conformations of these inhibitors are reliable. The results of docking studies provide an insight into the pharmacophoric structural requirements for the HIV-1 RT inhibitory activity of this class of molecules.