Mechanism of action in a 4,5-diarylpyrrole series of selective cyclo-oxygenase-2 inhibitors

One-pot metal-free synthesis of highly substituted pyrroles from 2-acetyl-3-methylene-1,4-dicarbonyl compounds and primary amines via TBHP and activated carbon oxidative aromatization of dihydropyrrole

A metal-free cascade process for the synthesis of highly substituted pyrroles with high yields and broad substrate tolerance via enamine, aza-Michael addition and TBHP, activated carbon oxidative aromatization is reported.

Redox ranking of inducers of a cancer-protective enzyme via the energy of their highest occupied molecular orbital

Induction of phase 2 enzymes is a major strategy in chemoprotection against cancer. Inducers belong to nine different chemical classes. In this study we found that a measure of the tendency of 30 plant phenylpropenoids and synthetic analogs to release electrons correlates linearly with their potency in inducing the activity of NAD(P)H:quinone reductase (NQO1), a prototypic phase 2 cancer-protective enzyme. The tendency to release electrons was determined by the energy of the highest occupied molecular orbital (E(HOMO)), calculated by simple quantum-mechanical methods. The correlations observed establish a clear conclusion: the smaller the absolute E(HOMO) of an agent, A, i.e., the lower its reduction potential, E(A*+/A), the stronger is its electron donor property and the greater its inducer potency. The finding of this redox ranking of the inducers demonstrates the possibility of controlling and predicting the genetic expression of an enzymatic defense against cancer by xenobiotics via one physicochemical parameter, the reduction potential, E(A*+/A).

Computer-aided design of non sulphonyl COX-2 inhibitors: an improved comparative molecular field analysis incorporating additional descriptors and comparative molecular similarity indices analysis of 1,3-diarylisoindole derivatives

A set of thirty five molecules of 1,3-diaryl-4,5,6,7-tetrahydro-2H-isoindoles endowed with selective COX-2 inhibitory activity was analyzed using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA). Besides conventional steric and electrostatic fields, seven additional descriptors were incorporated to the CoMFA models. An improved CoMFA model (r(2)(cv)=0.536, r(2)(conv)=0.968, SEE=0.222, r(2)(pred)=0.6564) was obtained by taking into account the CMR as additional descriptor. This analysis provided useful information regarding the pharmacophoric requirements for COX-2 inhibitory activity. FlexX was used to find out the binding orientation of this new class of 1,3-diaryl isoindoles in the active site of COX-2. The contour maps produced by improved CoMFA model was superimposed onto the active site revealing a good correlation between the contour maps and the active site residue interactions.