INTRODUCTION Previous work has shown that besifloxacin, an 8-chloro-fluoroquinolone, has more potent activity against gram-positive pathogens than moxifloxacin and gatifloxacin, which carry an 8-methoxy group. This study was conducted to determine the contribution of the R7 and R8 substituent to fluoroquinolone antibacterial activity. MATERIALS AND METHODS Besifloxacin, moxifloxacin, gatiflox...

N-Nitroso-N-oxybenzenamine ammonium salts with -OMe, -Me, -H, -F, -Cl, -CF3, and -SO2Me substituents at the para position of the phenyl ring constitute a new class of-redox sensitive nitric oxide (NO) releasing compounds. These compounds yield nitric oxide and the corresponding nitrosobenzene derivatives by a spontaneous dissociation mechanism after undergoing a one electron oxidation. Oxidatio...

Decarboxylation process in a series of PdL(2)X(η(2)-OOCAr(R)) complexes 2OS(R) (L = DMSO; X = OOCCF(3)(-); R = H, OMe, NO(2), Me and CN) with substituent R at an ortho, meta or para position were investigated with the aid of density functional theory calculations. Through our study, we found that the OOCCF(3)(-) ligand is not just a spectator ligand but assists the decarboxylation process. The ...

Successful control of photo-driven NAD(+)/NADH type hydrogenation reactions in ruthenium complexes has been accomplished by using a new NAD(+) model ligand with modulated distortion of the ligand taking advantage of the substituent effect.

The nature of the 7-substituent has a remarkable effect on the diastereoselectivity of the oxidative rearrangement of indole-2-carboxamides derived from (S)-2-methoxymethylpyrrolidine into chiral 3,3-disubstituted oxindoles.

We report evidence for a strongly geometry-dependent substituent effect. The rate constants for H-D exchange of the R-hydrogens, (kexch)OR, in a set of 19 !-alkoxy sulfones of known, fixed (or strongly preferred) H-CR-C!-OR torsion angles have been measured. Those of corresponding model compounds lacking the alkoxy group, (kexch)model, were also measured, thereby providing the ratio, kN ) (kexc...

thirty nine novel 1,2,3,4-tetrahydropyrimidinone (thione)s were subjected to conformational studies. density functional theory at b3lyp/6-31 g* was performed as the computational method of high accuracy. important dihedral angles and bond lengths were investigated and the values obtained were explainable. results of this work confirm a twisted boat tetrahydropyrimidine ring conformation with an...

a series of 1,4-dihydropyridine calcium channel blockers bearing 1-(4-x -benzyl)-5-imidazolyl substituent at 4 position (5a-e) (x=h, f) were synthesized and tested for antihypertensive activity in desoxycorticosterone acetate (doca)-induced hypertension in rats. amlodipine was used as the standard dihydropyridine. all compounds tested showed lower antihypertensive activity than that of amlodipi...