A practical and highly stereoselective approach to access 2,6-disubstituted piperidines using an amidine auxiliary is reported. Following the diastereoselective addition of Grignard reagents at the 2-position of an activated pyridinium salt, the amidine group directs a regioselective metalation at the 6-position, enabling further functionalization. A subsequent electrophilic quench or a Negishi...

In this study, novel condensed 1,4-dihydropyridines bearing cyclopentanone (1-21) or tetrahydrothiophene-1,1-dioxide ring (22-42) with various ester substituents were synthesized via a modified Hantzsch reaction and their calcium channel modulator activities were investigated on isolated rat ileum and rat thoracic aorta. The introduction of a cyclopentanone ring fused to the 1,4-dihydropyridine...

Three types of calcium channels have been identified voltage-sensitive, receptor operated (cardiac muscle and vascular smooth muscle) and stretch operated (in some blood vessels) channels. Using electrophysiological and pharmacological techniques, three different types of voltage-gated calcium channels have been identified, namely, L-type (for long lasting, large channels), T–type (for transien...

Objectives In order to provide a pharmacological profile for some newly synthesized dihydropyridines, we investigated their effects on the isolated rat colon segments and the isolated rat atrium contractility. The tested compounds include alkyl ester analogues of nifedipine, in which the ortho-nitrophenyl group at position 4 is replaced by 2-alkylthio-1-benzyl-5-imidazolyl substituent, and nif...

The radiation-induced damage to mitochondrial oxidative respiratory chain could lead to generating of superoxide anions (O2-) and secondary reactive oxygen species (ROS), which are the major resources of continuous ROS production after radiation. Scavenging radiation-induced ROS effectively can help mitochondria to maintain their physiological function and relief cells from oxidative stress. Di...

Using the whole-cell configuration of the patch-clamp technique, we have characterized two types of ionic currents through voltage-dependent Ca2+ channels in human granulosa cells. One is long-lasting, activates at approximately -20 mV, reaches the peak at approximately +20 mV, has an inactivation time constant of 132.5 +/- 5.6 msec at 20 mV, and is sensitive to dihydropyridines. The other is t...

In the title compound, C(18)H(22)N(2)O(4), the dihedral angle between the two rings is 87.90 (6)°. The mean devation of the atoms in the dihydropyridine plane is 0.082 (3) Å. In the crystal, mol-ecules are linked by inter-molecular N-H⋯N hydrogen bonds, generating chains.