Molecular interactions of 4-diphenylmethoxy-1-methylpiperidine derivatives with the calcium channel CaV1.1 (pdb:6JP5) are described. All compounds tested, previously shown to inhibit adrenergic vascular contractions, display similar binding energetics and trans-membrane domain 6JP5 on opposite side relative pore, where nifedipine, a known dihydropyridine Ca2+ blocker binds. Additionally, tested...

A series of dihydropyridines were identified that have an effect on the accumulation of tau, an important target in Alzheimer's disease. The dihydropyridine collection was expanded using the Hantzsch multicomponent reaction to develop preliminary structure-activity relationships.

We have investigated the modulation of L-type calcium channel currents in isolated ventricular cells by the dihydropyridine derivative amlodipine, a weak base with a pKa of 8.6. Under conditions that favor neutral drug molecules, amlodipine block resembles other, previously described, neutral dihydropyridine derivatives: block is more pronounced at depolarized voltages, repetitive pulsing is no...

The purpose of this study was to determine if there are alterations in the dihydropyridine and/or ryanodine receptors that might explain the excitation-contraction uncoupling associated with eccentric contraction-induced skeletal muscle injury. The left anterior crural muscles (i.e., tibialis anterior, extensor digitorum longus, and extensor hallucis longus) of mice were injured in vivo by 150 ...

The dihydropyridine calcium channel blocker, nitrendipine, was studied for its effects on the sodium current of single cultured ventricular cells from neonatal rats. The patch-clamp method of recording whole cell currents was used, and sodium currents were isolated by suppressing potassium and calcium currents. Potassium currents were blocked by replacing potassium with cesium in the internal a...

We have examined the effects of cAMP elevating agents on the phosphorylation of dihydropyridine-sensitive Ca2+ channels in intact newborn chick skeletal muscle. In situ treatment with the beta-adrenergic receptor agonist isoproterenol resulted in the phosphorylation of the 170-kDa alpha 1 subunit in the intact cells, as evidenced by a marked decrease in the ability of the alpha 1 peptide to ser...

group exhibits an extended antimicrobial spectrum including anti-pseudomonal activity and high stability to renal dehydropeptidase-I (DHP-I)1}. From the structureactivity relationship studies, we found that the basicity of the C-2 side chain is important for exhibiting antimicrobial activity especially against Pseudomonas aeruginosa by supporting good permeability through the outer membrane(OM)...

A sample of 0.104 M nicardipine in methanol was photoirradiated with a Philips 400 W UV lamp for 3 h in a photochemical chamber. A total of four major photoproducts were found from the HPLC chromatogram. The same sample was used for taking LC-MS, while eight major photoproducts were observed and the structures elucidated by analyzing the CID patterns of their respective mass spectra. A reaction...

The diastereotopy of the methylene protons at positions 2 and 6 in 1,4-dihydropiridine derivatives with various substituents has been investigated. NMR spectroscopy and quantum chemistry calculations show that the CH···O intramolecular hydrogen bond is one of the factors amplifying the chemical shift differences in the 1H-NMR spectra.

Plants that contain pyrrolizidine alkaloids are widely distributed in the world. Although pyrrolizidine alkaloids have been shown to be genotoxic and tumorigenic in experimental animals, the mechanisms of actions have not been fully understood. The results of our recent mechanistic studies suggest that pyrrolizidine alkaloids induce tumors via a genotoxic mechanism mediated by 6,7-dihydro-7-hyd...