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...

In the presence of water lithium tetrahydroborate is capable of reducing pyridine to 1,4dihydropyridine. The product, lithiumtetrakis(pyridine) tetrakis(1,4-hydropyridyl)borate, was isolated and characterized by NMR and IR spectroscopy and single crystal X-ray diffraction. [Li(py)4][B(pyH)4]2(1,4-dioxane) crystallized in space group P42/n, Z = 2. Similarly, NaBH4 can also reduce pyridine in the...

Effects of allixin, a phytoalexin of garlic, and its analogues were studied on the survival and morphology of primary cultured neurons from fetal rat brain. Addition of allixin (1-100 ng/ml) to medium significantly promoted the survival of neurons derived from various regions of brain and increased the number of branching points per axon in hippocampal neurons. Allixin, however, was cytotoxic a...

The corrosion inhibition of mild steel in 1 M HCl solution by some dihydropyridine has been studied using gravimetric, electrochemical impedance spectroscopy, potentiodynamic polarization techniques and quantum chemical study. results weight loss Tafel measurements showed that among the compounds, Isradipine good inhibiting properties for acidic bath, with 98% efficiency at optimum concentratio...

The effect of metabotropic glutamate receptor activation on Ca dihydropyridine (DHP)-sensitive channels recorded in the presence of 1 microM Bay K 8644 was examined on cultured cerebellar granule cells using the patch-clamp technique in the cell-attached configuration. Bath-applied agonist (trans-ACPD, 1S,3R-, and 1R,3S-ACPD isomers, and glutamate or quisqualate in the presence of CPP and CNQX)...