Synthesis and photodegradation studies of analogues of muscle relaxant 1,4-dihydropyridine compounds.

This paper describes the synthesis of 1,4-dihydropyridine compounds (DHPs) endowed with good muscle relaxant activity and stability to light. Six new condensed DHPs were synthesized by the microwave irradiation method. A long-chain ester moiety [2-(methacryloyloxy)ethyl] and various substituents on the phenyl ring were demonstrated to affect the muscle relaxant activity occurring in isolated rabbit gastric fundus smooth muscle strips.

Synthesis and Biological Evaluation of New Tricyclic Dihydropyridine Based Derivatives on Potassium Channels.

The present study reports a microwave-assisted method for the synthesis of twelve novel tricyclic 1,4-dihydropyridine derivatives in which dimethyl-substituted cyclohexane and / or tetrahydrothiophene rings are fused to the DHP ring. The structures of the compounds were confirmed by spectral methods and elemental analysis. The potassium channel opening effects of the compounds were determined on rat mesenteric arteries and urinary bladders.

Photodegradation studies of 1,4-dihydropyridine compounds by MCR analysis on UV spectral data.

Background: 1,4-Dihydropyridines (DHPs) are well-known light-sensitive compounds. Photostability studies are necessary to ensure safety in therapy.

Materials & Methods: Photodegradation experiments on 15 condensed DHP derivatives were made according to the International Conference on Harmonization rules.

Analgesic effect of a broad-spectrum dihydropyridine inhibitor of voltage-gated calcium channels.

Voltage-activated calcium channels are important facilitators of nociceptive transmission in the primary afferent pathway. Consequently, molecules that block these channels are of potential use as pain therapeutics. Our group has recently reported on the identification of a novel class of dihydropyridines (DHPs) that included compounds with preferential selectivity for T-type over L-type channels.

1,4-Dihydropyridine derivatives with T-type calcium channel blocking activity attenuate inflammatory and neuropathic pain.

We have recently identified a class of dihydropyridine (DHP) analogues with 30-fold selectivity for T-type over L-type calcium channels that could be attributed to a modification of a key ester moiety. Based on these results, we examined a second series of compounds with similar attributes to determine if they had enhanced affinity for T-type channels. Whole-cell patch clamp experiments in transfected tsA-201 cells were used to screen these DHP derivatives for high affinity and selectivity for Cav3.

Microwave-assisted synthesis and myorelaxant activity of 9-indolyl-1,8-acridinedione derivatives.

In this study a microwave-assisted method was applied for the synthesis of novel 9-(substituted indolyl)-3,4,6,7-tetrahydroacridine-1,8-(2H,5H,9H,10H)-dione derivatives. The structures of the compounds were confirmed by spectral methods including X-ray studies and elemental analysis. The Emax and pD2 values of the compounds and pinacidil were determined on noradrenaline precontracted tissues of isolated strips of rabbit gastric fundus smooth muscle.

Synthesis and evaluation of 1,4-dihydropyridine derivatives with calcium channel blocking activity.

1,4-Dihydropyridines (DHPs) are an important class of L-type calcium channel blockers that are used to treat conditions such as hypertension and angina. Their primary target in the cardiovascular system is the Cav1.2 L-type calcium channel isoform, however, a number of DHPs also block low-voltage-activated T-type calcium channels.

2,2,7,7-Tetra-methyl-1,2,3,4,5,6,7,8-octa-hydro-acridine-1,8-dione.

The whole molecule of the title compound, C17H21NO2, is generated by twofold rotational symmetry. The N atom and the C and H atoms in position 4 of the pyridine ring lie on the twofold axis. The cyclohexene ring has a sofa conformation with the CH2 C atom adjacent to the dimethyl-substituted C atom displaced by 0.

Ethyl 2,7,7-trimethyl-4-(1-methyl-1H-indol-3-yl)-5-oxo-1,4,5,6,7,8-hexa-hydro-quinoline-3-carboxyl-ate.

In the title mol-ecule, C24H28N2O3, the cyclo-hexene ring is in a sofa conformation and the 1,4-dihydro-pyridine ring is in a slight boat conformation. In the indole ring system, the pyrrole and benzene rings form a dihedral angle of 2.63 (7)°.

Ethyl 4-(5-bromo-1H-indol-3-yl)-2,6,6-trimethyl-5-oxo-1,4,5,6,7,8-hexa-hydro-quinoline-3-carboxyl-ate.

The title compound, C23H25BrN2O3, crystallizes with two independent mol-ecules in the asymmetric unit (Z' = 2) which differ in the twist of the 5-bromo-1H-indole ring with respect to the plane of the 4-methyl-1,4,5,6,7,8-hexa-hydro-quinoline ring [dihedral angles of 78.55 (9) and 89.70 (8)° in molecules A and B, respectively].

3,3,6,6-Tetra-methyl-9-(1-methyl-1H-indol-2-yl)-1,2,3,4,5,6,7,8,9,10-deca-hydro-acridine-1,8-dione.

In the acridine system of the title mol-ecule, C26H30N2O2, both cyclo-hex-2-enone rings adopt sofa conformations. The indole ring system is essentially planar, with a maximum deviation of 0.017 (2) Å for a bridgehead C atom.

9-(5-Bromo-1H-indol-3-yl)-1,2,3,4,5,6,7,8,9,10-deca-hydro-acridine-1,8-dione dimethyl sulfoxide monosolvate.

In the title compound, C21H19BrN2O2·C2H6OS, the indole ring system is essentially planar, with a maximum deviation of 0.050 (3) Å for the non-bridgehead C atom adjacent to the N atom. The two cyclo-hex-2-enone rings adopt half-chair conformations.

Two 1,4-dihydropyridine derivatives with potential calcium-channel antagonist activity.

The title compounds, benzyl 4-(3-chloro-2-fluorophenyl)-2-methyl-5-oxo-4,5,6,7-tetrahydro-1H-cyclopenta[b]pyridine-3-carboxylate, C(23)H(19)ClFNO(3), (I), and 3-pyridylmethyl 4-[2-fluoro-3-(trifluoromethyl)phenyl]-2,6,6-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate, C(26)H(24)F(4)N(2)O(3), (II), belong to a class of 1,4-dihydropyridines whose members sometimes display calcium modulatory properties. The 1,4-dihydropyridine ring in each structure has a shallower than usual shallow-boat conformation and is nearly planar in (I). In each structure, the halogen-substituted benzene ring is oriented such that the halogen substituents are in a synperiplanar orientation with respect to the 1,4-dihydropyridine ring plane.

Synthesis of 2-methyl-4-aryl-4,6,7,8-tetrahydro-5(1H)-quinolone derivatives and their effects on potassium channels.

In this study, twelve compounds having 2-methyl-4-aryl-4,6,7,8-tetrahydro-5(1H)-quinolone structure have been synthesized by the reaction of 4-aryl-3-butene-2-on derivatives with 1,3-cyclohexanedione analogs in the presence of ammonium acetate in methanol. The structures of the compounds have been elucidated by IR, 1H-NMR, 13C-NMR, mass spectroscopy and elementel analysis. Their potassium channel opener activities have been investigated on isolated rabbit bladder smooth muscle using pinacidil (CAS 85371-64-8) as standard.

Condensed 1,4-dihydropyridines with various esters and their calcium channel antagonist activities.

New alkyl 2,6,6-(2,7,7)-trimethyl-4-(2-fluoro-3-chloro-5-trifluoromethylphenyl)-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylates and 9-(3-chloro-2-fluoro-5-trifluoromethylphenyl)-6,6(7,7)-dimethyl-6,7-dihydrofuro[3,4-b]quinoline-1,8-diones have been synthesised and their calcium antagonistic activities on isolated rabbit sigmoid colon have been investigated and compared with Nifedipine. The investigation examined the influence of ester groups in the 3-position of the HHQ ring and the 2-methoxyethyl analogs were found to be the most active derivatives.

Spectroscopic study of hexahydroquinoline derivatives--a potential group of calcium antagonists.

Spectral properties of 2, 6, 6-trimethyl-3-carbmethoxy-4-phenyl-5-oxo -1,4,5,6,7,8-hexahydroquinoline derivatives (HHQ) with different substituents in the phenyl ring (-Cl, -NO2, -CF3, -CH3, -OCH3) have been studied. Their emission and absorption spectra have been analyzed and quantum yields of emission were determined. The quantum yield of emission was found to depend on the kind, number, and position of substituents in the phenyl ring: it was the highest for the chlorine derivatives of HHQ, and the lowest for the compounds containing -NO2 group.

Synthesis and calcium modulatory activity of 3-alkyloxy-carbonyl-4-(disubstituted)aryl-5-oxo-1,4,5,6,7,8-hexa-hydroquinoline derivatives.

In this study, twelve hexahydroquinoline derivatives which are condensed analogs of the 1,4-DHP molecule were synthesized and evaluated for their calcium-antagonistic activity. The results indicated that all compounds and nifedipine produced concentration-dependent relaxation in rabbit gastric fundus smooth muscle strips. The relaxant effects of the compounds on the tissues were expressed as percentage of the precontraction using Ca(2+).

Evaluation of myorelaxant activity of 7-substituted hexahydroquinoline derivatives in isolated rabbit gastric fundus.

In this article, 16 new methyl(ethyl) 4-(dichlorophenyl)-2,7-dimethyl-5-oxo-l,4,5,6,7,8-hexahydroquinoline-3-carboxylates and methyl(ethyl) 2-methyl-4-(dichlorophenyl)-5-oxo-7-phenyl-l,4,5,6,7,8-hexahydroquinoline-3-carboxylate derivatives have been synthesized by the Hantzsch reaction and screened for their myorelaxant and potassium channel opening activities. The maximum relaxant effects (E(max)) and pD(2) values on exogenous noradrenaline precontracted tissues and inhibitory effects on cholinergic neurotransmission of the compounds and pinacidil were determined on isolated strips of rabbit gastric fundus smooth muscle. Obtained results indicated that some compounds and pinacidil produced concentration-dependent relaxation on rabbit gastric fundus smooth muscle strips in the two test conditions.

4-difluoro-substituted phenl-5-oxohexahydroquinoline derivatives and their effects on calcium channels.

Twenty new methyl(ethyl) 2,6,6- or 2,7,7-trimethyl-5-oxo-4-(disubstituted phenyl)-1,4,5,6,7,8-hexahydroquinoline-3-carboxylates and ten new N,N-diethyl-2,6,6- or 2,7,7-trimethyl-5-oxo-4-(disubstituted phenyl)-1,4,5,6,7,8-hexahydroquinoline-3-carboxamide derivatives have been synthesised and screened for their calcium channel antagonistic activity. The compounds were synthesised by the Hantzsch reaction. Calcium antagonistic activities of the compounds were determined by the tests performed on isolated rat ileum and rat thoracic artery.

Fused 1,4-dihydropyridines as potential calcium modulatory compounds.

1,4-Dihydropyridine (1,4-DHP) derivatives nifedipine of which the prototype, are the most popular drugs having calcium antagonistic activity. Fused 1,4-dihydropyridines (DHPs) have also exhibit calcium modulatory activities. In this article, we emphasize calcium channels and fused 1,4-DHP derivatives affecting calcium channels.

(+/-)-Methyl and (+/-)-ethyl 4-(2,3-difluorophenyl)-2,6,6-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate.

The title compounds, C20H21F2NO3 and C21H23F2NO3, respectively, belong to a class of 1,4-dihydropyridines whose members sometimes display calcium modulatory properties. The 1,4-dihydropyridine rings have the usual shallow boat conformation. In each structure, the 2,3-difluorophenyl ring is oriented such that the fluoro substituents are in a synperiplanar orientation with respect to the 1,4-dihydropyridine ring plane and the oxocyclohexene ring has a slightly distorted envelope conformation.

Some arylacridine derivatives possessing potassium channel opening activity.

In this study, six new 2,2,7,7-tetramethyl-9-aryl-2,3,4,5,6,7,9,10-octahydro-1,8-acridinedione derivatives (1-6) were synthesised and their functional effects on vascular potassium channels and mechanism of induced relaxations on phenylephrine-induced contractile responses in isolated rat mesenteric arteries were investigated. Pinacidil was used as standard potassium channel opener. Compounds 1, 2, 5, 6 and pinacidil induced concentration-dependent relaxation response of vessel rings previously contracted with phenylephrine.

Studies on 3-diethylaminocarbonyl-1,4,5,6,7,8-hexahydroquinoline derivatives and their calcium channel antagonistic activities in vitro.

In this study, thirteen 2,6,6-trimethyl-3-carbamoyl-4-aryl-5-oxo-1,4,5,6,7,8-hexahydroquinoline derivatives were synthesized and screened for their calcium channel antagonistic actitivities. The hexahydroquinoline derivatives were synthesized according to Hantzsch reaction. The structures of the compounds were elucidated by IR, 1H-NMR, 13C-NMR, Distortionless Enhancement Polarization Transfer (DEPT), Correlation Spectroscopy (COSY), mass spectroscopy and elemental analyses.