Search results for "porphine"
showing 10 items of 24 documents
Synthesis of New 8-Arylisoquinoline Derivatives by Application of Palladium-Catalyzed Suzuki Cross-Coupling Reactions.
2005
Abstract New 8-(het)aryltetrahydroisoquinolines ( 10–14 ), 8-aryltetrahydroisoquinolin-4-ols ( 15 , 16 ), and 8-phenylisoquinolin-4-ol ( 17 ), flexible analogues of aporphine, were synthesized in good yields using palladium-catalyzed Suzuki cross-coupling reactions from 8-bromotetrahydroisoquinolin-4-one ( 6 ) as a common intermediate. We also describe the synthesis of this novel intermediate through an easy and efficient method, which involved intramolecular Friedel–Crafts cyclization.
Electroactive polymeric material with condensed structure on the basis of magnesium(II) polyporphine
2011
International audience; Previous publication of the authors presented evidences that electroch emical oxidation of Mg(II) porphine (fully unsubstituted porphyrin, MgP) in acetonitrile (AN) at a very low potential leads to deposition of films at electrode surface corresponding to typical electroactive polymers, with their reversible transition betwee n the electronconducting and insulating states depending on the electrode potential/oxidation level ("film of type I"). It is demonstrated in the actual publication that these films in contact with a monomer-free solution are subject to an irreversible transformation to quite a different material ("film of type II") under the influence of a high…
Reactive oxygen species (ROS) generation inhibited by aporphine and phenanthrene alkaloids semi-synthesized from natural boldine.
2004
Four phenanthrene and one aporphine alkaloids semi-synthesized from boldine were evaluated for their inhibitory effect on reactive oxygen species (ROS) generation. ROS generation by neutrophils stimulated with N-formyl-methionyl-leucyl-phenylalanine was inhibited in a concentration dependent manner. Alkaloids exerted similar inhibitory effect in the hypoxanthine-xanthine oxidase system than in stimulated neutrophils, which could be attributed to a direct ROS scavenging activity. None of the alkaloids assayed had any effect on xanthine oxidase activity. Therefore the synthesized alkaloids might constitute an alternative therapy in inflammation disorders in which ROS generation is involved.
"Dna binding of organotin(IV) complexes of meso-tetra (4 sulfonatophenyl) porphine showing cellular activity"
2016
Our research group has reported about the synthesis of alkynyl-substituted metallophthalocyanines of symmetric and unsymmetric nature. In this study, a novel phthalocyanine precursor bearing pyridin-3-ylethynyl groups and its tetrasubstituted metallo- phthalocyanines at peripheral positions were reported.
Halogenated derivatives of boldine with high selectivity for alpha1A-adrenoceptors in rat cerebral cortex.
1999
The selectivity of 3-nitrosoboldine and different halogenated derivatives of boldine (3-bromoboldine, 3,8-dibromoboldine and 3-chloroboldine) for alpha1-adrenoceptor subtypes was studied by examining [3H]-prazosin competition binding in rat cerebral cortex. In the competition experiments [3H]-prazosin binding was inhibited completely by all the compounds tested. The inhibition curves displayed shallow slopes which could be subdivided into high and low affinity components. The relative order of affinity and selectivity for alpha1A-adrenoceptors was 3-bromoboldine = 3,8-dibromoboldine = 3-chloroboldineboldine3-nitrosoboldine. The competition curves for 3-bromoboldine remained shallow and biph…
Vascular Activity of (-)-Anonaine, (-)-Roemerine and (-)-Pukateine, Three Natural 6a(R)-1,2-Methylenedioxyaporphines with Different Affinities for α1…
2004
We have studied the mechanism of action of three 6a( R)-1,2-methylenedioxyaporphines as vasorelaxant compounds. The alkaloids assayed showed different affinities for the three human cloned alpha (1)-adrenoceptor (AR) subtypes stably expressed in rat-1 fibroblasts, showing lower affinity for alpha(1B)-AR with regard to the alpha(1A)- or alpha(1D)-subtypes. These three natural compounds are more potent inhibitors of [ (3)H]-prazosin binding than of [ (3)H]-diltiazem binding to rat cerebral cortical membranes. As all these alkaloids inhibited noradrenaline (NA)-induced [ (3)H]-inositol phosphate formation in cerebral cortex and rat tail artery, they may be safely viewed as alpha (1)-AR antagon…
New alkaloid antibiotics that target the DNA topoisomerase I of Streptococcus pneumoniae
2011
16 pags, 3 figs, 3 tabs
The 5-HT and alpha-adrenoceptor antagonist effect of four benzylisoquinoline alkaloids on rat aorta.
1998
Abstract The action of four benzylisoquinoline alkaloids (two aporphines—glaucine and apomorphine, a benzylisoquinoline—papaverine and a bisbenzyltetrahydroisoquinoline—antioquine) on 5-HT-induced contraction in rat thoracic aorta has been examined and compared with that of the control drugs: ketanserin, nifedipine, prazosin and phentolamine. The relaxant action on 5-HT-induced contraction was contrasted with that on the contraction induced by noradrenaline and KCl. The results obtained with control drugs show that ketanserin has clear selectivity for 5-HT receptors, whereas prazosin and phentolamine have high selectivity for the α1-adrenoceptor and nifedipine seems to have a more potent ef…
3,4-Dihydroxy- and 3,4-methylenedioxy- phenanthrene-type alkaloids with high selectivity for D2 dopamine receptor.
2013
Abstract Dopamine-mediated neurotransmission plays an important role in relevant psychiatric and neurological disorders. Nowadays, there is an enormous interest in the development of new drugs acting at the dopamine receptors (DR) as potential new targets for the treatment of schizophrenia or Parkinson’s disease. Previous studies have revealed that isoquinoline compounds such as tetrahydroisoquinolines (THIQs) can behave as selective D 2 dopaminergic alkaloids. In the present study we have synthesized five aporphine compounds and five phenanthrene alkaloids and evaluated their potential dopaminergic activity. Binding studies on rat striatal membranes were used to evaluate their affinity and…
Electrocatalytic properties of manganese and cobalt polyporphine films toward oxygen reduction reaction
2018
International audience; Novel member of polymetalloporphines, namely manganese polymetalloporphine of type I (pMnP-I) obtained by ion exchange from magnesium polyporphine of type I (pMgP-I) is reported for the first time and compared to its cobalt analogue (pCoP-I). Both polymer films have been obtained via two-step procedure: demetaladon of the pMgP-I electrode film via its exposure to trifluoroacetic acid solution, resulting in formation of the metal-free polyporphine of type I (pH(2)P-I) followed by electrochemically induced incorporation of Co or Mn ions from the acetonitrile solution of cobalt and manganese perchlorates. A further oxidative transformation of pCoP-I, polymer films has l…