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G Fytas

Publications and source records attributed to G Fytas.

At least 37 records · Page 2Linked to original sources
PubMed1999

Synthesis of 2-(2-adamantyl)piperidines and structure anti-influenza virus A activity relationship study using a combination of NMR spectroscopy and molecular modeling.

The 2-(2-adamantyl)piperidines 13 and 15a-c were synthesized and evaluated for anti-influenza virus A and B activity. The parent N-H compound 13 was 3-4 times more active than amantadine and rimantadine against H2N2 influenza A. N-alkylation of 13 resulted in derivatives 15a-c that were devoid of biological activity. This dramatic reduction in biological activity may be attributed to the different conformational properties between N-H and N-alkyl piperidines, as deduced from the combination of computational chemistry and NMR spectroscopy.

Animals↗
PubMed1996

Probing Collective Motions of Terminally Anchored Polymers

Polymer chains attached by one end to an impenetrable surface at high coverage exemplify a tethered layer of mesoscopic dimensions. At equilibrium, thermal fluctuations of the segment density profile of the brushlike layer reflect the tethered chain dynamics; the probing of these fluctuations by evanescent-wave dynamic light scattering is reported. By utilizing a set of terminally attached layers with thicknesses (L0) from 45 to 130 nanometers, it was found that there is a preferred wavelength of order L0 of these fluctuations with a concurrent slowing down of their thermal decay rate. This technique could open the route for the investigation of the largely unexplored area of polymer surface dynamics.

Journal Article↗
PubMed1996

Synthesis and antiviral activity evaluation of some new aminoadamantane derivatives. 2.

The synthesis of some new aminoadamantane derivatives is described. The new compounds were evaluated against a wide range of viruses [influenza A H1N1, influenza A H2N2, influenza A H3N2, influenza B, parainfluenza 3, herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2), thymidine kinase-deficient (TK-) HSV-1, vaccinia, vesicular stomatitis, polio 1, Coxsackie B4, Sindbis, Semliki forest, Reo 1, varicella-zoster virus (VZV), TK- VZV, human cytomegalovirus (HCMV), and human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2)]. Some of them proved markedly active against the influenza A H2N2 (compounds 4a,b, 5a, 6a, and 7a), H3N2 (compounds 5a, 6a, and 7a), and H1N1 (compounds 4b,c and 6d). Since compounds 5a, 6a, and 7a, amantadine, and rimantadine showed the same comparative pattern of potency against influenza strains H2N2, H3N2, and B, it may postulated that they act according to a similar mechanism, with regard to their "amine" effect, on the M2 ion channel of influenza A (H1N1, H2N2, or H3N2). In general, no significant activity was noted with any of the new compounds against any of the other viruses tested, making their activity against influenza virus more specific and striking. Borderline activity was noted with some of the compounds (4b,c, 5a-c, and 8a) against HIV-1.

Adamantane↗
PubMed1996

Synthesis and pharmacological study of some new beta-(dialkylaminomethyl)- gamma-butyrolactones and their tetrahydrofuran analogues.

This paper describes the synthesis of beta-(dialkylaminomethyl)-gamma- butyrolactones (6 and 15) and their tetrahydrofuran analogs 7 and 16. Their convulsant activity was studied on mice and could display an antiGABAergic component, but, unlike the alpha-(dialkylaminomethyl)- gamma-butyrolactones, no antiglycinergic component was detected. The possibility of an activation of the glutamatergic receptors (NMDA), by indirect stimulation of their glycinergic site, by the tetrahydrofurans analogs 7 could be considered. These compounds exhibited, at low doses (1/3 to 1/20 of their convulsant doses), an anticonvulsant action in the maximal electroshock test and this is in agreement with the abovementioned possibility.

4-Butyrolactone↗
PubMed1995

[Synthesis and pharmacological study of adamantyl benzene propanamines and propenamines].

gamma-(1-Adamantyl)benzenepropanamines and gamma-(1-adamantyl)benzene-beta-propenamines were synthesized and their pharmacological action was studied on mice. Behavioral effects obtained with these compounds and specially the study of convulsions, induced by these derivatives, could show a rise of the gamma-(1-adamantyl)benzenepropanamine's antinicotinic component, which is characteristic of all the adamantanamines. On the contrary gamma-(1-adamantyl)benzene-beta-propenamine's molecular torsion, induced by the double bond, coudl confer to these derivatives agonistic properties on the central nicotinic receptor sites.

Adamantane↗
PubMed1994

Synthesis and antiviral activity evaluation of some aminoadamantane derivatives.

The synthesis of some spiro[cyclopropane-1,2'-adamantan]-2-amines and methanamines and some spiro[pyrrolidine-2,2'-adamantanes] is described. The title compounds were evaluated against a wide range of viruses (influenza A, influenza B, parainfluenza 3, RSV, HSV-1, TK- HSV-1, HSV-2, vaccinia, vesicular stomatitis, polio 1, coxsackie B4, sindbis, semliki forest, Reo 1, HIV-1, and HIV-2), and some of them (compounds 6b, 6c, 9a, 16a, 16b, and 17) inhibited the cytopathicity of influenza A virus at a concentration significantly lower than that of amantadine and also significantly lower than the concentrations at which they proved cytotoxic to the host cells. None of the new aminoadamantane derivatives was active against influenza B virus or any of the other viruses tested, which points to their specificity as anti-influenza A virus agents.

Adamantane↗
PubMed1994

3-Cyclopentyl-1-adamantanamines and adamantanemethanamines. Antiviral activity evaluation and convulsions studies.

The synthesis of 3-cyclopentyl-1-adamantanamines and adamantanemethanamines and some of their thioureas is described. The antiviral activity examination of these compounds indicated that some of them inhibited Respiratory Syncytial Virus (RSV) infection at concentrations that were slightly (up to 5-fold) lower than the cytotoxic concentration. Behavioral and convulsions studies of the above mentioned amines, in mice, did not show any dopaminomimetic activity and argue in favor of the existence of a glutamatergic component in the action of these derivatives.

Amines↗
PubMed1994

[The mechanism(s) of alpha-(aminoethyl)-gamma-butyrolactone. In vivo studies in mice].

This paper describes the synthesis of alpha-(dimethylaminoethyl)-gamma, gamma-diphenyl-gamma-butyrolactone 4. The study of convulsions induced, on mice, by this compound could show the existence of antiGABAergic and cholinergic action components, but, unlike the homologous alpha- (dialkylaminomethil)-gamma-butyrolactones (with one -CH2- less on the aminoalkyl chain), no antiglycinergic component was detected. The effects of atropine on the aminolactone 4 induced convulsions (antagonism 5mn and synergy 30 mn after atropine) could suggest an activation of the glutamatergic receptors (NMDA), by indirect stimulation of their glycinergic site, by the aminolactone 4.

4-Butyrolactone↗
PubMed1991

[Dopamine amides with essential or fundamental fatty acids. Synthesis and pharmacological study].

Dopamine amides with palmitic, stearic and linoleic acid, their diacetates and carbonates were synthesized and their action on mice and rats was studied. The experimental results which are obtained from these derivatives (antagonized or non antagonized hypomotility by neuroleptics in low doses on mice, potentiation of the haloperidol catalepsy or not, on rats) could be compatible with a selective action of these amides on the autoreceptors of the cerebral dopaminergic neurons and with a preferential activity of some derivatives on certain cerebral areas (mesencephalon or striatum).

Animals↗
PubMed1991

[Synthesis and pharmacological study of alpha-phenyl-1-adamantanemethanamine].

The alpha-phenyl-1-adamantanemethanamine 2 was synthesized and its pharmacological action was studied on mice. The behavior effects obtained with this compound (at low dose) as well as the antagonism of the convulsions and the lethality (induced by the amine 2 at high dose) by desimipramine, N-linoleylGABA or N-linoleylglycine, could suggest the existence of glutamatergic (NMDA), anti-GABAergic and antiglycinergic components in the action mechanism of this adamantanamine.

Adamantane↗
PubMed1989

[Synthesis and study of the convulsant action of polycyclic amino-gamma-lactone and of its tetrahydrofuran analogue].

In this paper, the synthesis of the gamma-benzyl-amino-gamma-lactone 6 and its tetrahydrofuran analogue 8 is described. Their convulsant action was studied in mice. They display a weak convulsant activity coming with sedation and myorelaxation. The introduction of the benzyl group abolishes the strong convulsant and lethal action characteristic of the already studied non benzylated aminolactones but leaves intact the aminoethers activity. These results could indicate that the activity of these amino-gamma-lactones is essentially antiglycinergic and those of the corresponding aminoethers is anti-GABAergic lined with a partial agonist action.

Animals↗