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Biomedical subjects

M J Mokrosz

Publications and source records attributed to M J Mokrosz.

At least 19 recordsLinked to original sources
PubMed2001

Influence of the terminal amide fragment geometry in some 3-arylideneindolin-2(1H)-ones on their 5-HT1A/5-HT2A receptor activity.

Several 1,4-disubstituted arylpiperazine derivatives of 3-arylideneindolin-2(1H)-one (Z and E isomers) were tested for their 5-HT1A and 5-HT2A receptor activity in vitro and in vivo. It was shown that introduction of 3-arylidene substituents to indolin-2(1H)-one moiety allowed to change the mixed 5-HT1A/5-HT2A receptor ligands to 5-HT2A ones with antagonistic in vivo activity.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed2001

Benzolactam derivatives and their affinity for alpha 1- and alpha 2-adrenoreceptors.

A series of benzolactam derivatives has been evaluated for their affinity for alpha 1 and alpha 2-adrenoreceptors. The influence of terminal amine and amide fragments on the affinity and selectivity has been investigated. It has been found that derivatives containing 1,2,3,4-tetrahydroisoquinoline (THIQ) as the basic component can form potent alpha 1 and/or alpha 2 ligands, and that their alpha 1/alpha 2 selectivity depends on the benzolactam fragment.

Animals↗
PubMed2000

Application of similarity matrices and genetic neural networks in quantitative structure-activity relationships of 2- or 4-(4-Methylpiperazino)pyrimidines: 5-HT(2A) receptor antagonists.

Antagonists of the 5-HT(2A) receptor are being used to treat many psychiatric disorders. The present work focuses on a group of 27 antagonists possessing varying affinities toward the receptor. These are 26 title compounds and clozapine as a reference antagonist. The active conformers of the conformationally flexible ligands were proposed by using the active rigid analogue approach and performing similarity calculations. The calculations involved genetic neural network (GNN) computations deriving QSARs from similarity matrices (SM) with cross-validated correlation coefficients exceeding 0.92. The performance of neural networks with variety of architectures was studied. As the computations were performed for cations and neutral molecules separately, the relevance of the ligand charging is discussed.

Animals↗
PubMed1999

On the bioactive conformation of NAN-190 (1) and MP3022 (2), 5-HT(1A) receptor antagonists.

Structural modifications of 1, a postsynaptic 5-HT(1A) receptor antagonist, provided its flexible (8, 12) and rigid (7, 9, 11, 13) analogues. Compounds 7, 8, 9, and 11 showed high 5-HT(1A) receptor affinity (K(i) = 4-72 nM). They acted as 5-HT(1A) postsynaptic receptor antagonists, since, like 1, they inhibited the behavioral syndrome, i.e., flat body posture (FBP) and forepaw treading (FT), in reserpine-pretreated rats as well as the lower lip retraction (LLR) in rats, both induced by 8-hydroxy-2-(di-n-propylamino)tetralin hydrobromide (8-OH-DPAT), a 5-HT(1A) receptor agonist. Compound 12, which demonstrated high 5-HT(1A) receptor affinity (K(i) = 50 nM), revealed properties of a partial 5-HT(1A) receptor agonist: it induced LLR and, at the same time, inhibited FT in rats. Compound 13 (K(i) = 1600 nM) was not tested in a behavioral study. Restriction of the conformational freedom in 2, a full 5-HT(1A) receptor antagonist, yielded compound 14 with high 5-HT(1A) receptor affinity (K(i) = 47 nM) and partial agonist properties at postsynaptic 5-HT(1A) receptors in the above tests in vivo; i.e., it induced LLR and inhibited FBP and FT in rats. New constrained analogues of 1 and 2 (compounds 7 and 14, respectively) were also synthesized to recognize a bioactive conformation of those 5-HT(1A) receptor antagonists. On the basis of in vitro and in vivo investigations, binding and functional properties of compound 7 were found to reflect those of 1 at 5-HT(1A) receptors. On the other hand, compound 14, a rigid analogue of 2, showed a different activity in vivo in comparison with the parent compound. PM3 and MM calculations revealed the existence of three low-energy conformers of 7 and six of 14, all of them belonging to the extended family of conformations. The optimized structures of both analogues had a different angle between aromatic planes of terminal fragments; moreover, the heteroaromatic system of those molecules occupied various space regions. Our present study provides support to the hypothesis that the bioactive conformation of 1, responsible for its postsynaptic 5-HT(1A) receptor antagonism, is an extended linear structure represented by 7.

Animals↗
PubMed1999

Structure-activity relationship studies of CNS agents. Part 38. Novel 1,4-benzoxazin-3(4H)-one, 1,2-benzoxazolin-3-one and 1,3-benzoxazolin-2,4-dione arylpiperazine derivatives with different 5-HT1A and antagonistic 5-HT2A activities.

New 1-arylpiperazine (series d-f) and 1,2,3,4-tetrahydroisoquinoline (series g) derivatives of 1,4-benzoxazin-3(4H)-one 1, 1,2-benzoxazolin-3-one 2, and 1,3-benzoxazolin-2,4-dione 3 with an n-butyl chain were synthesized in order to explore the effect of spacer elongation on their binding affinity and in vivo functional activity at 5-HT1A and 5-HT2A receptors in comparison with trimethylene analogues (a, bc). 5-HT1A receptor binding constants of derivatives 1d-g, 2d-f, and 3d-f were very high (Ki = 1.25-54 nM), and 5-HT2A affinities were maintained at a similar, high level (Ki = 27-85 nM) for series d and e, and moderate (Ki = 246-495 nM) for series f. In respect of a spacer, the obtained results showed either no effect or a slight increase in the 5-HT1A/5-HT2A affinity in case of derivatives of 1 and 2, respectively. A striking effect was observed for derivatives 3d and 3f, whose 5-HT1A affinity was reinforced by two orders of magnitude with a simultaneous decrease in 5-HT2A binding constants in comparison with trimethylene analogues. As shown by X-ray crystallography, this phenomenon may be attributed to the position of non-carbonyl oxygen atom in the amide moiety. In vivo studies demonstrated that compounds 1e-g, 2d-f, and 3f behaved like typical postsynaptic 5-HT1A receptor antagonists, whereas 3d and 3e might be qualified as their potential partial agonists. Moreover, 1e, 2e, and 3e demonstrated 5-HT2A receptor antagonistic properties. Of the tested compounds, two derivatives showed some very outstanding properties: 3e may be regarded as a potential anxiolytic and/or antidepressant agent, while 3f as a new potent 5-HT1A antagonist.

Animals↗
PubMed1999

Immunomodulating action and structure-activity relationships of substituted phenylamides of 5-amino-3-methylisoxazole-4-carboxylic acid.

A series of 5-amino-3-methylisoxazole-4-carboxylic acid amides has been prepared by condensation of 5-amino-3-methylisoxazole-4-carboxylic acid with ethyl chloroformate. The resulting mixed anhydride undergoes condensation with appropriate phenylamides to form the corresponding amides 6-16. The compounds obtained were evaluated for their immunological activities in cultures of human peripheral blood mononuclear cells (PMBC). We found that the activities of the compounds in the proliferation test and in the lipopolysaccharide (LPS)-induced cytokine production in PBMC cultures were differential. The stimulatory or inhibitory effects depended strongly on the origin and location of substituents in the phenyl ring which is described in the discussion and was supported by QSAR studies.

Adjuvants, Immunologic↗
PubMed1999

1,2,3,4-tetrahydroisoquinoline derivatives: a new class of 5-HT1A receptor ligands.

Three series of new N-substituted 1,2,3,4-tetrahydroisoquinolines with 2-, 3-, and 4-membered alkyl chains (a, b, and c, respectively) were synthesized, and the effect of some structural modifications on their 5-HT1A receptor affinities and functional properties was discussed. It was found that the volume of the terminal amide substituent was a crucial parameter which determined 5-HT1A receptor affinities of the tested compounds, while the in vivo activity seemed to depend on both the R-volume and the length of a hydrocarbon chain. It was demonstrated that the most active ligands behaved like agonists or partial agonists at postsynaptic 5-HT1A receptors.

Adrenergic Uptake Inhibitors↗
PubMed1999

1,2,3,4-tetrahydroisoquinoline derivatives; lipophilicity evaluation vs. 5-HT1A receptor affinity.

Retention parameters (log k') of 1,2,3,4-tetrahydroisoquinoline derivatives--a new class of 5-HT1A receptor ligands--were determined on the basis of reversed-phase HPLC experiments. Good correlations were found between the log k' values and the calculated log Pc, van der Waals volume of the R substituent (VR) as well as the 5-HT1A receptor affinity (Ki) of the investigated compounds. It was demonstrated that hydrophobic forces played a pivotal role in stabilizing the ligand-receptor bioactive complex for that group of compounds.

Animals↗
PubMed1998

A search for new 5-HT1A/5-HT2A receptor ligands. In vitro and in vivo studies of 1-[omega-(4-aryl-1-piperazinyl)alkyl]indolin-2(1H)-ones.

A series of 1-¿omega-(4-aryl-1-piperazinyl)alkyl]indolin-2(1H)-one derivatives 2-14 was synthesized in order to obtain ligands with a dual 5-HT1A/5-HT2A activity. The majority of those compounds (2-5, 7, 10-13) exhibited a high 5-HT1A (Ki = 2-44 nM) and/or 5-HT2A affinity (Ki = 51 and 39 for 5 and 7, respectively). Induction of lower lip retraction (LLR) and behavioral syndrome and inhibition of these effects evoked by 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) were used for determination the agonistic and antagonistic activity, respectively, at 5-HT1A receptors. The 5-HT2A antagonistic activity was assessed by the blocking effect on the head twitches induced by (+/-)-1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI) in mice. Two of the tested compounds, 1-¿3-[4-(3-chlorophenyl)-1-piperazinyl]propyl¿-6-fluoroindolin-2(1 H)-one (5) and 1-¿3-[4-(2-methoxyphenyl)-1-piperazinyl]propyl¿indolin-2(1H)-one (7), demonstrated a high 5-HT1A/5-HT2A affinity and an in vivo antagonistic activity towards both receptor subtypes.

Animals↗
PubMed1997

Structure-activity relationship studies of CNS agents, Part 32: Effect of structural modifications in 1-arylpiperazine derivatives on alpha(1) -adrenoreceptor affinity.

The alpha(1)-adrenergic and 5-HT1A serotonergic receptor affinities of a series of 1-arylpiperazines are presented. The role of the spacer and the influence of the terminal substituents on the alpha(1)-adrenoreceptor affinity and the 5-HT1A/alpha(1) receptor selectivity are discussed.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1997

5-HT1A and 5-HT2A receptor affinity and functional profile of some N-[3-(4-aryl-1-piperazinyl)propyl] derivatives of indolin-2(1H)-one, quinolin-2(1 H)-one and isoquinolin-1(2H)-one. Part 30: Structure-activity relationship studies of CNS agents.

A series of new 1-aryl-4-propylpiperazines containing the modified terminal amide fragment 9, 15-19, 21, 23 and 25 were synthesized and their 5-HT1A and 5-HT2A receptor affinities were determined. All the compound were highly potent 5-HT1A receptor ligands with a diverse 5-HT2A receptor affinity. It was found that the 5-HT2A receptor affinity depends on the dipole moment and lipophilicity of amide moiety. Compound 9b was found to be a 5-HT2A receptor antagonist and a weak 5-HT1A receptor agonist.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1996

8-[4-[2-(1,2,3,4-Tetrahydroisoquinolinyl]butyl-8-azaspiro[4.5]decane-7,9-dione: a new 5-HT1A receptor ligand with the same activity profile as buspirone.

A new analog of buspirone (1), i.e., 8-[4-[2-(1,2,3,4-tetrahydroisoquinolinyl)]butyl]-8-azaspiro- [4.5]decane-7,9-dione (6a), was synthesized. In was demonstrated that buspirone and its analog 6a were equipotent 5-HT(1A) ligands. Several behavioral models showed that 6a had essentially the same functional profile at 5-HT(1A) receptors as buspirone. The obtained results permit a conclusion that the basic nitrogen atom and terminal, bulky cycloimide moiety, but not the 2-pyrimidinyl group, of buspirone are directly involved in the formation of the bioactive complex with 5-Ht1A receptors.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1996

3-(omega-Aminoalkyl)-5,5-dialkyl(or spirocycloalkyl-1',5-)hydantoins as new 5-HT1A and 5-HT2A receptor ligands.

A series of new 3-(omega-aminoalkyl)-5,5-disubstituted hydantoins, containing 1-phenylpiperazine, 1-(o-methoxyphenyl)piperazine or 1,2,3,4-tetrahydroisoquinoline fragments, were synthesized by standard alkylation procedures and their 5-HT1A and 5-HT2A receptor affinities were determined. It has been shown that the investigated derivatives are recognized by 5-HT1A and 5-HT2A receptors due to the presence of a 1-arylpiperazine fragment however, the terminal hydantoin moiety plays an important role in stabilization of the receptor-ligand complex. It has also been found that the two 1-phenylpiperazine derivatives 32 and 36 are new selective 5-HT2A receptor ligands (Ki = 34 and 37 nM, respectively), whereas the derivative of 1-(o-methoxyphenyl)piperazine (38) is a new, highly potent 5-HT1A receptor ligand (Ki = 0.51 nM) with a moderate affinity for 5-HT2A receptors (Ki = 213 nM).

Amines↗
PubMed1995

Structure-activity relationship studies of CNS agents, XIX: Quantitative analysis of the alkyl chain effects on the 5-HT1A and 5-HT2 receptor affinities of 4-alkyl-1-arylpiperazines and their analogs.

The 5-HT1A and 5-HT2 receptor affinity of a set of 44 N-alkylated 1-aryl-piperazines and their analogs has been analyzed: the n-hexyl derivatives were the most potent and the most selective 5-HT1A ligands of all the investigated N-alkyl homologues. The alkyl chain may stabilize the 5-HT1A receptor-ligand complex by hydrophobic forces. A set of the alkyl substituent contributions (CHT1A) for prediction of the 5-HT1A affinity of N-alkyl derivatives of 1-arylpiperazines and related compounds have been defined on the basis of the Free-Wilson analysis.

Animals↗
PubMed1995

Structure-activity relationship studies of CNS agents, Part 25. 4,6-di(heteroaryl)-2-(N-methylpiperazino)pyrimidines as new, potent 5-HT2A receptor ligands: a verification of the topographic model.

A series of new 4,6-di(heteroaryl)pyrimidines containing an N-methylpiperazino group (6-13) or an ethylenediamine chain (15-20) in position 2 were synthesized and their 5-HT1A and 5-HT2A receptor affinities were determined. It was shown that the substituent effects on the 5-HT2A affinity are additive and could be described quantitatively. In a behavioral model it was also demonstrated that 6-11 are 5-HT2A receptor antagonists. The molecular modelling results suggested that the distances between the basic nitrogen atom and the two aromatic centers (d1 = 5.2-8.4 A, d2 = 5.7-8.5 A, and d3 = 4.6-7.3 A) define the molecular topography of the 5-HT2A receptor antagonists under study.

Animals↗
PubMed1995

Structure-activity relationship studies of CNS agents--XVII. Spiro[piperidine-4',1-(1,2,3,4-tetrahydro-beta-carboline)] as a probe defining the extended topographic model of 5-HT1A receptors.

Spiro[piperidine-4',1-(1,2,3,4-tetrahydro-beta-carboline)] (10), its derivatives 11-15 and its analogs 16 and 17 were examined as ligands of serotonin 5-HT1A receptors. It was shown that compounds 12 and 14 had essentially the same 5-HT1A affinity as 1-phenylpiperazine and its rigid analog 7, whereas there were substantial differences in the steric arrangement of their crucial pharmacophores, i.e. aromatic and protonation centers. On the basis of the existing models and using the (+)-LSD structure as a template, a new, extended three-point topographic model of 5-HT1A receptors has been proposed.

Animals↗
PubMed1994

Structure-activity relationship studies of central nervous system agents. 13. 4-[3-(Benzotriazol-1-yl)propyl]-1-(2-methoxyphenyl)piperazine, a new putative 5-HT1A receptor antagonist, and its analogs.

A new set of 4-alkyl-1-(o-methoxyphenyl)piperazines containing a terminal benzotriazole fragment were synthesized, and their 5-HT1A and 5-HT2 affinity was determined. It was shown that the benzotriazole moiety contributes to both the 5-HT1A and 5-HT2 receptor affinity. It was demonstrated in several behavioral models that 4-[3-(benzotriazol-1- yl)propyl]-1-(2-methoxyphenyl)piperazine (11) is a new, potent presynaptic and postsynaptic 5-HT1A receptor antagonist. However, it is not selective for 5-HT1A versus alpha 1 receptors.

8-Hydroxy-2-(di-n-propylamino)tetralin↗