RESUMEN
Prodrugs of (-)-beta-D-(2R,4R)-1,3-dioxolane-2,6-diamino purine (DAPD), organic salts of DAPD, 5'-L-valyl DAPD and N-1 substituted (-)-beta-D-(2R,4R)-1,3-dioxolane guanosine (DXG) have been synthesized with the objective of finding molecules which might be superior to DAPD and DXG in solubility as well as pharmacologic profiles. Synthesized prodrugs were evaluated for anti-HIV activity against HIV-1(LAI) in primary human lymphocytes (PBM cells) as well as their cytotoxicity in PBM, CEM and Vero cells. DAPD prodrugs, modified at the C6 position of the purine ring, demonstrated several folds of enhanced anti-HIV activity in comparison to the parent compound DAPD without increasing the toxicity. The presence of alkyl amino groups at the C6 position of the purine ring increased the antiviral potency several folds, and the most potent compound (-)-beta-D-(2R,4R)-1,3-dioxolane-2-amino-6-aminoethyl purine (8) was 17 times more potent than that of DAPD. 5'-L-Valyl DAPD 20 and organic acid salts 21-24 also exhibited enhanced anti-HIV activity in comparison to DAPD, while DXG prodrugs 16 and 17 exhibited lower potency than that of DXG or DAPD.
Asunto(s)
Fármacos Anti-VIH/farmacología , Dioxolanos/síntesis química , Dioxolanos/farmacología , Guanosina/análogos & derivados , VIH/efectos de los fármacos , Profármacos/farmacología , Nucleósidos de Purina/síntesis química , Nucleósidos de Purina/farmacología , Animales , Fármacos Anti-VIH/síntesis química , Fármacos Anti-VIH/química , Fármacos Anti-VIH/metabolismo , Línea Celular , Dioxolanos/química , Dioxolanos/metabolismo , Estabilidad de Medicamentos , Guanosina/síntesis química , Guanosina/química , Guanosina/metabolismo , Guanosina/farmacología , VIH/fisiología , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , Humanos , Leucocitos Mononucleares/virología , Profármacos/síntesis química , Nucleósidos de Purina/química , Nucleósidos de Purina/metabolismo , SolubilidadRESUMEN
An examination of several amine-substituted analogs of N(1)-benzenesulfonylindoles reveals that although they bind at human 5-HT(6) serotonin receptors with high affinity, they are likely to bind in a dissimilar manner.
Asunto(s)
Indoles/química , Receptores de Serotonina/química , Aminas/química , Humanos , Unión ProteicaRESUMEN
To determine if the indolic nitrogen atom is required for the binding of N(1)-benzyltryptamines at h5-HT(6) serotonin receptors, several isotryptamines and indene analogs were examined. The affinity of 3-benzyl-N(1)-(N,N-dimethylaminoethyl)indole (5, K(i)=32nM) and 1-benzyl-3-(N,N-dimethylaminoethyl)indene (11, K(i)=3nM) indicates that the indolic nitrogen atom is not essential for binding.
Asunto(s)
Indenos/metabolismo , Receptores de Serotonina/metabolismo , Triptaminas/metabolismo , Sitios de Unión , Humanos , Indenos/química , Unión Proteica , Receptores de Serotonina/química , Triptaminas/químicaRESUMEN
4-Sulfonyl analogs of 1-(1-naphthyl)piperazine bind at human 5-HT6 receptors and represent a novel class of human 5-HT6 receptor ligands.
Asunto(s)
Piperazinas/química , Receptores de Serotonina/metabolismo , Ligandos , Modelos Químicos , Estructura Molecular , Piperazinas/farmacología , Unión Proteica , Relación Estructura-Actividad , Triptaminas/química , Triptaminas/farmacologíaRESUMEN
A graphics model of the human 5-HT6 receptor was constructed and automated docking studies were performed. The model suggests that 5-HT6 antagonist arylsulfonyltryptamines might bind differently than that of the agonist serotonin. Furthermore, the model explains many of the empirical results from our previous structure-affinity studies.
Asunto(s)
Receptores de Serotonina/metabolismo , Antagonistas de la Serotonina/química , Antagonistas de la Serotonina/metabolismo , Agonistas de Receptores de Serotonina/química , Agonistas de Receptores de Serotonina/metabolismo , Humanos , Unión Proteica/fisiologíaRESUMEN
Two agents gaining popularity on the illicit drug market are the phenylalkylamines 4-MTA and 2C-T-7 [or 1-(4-methylthiophenyl)-2-aminopropane and 2-(2,5-dimethoxy-4-n-propylthiophenyl)-1-aminoethane, respectively]. At this time, there exists a paucity of information on the behavioral actions of these sulfur-containing agents. The present investigation examined these agents, and the N-monomethyl analog of 4-MTA (i.e., 4-MTMA), in tests of stimulus generalization (substitution) using a two-lever drug discrimination task with groups of rats trained to discriminate either the hallucinogen DOM [1-(2,5-dimethoxy-4-methylphenyl)-2-aminopropane], the stimulant cocaine, or the empathogen MDMA from vehicle. 4-MTA and its N-monomethyl analog 4-MTMA (ED50 = 0.8 mg/kg in both cases) substituted only for the MDMA stimulus, whereas 2C-T-7 (ED50 = 0.8 mg/kg) substituted only for the DOM stimulus. Thus, at the doses examined, 4-MTA and 4-MTMA appear to be MDMA-like agents, and 2C-T-7 seems best classified as a DOM-like hallucinogen. These results provide additional data that extend the structure-activity relationships of phenylalkylamines and that are consistent with what little is currently known about the action of 4-MTA and 2C-T-7 in humans.
Asunto(s)
Estimulantes del Sistema Nervioso Central/farmacología , Drogas Ilícitas/farmacología , Fenetilaminas/farmacología , Propilaminas/farmacología , Sulfuros/farmacología , 2,5-Dimetoxi-4-Metilanfetamina/farmacología , Animales , Estimulantes del Sistema Nervioso Central/química , Cocaína/farmacología , Discriminación en Psicología/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Alucinógenos/farmacología , Drogas Ilícitas/química , Masculino , N-Metil-3,4-metilenodioxianfetamina/farmacología , Fenetilaminas/química , Propilaminas/química , Ratas , Ratas Sprague-Dawley , Relación Estructura-Actividad , Sulfuros/química , Azufre/químicaRESUMEN
Evidence suggests that +/- 3,4-methylenedioxymethamphetamine (MDMA) and psychostimulants produce similar but non-identical stimulus effects in animals. To examine this hypothesis, groups of rats were trained to discriminate either MDMA (1.5 mg/kg) or cocaine (8 mg/kg) from saline vehicle using a two-lever operant procedure under a variable interval (VI) 15 s schedule of reinforcement. Once the animals were trained, tests of stimulus generalization were conducted with +/- MDMA, cocaine, S+ MDMA, and R- MDMA. As previously demonstrated, both S+ MDMA and R- MDMA (ED50 = 0.8 and 1.2 mg/kg, respectively) substituted for +/- MDMA. Stimulus generalization also occurred upon administration of cocaine (ED50 = 4.6 mg/kg) to the +/- MDMA-trained animals. In the cocaine-trained animals, however, stimulus generalization did not occur to +/- MDMA, S+ MDMA nor R- MDMA. Receptor binding profiles for MDMA and cocaine were compared in an effort to identify any novel and common receptor-based mechanism(s) to explain stimulus generalization of MDMA-trained animals to the effects of cocaine, but only their actions on neurotransmitter transporters seem applicable. Taken together, the results indicate that stimulus substitution between MDMA and cocaine is asymmetric and suggest that although similarities exist between the stimulus actions of MDMA and cocaine, differences might be explained by their differential effects on increasing synaptic concentrations of serotonin (5-HT), dopamine (DA), and/or norepinephrine (NE).
Asunto(s)
Cocaína/farmacología , Aprendizaje Discriminativo/efectos de los fármacos , N-Metil-3,4-metilenodioxianfetamina/farmacología , Tiempo de Reacción/efectos de los fármacos , Animales , Cocaína/metabolismo , Aprendizaje Discriminativo/fisiología , Relación Dosis-Respuesta a Droga , Masculino , N-Metil-3,4-metilenodioxianfetamina/metabolismo , Unión Proteica/efectos de los fármacos , Unión Proteica/fisiología , Ratas , Ratas Sprague-Dawley , Tiempo de Reacción/fisiologíaRESUMEN
5-HT(6) serotonin receptors are distributed within some dopamine terminal regions in the brain leading to suggestions that they might influence dopaminergic function. In the present study, the 5-HT(6) antagonist 5-methoxy-N,N-dimethyl-N(1)-benzenesulfonyltryptamine (MS-245) was without effect when administered (3.0-7.5 mg/kg) to rats trained to discriminate (+)amphetamine (1.0 mg/kg) from saline vehicle in a two-lever drug discrimination task. Administered in combination, 0.3 mg/kg (i.e., the ED(50) dose) of (+)amphetamine plus 5.0 mg/kg of MS-245 elicited 95% amphetamine-appropriate responding. Similar studies were conducted using rats trained to discriminate cocaine (8.0 mg/kg) from saline vehicle, but a combination of 2.0 mg/kg (i.e., the ED(50) dose) of cocaine together with relatively low doses of MS-245 resulted in the percent response (approximately 50%) expected from administration of this dose of cocaine or in disruption of the animals' behavior. The present results confirm findings from other laboratories that 5-HT(6) antagonists can modulate amphetamine-induced behavioral actions, and further extend these findings to an example of a different structural class of 5-HT(6) antagonists and to a different behavioral paradigm. Taken together, the data suggest that 5-HT(6) serotonin agents (or at least MS-245) could have potential clinical application in therapies that involve modulation of dopamine neurotransmission.
Asunto(s)
Anfetamina/farmacología , Receptores de Serotonina/fisiología , Antagonistas de la Serotonina/farmacología , Triptaminas/farmacología , Animales , Relación Dosis-Respuesta a Droga , Masculino , Ratas , Ratas Sprague-DawleyRESUMEN
1-Benzenesulfonyl-5-methoxy-N,N-dimethyltryptamine (3; K(i)=2.3 nM) is a 5-HT(6) receptor antagonist; removal of the 5-methoxy group (i.e., 6; K(i)=4.1 nM) has little impact on receptor affinity. In the present study, it is shown that the aminomethyl portion of 6 can be shortened to gramine analogue 10a (K(i)=3.1 nM); a related skatole derivative 11b (K(i)=12 nM) also binds with high affinity indicating that the aminoethyl portion of the tryptamines is not required for binding. Compounds 10a and 11b represent members of novel classes of 5-HT(6) antagonists.