congresos y reuniones científicas
Dopaminergic isoquinolines with hexahydrocyclopenta[ij]-isoquinolines as D2-like selective ligands
ROJAS, SEBASTIÁN; PARRAVICINI, OSCAR; ANDUJAR, SEBASTIÁN A.; ENRIZ, RICARDO D.
Simposio; IIILAFeBS, IX IberoAmerican congress of Biophysics, XLV SAB Annual Meeting; 2016
Dopamine receptors (DR) ligands are potential drug candidates for treating neurological disorders including schizophrenia or Parkinson?s disease. Three series of isoquinolines: (E)-1-styryl-1,2,3,4- tetrahydroisoquinolines (series 1), 7-phenyl-1,2,3,7,8,8a-hexahydrocyclopenta[ij]-IQs (HCPIQs) (series 2) and (E)-1-(prop-1-en-1-yl)-1,2,3,4- tetrahydroisoquinolines (series 3), were prepared to determinetheir affinity for both D 1 and D 2 -like DR. The effect of different substituents on the nitrogen atom (methyl or allyl), the dioxygenated function (methoxyl or catechol), the substituent at the b -position of the THIQ skeleton, and the presence or absence of the cyclopentane motif, were studied. We observed that the most active compounds in the three series (2c, 2e, 3a, 3c, 3e, 5c and 5e) possessed a high affinity for D 2 -like DR and these remarkable features: a catechol group in the IQ-ring and the N-substitution (methyl or allyl). The series showed the following trend to D 2 -RD affinity: HCPIQs > 1-styryl > 1-propenyl. Therefore, the substituent at the b -position of the THIQ and the cyclopentane ring also modulated this affinity. Among these dopaminergic isoquinolines, HCPIQs stood out for unexpected selectivity to D 2 -DR since the Ki D 1 /D 2 ratio reached values of 2465, 1010 and 382 for compounds 3a, 3c and 3e, respectively. None of the most active THIQs in D 2 DR displayed relevant cytotoxicity in human neutrophils and HUVEC. Finally, and in agreement with the experimental data, molecular modeling studies on DRs of the most characteristic ligands of the three series revealed stronger molecular interactions with D 2 DR than with D 1 DR, which further supports to the encountered enhanced selectivity to D 2 DR