Conformationally defined adrenergic agents. 5. Resolution, absolute configuration, and pharmacological characterization of the enantiomers of 2-(5,6-dihydroxy-1,2,3,4-tetrahydro-1-naphthyl)imidazoline: a potent agonist at alpha-adrenoceptors

Separation of tetrahydrozoline enantiomers in capillary electrophoresis with cyclodextrin-type chiral selectors and investigation of chiral recognition mechanisms

The recognition power and affinity pattern of various cyclodextrins (CD) towards the enantiomers of tetrahydrozoline (THZ) were studied using capillary electrophoresis (CE). As expected, affinity of THZ enantiomers and selectivity of recognition towards CD derivatives was strongly dependent on the cavity size and substituent type and pattern on the CD rims. Not only were the affinity strength and selectivity of recognition affected by the size of the cavity and chemistry of the CDs but also the affinity pattern. Another interesting example of opposite affinity pattern of enantiomers towards α- and β-CD was observed here. In addition, opposite affinity pattern of THZ enantiomers was seen towards β-CD and its acetylated derivatives, while methylation of β-CD did not affect the affinity pattern of THZ enantiomers. In order to get more information about structural mechanisms of the multivariate dependences mentioned above, rotating frame Overhauser enhancement spectroscopy (ROESY) and computation techniques were used. Significant differences between the structure of THZ complexes with different CDs with both methods were encountered. Good correlations between experimentally determined and computed structure of complexes, as well as between computed complex stabilities and enantiomer migration order (EMO) in CE were observed.

Quantitative structure-activity relationships for substituted aminotetralin analogues. II: Inhibition of dopamine uptake

Quantitative structure-activity relationships of 44 substituted aminotetralin analogues with regard to dopamine (DA) uptake inhibitory potency are examined in this study. Lipophilic substituents at R3 and hydrophilic substituents at R6 and/or R9 positions, as well as the overall lipophilicity of the molecule contribute toward increasing the inhibitory potency. Unlike with norepinephrine uptake inhibition, little effects are seen from the nitrogen substituent. Among the ring substituents examined, an hydroxy group at the R6 position increases the DA uptake inhibitory potency, whereas a methoxy group at the R7 position decreases it. A comparative quantitative structure-activity relationship study shows that a bromine at the R6 position and/or hydrogen at the R9 position make the compound a better norepinephrine uptake inhibitor than a DA uptake inhibitor, whereas hydrogen at the R6 and/or a substituent larger than a propyl group at the R2 position make the compound a more potent DA uptake inhibitor.

Quantitative structure-activity relationships for substituted aminotetralin analogues. I: Inhibition of norepinephrine uptake

Quantitative structure-activity relationships of 57 substituted aminotetralin analogues, an overview of their syntheses, and their pharmacological activity are described in this study. Lipophilic substituents at R3 as well as the overall lipophilicity of the molecule contribute toward increasing the inhibitory potency. An ethyl group is preferred, and a group larger than a propyl is not desirable as a nitrogen substituent. Among the ring substituents examined, an hydroxy group at the R6 position and either an unsubstituted R9 position or a methoxy substituent at the R9 position increase the inhibitory potency, whereas a methoxy group at the R7 position decreases inhibitory potency.