2,3,9- and 2,3,11-Trisubstituted tetrahydroprotoberberines as D2 dopaminergic ligands
摘要:
Dopamine-mediated neurotransmission plays an important role in relevant psychiatric and neurological disorders. Nowadays, there is an enormous interest in the development of new dopamine receptors (DR) acting drugs as potential new targets for the treatment of schizophrenia or Parkinson's disease. Previous studies have revealed that isoquinoline compounds such as tetrahydroisoquinolines (THIQs) and tetrahydroprotoberberines (THPBs) can behave as selective D-2 dopaminergic alkaloids since they share structural similarities with dopamine. In the present study we have synthesized eleven 2,3,9- and 2,3,11-trisubstituted THPB compounds (six of them are described for the first time) and evaluated their potential dopaminergic activity. Binding studies on rat striatal membranes were used to evaluate their affinity and selectivity towards D-1 and D-2 DR and establish the structure activity relationship (SAR) as dopaminergic agents. In general, all the tested THPBs with protected phenolic hydroxyls showed a lower affinity for D-1 and D-2 DR than their corresponding homologues with free hydroxyl groups. In previous studies in which dopaminergic affinity of 1-benzyl-THIQs (BTHIQs) was evaluated, the presence of a Cl into the A-ring resulted in increased affinity and selectivity towards D-2 DR. This is in contrast with the current study since the existence of a chlorine atom into the A-ring of the THPBs caused increased affinity for D-1 DR but dramatically reduced the selectivity for D-2 DR. An OH group in position 9 of the THPB (9f) resulted in a higher affinity for DR than its homologue with an OH group in position 11 (9e) (250 fold for D-2 DR). None of the compounds showed any cytotoxicity in freshly isolated human neutrophils. A molecular modelling study of three representative THPBs was carried out. The combination of MD simulations with DFT calculations provided a clear picture of the ligand binding interactions from a structural and energetic point of view. Therefore, it is likely that compound 9d (2,3,9-trihydroxy-THPB) behave as D-2 DR agonist since serine residues cluster are crucial for agonist binding and receptor activation. (C) 2013 Elsevier Masson SAS. All rights reserved.
Biocatalytic Enantioselective Oxidative CC Coupling by Aerobic CH Activation
作者:Joerg H. Schrittwieser、Verena Resch、Johann H. Sattler、Wolf-Dieter Lienhart、Katharina Durchschein、Andreas Winkler、Karl Gruber、Peter Macheroux、Wolfgang Kroutil
DOI:10.1002/anie.201006268
日期:2011.2.1
CC coupling that leads to a new intramolecular bond. This unique transformation requires O2 as sole stoichiometric oxidant and gives access to novel opticallypure (S)‐berbine 2 and (R)‐1‐benzyl‐1,2,3,4‐tetrahydroisoquinoline 1 alkaloid derivatives by kinetic resolution.
弥合差距:小檗碱桥酶 (BBE) 被用于第一个制备性氧化生物催化 C C 偶联,导致新的分子内键。这种独特的转化需要 O 2作为唯一的化学计量氧化剂,并通过动力学拆分获得新的光学纯 ( S )-小檗碱2和 ( R )-1-苄基-1,2,3,4-四氢异喹啉1生物碱衍生物。
2,3,9- and 2,3,11-Trisubstituted tetrahydroprotoberberines as D2 dopaminergic ligands
Dopamine-mediated neurotransmission plays an important role in relevant psychiatric and neurological disorders. Nowadays, there is an enormous interest in the development of new dopamine receptors (DR) acting drugs as potential new targets for the treatment of schizophrenia or Parkinson's disease. Previous studies have revealed that isoquinoline compounds such as tetrahydroisoquinolines (THIQs) and tetrahydroprotoberberines (THPBs) can behave as selective D-2 dopaminergic alkaloids since they share structural similarities with dopamine. In the present study we have synthesized eleven 2,3,9- and 2,3,11-trisubstituted THPB compounds (six of them are described for the first time) and evaluated their potential dopaminergic activity. Binding studies on rat striatal membranes were used to evaluate their affinity and selectivity towards D-1 and D-2 DR and establish the structure activity relationship (SAR) as dopaminergic agents. In general, all the tested THPBs with protected phenolic hydroxyls showed a lower affinity for D-1 and D-2 DR than their corresponding homologues with free hydroxyl groups. In previous studies in which dopaminergic affinity of 1-benzyl-THIQs (BTHIQs) was evaluated, the presence of a Cl into the A-ring resulted in increased affinity and selectivity towards D-2 DR. This is in contrast with the current study since the existence of a chlorine atom into the A-ring of the THPBs caused increased affinity for D-1 DR but dramatically reduced the selectivity for D-2 DR. An OH group in position 9 of the THPB (9f) resulted in a higher affinity for DR than its homologue with an OH group in position 11 (9e) (250 fold for D-2 DR). None of the compounds showed any cytotoxicity in freshly isolated human neutrophils. A molecular modelling study of three representative THPBs was carried out. The combination of MD simulations with DFT calculations provided a clear picture of the ligand binding interactions from a structural and energetic point of view. Therefore, it is likely that compound 9d (2,3,9-trihydroxy-THPB) behave as D-2 DR agonist since serine residues cluster are crucial for agonist binding and receptor activation. (C) 2013 Elsevier Masson SAS. All rights reserved.