Convergent and Sequential Synthesis of Dendritic, Multivalent Complexing Agents
作者:Nils O. Petersen、Cuihua Liu、Robert H. Hudson
DOI:10.1055/s-2002-33116
日期:——
convergent and sequential pathways. Tetrafluorophenyl esters were employed as activating reagents in the coupling step of assembling NTA groups to the cyclic polyamine head. A key step of the sequential synthesis is the use of the coupling reagent. 2-(3,4-dihydro-4-oxo-1,2,3-benzotriazin-3-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate (TBTU) for the formation of amide bonds between the cyclic polyamine
通过收敛和顺序途径合成了两个系列具有不同长度接头的大环多胺衍生物作为含有两个、三个、四个、五个或六个末端次氮基三乙酸 (NTA) 基团的树枝状配体。在将 NTA 基团组装到环状多胺头的偶联步骤中,四氟苯基酯被用作活化试剂。顺序合成的一个关键步骤是使用偶联剂。2-(3,4-dihydro-4-oxo-1,2,3-benzotriazin-3-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate (TBTU) 用于在环状多胺和挂件组。最后,使用两种具有代表性的化合物来证明化学计量蛋白质组装体的形成。
Homobivalent Ligands of the Atypical Antipsychotic Clozapine: Design, Synthesis, and Pharmacological Evaluation
作者:Fiona M. McRobb、Ian T. Crosby、Elizabeth Yuriev、J. Robert Lane、Ben Capuano
DOI:10.1021/jm201420s
日期:2012.2.23
To date all typical and atypical antipsychotics target the dopamine D-2 receptor. Clozapine represents the best-characterized atypical antipsychotic, although it displays only moderate (submicromolar) affinity for the dopamine D-2 receptor. Herein, we present the design, synthesis, and pharmacological evaluation of three series of homobivalent ligands of clozapine, differing in the length and nature of the spacer and the point of attachment to the pharmacophore. Attachment of the spacer at the N4' position of clozapine yielded a series of homobivalent ligands that displayed spacer-length-dependent gains in affinity and activity for the dopamine D-2 receptor. The 16 and 18 atom spacer bivalent ligands were the highlight compounds, displaying marked low nanomolar receptor binding affinity (1.41 and 1.35 nM, respectively) and functional activity (23 and 44 nM), which correspond to significant gains in affinity (75- and 79-fold) and activity (9- and 5-fold) relative to the original pharmacophore, clozapine. As such these ligands represent useful tools with which to investigate dopamine receptor dimerization and the atypical nature of clozapine.
Functional mimics of copper enzymes. Synthesis and stereochemical properties of the copper(II) complexes of a trinucleating ligand derived from l-histidine
[CuIH]2+ have been also prepared. These copper(II) model complexes are the first reported which are directly derived from chiral l-histidine residues. A detailed analysis of the UV–vis, CD and EPR spectra of the complexes has established that the Cu(II) centers bound to PHI A sites are square-pyramidal in solution, with the amino and one imidazole donor in the equatorial plane and the additional imidazole