Tetrahydroprotoberberine alkaloids with dopamine and σ receptor affinity
摘要:
Two series of analogues of the tetrahydroprotoberberine (THPB) alkaloid (+/-)-stepholidine that (a) contain various alkoxy substituents at the C10 position and, (b) were de-rigidified with respect to (+/-)-stepholidine, were synthesized and evaluated for affinity at dopamine and sigma receptors in order to evaluate effects on D3 and sigma 2 receptor affinity and selectivity. Small n-alkoxy groups are best tolerated by D3 and sigma 2 receptors. Among all compounds tested, C10 methoxy and ethoxy analogues (10 and 11 respectively) displayed the highest affinity for sigma 2 receptors as well as sigma 2 versus sigma 1 selectivity and also showed the highest D3 receptor affinity. De-rigidification of stepholidine resulted in decreased affinity at all receptors evaluated; thus the tetracyclic THPB framework is advantageous for affinity at dopamine and sigma receptors. Docking of the C10 analogues at the D3 receptor, suggest that an ionic interaction between the protonated nitrogen atom and Asp110, a H-bond interaction between the C2 phenol and Ser192, a H-bond interaction between the C10 phenol and Cys181 as well as hydrophobic interactions of the aryl rings to Phe106 and Phe345, are critical for high affinity of the compounds. (C) 2016 Elsevier Ltd. All rights reserved.
An Efficient Formal Synthesis of the Human Telomerase Inhibitor (±)-γ-Rubromycin
作者:Dominea C. K. Rathwell、Sung-Hyun Yang、Kit Y. Tsang、Margaret A. Brimble
DOI:10.1002/anie.200903316
日期:2009.10.12
in the naphthazarin and isocoumarin fragments facilitates the acid‐mediated spiroketalization step to afford the key densely functionalized spiroketal (see picture; EOM=ethoxymethyl) in the formal synthesis of (±)‐γ‐rubromycin. A novel regioselective allyloxylation/Claisen rearrangement of 2‐azido‐1,4‐naphthoquinone provides access to the highly oxygenated naphthazarin fragment.
A divergent route to 9,10-oxygenated tetrahydroprotoberberine and 8-oxoprotoberberine alkaloids: synthesis of (±)-isocorypalmine and oxypalmatine
作者:Satishkumar Gadhiya、Shashikanth Ponnala、Wayne W. Harding
DOI:10.1016/j.tet.2015.01.004
日期:2015.2
A new route which is germane to the synthesis of 9,10-oxygenated tetrahydroprotoberberines and 8-oxoprotoberberines is described. The route features the use of a diester (14) generated from reaction of dimethylmalonate with an aryl halide in the presence of n-butyllithium. The amide 17 prepared in subsequent steps is a versatile precursor for the synthesis of tetrahydroprotoberberine and 8-oxoprotoberberine