New halogenated phenylcoumarins as tyrosinase inhibitors
摘要:
With the aim to find out structural features for the tyrosinase inhibitory activity, in the present communication we report the synthesis and pharmacological evaluation of a new series of phenylcoumarin derivatives with different number of hydroxyl or ether groups and bromo substituent in the scaffold. The synthesized compounds 5-12 were evaluated as mushroom tyrosinase inhibitors showing, two of them, lower IC50 than the umbelliferone. Compound 12 (IC50 = 215 mu M) is the best tyrosinase inhibitor of this series. (C) 2011 Elsevier Ltd. All rights reserved.
Structure-Based Optimization of Coumarin hA3 Adenosine Receptor Antagonists
摘要:
Adenosine receptors participate in many physiological functions. Molecules that may selectively interact with one of the receptors are favorable multifunctional chemical entities to treat or decelerate the evolution of different diseases. 3-Arylcoumarins have already been studied as neuroprotective agents by our group. Here, differently 8-substituted 3-arylcoumarins are complementarily studied as ligands of adenosine receptors, performing radioligand binding assays. Among the synthesized compounds, selective A(3) receptor antagonists were found. 3-(4-Bromophenyl)-8-hydroxycoumarin (compound 4) displayed the highest potency and selectivity as A(3) receptor antagonist (K-i = 258 nM). An analysis of its X-ray diffraction provided detailed information on its structure. Further evaluation of a selected series of compounds indicated that it is the nature and position of the substituents that determine their activity and selectivity. Theoretical modeling calculations corroborate and explain the experimental data, suggesting this novel scaffold can be involved in the generation of candidates as multitarget drugs.