Flavonoids from Perovskia atriplicifolia and Their in Vitro Displacement of the Respective Radioligands for Human Opioid and Cannabinoid Receptors

摘要

Bioassay-guided fractionation of the leaves of Perovskia atriplicifolia (Russian sage) resulted in the isolation of four previously known flavonoid derivatives, 5-hydroxy-6,7,3',4'-tetramethoxyflavone (1), 5,7-dihydroxy-6,3',4'-trimethoxyflavone (2), 5-hydroxy-6,7,4'-trimethoxyflavone (3), and 5,7-dihydroxy-6,4'-dimethoxyflavone (4). Compounds 1, 3, and 4 showed displacement of the radioligand for the cloned human delta opioid receptor with K-i values ranging from 3.1 to 26.0 mu M. In addition, the binding mode of the compounds in the active site of the delta opioid receptor was investigated through molecular modeling algorithms. This study may have implications in better understanding non-nitrogenous d opioid receptor ligands.