Lignans isolated from valerian: Identification and characterization of a new olivil derivative with partial agonistic activity at A1adenosine receptors

A methanolic extract of the roots of Valeriana officinalis (valerian) was investigated for its lignan content. In addition to the lignans 8‘-hydroxypinoresinol (1) and pinoresinol-4-O-β-d-glucoside (2), which had already been isolated from valerian in an earlier study, the 7,9‘-monoepoxylignans massoniresinol-4‘-O-β-d-glucoside (3), 4‘-O-β-d-glucosyl-9-O-(6‘ ‘-deoxysaccharosyl)olivil (4), and berchemol-4‘-O-β-d-glucoside (5) and the 7,9‘:7‘,9-diepoxylignans pinoresinol-4,4‘-di-β-O-d-glucoside (6), 8-hydroxypinoresinol-4‘-O-β-d-glucoside (7), and 8‘-hydroxypinoresinol-4‘-O-β-d-glucoside (8) were identified. While lignans 3, 6, 7, and 8 had already been isolated from other plants, lignans 4 and 5 are new natural products. The lignans were investigated in radioligand binding assays at various receptors of the central nervous system, including GABAA, benzodiazepine, 5-HT1A, and adenosine A1 and A2A receptors, to investigate their potential contribution to the pharmacological activity of valerian. The novel ol...