Benzophenanthridine alkaloids isolated from Eschscholtzia californica cell suspension cultures interact with vasopressin (V1) receptors.

Chelerythrine and sanguinarine, two benzophenanthridine alkaloids, have been isolated from a crude methanolic extract of Eschscholtzia californica cell suspension cultures by successive fractionations. These two molecules exhibited affinity for rat liver vasopressin V1 receptors and are competitive inhibitors of [3H]-vasopressin binding within the micromolar range (Ki). Chelerythrine and sanguinarine represent two of the first non-peptidic structures providing original chemical leads for the design of synthetic vasopressin compounds.