In the course of a random screen of various plant extracts, khusimol [1], a nonpeptide molecule isolated from the root of Vetiveria zizanioides, was found to competitively inhibit the binding of vasopressin to rat liver Vu receptors (K¡=50 µ ). The of this sesquiterpene alcohol were assigned unambiguously.

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.