The histamine amides of Acacia longifolia.

Extracts of Acacia longifolia yielded two major histamine aldaloiks which were separated by tlc. Nmr, ms, uv, ir and other physical measurements led to structural assignments of the compounds as N-(2-imidazol-4-yl-ethyl)-trans-cinnamamide and N-(2-imidazol-4-yl-ethyl)-deca-trans-2, cis-4-dienamide. Confirmation of these structures was by comparison of literature data in the case of the cinnamamide and by synthesis of the new decadienamide. Dowex-50 ion exchange resin (H+ form) was found to be highly efficient in the isolation of these compounds from crude plant extracts.