Isolation of biologically active fractions from the water soluble components of fulvic and ulmic acids from peat.

With a view to clarifying the excitatory action of aqueous peat extract (APE) on the spontaneous contractile activity (SCA) of the smooth muscles, in vitro studies were made of the influences of the water-soluble HPLC-fractions of fulvic and ulmic acids separated from peat on smooth-muscle preparations of guinea-pig stomach. The results obtained show that peat contains a large number of water-soluble components, which possess agonistic or partial agonistic actions on the alpha2-adreno- and D2-dopamine receptors. These are chemically stable substances, which retain for months their biological activity unchanged in aqueous solution. The excitatory effect of APE on the SCA of the smooth-muscle preparations was found to be more pronounced than the reactivity of alpha2-adrenoreceptors.