Discovery, production and purification of the Na+, K+ activated ATPase inhibitor, L-681,110 from the fermentation broth of Streptomyces sp. MA-5038.

The maximum yield for the production of L-681,110 by Streptomyces sp. MA-5038 (ATCC 31587) was observed after 5 days' incubation at 28 degrees C and pH about 8.3. L-681,110 was isolated from the fermentation broth by acetone extraction of the mycelia, absorption to Amberlite XAD-2 resin and two separations by thin-layer chromatography. The structure of L-681,110 was found to consist of a sixteen-membered lactone with a new type of substitution. The inhibition of ATPase, activity against Caenorhabditis elegans and stimulation of gamma-aminobutyric acid release indicate that L-681,110 possesses some characteristics of both oligomycin and avermectin. L-681,110 was also active against tapeworm and ticks in an in vivo assay.