Odorous compounds in natural waters. An earthy-smelling compound associated with blue-green algae and actinomycetes

Earthy-smelling compounds isolated from blue-green algae (Symploca muscorum and Oscillatoria tenuis) and actinomycetes, were found to include geosmin, and chromatographic odour profiles of cultures of the organisms showed that geosmin was the main or only significant odorous component. In confirmation of the work of GERBER N. N. and LECHEVALIER H. A. , who first isolated and named the substance from actinomycetes, acid treatment of geosmin destroyed its odour. Mass, infra-red, and proton magnetic resonance spectra of geosmin are shown, and its structure is discussed; it is a dimethyl-substituted saturated tertiary alcohol with the hydroxyl group sterically hindered.