Isolation and partial structure determination of a clonidine-displacing substance from bovine lung and brain.

A large scale extraction and isolation method was developed for the purification of clonidine-displacing substance (CDS) activity from bovine lung or brain. This optimised method used direct freeze drying of tissue, hexane removal of lipids, and methanol extraction of CDS activity. Using a bioassay directed isolation strategy a new CDS compound was purified from an extract of bovine lung. The isolation strategy involved subsequent steps of flash C-18 chromatography, ion exchange, size exclusion, and C-18 HPLC. An HPLC detection method was developed and applied to show that the new CDS is present in both lung and brain tissue. Spectroscopic data for this new CDS indicates that it is related to guanosine, but is not noradrenaline, adrenaline, histamine, agmatine, guanosine, GMP, GDP or GTP.