Rooster’s comb

The Australian lungfish has four big teeth which look as though they have grown together into fan-shaped cmshing plates somewhat resembling a rooster s comb. 

Androgens, the male sex hormones, proved far more elusive that either the estrogens and progestins since they occur at much lower concentrations in biological fluids. The bioassay used to track the isolation in this case comprised the capon unit . This was the amount of extract that produced a 20% increase in the surface of a rooster s comb. The 15 mg of pure crystalline testosterone isolated in 1931 came from about 15 0001 of urine. The structural investigations of this series relied on the then newly discovered side chain oxidations of cholestanol (13-1) (Scheme 1.13). This method in essence comprised fairly drastic oxidation of reduced cholesterols of known stereochemistry at the A-B junction to afford in fairly low yield products in which the side chain at Cn had been consumed to leave behind a carbonyl group. One of these products proved to be identical with androsterone (13-2). That compound had in turn been obtained from a sequence of reactions starting from dehydroepiandrosterone (13-3) that had been isolated from male urine. 

Highly purified proteoglycan fractions Al-Dl-Dl and Al-Dl isolated from bovine nasal cartilage was used in this experiment. The samples had been determined to be free of contamination by hyaluronic acid or link protein. Details of isolation and purification of these fractions are described in the literature. Hyaluronic acid sample from Rooster s Comb was generously supplied by Dr. Swann, Harvard Medical School. An Al-Dl subunit fraction which had been treated with CNBr was supplied by Dr. E. 

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