Polypeptide compounds

In 1958 Hanson and Fittkau (HI) published their new method designed for the isolation of polypeptide compounds from urine. Using this method, they isolated more than ten peptides starting with 83 liters of normal urine. The general outline of the method was as follows urine was treated with activated carbon and the adsorbed substances eluted with aqueous acetone containing hydrogen sulfide. The effluent was then... 

Polymyxin B and colistin (polymyxin E) (Fig. 3.9) are the least toxic of the five polymyxin antibiotics designated alphabetically A-E. Both polymyxin B and colistin are complex polypeptide compounds with specialized activity against gram-negative organisms but they are both nephrotoxic. Topical application and oral administration are more commonly used routes. Polymyxin B is used widely in ointments for topical applications and may be effective in case of mastitis, but it seldom is administered parenterally because of the possibility of renal toxicity. 

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