New Series of Reagents Useful in Fractionation of Biologically Active Material.

Abstract

Aside from the classical procedure of Kossel and Kutscher for the fractionation of nitrogenous bases, we possess no methods which permit a systematic biochemical analysis of nitrogenous substances occurring in nature. The Kossel procedure, although extremely useful for the fractionation of stable substances, interferes very often with the activity of relatively unstable substances, such as vitamines, hormones and enzymes. Various aromatic nitro compounds have been extensively used in biochemistry, such as picric, picrolonic and flavianic acids. These reagents often yield characteristic, slightly soluble compounds with relatively pure substances, but often give little or nothing when we deal with complicated mixtures. The idea occurred to me that by using the salts of these acids a series of more specific reagents could be obtained. This expectation was realized. Where the free acid fails to affect a notable separation of active material, this was accomplished by using a salt of a particular acid, or a series of salts, one after the other. The salts used so far were barium, lead, silver and mercury salts, metals which can be removed from the solution without difficulty. In some cases sodium salts were used with success. The method was used either systematically, starting with picric acid and then using the various salts, or one particular salt was used exclusively. It is hoped that by introducing other salts, or salts of other acids, a systematic biochemical analysis of unknown substances can be effected.

Using this new method, vitamine B was separated quantitatively from yeast as well as from rice polishings, but curiously enough, not by the use of one single salt. A combination of Ag- and Hg-picrates was necessary to attain this end, which corroborates my view perhaps as to the complex nature of this substance.