Carnosine and Anserine in Mammalian Skeletal Muscle *

Two imidazole derivatives, carnosine and anserine, have been isolated from vertebrate skeletal muscle. Carnosine may be readily obtained from the ox (l), horse (2), pig (3), etc. Anserine, a methyl carnosine, has been isolated from birds, a reptile (4), fish (5), and certain mammals (6). The presence of the two compounds in muscles from the same animal has been adequately demonstrated only once: Hoppe-Seyler, Linneweh, and Linneweh (4) obtained anserine and a small amount of carnosine from the crocodile. We report below information which, together with the data in a previous paper (6), demonstrates that both carnosine and anserine are present in the muscles of several mammals. Isolation of Anserine-The procedure of Ackermann, Timpe, and Poller (7) as modified by us (6) was employed for anserine isolations. Further modifications in the original procedure were made by precipitating copper anserine from aqueous solution with acetone and recrystalhzing from ammonia, steps used by von Fiirth and Hryntschak (8) and Kuen (9) in the estimation of carnosine. In outline, the present isolations were made as follows. A concentrated protein-free aqueous extract of muscle was precipitated with mercuric sulfate and alcohol. The mercury precipitate was decomposed with hydrogen sulfide and the solution was