Isolation of vitamin K from animal tissue

Abstract

The isolation of phylloquinone from beef liver has been attempted. Development and use of a biological assay system has demonstrated that beef liver, beef liver lipid extracts, beef liver mitochondria, and the beef liver mitochondrial lipid extracts contain some compound that can alleviate elevated prothrombin times produced in chicks by a vitamin K-deficient diet. All attempts to isolate and identify this activity have been unsuccessful. The adoption of a modification of an isolation method developed by Fieser [ J. Am. Chem. Soc., 61, 3467 (1939)] facilitated the separation of two compounds from rabbit, chicken, and swine liver, one of which has been tentatively identified as a phylloquinone. The highest concentration was observed in rabbit liver (5 μg/gm lipid extract), and chicken liver contained a lower concentration (3.33 μg/gm lipid extract). Although absolute proof of the structure must await further work, the evidence thus far suggests that the compound may be 2-methyl-3-Δ 6-dehydrophytyl-1,4-naphthoquinone. The data obtained on the second compound isolated from rabbit, chicken, and swine liver do not permit any conclusion to be reached at present, but its spectral properties appear to be identical with those of α-tocopherolquinone.