%vitamin k3%

n. menadione, (C11H8O2) being chemically 2-methyl-1, 4, -naphthoquinone. Having no side chain in the 3 position, it cannot exert all functions of a true K vitamin and the designation as vitamin K3 has been discouraged [ MI11 ]
Syn. -- vitaminK2(0); menaphthone. [ WordNet 1.5 ]