To provide a new compound constituting a new biosynthetic route of menaquinone, a method for producing the new compound by utilizing the route, a method for increasing the quantity of production of the menaquinone by utilizing the compound, and a method for searching an inhibitor specific to the route.

A specific compound is provided. The method for producing the compound includes reacting futalosine with an enzyme for carrying out de-hypoxanthine of the futalosine or a recombinant enzyme having activity for carrying out the de-hypoxanthine of the futalosine, and a reducing agent in the presence of water or a buffer solution. The method for producing the new compound includes making an orthologous gene-broken strain of a microorganism having a new synthetic route of the menaquinone, and culturing the broken strain in the presence of the menaquinone. A method for searching an inhibitor by synthesizing a structural analogue of the compound, adding the material to a microorganism having the new biosynthetic route of the menaquinone, and identifying the structural analogue as the inhibitor specific to the new biosynthetic route of the menaquinone from proliferation-inhibiting activity of the microorganisms and inhibitory activity against the enzyme carrying out the de-hypoxanthine of the futalosine.