PURPOSE: To obtain all trans form vitamin K2 of natural type having slight side effects and high medicinal activity, irradiating a solution of cis form vitamin D2 or cis-trans form mixed vitamin K2 with laser beam optionally in the presence of a sensitizer.
CONSTITUTION: A solution of cis form vitamin K2 or mixed vitamin K2 is cis and trans form, preferably a solution in an organic solvent such as preferably diisopropyl ether, isooctane, ethyl acetate, n-hexane, dichloromethane, chloroform, etc., optionally in the presence of a sensitizer such as acetone, benzene, acetophenone, benzophenone, naphthalene, metamethoxyacetophenone, etc., is irradiated with laser beam having preferably 190W600nm wavelength to give all trans-form vitamin K2 of natural type which has activating action on mechanism of hemostasis of organism and shows high medicinal activity in high purity, in high yield, industrially, economically and advantageously.
NAKANO KIYOSHI
MURAKAMI KAZUMASA
NARABE YUKIO
IMAI AKIO
TAKAHASHI KAZUMASA
UDAGAWA TAKESHI
KUSABA YOSHIO
MURAMATSU TAKEHIKO
KATAYAMA AKIRA
ISHIKAWAJIMA HARIMA HEAVY IND