Patents by Inventor Akikazu Mitsunobu

Akikazu Mitsunobu has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • 14.alpha.-hydroxy-4-androstene-3,6,17-trione hydrate and process for producing same
    Patent number: 5648507
    Abstract: Provided are stable hydrate crystals of 14.alpha.-hydroxy-4-androstene-3,6,17-trione having a biological activity of human placenta-originating estrodiene synthesis enzyme inhibitory action. These hydrate crystals include two kinds of 14.alpha.-hydroxy-4-androstene-3,6,17-trione hydrate crystals having a diffraction pattern having characteristic peaks at diffraction angles in crystalline powder X-ray diffraction. Processes for producing these hydrate crystals are also provided.
    Type: Grant
    Filed: May 30, 1995
    Date of Patent: July 15, 1997
    Assignees: Nippon Kayaku Kabushiki Kaisha, Snow Brank Milk Products Co., Ltd.
    Inventors: Kazuo Ohtsuki, Akikazu Mitsunobu, Yoshihiro Imaizumi, Nobuyoshi Honda, Satoshi Inoue
  • 14.alpha.-hydroxy-4-androstene-3,6,17-trione hydrate crystal and process for producing same
    Patent number: 5614651
    Abstract: Provided are stable hydrate crystals of 14.alpha.-hydroxy-4-androstene-3,6,17-trione having a biological activity of human placenta-originating estrodiene synthesis enzyme inhibitory action. These hydrate crystals include two kinds of 14.alpha.-hydroxy-4-androstene-3,6,17-trione hydrate crystals having a diffraction pattern having characteristic peaks at diffraction angles in crystalline powder X-ray diffraction. Processes for producing these hydrate crystals are also provided.
    Type: Grant
    Filed: May 23, 1994
    Date of Patent: March 25, 1997
    Assignee: Snow Band Milk Products, Co., Ltd.
    Inventors: Kazuo Ohtsuki, Akikazu Mitsunobu, Yoshihiro Imaizumi, Nobuyoshi Honda, Satoshi Inoue
  • Process for producing .alpha.-aspartyl-phenylalanine ester
    Patent number: 4730076
    Abstract: The present invention relates to a process for producing .alpha.-aspartyl-phenylalanine ester represented by the general formula ##STR1## wherein R' represents an alkyl group having 1 to 4 carbon atoms, by reducing an N-protected-N-hydroxymethyl-.alpha.-aspartyl-phenylalanine ester represented by the general formula ##STR2## wherein R represents an organic mioety which can be substituted reductively by hydrogen, and R' is as defined above, with hydrogen gas or formic acid, in the presence of a reduction catalyst and an aromatic primary amine. According to the present invention, there can be obtained a high purity .alpha.-aspartyl-phenylalanine ester with a high yield.
    Type: Grant
    Filed: December 16, 1986
    Date of Patent: March 8, 1988
    Assignee: Nippon Kayaku Kabushiki Kaisha
    Inventors: Tadashi Fujii, Hiroshi Yagiuchi, Akikazu Mitsunobu, Shigeru Aoki, Makoto Tsuda
  • Process for producing optically active phenylalanine
    Patent number: 4582928
    Abstract: This invention relates to a process for producing optically active phenylalanine, characterized by optically resolving DL-phenylalanine.optically active mandelic acid complexes in an aqueous solvent in the presence of an acidic compound having a pKa value of 0.90 to 2.10 and isolating optically active phenylalanine from the obtained optically active phenylalanine.optically active mandelic acid complex.According to the process of the present invention, it is possible to decrease the amount of a mother liquor of resolution to 1/5 to 1/10 of that when no acidic compound is used and to obtain optically active phenylalanine having an optical purity of as high as 96.5% or above without a step of optical purification when optically active phenylalanine is isolated from the obtained optically active phenylalanine.optically active mandelic acid complex.
    Type: Grant
    Filed: March 27, 1985
    Date of Patent: April 15, 1986
    Assignee: Nippon Kayaku Kabushiki Kaisha
    Inventors: Shigeru Aoki, Mamoru Katagiri, Ryoichi Hasegawa, Akikazu Mitsunobu, Yasuhisa Tashiro