Patents by Inventor Tohru Yasuzawa

Tohru Yasuzawa 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).

  • Process for producing xanthine derivatives with bacteria and fungi
    Patent number: 6107064
    Abstract: The present invention relates to a process for producing a xanthine derivative represented by formula (II), comprising converting a xanthine derivative represented by formula (I) {hereinafter, referred to as Compound (I)}: ##STR1## (wherein R.sup.1 and R.sup.2 independently represent hydrogen, or hydroxy-substituted, oxo-substituted, or unsubstituted lower alkyl) into a xanthine derivative represented by formula (II) {hereinafter, referred to as Compound (II)}: ##STR2## (wherein R.sup.3 and R.sup.4 independently represent hydrogen, or hydroxy-substituted, oxo-substituted, or unsubstituted lower alkyl; R.sup.5 and R.sup.6 independently represent hydrogen, hydroxy, or oxo; with the proviso that R.sup.5 and R.sup.6 are both hydrogen, at least one of R.sup.3 and R.sup.
    Type: Grant
    Filed: January 17, 1996
    Date of Patent: August 22, 2000
    Assignee: Kyowa Hakko Kogyo Co., Ltd.
    Inventors: Junichi Shimada, Tamotsu Eguchi, Kenichi Mochida, Akira Horiguchi, Tohru Yasuzawa, Hideaki Kusaka, Hiromi Nonaka, Fumio Suzuki
  • 8-tricycloalkyl xanthine derivatives
    Patent number: 5395836
    Abstract: There is provided a novel xanthine Compound(I) ##STR1## wherein R.sup.1 and R.sup.2 are the same or different and each represent hydroxy-substituted, oxo-substituted or unsubstituted lower alkyl, Y is a single bond or alkylene, and Q is ##STR2## wherein R.sup.3 and R.sup.4 are the same or different and each represent hydrogen or hydroxy, n is 0 or 1; provided that when both of R.sup.3 and R.sup.4 are hydrogen, at least one of R.sup.1 and R.sup.2 is hydroxy-substituted or oxo-substituted lower alkyl; or a pharmaceutically acceptable salt thereof.The xanthine compound has adenosine A.sub.1 receptor antagonizing activity, and thus shows diuretic effect, renal-protecting effect, bronchodilatory effect, cerebral function improving effect and anti-dementia effect.
    Type: Grant
    Filed: April 5, 1994
    Date of Patent: March 7, 1995
    Assignee: Kyowa Hakko Kogyo Co., Ltd.
    Inventors: Junichi Shimada, Takashi Kuwabara, Tohru Yasuzawa, Hiroshi Magara, Hiromi Nonaka, Hideaki Kusaka, Fumio Suzuki
  • Compound KS-505 useful for improving cerebral function
    Patent number: 5079232
    Abstract: A new compound designated KS-505 having amnesia-inhibiting activity may be prepared by fermentation of a suitable strain of Streptomyces, preferably Streptomyces argenteolus A-2 (FERM BP-2065).
    Type: Grant
    Filed: December 8, 1989
    Date of Patent: January 7, 1992
    Assignee: Kyowa Hakko Rogyo Kabushiki Kaisha
    Inventors: Keiko Ohsawa, Satoshi Nakanishi, Hiroshi Kase, Isao Kawamoto, Tohru Yasuzawa, Yutaka Saito, Hiroshi Sano, Shizuo Shiozaki, Katsuichi Shutoh
  • DC-88A derivatives
    Patent number: 5008271
    Abstract: A novel DC-88A derivative represented by general formula: ##STR1## wherein ##STR2## represents ##STR3## has an excellent antitumor activity and is useful as an antitumor agent.
    Type: Grant
    Filed: October 18, 1989
    Date of Patent: April 16, 1991
    Assignee: Kyowa Hakko Kogyo Co., Ltd.
    Inventors: Yutaka Kanda, Tohru Yasuzawa, Hiromitsu Saito, Hiroshi Sano, Eiji Kobayashi, Makoto Morimoto
  • Substance K-259-2 and a process for producing the same
    Patent number: 4692310
    Abstract: A new substance K-259-2 having a molecular formula of C.sub.21 H.sub.18 O.sub.7, a molecular weight of 382 and an elemental analysis (%) of H: 4.50, C: 65.53 and N: 0. This substance is of interest in providing a new vasodilating agent in view of its ability to dilate the blood vessel, particularly the artery, of mammals. This substance may be obtained by fermentation of a microorganism Micromonospora sp. K-259 (FERM BP 569).
    Type: Grant
    Filed: April 16, 1986
    Date of Patent: September 8, 1987
    Assignee: Kyowa Hakko Kogyo Kabushiki Kaisha
    Inventors: Hiroshi Kase, Yuzuru Matsuda, Isao Kawamoto, Kozo Asano, Kunikatsu Shirahata, Tohru Yasuzawa, Koji Yamada