Patents by Inventor Koki Fujita

Koki Fujita 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).

  • Patent number: 5623071
    Abstract: A cyclodextrin having a galactosyl group which is bonded to a 6-hydroxyl group of a glucosyl group of the cyclodextrin via an .alpha.-bond or a .beta.-bond; a cyclodextrin having a mannosyl group which is bonded to a 6-hydroxyl group of the cyclodextrin via an .alpha.-bond.
    Type: Grant
    Filed: June 1, 1995
    Date of Patent: April 22, 1997
    Assignees: Ensuiko Sugar Refining Co., Ltd., Sumio Kitahata
    Inventors: Sumio Kitahata, Koji Hara, Koki Fujita, Nobuhiro Kuwahara, Kyoko Koizumi
  • Patent number: 5622844
    Abstract: A method of producing a mannosyl-cyclodextrin having a mannosyl group bonded to the hydroxyl group of the glucosyl group of a cyclodextrin via an alpha-bond. The method includes treating a liquid containing a cyclodextrin and an alpha-mannosyl compound with an alpha-mannosyl transfer agent.
    Type: Grant
    Filed: June 1, 1995
    Date of Patent: April 22, 1997
    Assignees: Ensuiko Sugar Refining Co., Ltd., Sumio Kitahata
    Inventors: Sumio Kitahata, Koji Hara, Koki Fujita, Nobuhiro Kuwahara, Kyoko Koizumi
  • Patent number: 5523218
    Abstract: Disclosed are (1) a novel galactosyl-cyclodextrin having a galactosyl group as bonded to the hydroxyl group of the glucosyl group of a cyclodextrin via an .alpha.-bond and a method of producing said galactosyl-cyclodextrin; (2) a novel galactosyl-cyclodextrin having a galactosyl group as bonded to the hydroxyl group of the glucosyl group of a cyclodextrin via a .beta.-bond and a method of producing said galactosyl-cyclodextrin; and (3) a novel mannosyl-cyclodextrin having a mannosyl group as bonded to the hydroxyl group of the glucosyl group of a cyclodextrin via an .alpha.-bond and a method of producing said mannosyl-cyclodextrin. The new branched cyclodextrins are expected to be widely useful in various fields of drug industry, food industry and cosmetic industry.
    Type: Grant
    Filed: December 30, 1994
    Date of Patent: June 4, 1996
    Assignees: Ensuiko Sugar Refining Co., Ltd., Sumio Kitahata
    Inventors: Sumio Kitahata, Koji Hara, Koki Fujita, Nobuhiro Kuwahara, Kyoko Koizumi
  • Patent number: 5463039
    Abstract: A method of preparing a hetero-branched cyclodextrin comprising a glucosyl or a maltosyl group side chain and a mannosyl group .alpha.-bonded to a hydroxyl group of the glucosyl group or the maltosyl group of the side chain, the method involving reacting a liquid containing a branched cyclodextrin having a glucosyl or maltosyl group as the side chain and an .alpha.-mannosyl compound with an .alpha.-mannosyl transfer enzyme.
    Type: Grant
    Filed: June 21, 1994
    Date of Patent: October 31, 1995
    Assignees: Ensuiko Sugar Refining Co., Ltd., Osaka-shi, Kyoko Koizumi
    Inventors: Koji Hara, Koki Fujita, Nobuhiro Kuwahara, Sumio Kitahata, Kyoko Koizumi
  • Patent number: 5393660
    Abstract: A reagent for determining a-amylase activity, comprising a maltooligosaccharide derivative of the following formula ##STR1## (wherein either one of R.sub.1 and R.sub.2 is .beta.-galactopyranosil and the other is hydrogen, R.sub.3 is a group bonded to the reducing terminal glucose via a bond cleavable by .alpha.-amylase, which becomes a measurable substance upon cleavage of the bond, and n is an integer of 0-2), which does not comprise adjuvant enzymes; and a method for determining .alpha.-amylase activity which comprises use of the reagent. The reagent of the present invention does not require use of any adjuvant enzyme and is stable since the substrate is not exposed to the decomposition by an adjuvant enzyme. The substrate used in the present invention has high affinity for .alpha.-amylase. Thus, the reagent and the determination method of the present invention make it possible to determine .alpha.-amylase activity with high sensitivity.
    Type: Grant
    Filed: November 4, 1993
    Date of Patent: February 28, 1995
    Assignees: Toyo Boseki Kabushiki Kaisha, Ensuiko Sugar Refining Co., Ltd.
    Inventors: Sumio Kitahata, Nobuhiro Kuwahara, Koki Fujita, Koji Hara, Keiichi Majima, Shin-ichi Teshima, Yuzo Hayashi
  • Patent number: 5366879
    Abstract: Disclosed is a method of producing a branched cyclodextrin where a liquid containing a cyclodextrin and a branched oligosaccharide is treated with a debranching enzyme. By the method, a branched cyclodextrin having a maltosyl or maltotriosyl group as bonded to the glucose of a CD molecule via an .alpha.-1,6 bond is obtained efficiently.
    Type: Grant
    Filed: December 17, 1992
    Date of Patent: November 22, 1994
    Assignees: Ensuiko Sugar Refining Co., Ltd., Sumio Kitahata, Hirofumi Nakano
    Inventors: Sumio Kitahata, Koji Hara, Koki Fujita, Nobuhiro Kuwahara, Hirofumi Nakano
  • Patent number: 5356884
    Abstract: A hetero-branched cyclodextrin (CD) having a glucosyl or maltosyl group as the side chain, in which a mannosyl group is .alpha.-bonded to the hydroxyl group of the glucosyl group of the side chain; and a method of efficiently preparing the same by reacting a branched cyclodextrin with an .alpha.-mannosidase. The hetero-branched CDs are useful in various fields such as in drugs, foods and cosmetics.
    Type: Grant
    Filed: October 8, 1992
    Date of Patent: October 18, 1994
    Assignees: Ensuiko Sugar Refining Co., Ltd., Osaka-shi, Kyoko Koizumi
    Inventors: Koji Hara, Koki Fujita, Nobuhiro Kuwahara, Sumio Kitahata, Kyoko Koizumi
  • Patent number: 5089401
    Abstract: An enzymatic method for the preparation of a fructose-containing oligosaccharide, in which a .beta.-fructofuranosidase obtained by culturing Arthrobacter sp. K-1 (FERM BP-3192) as an enzyme is reacted on sucrose, raffinose or stachyose as the donor in the presence of an aldose or ketose as the receptor. The enzyme is characterized by:(1) activity on sucrose for the transglycosidation of a fructosyl group to the receptor in the presence of a monosaccharide, sugar alcohol, alkyl alcohol, glycoside or oligosaccharide;(2) activity for the decomposition of sucrose, elrose, neokestose, xylsucrose, raffinose and stachyose with inactivity on a saccharide selected from the group consisting of 1-kestose, nistose, inulobiose and levan biose;(3) optimum pH of 6.5 to 6.8 at 40.degree. C. with stability at a pH of 5.5 to 10;(4) optimum temperature of 55.degree. C. at a pH of 6.5 exhibiting at least 70% of residual activity at 60.degree. C.
    Type: Grant
    Filed: March 20, 1991
    Date of Patent: February 18, 1992
    Assignee: Ensuiko Sugar Refining Co., Ltd.
    Inventors: Koki Fujita, Kozo Hara, Hitoshi Hashimoto, Sumio Kitahata