Patents by Inventor Tadakatsu Mandai
Tadakatsu Mandai 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).
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Publication number: 20070025995Abstract: To provide a taxoid derivative that has improved solubility in water and acts specifically with respect to tumors, thereby mitigating side effects. The present invention provides an anticancer agent comprises covalent bond compound of an antibody that reacts specifically with respect to cancer cells with a taxoid derivative and a method for preparing the anticancer agent according to claim 1, characterized by reacting, in the presence of reduction agent, an antibody that reacts specifically with respect to cancer cells with a reaction product obtained by allowing periodic acid or periodate to act on a taxoid derivative.Type: ApplicationFiled: September 7, 2005Publication date: February 1, 2007Inventors: Hiroki Hamada, Katsuhiko Mikuni, Katsuyoshi Nakanishi, Tadakatsu Mandai
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Patent number: 6410757Abstract: The object of the invention is to develop baccatin derivatives useful for preparing taxoid compounds such as paclitaxel and a process for the producing the same. The invention provides baccatin derivatives represented by the general formula (I) as well as a process for producing baccatin derivatives represented by the general formula (I) above, which comprises allowing a baccatin represented by the general formula (II) to react with a &bgr;-ketoester in the absence of a catalyst or in the presence of a tin compound or an amine base, preferably under reduced pressure.Type: GrantFiled: February 7, 2000Date of Patent: June 25, 2002Assignees: Bio Research Corporation of Yokohama, Ensuiko Sugar Refining Co. Ltd.Inventors: Tadakatsu Mandai, Hiroshi Okumoto, Katsuyoshi Nakanishi, Koji Hara, Katsuhiko Mikuni, Kozo Hara
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Patent number: 6306893Abstract: An object of the invention is to develop galactose or mannose derivatives of docetaxel, etc. having improved solubility and physiological activity, to alleviate burden imposed on patients and to provide effective therapeutic drug for tumors. The present invention provides taxoid derivatives comprising any of paclitaxel, docetaxel and 10-deacetyl-baccatin III to which galactose or mannose is linked through a spacer, and methods for producing taxoid derivatives comprising reacting paclitaxel, docetaxel or 10-deacetyl-baccatin III with tetrabenzyl acetyloxygalactoside or tetrabenzyl acetyloxymannoside, subjecting the product to debenzylation reaction, and optionally to detriethylsilylation reaction.Type: GrantFiled: April 7, 2000Date of Patent: October 23, 2001Assignees: Ensuiko Sugar Refining Company, Ltd, Bio Research Corporation of Yokohama, Kaken Pharmaceutical Company, Ltd.Inventors: Tadakatsu Mandai, Hiroshi Okumoto, Koji Hara, Katsuhiko Mikuni, Kozo Hara, Yoshinori Tsuchiya, Kosho Nakamura, Teruhiko Umetsu
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Patent number: 6136990Abstract: A taxoid compound represented by general formula (I) ##STR1## where the symbols R.sup.1, R.sup.2, R.sup.3, R.sup.4, Bz, and Ac have specified meanings. Also, a method for producing the taxoid derivative from a baccatin derivative having a .beta.-ketoester group at the 13-position by transesterification and a method for producing taxoid compound such as paclitaxel from the taxoid derivative under mild condition are disclosed.Type: GrantFiled: February 15, 2000Date of Patent: October 24, 2000Assignees: Bio Research Corporation of Yokohama, Ensuiko Sugar Refining Co., Ltd., Tadakatsu MandaiInventors: Tadakatsu Mandai, Hiroshi Okumoto, Katsuyoshi Nakanishi, Koji Hara, Katsuhiko Mikuni, Kozo Hara
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Patent number: 6075132Abstract: Disclosed are ursodeoxycholic acid derivatives having an increased solubility in water, and methods for producing the derivatives. To produce the derivatives, ursodeoxycholic acid is protected at its carboxyl group with a benzyl group, then reacted with tetrabenzyl-acetic acid-oxyglucoside of the following formula (1), and de-benzylated; or ursodeoxycholic acid is protected at its hydroxyl group with a t-butyldimethylsilyl group, then reacted with tetrabenzyl-2-hydroxyethyloxyglucoside of the following formula (2), and de-t-butyldimethylsilylated and de-benzylated.Type: GrantFiled: April 30, 1998Date of Patent: June 13, 2000Assignees: Bio Research Corporation of Yokohama, Ensuiko Sugar Refining Co., Ltd., Kaken Pharmaceutical Co., Ltd.Inventors: Tadakatsu Mandai, Hiroshi Okumoto, Katsuyoshi Nakanishi, Koji Hara, Katsuhiko Mikuni, Kozo Hara, Teruhiko Umetsu
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Patent number: 5854408Abstract: A sugar derivative wherein a hydroxy-carboxylic acid is combined to a position 1 of a sugar via ether linkage, and other hydroxyl groups are protected with a protective groups. A method of producing the sugar derivative, comprises allowing glycolic ester to react with a compound so as to combine said glycolic ester at the position 1 of the sugar skeleton, and then saponifying, said compound has on the position 1 any of hydroxyl group, halogen atom and sulfur atom with a substitutent group, and has other hydroxyl groups being protected with a protective groups.Type: GrantFiled: June 3, 1997Date of Patent: December 29, 1998Assignees: Ensuiko Sugar Refining Co., Ltd., Tadakatsu MandaiInventors: Tadakatsu Mandai, Hiroshi Okumoto, Koji Hara, Katsuhiko Mikuni, Kozo Hara, Hiroki Hamada
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Patent number: 5767297Abstract: A taxoid derivative wherein sugar is combined with any one of paclitaxel, docetaxel and 10-deacetyl-bacatin III via a spacer. A method of producing the taxoid derivative comprises protecting hydroxyl groups at specific position of paclitaxel or docetaxel by protective compound followed by reacting with tetrabenzyl acetyloxyglucoside, and then carrying out debenzyl and detriethylsilyl reactions. A method of producing the taxoid derivative comprises reacting paclitaxel or docetaxel with tetrabenzyl acetyloxyglucoside, and then carrying out debenzyl reaction.Type: GrantFiled: June 3, 1997Date of Patent: June 16, 1998Assignees: Ensuiko Sugar Refining Co., Ltd., Tadakatsu MANDAI, Kaken Pharmaceutical Co., Ltd.Inventors: Tadakatsu Mandai, Hiroshi Okumoto, Koji Hara, Katsuhiko Mikuni, Kozo Hara, Hiroki Hamada
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Patent number: 5600047Abstract: A process for producing an optically active olefin represented by a formula ##STR1## wherein R.sup.1 represents an organic group and X represents a polycyclic carbon ring group, by reacting a corresponding optically active ester derivative represented by a formula ##STR2## wherein R.sup.1 and X are as defined above and R represents a hydrogen atom, an alkoxy group, an alkenyloxy group or a substituted or unsubstituted aralkyloxy group, with formic acid or a salt thereof in the presence of a catalyst comprising a palladium salt and a tertiary phosphine.Said process makes it possible to produce, at a high yield at a high selectivity, an optically active olefin which has a physiological activity and is useful as a medicine or is useful as an intermediate for the synthesis of physiologically active steroids. Further, said process uses no harmful reagent such as mercury or the like. Thus, it is advantageous as an industrial process.Type: GrantFiled: June 2, 1995Date of Patent: February 4, 1997Assignee: Kuraray Co., Ltd.Inventors: Tadakatsu Mandai, Jiro Tsuji, Manzo Shiono
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Patent number: 5322939Abstract: A process for preparing an azetidin-2-one derivative represented by formula (2): ##STR1## wherein R.sup.4 and R.sup.5, which may be the same or different, each represents a hydrogen atom, an alkyl group having from 1 to 8 carbon atoms, or an alkyl group having from 1 to 8 carbon atoms substituted with an alkoxy group, an acyl group, or an alkoxycarbonyl group; R.sup.6 represents a protective group for an amino group; and R.sup.7 represents a vinylidene group of formula ##STR2## or an acetylene group of formula ##STR3## wherein R.sup.2 and R.sup.3, which may be the same or different, each represents a hydrogen atom or an alkyl group having from 1 to 8 carbon atoms; and R.sup.8 represents an alkyl group having from 1 to 8 carbon atoms corresponding to R.sup.2 or R.sup.3, which comprises reacting a propargyl alcohol derivative represented by formula (1): ##STR4## wherein R.sup.1 represents an alkyl group having from 1 to 6 carbon atoms, a phenyl group, or a halogen-substituted phenyl group; R.sup.2, R.sup.3, R.Type: GrantFiled: July 7, 1992Date of Patent: June 21, 1994Assignee: Takasago International CorporationInventors: Tadakatsu Mandai, Jiro Tsuji
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Patent number: 4876400Abstract: A process for producing vitamin A represented by the formula ##STR1## which comprises treating a compound represented by the formula ##STR2## wherein R.sup.1 represents an aryl group which may be substituted, R.sup.21 and R.sup.22 each represent a hydrogen atom or a lower alkanoyl group, R.sup.3 represents an acetal-type protective group for a hydroxyl group, and X represents a halogen atom, with a base; and novel intermediate compounds useful for the above process.Type: GrantFiled: July 5, 1988Date of Patent: October 24, 1989Assignee: Kuraray Co., Ltd.Inventors: Junzo Otera, Tadakatsu Mandai, Mikio Kawada
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Patent number: 4825006Abstract: A process for producing vitamin A represented by the formula ##STR1## which comprises treating a compound represented by the formula ##STR2## wherein R.sup.1 represents an aryl group which may be substituted, R.sup.21 and R.sup.22 each represents a hydrogen atom or a lower alkanoyl group, R.sup.3 represents an acetal-type protective group for a hydroxyl group, and X represents a halogen atom, with a base; and novel intermediate compounds useful for the above process.Type: GrantFiled: December 3, 1985Date of Patent: April 25, 1989Assignee: Kuraray Co., Ltd.Inventors: Junzo Otera, Tadakatsu Mandai, Mikio Kawada