Patents by Inventor Rokuro Okamoto
Rokuro Okamoto 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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Patent number: 5474923Abstract: A method for introducing hydroxyl groups into vitamin D compound at the 1.alpha.- and/or 25-positions in the presence of a cyclodextrin compound by the use of a reaction mixture containing a microorganism being capable of hydroxylating vitamin D compound or a enzyme produced from the microorganism, is disclosed.Type: GrantFiled: June 7, 1991Date of Patent: December 12, 1995Assignee: Mercian CorporationInventors: Koji Takeda, Kiyoshi Kimura, Kazuhiko Okamura, Rokuro Okamoto, Joji Sasaki, Takashi Adachi, Sadafumi Omura
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Patent number: 5322937Abstract: A DNA fragment or a restriction enzyme-digested DNA fragment, the DNA fragment containing a gene, acyA, encoding a 3-acylation enzyme for macrolide antibiotics, characterized by being derived from a strain belonging to the genus Streptomyces, having a size of about 1.8 kb or about 3.2 kb, and having a DNA base sequence shown in a restriction enzyme map shown in FIG. 1(A) or FIG. 1(B), respectively, in the attached drawing. 3-Acylated macrolide antibiotics can be produced advantageously using macrolide antibiotics-producing bacteria transformed with vector plasmids having inserted therein the DNA fragment.Type: GrantFiled: May 31, 1991Date of Patent: June 21, 1994Assignee: Mercian CorporationInventors: Akira Arisawa, Naoto Kawamura, Ikuo Kojima, Kazuhiko Okamura, Hiroshi Tone, Rokuro Okamoto
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Patent number: 5240849Abstract: A DNA fragment containing acyB gene coding for an enzyme capable of acylating the 4"-position of a macrolide antibiotic, said DNA fragment being derived from a microorganism of the genus Streptomyces, having a size of about 3.1 kb and being characterized by the restriction endonuclease map shown in FIG. 1 , and a DNA restriction fragment resulting from digestion with a restriction endonuclease; a recombinant DNA plasmid containing this DNA fragment; a microorganism transformed with this recombinant plasmid; and a process for producing a 4"-acylated macrolide antibiotic by using the transformant.Type: GrantFiled: May 23, 1989Date of Patent: August 31, 1993Assignee: Sanraku IncorporatedInventors: Akira Arisawa, Naoto Kawamura, Ikuo Kojima, Yasushi Okumura, Kazuhiko Okamura, Hiroshi Tone, Rokuro Okamoto
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Patent number: 5232943Abstract: Antibiotic Mer-AF1032A represented by the following formula (I) and its isomer antibiotic Mer-AF1032B are disclosed. Also disclosed are a method for preparing the antibiotics comprising the cultivation of a strain belonging to genus Penicillium and a pharmaceutical composition comprising one of these antibiotics and useful as an antifungal agent.Type: GrantFiled: May 20, 1992Date of Patent: August 3, 1993Assignee: Mercian CorporationInventors: Hitosi Agematu, Yoshio Watanabe, Hiroyuki Chiba, Rei Kaneto, Norio Shibamoto, Takeo Yoshioka, Toshihiko Kumamoto, Hiroshi Nishida, Rokuro Okamoto
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Patent number: 5223519Abstract: 4-Hydroxypyridine derivative represented by the following formula ##STR1## wherein R represents a methyl group or an isopropyl group, and the method for preparing the derivative comprising the step of cultivating a strain belonging to Streptomyces karnatakensis are disclosed. Also disclosed are the pharmaceutical composition comprising the same and a method for treating circulatory diseases comprising the step of administering said compound to a patient.Type: GrantFiled: December 13, 1991Date of Patent: June 29, 1993Assignee: Mercian CorporationInventors: Shin-ichi Hirano, Yoshio Watanabe, Kaichiro Kominato, Naoki Agata, Yutaka Hara, Norio Shibamoto, Takeo Yoshioka, Tomoyuki Kioka, Hiroshi Iguchi, Masataka Shirai, Hiroshi Tone, Rokuro Okamoto
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Patent number: 5183883Abstract: Adriamycin derivatives represented by formula (I) ##STR1## wherein R denotes a divalent hydrocarbon group,CD denotes a cyclodextrin residue,m is 1 to 8, andn is 0 to 8.The compounds exhibit excellent anti-cancer activity over a wide administration range, have low toxicity and sustained release, and maintain activity for a long period of time; thus, they are quite useful as an anti-cancer agent.Type: GrantFiled: September 27, 1991Date of Patent: February 2, 1993Assignee: Mercian CorporationInventors: Hiroshi Tanaka, Kaichiro Kominato, Takeo Yoshioka, Hiroshi Iguchi, Shin-ichi Hirano, Yasuo Okajima, Reijko Yamamoto, Masataka Shirai, Hiroshi Nishida, Hiroshi Tone, Rokuro Okamoto
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Patent number: 5149802Abstract: A process for producing 2-azetidinone derivatives represented by formula ##STR1## wherein R.sup.1 denotes a protecting group of a hydroxyl group,Z denotes a hydrogen atom or a protecting group of an amino group, andQ denotes ##STR2## in which X denotes a halogen atom, Y denotes a halogen atom or OR.sup.2, R.sup.2 denotes a hydrogen atom or a protecting group of a carboxyl group, and Y.sup.2 denotes OR.sup.3 or SR.sup.4 in which R.sup.3 denotes a hydrogen atom, a protecting group of a carboxyl group or an ester residue and R.sup.4 denotes an ester residue.Type: GrantFiled: July 10, 1991Date of Patent: September 22, 1992Assignee: Mercian CorporationInventors: Takeo Yoshioka, Ryoichi Miyata, Toshio Tsuchida, Hiroshi Tone, Rokuro Okamoto
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Patent number: 5091370Abstract: An angolamycin derivative represented by the following formula ##STR1## wherein X represents an acetyl, methanesulfonyl, methylthio, benzoyl or methoxy group. This compound is useful as a medicament such as antibacterial agent and an animal feed additive.Type: GrantFiled: June 18, 1990Date of Patent: February 25, 1992Assignee: Sanraku IncorporatedInventors: Takeo Yoshioka, Azuma Watanabe, Koichiro Kominato, Hiroshi Tone, Rokuro Okamoto, Tsutomu Sawa, Tomio Takeuchi
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Patent number: 5055259Abstract: This invention provides a blood typing training kit comprising a red blood cell model and an antiserum model with no use of human blood in experiments for blood agglutination and in learning of blood typing, the red blood cell model being an easily available granule which can be suspended in water such as agarose bead, Sepharose, cellulose, Sephadex, cellulofine, alginate, tamarind polysaccharide, gelatin, xanthan gum, etc. or the saccharide- or protein-bound form thereof and the antiserum model being lectin, boric acid-containing liquid or immunoglobulin G.Type: GrantFiled: July 24, 1989Date of Patent: October 8, 1991Assignee: Sanraku IncorporatedInventors: Tsutomu Inoue, Kazuhiko Okamura, Naoto Kawamura, Hiroshi Tone, Rokuro Okamoto
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Patent number: 4997922Abstract: 14-Trifluoromethanesulfonyloxydaunomycin represented by the following formula ##STR1## and its salt. This compound is useful as an intermediate for production of adriamycin.Type: GrantFiled: January 17, 1989Date of Patent: March 5, 1991Assignee: Sanraku IncorporatedInventors: Takeo Yoshioka, Toshio Tsuchida, Ryoichi Miyata, Hiroshi Tone, Rokuro Okamoto
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Patent number: 4954438Abstract: This invention relates to a process for preparing an antibiotic D788-7 wherein, after culturing carborubicin-producing bacteria, the obtained culture liquid is extracted in acidic conditions while stirring to be absorbed to synthetic resin, followed by desorption from the resin and elution with acetone and the resulting acetone solution containing carborubicin is converted into an antibiotic D788-7 by photo radiation, for obtaining D788-7 in the purified form from the reaction solution. The production yield for D788-7 is extremely high and its use as an antitumor agent can be made possible.Type: GrantFiled: August 21, 1989Date of Patent: September 4, 1990Assignee: Sanraku IncorporatedInventors: Akihiro Yoshimoto, Osamu Jodo, Yoshio Watanabe, Rokuro Okamoto, Tomio Takeuchi
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Patent number: 4933439Abstract: Tylosin derivatives represented by the following general formula (I): ##STR1## [wherein R denotes a hydrogen atom, acetyl, propionyl or a radical of Si(R.sup.2).sub.3 (in which R.sup.2 is a lower alkyl group), and R.sup.1 stands for a hydrogen atom or a radical of Si(R.sup.2 .sub.3 ] are useful as intermediates for the synthesis of 4"-acyl derivatives of tylosin because, after introduction of any desired acyl group at the 4"-hydroxyl group, the silyl protective group can be readily removed without liberation of the acyl group. This invention also provides processes for producing the tylosin derivatives. More specifically, it provides a melthod of selectively protecting 2'- and 4"'-hydroxyl groups of tylosin (those of higher reactivity among the hydroxyl groups involved); a method of selectively protecting only the 4"'-hydroxyl group of tylosin; a method of selectively protecting the 3- and 4"'-hydroxyl groups of 2'-O-acyltylosin; and a method of protecting 3-, 2'- and 4"'-hydroxyl groups of tylosin.Type: GrantFiled: November 17, 1988Date of Patent: June 12, 1990Assignee: Sanraku IncorporatedInventors: Takeo Yoshioka, Azuma Watanabe, Hiroyuki Chiba, Kaichiro Kominato, Kohki Kiyoshima, Yasuo Fukagawa, Hiroshi Tone, Rokuro Okamoto
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Patent number: 4918172Abstract: Disclosed are anthracycline antibiotics of a formula (I): ##STR1## in which R.sup.1 and R.sup.2 are hydroxyl groups, R.sup.3 is ethyl group, R.sup.4 is methoxycarbonyl group and X represents daunosamine-rhodenose or daunosamine-deoxyfucose; orR.sup.1 and R.sup.2 are hydroxyl groups, R.sup.3 is 1-hydroxyethyl group, R.sup.4 is hydrogen atom and X represents daunosamine-rhodenose or daunosamine-deoxyfucose; orR.sup.1, R.sup.2 and R.sup.4 are hydroxyl groups, R.sup.3 is ethyl group and X represents daunosamine-rhodenose, daunosamine-deoxyfucose, rhodosamine-rhodenose, N-monomethyldaunosamine-rhodenose or N-monomethyldaunosamine-deoxyfucose; orR.sup.1 is methoxy group, R.sup.2 is hydroxyl group, R.sup.3 is ethyl group, R.sup.4 is methoxycarbonyl group and X represents daunosamine-rhodenose or daunosamine-deoxyfucose; orR.sup.1 and R.sup.4 are hydroxy groups, R.sup.2 is hydrogen atom, R.sup.Type: GrantFiled: October 3, 1988Date of Patent: April 17, 1990Assignee: Sanraku IncorporatedInventors: Akihiro Yoshimoto, Osamu Jodo, Yoshio Watanabe, Rokuro Okamoto, Tomoyuki Ishikura, Hiroshi Naganawa, Tsutomu Sawa, Tomio Takeuchi
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Patent number: 4612372Abstract: Novel tylosin derivatives are represented by formula: ##STR1## wherein R represents a hydrogen atom, an acetyl group or a propionyl group; X represents a group --CO-- or --SO.sub.2 --; Y represents a fluorine atom, an acetyl group, a methanesulfonyl group, a methylthio group, a benzoyl group or a methoxy group bound to the benzyl group at the 2-position or 4-position; and Z represents a hydrogen atom or a D-mycinose residue: ##STR2## The tylosin derivatives which are antibiotics of macrolide type provide improved antibacterial activity and improved ability of absorption and excretion in vivo.Type: GrantFiled: July 12, 1985Date of Patent: September 16, 1986Assignee: Sanraku IncorporatedInventors: Takeo Yoshioka, Miharu Maeda, Rokuro Okamoto, Yasutaka Shimauchi, Tomoyuki Ishikura, Tsutomu Sawa, Tomio Takeuchi, Hamao Umezawa
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Patent number: 4463171Abstract: Compounds of the following general formula ##STR1## wherein R.sup.1 and R.sup.2 represent a hydrogen atom or a lower alkanoyl group;R.sup.3 represents a hydrogen atom or the group --COCH.sub.2 R.sup.5 in which R.sup.5 represents a lower alkyl group or an aryl or pyridyl group bonded through a sulfur atom;R.sup.4 represents a methyl group which may be substituted by aryl, pyridyl, pyridylthio, hydroxyl or arylthioamino, an aryl group, a nitrile group, a 5- or 6-membered heterocyclic group having 1 to 4 hetero atoms selected from nitrogen and sulfur atoms, or a tetrahydropyranyl group which may be substituted by methoxy;A represents the group --OCO--, --OSO.sub.2 --, --O-- or --S--, or A and R.sup.4, taken together, represent a halogen atom, a nitrile group or a group of the formula ##STR2## in which R.sup.Type: GrantFiled: June 9, 1983Date of Patent: July 31, 1984Assignee: Sanraku-Ocean Co., Ltd.Inventors: Hamao Umezawa, Tomio Takeuchi, Kuniaki Tatsuta, Tomoyuki Ishikura, Rokuro Okamoto, Masao Yamamoto, Kohki Kiyoshima
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Patent number: 4451401Abstract: A compound represented by the following formula ##STR1## wherein R represents a hydrogen atom or a methyl group,R.sup.1 represents a hydrogen atom or an ester residue, andR.sup.2 and R.sup.3 represent hydrogen atoms respectively, or taken together, a group of the formula ##STR2## in which each of R.sup.4 and R.sup.5 represents a hydrogen atom, a lower alkyl group or a phenyl group,and its salt; and a process for the production thereof.Type: GrantFiled: July 1, 1982Date of Patent: May 29, 1984Assignee: Sanraku-Ocean Co., Ltd.Inventors: Mitsuyasu Okabe, Takeo Yoshioka, Yasuo Fukagawa, Rokuro Okamoto, Kageaki Kouno, Tomoyuki Ishikura
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Patent number: 4426390Abstract: A compound of the formula ##STR1## wherein R.sub.1 represents a hydrogen atom, --OH or --OSO.sub.3 H, and R.sub.2 represents a hydrogen atom or an unsubstituted or substituted benzyl group; and a salt thereof; processes for production thereof by fermentation; and uses thereof as antimicrobial agents.Type: GrantFiled: September 29, 1981Date of Patent: January 17, 1984Assignee: Sanraku-Ocean Co., Ltd.Inventors: Mitsuyasu Okabe, Takeo Yoshioka, Yasuo Fukagawa, Rokuro Okamoto, Kageaki Kouno, Tomoyuki Ishikura
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Patent number: 4205163Abstract: A number of 4"-acyl derivatives of tylosin and acetyltylosin which are prepared by first protectively acylating at the 2'-hydroxyl group of tylosin or acetyltylosin, secondly at the 4'"-hydroxyl group thereof, thirdly at the 4"-hydroxyl group thereof and finally deacylating the 2'- and 4'"-acyl groups to produce new 4"-acyl derivatives of tylosin or acetyltylosin which effect high blood level compared to those tylosin derivatives heretofore are disclosed.Type: GrantFiled: October 23, 1978Date of Patent: May 27, 1980Assignee: Sanraku-Ocean Co., Ltd.Inventors: Shunro Mori, Rokuro Okamoto, Taiji Inui, Tomio Takeuchi
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Patent number: 4201843Abstract: New tylosin derivatives having at least one acyl group at the 3- and 4"-positions of tylosin, and the acid addition salts thereof, which inhibit the growth of various microorganisms including drug-resistant bacterial isolants and which produce high blood levels through oral administration are produced by a biochemical reaction using the microorganisms of the genus Streptomyces which are selected for their newly-found ability to acylate at least one of the 3- and 4"-positions of macrolide antibiotics; they are recovered from the reacted mixture by conventional methods for recovering macrolide antibiotics.Type: GrantFiled: February 27, 1978Date of Patent: May 6, 1980Assignee: Sanraku Ocean Co., Ltd.Inventors: Rokuro Okamoto, Tsumoru Fukumoto, Akira Takamatsu, Tomio Takeuchi
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Patent number: 4092473Abstract: New tylosin derivatives having at least one acyl group at the 3- and 4"-positions of tylosin, and the acid addition salts thereof, which inhibit the growth of various microorganisms including drug-resistant bacterial isolants and which produce high blood levels through oral administration are produced by a biochemical reaction using the microorganisms of the genus Streptomyces which are selected for their newly-found ability to acylate at least one of the 3- and 4"-positions of macrolide antibiotics; they are recovered from the reacted mixture by conventional methods for recovering macrolide antibiotics.Type: GrantFiled: July 23, 1976Date of Patent: May 30, 1978Assignee: Sanraku Ocean Co., Ltd.Inventors: Rokuro Okamoto, Tsumoru Fukumoto, Akira Takamatsu, Tomio Takeuchi