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US4746734A
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Partially methylated cyclodextrins and process for producing the same
Assignee: Mercian Corp
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Filing: 1987-02-27
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Granted: 1988-05-24
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Expires: 2007-02-27
Abstract
Abstract Partially methylated cyclodextrins with enhanced solubility in water have an average degree of methylation of hydroxyl groups at different positions in all the glucose units involved of about 53-64% for the 2-position, about 38-51% for the 3-position and about 70-100% for the 6-position. The partially methylated cyclodextrins are prepared by reacting beta -cyclodextrin with more than about 30 equivalent proportions based on the beta -cyclodextrin of dimethyl sulfate and more than about 30 equivalent proportions of an alkali metal hydroxide, wherein the concentration of reactants is greater than 10% (wt/wt).
Inventors
- 👤 Yukio Tsuchiyama
- 👤 Michikatsu Sato
- 👤 Yoshiaki Yagi
- 👤 Tomoyuki Ishikura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:21
CPC Classifications
C; C08; C08B; C08B37/00; C08B37/0006; C08B37/0009; C08B37/0012
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
39 words
A partially methylated β-cyclodextrin composition having an average degree of methylation of hydroxyl groups at different positions in all glucose units involved of about 53-64% for the 2-position, about 38-51% for the 3-position, and about 70-100% for the 6-position.
Claim 2
Dependent Claim
39 words
A partially methylated β-cyclodextrin composition having an average degree of methylation of hydroxyl groups at different positions in all glucose units involved of about 53-64% for the 2-position, about 38-51% for the 3-position, and about 70-100% for the 6-position.
Claim 3
Dependent Claim
70 words
A partially methylated β-cyclodextrin composition as defined in claim 1, wherein the composition has the following properties: (A) average degree of methylation 2-position: 55-64%, 3-position: 43-51%, 6-position: 99-100%, (B) A melting point calculated by the capillary method of 142°-161° C., (C) A specific rotation of [α] D 25 : 158°-162° (c=1, water), and produces a single spot on a silica gel thin-layer chromatography having a developer: chloroform/methanol ratio of 9/1.
Claim 4
Dependent Claim
70 words
A partially methylated β-cyclodextrin composition as defined in claim 1, wherein the composition has the following properties: (A) Average degree of methylation 2-position: 55-60%, 3-position: 39-45%, 6-position: 86-88%, (B) A melting point calculated by the capillary method of 159-°170° C., (C) A specification rotation of [α] D 25 : 156°-159° (c=1, water), and produces a single spot on a silica gel thin-layer chromatography having a developer: chloroform/methanol ratio of 9/1.
Claim 5
Dependent Claim
70 words
A partially methylated β-cyclodextrin composition as claimed in claim 1, wherein the composition has the following properties: (A) Average degree of methylation 2-position: 53-61%, 3-position: 38-45%, 6-position: 70-77%, (B) A melting point calculated by the capillary method of 167°-180° C., (C) A specific rotation of [α] D 25 : 167°-180° (c=1, water), and produces a single spot on a silica gel thin-layer chromatography having a developer: chloroform/methanol ratio of 9/1.
Claim 6
Dependent Claim
89 words
A process for producing a partially methylated β-cyclodextrin composition having an average degree of methylation at hydroxyl groups at different positions in all glucose units involved of about 53-64% for the 2-position, about 38-51% for the 3-position, and about 70-100% for the 6-position comprising reacting a β-cyclodextrin with more than about 30 equivalent proportions of dimethyl sulfate based on said β-cyclodextrin and more than about 30 equivalent proportions of sodium hydroxide based on said β-cyclodextrin, wherein the concentration of dimethyl sulfate and sodium hydroxide is greater than 10% wt/wt.
Claim 7
Dependent Claim
89 words
A process for producing a partially methylated β-cyclodextrin composition having an average degree of methylation at hydroxyl groups at different positions in all glucose units involved of about 53-64% for the 2-position, about 38-51% for the 3-position, and about 70-100% for the 6-position comprising reacting a β-cyclodextrin with more than about 30 equivalent proportions of dimethyl sulfate based on said β-cyclodextrin and more than about 30 equivalent proportions of sodium hydroxide based on said β-cyclodextrin, wherein the concentration of dimethyl sulfate and sodium hydroxide is greater than 10% wt/wt.
Claim 8
Dependent Claim
43 words
A process for producing a partially methylated β-cyclodextrin composition as defined in claim 5, wherein the equivalent proportion of dimethyl sulfide is 100 to 200, the equivalent proportion of sodium hydroxide is 80 to 200, and the concentration is 40 to 60% wt/wt.
Claim 9
Dependent Claim
32 words
A process for producing a partially methylated β-cyclodextrin composition as defined in claim 5, wherein the reaction is carried out with stirring at 10° to 80° C. for at least one hour.
Claim 10
Dependent Claim
32 words
A process for producing a partially methylated β-cyclodextrin composition as defined in claim 7, wherein the reaction is carried out with stirring at 20° to 50° C. for 5 to 20 hours.
References Cited (Backward Citations)
US4542211A
Cited
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