Enzymatic Synthesis of AA-2G Avoiding Structural Isomers
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Solution Overview
Problem
Conventional processes for producing 2-O-α-D-glucopyranosyl-L-ascorbic acid (AA-2G) face challenges in separating structural isomers AA-5G and AA-6G, which inhibit purification and crystallization, requiring complex and costly oxidizing treatments to achieve high yields.
Innovation Solution
Using α-isomaltosyl glucosaccharide-forming enzyme together with or without cyclomaltodextrin glucanotransferase (CGTase) to transfer a glucosyl residue from an α-glucosyl saccharide to L-ascorbic acid, avoiding the formation of AA-5G and AA-6G, thereby enabling efficient purification and crystallization of AA-2G without the need for oxidizing treatments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If cyclomaltodextrin glucanotransferase or α-glucosidase is used as the saccharide-transferring enzyme, then AA-2G can be produced, but structural isomers AA-5G and AA-6G are formed as by-products that cannot be separated from AA-2G by column chromatography
Solution Approach 1:
The patent extracts and eliminates the harmful factor (structural isomers AA-5G and AA-6G) from the reaction system by selecting a specific enzyme (α-isomaltosyl glucosaccharide-forming enzyme) that does not produce these isomers, thereby achieving high purity AA-2G without requiring complex separation processes
Solution Approach 2:
The patent changes the enzyme parameter from conventional choices (cyclomaltodextrin glucanotransferase or α-glucosidase) to a specific enzyme (α-isomaltosyl glucosaccharide-forming enzyme) that has different substrate specificity and does not produce structural isomers, thereby resolving the purification problem
2Manufacturing precision
If oxidizing treatment is applied to remove structural isomers, then AA-2G purity can be improved, but the process becomes complex and costly
Solution Approach 1:
The patent applies preliminary anti-action by selecting an enzyme that prevents the formation of structural isomers in the first place, rather than allowing them to form and then requiring subsequent removal through oxidizing treatment, thereby simplifying the overall process
3Productivity
If multiple crystallization steps are performed to improve AA-2G yield, then production efficiency increases, but structural isomers in the mother liquor inhibit subsequent crystallization
Solution Approach 1:
The patent applies preliminary action by ensuring that structural isomers are not formed during the enzymatic reaction step, thereby eliminating the inhibition problem in subsequent crystallization steps and allowing for efficient multi-step crystallization to achieve high yield
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method allows for the production of AA-2G with high purity and yield in industrial scales, eliminating the need for complex separation processes and reducing production costs by preventing the formation of structural isomers, thus facilitating easy crystallization and biological activity.
Implementation Method 1
transferring a glucosyl residue from an α-glucosyl saccharide to L-ascorbic acid using an α-isomaltosyl glucosaccharide-forming enzyme
Implementation Method 2
subjecting the resulting reaction mixture containing AA-2G together with other by-products and remaining substrates to a column chromatography using a strongly-acidic cation exchange resin
Implementation Method 3
crystallizing and collecting AA-2G in the solution
Data Source
AI summary
The object of the present invention is to provide a method and a process for producing 2-O-α-glucopyranosyl-L-ascorbic acid where 5-O-α-glucopyranosyl-L-ascorbic acid and 6-O-α-glucopyranosyl-L-ascorbic acid are not formed or formed in such a small amount that the formation of these can nor be detected. The present invention solves the above object by providing a process for producing 2-O-α-glucopyranosyl-L-ascorbic acid comprising the steps of allowing α-isomaltosyl glucosaccharide-forming enzyme together with or without cyclomaltodextrin glucanotransferase (EC 2.4.1.19) to act on a solution comprising L-ascorbic acid and, an α-glucosyl saccharide to form 2-O-α-glucopyranosyl-L-ascorbic acid and collecting the formed 2-O-α-glucopyranosyl-L-ascorbic acid.