Method for purifying L-phenylalanine
AssigneeMitsui Toatsu Chemicals, Inc.
InventorsMakoto Yanaka, Tooru Miyahara, Daisuke Ura, Nobuhiro Fukuhara
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Abstract
L-Phenylalanine is isolated in pure form from an aqueous solution thereof containing cinnamic acid by subjecting the aqueous solution to toluene extraction to extract cinnamic acid therefrom; separating the toluene phase; and then concentrating the aqueous phase, until crystals of L-phenylalanine form therein, while concurrently separating the crystalline L-phenylalanine from the liquid aqueous phase.
Claims20
A method for purifying L-phenylalanine which comprises the steps of:
- (a) subjecting an aqueous solution containing mainly cinnamic acid and L-phenylalanine to toluene extraction to extract cinnamic acid therefrom followed by separating the extracting toluene solution from the extracting aqueous solution;
- (b) concentrating as an aqueous phase concurrently with the separated extracted aqueous solution until a solid phase comprising L-phenylalanine forms therein;
- (c) collecting a solid phase comprising the solid phase comprising crystals of L-phenylalanine separated in said step (b).
A method for preparing and isolating L-phenylalanine in pure form which comprises the steps of:
- (i) reacting cinnamic acid with an ammonia source in the presence of phenylalanine ammonia lyase to obtain a reaction solution;
- (ii) clarifying said reaction solution to obtain a clarified liquid;
- (iii) removing said ammonia source from said clarified liquid;
- (iv) extracting said clarified liquid obtained in step (iii) with toluene and then separating the resulting toluene phase from the thus-extracted aqueous phase;
- (v) concentrating the extracted aqueous phase obtained in step (iv) until a solid phase forms therein while concurrently subjecting said aqueous phase to a solid/liquid separation and recycling the separated liquid phase back to said aqueous phase;
- and
- (vi) recovering the solid phase consisting essentially of pure L-phenylalanine crystals obtained in said step (v).
A method for isolating L-phenylalanine in pure form which comprises the steps of (a) subjecting an aqueous solution containing mainly cinnamic acid and L-phenylalanine to toluene extraction to extract cinnamic acid therefrom followed by separating the extracting toluene solution from the extracted aqueous solution;
- (b) concentrating as an aqueous liquid phase the separated extracted aqueous solution until a solid phase comprising crystals of L-phenylalanine forms therein;
- and (c), concurrently with step (b), separating by solid/liquid separation the solid phase comprising crystals of L-phenylalanine from the aqueous liquid phase.
Dependencies are inferred from the claim text.