Preparation of N-acetylneuraminic acid from delipidated egg yolk.
Egg yolk, a large proportion of the egg, was studied for the preparation of N-acetylneuraminic acid (Neu5Ac). The delipidated hen egg yolk (DEY; 500 kg containing 0.2% w/w, Neu5Ac) was hydrolysed with HCl (pH 1.4) at 80 degrees C and neutralized with NaOH (pH 6.0). The mixture was filtered and electrodialysed until the conductivity was 240 microS cm-1. The filtrate was applied on a column of Dowex HCR-W2 (20-50 mesh), followed by a column of Dowex 1-X8 (200-400 mesh). The latter column was washed with water, and then eluted with a linear gradient of HCO2H (0-2 M). The eluates containing Neu5Ac were concentrated using a reverse osmosis membrane and, finally, rotary evaporated at 40 degrees C. The residue was then lyophilized to yield 500 g Neu5Ac. The purity of Neu5Ac was > 98% (TBA method). HPLC, NMR spectroscopy and TLC chromatography of the product obtained from the DEY showed that Neu5Ac was the sole derivative present in egg yolk. The DEY, a byproduct from egg processing plants, was found to be an excellent source for the large-scale preparation of Neu5Ac.
Koketsu
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Basic Research Laboratories, Taiyo Kagaku Co. Ltd, Mie, Japan.
Juneja
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LR
Kawanami
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Kim
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Yamamoto
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D000596:Amino Acids / Q000032:analysis; D000818:Animals; D000837:Anion Exchange Resins; D002411:Cation Exchange Resins; D002645:Chickens; D002852:Chromatography, Ion Exchange; D004530:Egg Yolk / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D009682:Magnetic Resonance Spectroscopy; D019158:N-Acetylneuraminic Acid; D012794:Sialic Acids / Q000138:chemical synthesis* / Q000302:isolation & purification
D000596:Amino Acids; D000837:Anion Exchange Resins; D002411:Cation Exchange Resins; D012794:Sialic Acids; D019158:N-Acetylneuraminic Acid