Anoopjit Singh Kooner, et al. Frontiers in immunology, 2019, 10, 451547.
N-Glycolylneuraminic acid (Neu5Gc) is one of the most common forms of sialic acid found in nature. The one-pot multi-enzyme (OPME) chemoenzyme method is an efficient synthetic strategy for Neu5Gc-sialoside and its derivatives, which can be used to synthesize Neu5Gc simple glycosides, Neu5Gc-containing oligosaccharides, Neu5Gc-containing oligosaccharides, and Neu5Gc-containing glycoconjugates.
Synthesis example of Neu5Gc simple glycoside
· Simple glycosides of Neu5Gc were synthesized from the corresponding Neu5Ac derivatives by direct de-N-acetylation of the N-acetyl group of Neu5Ac under strongly basic conditions, followed by acylation and deprotection.
· Example A: To create the allyl α-Neu5Gc-glycoside, the N-acetyl group was removed from the carboxyl protected allyl α-Neu5Ac-glycoside through refluxing in tetramethylammonium hydroxide, resulting in an 80% yield. The next steps involved acylation with acetoxyacetyl chloride and hydrolysis of the ester.
· Example B: The methyl α-Neu5Ac glycoside was subjected to treatment with 2.0 M of NaOH using optimized microwave irradiation conditions, resulting in the desired 5-amino derivative with a yield of 91%. Subsequently, the resulting compound was transformed into the target methyl α-Neu5Gc glycoside (Neu5GcαOMe) through a reaction with acetoxyacetyl chloride, followed by de-O-acetylation.
Sharon Yehuda, et al. Frontiers in immunology, 2020, 11, 502962.