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Electrochemical lactonization of trisialic acid
Author(s) -
Chen ChienSheng,
Xu Lai,
Lee WeiJen
Publication year - 2018
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.201800080
Subject(s) - chemistry , electrolysis , acetic acid , aqueous solution , electrochemistry , capillary electrophoresis , lactone , aldonic acid , mass spectrometry , electrode , chromatography , nuclear chemistry , inorganic chemistry , organic chemistry , electrolyte
A sensitive method using high‐performance capillary electrophoresis (HPCE) is employed to study the electrochemical lactonization of α2,8‐trisialic acid. Analysis shows that the sialyl lactonization of trisialic acid in an acidic aqueous solution (pH 4.2–6) is highly enhanced by a supporting electrical current (30–100 μA). CE results indicate that this electrochemical lactonization with a supporting current is faster than the acid‐catalyzed lactonization in acetic acid. This acceleration in the reaction suggests that the acidity increases close to the Pt electrode and assists the sialyl lactonization during electrolysis. Three lactone species of trisialic acid formed in the acidic aqueous solution were detected with HPCE, and the fully lactonized species were examined with time‐of‐flight mass spectrometry and NMR spectroscopy. The elution order of the lactone isomers obtained from previous report and from this study together reveals a regioselective lactoziation in which the sialyl residue close to the reducing end was more reactive than that close to the nonreducing end.