Isolation of 2-hydroxycarboxylic acids with a boronate affinity gel.
Boric acid has been known to make a complex with 2-hydroxycarboxylic acids. Based on this principle, we have developed a new method for isolation of vanillylmandelic acid, p-hydroxymandelic acid, vanillyllactic acid, and p-hydroxyphenyllactic acid in urine. The technique involves two steps: extraction of lipophilic compounds from urine with n-butanol and selective isolation of 2-hydroxy acids in the n-butanol phase on a phenylboronate gel column. 2-Hydroxy acids were eluted from the column with 1.5 ml of 2% acetyl chloride in methanol with the recoveries of ca. 70%. According to analysis of urinary extract by gas chromatography--mass spectrometry, the mean excretion rates of the above four compounds in 12 healthy subjects were 3.68, 1.93, 0.091, and 1.08 mg/day, respectively.
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D001897:Boronic Acids; D002846:Chromatography, Affinity / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D006719:Homovanillic Acid / Q000031:analogs & derivatives / Q000652:urine; D006801:Humans; D006880:Hydroxy Acids / Q000652:urine*; D008333:Mandelic Acids / Q000652:urine; D010666:Phenylpropionates / Q000652:urine; D014642:Vanilmandelic Acid / Q000652:urine
D001897:Boronic Acids; D006880:Hydroxy Acids; D008333:Mandelic Acids; D010666:Phenylpropionates; C014600:4-hydroxymandelic acid; C003753:vanillactic acid; C001418:4-hydroxyphenyllactic acid; D014642:Vanilmandelic Acid; C010686:benzeneboronic acid; D006719:Homovanillic Acid