Specific extraction of S-adenosylhomocysteine from urine with boronate affinity mechanism based on a tube-tip adsorbent

Abstract

Back ground

The concentration of S-adenosylhomocysteine in human urine is associated with atherosclerosis and may be used as an early marker of atherosclerosis, and accurate quantitative analysis of S-adenosylhomocysteine in high risk group urine is significant for the prevention and early diagnosis. Therefore, monitoring of S-adenosylhomocysteine in the urine of high-risk groups may provide some reference for the prevention and early diagnosis of atherosclerosis. Due to the complexity of biological samples and the low content of target component, sample pretreatment is a prerequisite to ensure the accuracy of quantitative analysis results.

Results

In this study, we developed an adsorbent having phenylboronic acid group in a tube-tip through polymerization reaction using 4-allylcarbamoylphenylboronic acid as the monomer, aiming to the cis-diol structure of the S-adenosylhomocysteine. The prepared adsorbent not only has a macro-porous structure, but also has a high specific surface area of 428 m²/g, which is beneficial to improve the mass transfer and enhance the sample load. The synthesized adsorbent was used for the extraction of S-adenosylhomocysteine from the human urine, and the results indicated that the S-adenosylhomocysteine concentration in the urine of atherosclerosis patients is much higher than that of healthy. Furthermore, the adsorbent exhibited specific selectivity due to the boron affinity interaction force between the phenylboronic acid group on the surface of the adsorbent and the cis-diol structure of S-adenosylhomocysteine: the cis-diol structure of S-adenosylhomocysteine can form a five-membered cyclo-ester with the phenylboronic acid in the adsorbent surface under a basic condition, and the five-membered cyclo-ester opens and releases the cis-diol structure under acidic condition.

Significance

The methodological validation showed that the present method is feasible for the quantitative analysis of S-adenosylhomocysteine in human urine. This work presents a robust method for the specific extraction of S-adenosylhomocysteine from human urine and offers a valuable approach for the extraction of other components having cis-diol structure from biological samples.