Selective recognition of nucleosides by boronate affinity organic-inorganic hybrid monolithic column

Boronic acids are important ligands used to selectively recognize and enrich compounds containing cis-diol groups such as nucleosides. In the present study, organic-inorganic hybrid [POSS-MAH-BPA] monolithic column was prepared for the first time in the literature as a new boronate affinity system for the recognition of nucleosides. The selectivity of the [POSS-MAH-PBA] boronate affinity monolithic column for the recognition of cis-diol containing adenosine nucleoside from its analogue molecule of deoxyadenosine triphosphate, dATP, non-cis-diol containing compound was investigated both by UV and HPLC studies. When the relative selectivity coefficients are compared, the [POSS-MAH-PBA] boronate affinity monolithic column is 4.25 times more selective for adenosine than [POSS-MAH] monolithic column. Besides, to determine endogenous nucleosides in biological fluids, which may serve as non-invasive cancer biomarkers, nucleosides were spiked into the urine solutions and passed through the [POSS-MAH-PBA] boronate affinity monolithic column, and the nucleosides were confirmed by HPLC. The adenosine recognition capability of the [POSS-MAH-PBA] boronate affinity monolithic column with an average enrichment factor of 48.9-fold was apparently superior to that of the [POSS-MAH] monolithic column. Methacryl Polyhedral Oligomeric Silsesquioxanes (POSS-MA) with nano-sized stable 3-dimensional architectures provided the advantage of being used as an adsorbent for the monolithic structure by providing high surface area, 507.60 m²/g, and enabling vinyl groups to function with amino acid-based MAH monomers capable of providing electrons to coordinate PBA. Recovery results of more than 90% for adenosine showed that the [POSS-MAH-PBA] boronate affinity monolithic column could be a promising adsorbent for selective adsorption of cis-diol containing compounds such as nucleosides.