A graphene oxide functionalized with 3-aminophenylboronic acid for the selective enrichment of nucleosides, and their separation by capillary electrophoresis

Insights into the methods for separation and chromatographic determination of nucleotides/nucleosides in Cordyceps spp

Cordyceps genus is entomopathogenic mushrooms that have traditionally been used in ethnomedicine in Asian countries. Nucleosides (Ns), nucleotide(Nt), Nucleobases (Nb) and their analogues play a critically physiological role and have a great potential in drug development, such as pentostatin and cordycepin (COR). Due to their significance bioactivity, several Nt/Ns were used as markers for quality evaluation for medicinal Cordyceps, including adenosine, inosine, guanosine, uridine and COR. Among them, COR is the most considerable adenosine analogue, exhibiting significant therapeutic potential and has many intracellular targets. Nt/Ns contains polar compounds and the phosphate groups of Nt deprotonate and carry negative charges with a broad range of pH values. Recent years, various advanced methods of extraction and separation, and nanomaterials have been developed to extract, isolate and determine these molecules, such as ultrasound-assisted extraction (UAE), Supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE) for the extraction, the solid phase extraction (SPE) methods (microextraction SPE (SPME), magnetic SPE (MSPE), and unique SPE materials based on the boronate affinity for the separation, and chromatography methods employing ultraviolet (UV), fluorescence, MS detection and electrospray ionization (ESI), along with matrix-assisted laser desorption/ ionization (MALDI) for the determination. COR derived from adenosine and its structure is very similar to that of 2'-deoxyadenosine (2'-dA) and adenosine, resulting in an incorrect identification, which will influence its therapeutic effects. Therefore, this review primarily focused on the characteristics of Nt/Ns, the advanced methods, strategies, nanomaterials for extracting and determining Nt/Ns (COR in particular) in Cordyceps spp, as well as the methods for distinguishing COR from its structure analogs.

Enriching adenosine by thymine-rich DNA oligomers

Adenosine levels are important in various physiological and pathological activities, but detecting them is difficult because of interference from a complex matrix. This study designed a series of DNA oligomers rich in thymine to enrich adenosine. Their binding affinity (K_d range: 1.25-5.0 mM) to adenosine varied based on the DNA secondary structures, with a clamped hairpin structure showing the highest binding affinity. Compared to other designs, this clamped DNA hairpin underwent the least conformational change during adenosine binding. These DNAs also suppressed the precipitation of supersaturated adenine. Taken together, these results suggest that thymine-rich DNAs could be used to enrich and separate adenosine.

Preparation of a boronate-affinity monolithic column for adsorption of nucleosides

Chitosan is a considerably versatile and promising biomaterial and can easily form a 3D hierarchical porous scaffold. In this work, a novel boronate-affinity monolithic column modified with a boronic acid-chitosan complex was prepared and characterized by different methods such as Fourier transform infrared spectroscopy, scanning electron microscopy, thermal gravimetric analysis, specific surface area analysis and pore size distribution analysis. The synthesized monolithic column was used for polymer monolithic microextraction combined with high performance liquid chromatography for the simultaneous determination of cytidine, uridine, inosine, and guanosine in milk powder samples. Several parameters affecting extraction efficiency, including the eluent proportion, eluent flow rate, sample flow rate, sample volume, and sample pH were investigated. The boronate-affinity monolithic column showed high enrichment ability due to the selective formation of cyclic borate esters between nucleosides and boronic acid groups at high pH and the release of cyclic borates at low pH values. Under the optimum operating conditions, the linear range was 0.1-50 μg mL^-1, and the correlation coefficients were in the range of 0.9993-0.9994. The LOD and LOQ were in the range of 0.0027-0.0034 and 0.0090-0.011 μg mL^-1, respectively. In addition, the results of recovery and relative standard deviation were satisfactory.

Extraction of nucleobases, nucleosides and nucleotides by employing a magnetized graphene oxide functionalized with hydrophilic phytic acid and titanium(IV) ions

A magnetite@graphene oxide nanocomposite was first coated with polyethylenimine and then modified with phytic acid and titanium(IV) ions. The high loading with Ti(IV) and the good hydrophilicity of PEI and PA result in a material that can be applied to the efficient extraction of highly polar nucleobases, nucleosides and nucleotides. The physicochemical properties of the composite were investigated by scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, water contact angle measurements, thermogravimetric analysis, and vibrating sample magnetometry. A series of parameters that affect extraction and elution under the conditions of immobilized metal affinity chromatography (IMAC) and hydrophilic interaction liquid chromatography (HILIC) were examined. The analytes were eluted from the nanocomposites using 10 mM trisodium phosphate as the elution solution in the IMAC mode, and 50% methanol-water as elution solution in the HILIC mode. Figures of merit include (a) an intra-day precision of 0.1-1.0% in the IMAC mode; (b) an intra-day precision of 0.4%-0.8% in the HILIC mode; (c) detection limits between 1.8-2.8 ng mL^-1 in the IMAC mode; and (d) detection limits of 4.0-10.5 ng mL^-1 in the HILIC mode. The method was applied to the extraction of the nucleotides cytidine-5'-monophosphate (CMP), uridine-5'-monophosphate (UMP), guanosine-5'-monophosphate (GMP), and adenosine-5'-monophosphate (AMP), and the nucleobases and nucleosides hypoxanthine, adenosine, cytosine, inosine and cytidine from Cordyceps sinensis, Lentinus edodes and plasma samples. Graphical abstract Schematic presentation of the workflow for the extraction of nucleobases, nucleosides and nucleotides using phytic acid-Ti(IV) functionalized magnetite@graphene oxide nanocomposites under two distinct modes.

Recent development and trends in sample extraction and preparation for mass spectrometric analysis of nucleotides, nucleosides, and proteins

This review describes the recent developments in sample extraction and preparation techniques for mass spectrometric analysis of nucleotides, nucleosides, and proteins. Unique materials and techniques have been developed for highly selective extraction of nucleotides and nucleosides by solid-phase extraction strategies using various affinities. However, for proteins, the analysis of small-scale sections of diseased tissues (formalin-fixed, paraffin-embedded tissues) and the direct analysis of an exact lesion on the surface of diseased tissues (liquid extraction surface analysis) have become important advances in this field. In this review, we focus on the latest developments of these techniques and strategies.

A boronate-decorated porous carbon material derived from a zinc-based metal–organic framework for enrichment of cis-diol-containing nucleosides

A new boronate-decorated carbon material derived from Zn-MOF was synthesized and used to selectively enrich cis-diol nucleosides.

Immobilization of zirconium-glycerolate nanowires on magnetic nanoparticles for extraction of urinary ribonucleosides

The authors have immobilized nanowires made from zirconium glycerolate (ZrGly) on magnetite (Fe₃O₄) nanoparticles by applying a solvothermal growth process using metal-glycerolate as a precursor. The structure and the dissolution-recrystallization mechanism of the resulting Fe₃O₄@ZrGly composite were investigated by attenuated total reflection-FTIR, energy-dispersive X-ray analysis, thermogravimetric analysis and solid-state cross polarization/magic angle spinning ¹³C NMR spectroscopy. The interaction between the zirconium glycerolate in Fe₃O₄@ZrGly and cis-diols leads to efficient adsorption of riboncleosides which then can be quantified by HPLC with UV detection. The sorbent was successfully applied to the selective enrichment of adenosine, cytidine, uridine and guanosine from spiked human urine samples. The detection limit of the method is in the range from 1.7 to 19 ng·mL^-1 of nucleosides in spiked human urine, with relative standard deviations of lower than 12.4% and recoveries ranging from 90.6 to 113%. Graphical abstract Fe₃O₄@ZrGly with high selectivity towards ribonucleosides was designed and applied for quantitation of urinary ribonucleosides.

Boronate-affinity hollow molecularly imprinted polymers for the selective extraction of nucleosides

Preparation of a boronate-affinity hollow molecularly imprinted polymer and its application as an SPE adsorbent for the selective enrichment of nucleosides.

Zirconium-doped magnetic microspheres for the selective enrichment of cis-diol-containing ribonucleosides

Zirconium-doped magnetic microspheres (Zr-Fe3O4) for the selective enrichment of cis-diol-containing biomolecules were easily synthesized via a one-step hydrothermal method. Characterization of the microspheres revealed that zirconium was successfully doped into the lattice of Fe3O4 at a doping level of 4.0 at%. Zr-Fe3O4 possessed good magnetic properties and high specificity towards cis-diol molecules, as shown using 28 compounds. For ribonucleosides, the adsorbent not only has favorable anti-interferential abilities but also has a high adsorption capacity up to 159.4μmol/g. As an example of a real application, four ribonucleosides in urine were efficiently enriched and detected via magnetic solid-phase extraction coupled with high-performance liquid chromatography. Under the optimized extraction conditions, the detection limits were determined to be between 0.005 and 0.017μg/mL, and the linearities ranged from 0.02 to 5.00μg/mL (R≥0.996) for these analytes. The accuracy of the analytical method was examined by studying the relative recoveries of the analytes in real urine samples, with recoveries varying from 77.8% to 119.6% (RSDs<10.6%, n=6). The results indicate that Zr-Fe3O4 is a suitable adsorbent for the analysis of cis-diol-containing biomolecules in practical applications.