The reaction of phenylboronic acid with nucleosides and mononucleotides

Synthesis of nucleoside-boronic esters hydrophobic pro-drugs: A possible route to improve hydrophilic nucleoside drug loading into polymer nanoparticles

“…Phenyl boronic acid (PBA) and 4-butoxy-3,5-dimethyl phenyl boronic acid (BPBA) were conjugated to ribavirin (RV) using the previous reported methodology (49). Briefly, a pyridine solution of PBA or BPBA (5 mmol in 50 ml of solvent) was added dropwise to equimolar amount of RV dissolved in pyridine (5 mmol, 100 ml) in a 250 ml-RBF.…”

“…Ribavirin boronic derivatives were synthesized (Figure 3) as previously reported (49) to increase the hydrophobicity of RV and hence its ability to be incorporated within hydrophobic polymeric carriers. Chemical modification was carried out by conjugation of hydrophobic moieties to RV, through formation of a biodegradable boronic ester linkage.…”

Boronate Derivatives of Functionally Diverse Catechols: Stability Studies

“…The Infrared spectra of the cyclic boronate derivatives of compounds 1 – 7 exhibited two characteristic bands, for B-O and Ph-O absorption in the regions 1,325-1,380 cm −1 and 1,390-1,455 cm −1 , respectively. The other bands were characteristic for the remaining functional groups of the listed compounds [ 5 , 8 , 35 ].…”

“…The selective reactions of boronic acids with compounds containing two or more suitably disposed proximal polar functional groups (OH, NH, SH, COOH) can afford cyclic derivatives of reduced polarity, of value in analytical characterization and in separation of polyfunctional compounds [ 1 , 2 ]. Crystalline benzeneboronates from the reactions of benzeneboronic acid with polyols [ 3 ], sugars [ 4 , 5 ], other carbohydrates [ 6 , 7 , 8 ], macrolide aglycones [ 9 ] and steroids [ 10 ] have been isolated and characterized. Depending on the substrates, the condensations could take place in aqueous and aqueous-methanol solutions [ 3 ], organic solventc [ 6 ], reactions by fusion techniques, or by reaction in anhydrous solvents followed by azeotropic removal of water [ 5 ].…”

“…Depending on the substrates, the condensations could take place in aqueous and aqueous-methanol solutions [ 3 ], organic solventc [ 6 ], reactions by fusion techniques, or by reaction in anhydrous solvents followed by azeotropic removal of water [ 5 ]. Boronate derivatives have a wide range of applications in: separation of isomeric pairs of cis and trans diols [ 11 ] and as extracting probes to capture and enrich cis -diol-containing biomolecules [ 12 ]; The differences in the solubility of the boronates of isomeric carbohydrates greatly facilitate their separation by fractional re-crystallization [ 13 ]; Boronate affinity chromatography (BAC) is an important tool for specific capture and separation of cis -diol-containing compounds such as glycoproteins, RNA and carbohydrates [ 14 ]. Systematical investigation on the retention mechanism revealed that multiple intermolecular interactions occur between the analytes and the boronate affinity monolith, including boronate affinity, reversed-phase, cation-exchange and hydrogen bonding interactions, depending on the conditions used [ 15 ]; A variety of cyclic boronates that are stable to hydrolysis has been studied by reversed-phase high pressure liquid chromatography (HPLC) [ 16 ].…”