Methacrylation phosphoramidites containing a linker cleavable with acetic acid were synthesized, and used for synthetic oligodeoxynucleotide (ODN) purification. During automated synthesis, the full-length ODN was tagged with the phosphoramidite. The failure sequences were not. In purification, the full-length ODN was co-polymerized into a polyacrylamide gel, and the failure sequences and other impurities were removed by washing. Pure ODN was cleaved from the gel with 80% acetic acid. Using this method, purification of sequences as long as a 197-mer, which are from the phi29 DNA polymerase gene, and at scales as large as 50 μmol was demonstrated. The products have high purity and the recovery yields are high. The method does not use any type of chromatography and purification is achieved through simple manipulations such as shaking and filtration. Compared with gel electrophoresis and HPLC purification methods, the new technology is less labor-demanding and more amendable for automation, consumes a smaller amount of environmentally harmful organic solvents and requires little energy for solvent evaporation. Therefore, it is ideal for high throughput purification and large scale ODN-based drug purification as well as small scale purification.

By use of 1,3-dithian-2-yl-methoxycarbonyl (Dmoc) as a protecting group and linker for oligodeoxynucleotide (ODN) synthesis, deprotection and cleavage are achieved under non-nucleophilic oxidative conditions. The nucleophile-sensitive thioester and α-chloroacetyl groups are conveniently incorporated into ODN sequences. The technology could be universally useful for electrophilic ODN synthesis.

•Tritylation of secondary alcohols with high efficiency.•Mild conditions and short reaction time.•More sustainable because no need of expensive silver salts.•Uses more stable and potentially cheaper trityl alcohol instead of trityl chloride.Secondary alcohols were conveniently tritylated under mild conditions within a short running time with tritylium trifluoroacetate generated in situ from trityl alcohols and trifluoroacetic anhydride. No expensive silver salts were needed for the reactions. Four secondary alcohols were tritylated with both mono- and dimethoxy trityl alcohols giving good to excellent isolated yields. The reaction was also tested on four nucleoside derivatives that have primary alcohols. Satisfactory results were also obtained.

During automated solid-phase peptide synthesis, failure sequences were capped with acetic anhydride. After synthesis, a polymerizable methacrylamide tag was attached to the full-length sequences. Peptide purification was then achieved by polymerizing the full-length sequences, washing away impurities, and cleaving the peptide product from the polymer.

Oligodeoxynucleotide (ODN) purification was achieved by capping failure sequences with a polymerizable methacrylamide phosphoramidite during automated synthesis, polymerizing the failure sequences into an acrylamide gel after cleavage and deprotection, and extraction of full-length sequences with water. The details regarding the technology including the capping efficiency of four polymerizable phosphoramidites, optimal capping time, diffusion speeds of ODN from gels with different cross-linking ratios to solution, and the efficiency of ODN extraction from gel were investigated. In addition, the technology was tested for purification of a long sequence and purification on larger scales. We also found that polymerization of failure sequences in a centrifuge tube in air did not affect purification results. Finally, we provided additional evidence that ODNs are stable under radical polymerization conditions by complete digestion of ODN followed by reversed-phase HPLC analysis of nucleosides.

The readily scalable catching by polymerization purification technology has been further advanced to purify 5′-phosphorylated synthetic oligodeoxynucleotides (ODNs). The new technology utilizes a phosphoramidite that contains a fluoride-cleavable diisopropylsilyl acetal linker and a polymerizable methacrylamide group, and is capable of phosphorylation of ODN. For purification, the phosphoramidite was coupled to the 5′-end of full-length ODN on a synthesizer. Because failure sequences were capped in each synthetic cycle, only the full-length sequences were phosphinylated and acrylated. After cleavage and deprotection, the crude ODN was subjected to polymerization under typical acrylamide gel formation conditions. The full-length ODN was incorporated into polymer. The failure sequences and other impurities were simply removed by washing with water. Pure full-length ODN that contained a 5′-phosphate group was cleaved from the polymer with HF–pyridine. Reversed-phase (RP) HPLC showed that the ODN was pure, and the recovery yield was higher than that of typical preparative HPLC purification.

Synthetic oligodeoxynucleotide is purified by capping failure sequences with an acrylated phosphoramidite followed by polymerization and product extraction. The method is suitable for large scale oligonucleotide drug purification.

Several ferrosalen and ferrosalen-type ligands, 1−10, were prepared and fully characterized. The structure of one of these ligands ligated to Cu(II) was determined by single-crystal X-ray diffraction analysis. In comparison with the parent ligand 1, the two six-membered rings of ligand 2 are not aromatized and the synthesis was more facile. Diastereoisomers 3 and 4, containing substituents on the ethylene chain, were synthesized. The aromatized versions of 3 and 4, namely 5 and 6, were also prepared. Further modulation of the ethylene backbone produced ligands 7 and 8. Replacing the Cp ligands with Cp* and CpPh5 gave ligands 9 and 10, respectively. All these ligands were tested for catalytic asymmetric reactions, including the Co(III)-catalyzed carbonyl-ene reaction, Al(III)-catalyzed Strecker reaction, and Al(III)-catalyzed silylcyanation of aldehyde.

Synthetic oligodeoxynucleotides are purified with use of a catching by polymerization, washing, and releasing approach. The method does not require any chromatography, and purification is achieved by simple operations such as shaking, washing, and extraction. It is therefore useful for large-scale purification of synthetic oligonucleotide drugs. In addition to purification of oligonucleotides, this catching by polymerization concept is expected to be equally useful for purification of other synthetic oligomers such as peptides and oligosaccharides.

Synthetic oligodeoxynucleotide is purified by capping failure sequences with an acrylated phosphoramidite followed by polymerization and product extraction. The method is suitable for large scale oligonucleotide drug purification.