A P(V)-Platform for Oligonucleotide Synthesis

<div><div><div><p>The early promise of gene-based therapies is currently being realized at an accelerated pace with over 155 active clinical trials for antisense compounds and multiple FDA-approved oligonucleotide therapeutics. Fundamental advances in this area are vital and present an unprecedented opportunity to both address disease states that have been resistant to other common modalities and improve the significant sustainability challenges associated with production of these complex molecules on a commercial scale. The advent of phosphoramidite coupling chemistry and solid-phase synthesis 40 years ago democratized oligonucleotide synthesis to the scientific community, paving the way for many of these stunning developments. The reliability and generality of this approach for the preparation of native phosphate-diesters is attributed to the high reactivity of phosphorus when in the P(III)-oxidation state versus the desired P(V), as it enables rapid P-heteroatom bond formation. However, the growing demand for more diverse phosphorus-based linkages has challenged the limits of this technology. For example, the phosphorothioate (PS) linkage, which stabilizes oligonucleotides towards nuclease cleavage, is universally employed in current oligonucleotide therapeutics but is generally incorporated in racemic form. Stereodefined PS oligonucleotides may have desirable biological and physical properties but are accessed with difficulty using phosphoramidite chemistry. Here we report a flexible and efficient [P(V)]-based platform that can install a wide variety of phosphate linkages at will into oligonucleotides. This approach uses readily accessible reagents and can efficiently install not only stereodefined or racemic thiophosphates, but can install any combination of (S, R or rac)-PS with native phosphodiester (PO2) and phosphorodithioate (PS2) linkages into DNA and other modified nucleotides. Importantly this platform easily accesses this diversity under a standardized coupling protocol with sustainably prepared, stable, P(V) reagents.</p></div></div></div>

A P(V)-Platform for Oligonucleotide Synthesis

<div><div><div><p>The early promise of gene-based therapies is currently being realized at an accelerated pace with over 155 active clinical trials for antisense compounds and multiple FDA-approved oligonucleotide therapeutics. Fundamental advances in this area are vital and present an unprecedented opportunity to both address disease states that have been resistant to other common modalities and improve the significant sustainability challenges associated with production of these complex molecules on a commercial scale. The advent of phosphoramidite coupling chemistry and solid-phase synthesis 40 years ago democratized oligonucleotide synthesis to the scientific community, paving the way for many of these stunning developments. The reliability and generality of this approach for the preparation of native phosphate-diesters is attributed to the high reactivity of phosphorus when in the P(III)-oxidation state versus the desired P(V), as it enables rapid P-heteroatom bond formation. However, the growing demand for more diverse phosphorus-based linkages has challenged the limits of this technology. For example, the phosphorothioate (PS) linkage, which stabilizes oligonucleotides towards nuclease cleavage, is universally employed in current oligonucleotide therapeutics but is generally incorporated in racemic form. Stereodefined PS oligonucleotides may have desirable biological and physical properties but are accessed with difficulty using phosphoramidite chemistry. Here we report a flexible and efficient [P(V)]-based platform that can install a wide variety of phosphate linkages at will into oligonucleotides. This approach uses readily accessible reagents and can efficiently install not only stereodefined or racemic thiophosphates, but can install any combination of (S, R or rac)-PS with native phosphodiester (PO2) and phosphorodithioate (PS2) linkages into DNA and other modified nucleotides. Importantly this platform easily accesses this diversity under a standardized coupling protocol with sustainably prepared, stable, P(V) reagents.</p></div></div></div>

Recent Advances in the Synthesis of High Boron-Loaded Nucleic Acids for BNCT

Boron clusters attract considerable attention as promising therapeutic tools for boron neutron capture therapy (BNCT). They combine high boron content with high chemical and biological stability, biorthogonality, and low toxicity. The development of oligonucleotide-based constructs and nucleic acid-like molecules, such as oligomeric phosphate diesters, bearing one or multiple boron clusters permits to create potential high boron-loaded agents for BNCT with good bioavailability, specifically interacting with nucleic acids inside the cell. Here, we shortly review the strategies and solutions in the design of oligonucleotide conjugates with boron clusters in light of the requirements for effective BNCT and future prospects of their practical use.

Binuclear Metal Complexes with Novel Hexadentate Imidazole Derivative for the Cleavage of Phosphate Diesters and Biomolecules: Distinguishable Mechanisms

Phosphate bond cleavage is essential to physiological activity, antibacterial or antitumor as well the elimination of chemical warfare agents. In this work, three transition metal binuclear complexes (Cu2LCl4, Co2LCl4, Zn2LCl4)...

LC-MS screening of poly- and perfluoroalkyl substances in contaminated soil by Kendrick mass analysis

The application of contaminated paper sludge on arable land in southwest Germany caused the occurrence of a broad range of poly- and perfluoroalkyl substances (PFASs) on soil. Recently, the dead-end transformation products (TPs) perfluorooctanoic acid and perfluorooctanesulfonic acid were detected in groundwater and drinking water. The precursors and other transformation products mostly remained unknown. Therefore, HRMS screening by Kendrick mass analysis and assignment of homologous series in combination with suspect screening were applied to identify original PFASs and their TPs in four different soil samples from sites where contaminated paper sludge was applied. In total, twelve compound classes comprising more than 61 PFASs could be fully or tentatively identified. The data reveal that contamination mainly originates from polyfluorinated dialkylated phosphate esters (from 4:2/6:2 to 12:2/14:2), N-ethyl perfluorooctane sulfonamide ethanol–based phosphate diesters (only C8/C8) and transformation products of these precursors. Contamination patterns can be attributed to PFASs used for paper impregnation and can vary slightly from site to site.

Fabrication of highly active phosphatase-like fluorescent cerium-doped carbon dots for in situ monitoring the hydrolysis of phosphate diesters

The hydrolytic cleavage of BNPP was catalyzed and monitored by the fluorescent CeCDs.