The Synthesis of Hypodiphosphoric Acid and Derivatives with P-P Bond, including Esters and Diphosphine Dioxides: A Review

Substrate Specificity of T7 RNA Polymerase toward Hypophosphoric Analogues of ATP

Modified nucleotides are commonly used in molecular biology as substrates or inhibitors for several enzymes but also as tools for the synthesis of modified DNA and RNA fragments. Introduction of modification into RNA, such as phosphorothioate (PS), has been demonstrated to provide higher stability, more effective transport, and enhanced activity of potential therapeutic molecules. Hence, in order to achieve widespread use of RNA molecules in medicine, it is crucial to continuously refine the techniques that enable the effective introduction of modifications into RNA strands. Numerous analogues of nucleotides have been tested for their substrate activity with the T7 RNA polymerase and therefore in the context of their utility for use in in vitro transcription. In the present studies, the substrate preferences of the T7 RNA polymerase toward β,γ-hypophospho-modified ATP derivatives for the synthesis of unmodified RNA and phosphorothioate RNA (PS) are presented. The performed studies revealed the stereoselectivity of this enzyme for α-thio-β,γ-hypo-ATP derivatives, similar to that for α-thio-ATP. Additionally, it is demonstrated herein that hypodiphosphoric acid may inhibit in vitro transcription catalyzed by T7 RNA polymerase.

Organophosphorus Chemistry 2021

Forty years have passed since a real "phosphabenzene" (a phosphinine) was prepared for the first time applying steric protection methodology with the sterically demanding 2,4,6-tri-tertiary-butylphenyl ("supermesityl") group [...].

Synthesis and Spectroscopic Characterization of Selected Phenothiazines and Phenazines Rationalized Based on DFT Calculation

Two unique structures were isolated from the phosphorylation reaction of 10H-phenothiazine. The 5,5-dimethyl-2-(10H-phenothiazin-10-yl)-1,3,2-dioxaphosphinane 2-oxide (2a) illustrates the product of N-phosphorylation of phenothiazine. Moreover, a potential product of 2a instability, a thiophosphoric acid 2b, was successfully isolated and structurally characterized. Molecule 2a, similarly to sulfoxide derivative 3, possesses interesting phosphorescence properties due to the presence of d-pπ bonds. The X-ray, NMR, and DFT computational studies indicate that compound 2a exhibits an anomeric effect. Additionally, the syntheses of selected symmetrical and unsymmetrical pyridine-embedded phenazines were elaborated. To compare the influence of phosphorus and sulfur atoms on the structural characteristics of 10H-phenothiazine derivatives, the high-quality crystals of (4a,12a-dihydro-12H-benzo[5,6][1,4]thiazino[2,3-b]quinoxalin-12-yl)(phenyl)methanone (1) and selected phenazines 5,12-diisopropyl-3,10-dimethyldipyrido[3,2-a:3′,2′-h]phenazine (5) and 5-isopropyl-N,N,3-trimethylpyrido[3,2-a]phenazin-10-amine (6a) were obtained. The structures of molecules 1, 2a, 2-mercapto-5,5-dimethyl-1,3,2-dioxaphosphinane 2-oxide (2b), 3,7-dinitro-10H-phenothiazine 5-oxide (3), 5 and 6a were determined by single-crystal X-ray diffraction measurements.