An Efficient Protection-Free One-Pot Chemical Synthesis of Modified Nucleoside-5'-Triphosphates

A selective and atom-economic rearrangement of uridine by cascade biocatalysis for production of pseudouridine

As a crucial factor of their therapeutic efficacy, the currently marketed mRNA vaccines feature uniform substitution of uridine (U) by the corresponding C-nucleoside, pseudouridine (Ψ), in 1-N-methylated form. Synthetic supply of the mRNA building block (1-N-Me-Ψ-5'-triphosphate) involves expedient access to Ψ as the principal challenge. Here, we show selective and atom-economic 1N-5C rearrangement of β-D-ribosyl on uracil to obtain Ψ from unprotected U in quantitative yield. One-pot cascade transformation of U in four enzyme-catalyzed steps, via D-ribose (Rib)-1-phosphate, Rib-5-phosphate (Rib5P) and Ψ-5'-phosphate (ΨMP), gives Ψ. Coordinated function of the coupled enzymes in the overall rearrangement necessitates specific release of phosphate from the ΨMP, but not from the intermediary ribose phosphates. Discovery of Yjjg as ΨMP-specific phosphatase enables internally controlled regeneration of phosphate as catalytic reagent. With driving force provided from the net N-C rearrangement, the optimized U reaction yields a supersaturated product solution (∼250 g/L) from which the pure Ψ crystallizes (90% recovery). Scale up to 25 g isolated product at enzyme turnovers of ∼10⁵mol/mol demonstrates a robust process technology, promising for Ψ production. Our study identifies a multistep rearrangement reaction, realized by cascade biocatalysis, for C-nucleoside synthesis in high efficiency.

An Efficient Gram-Scale Chemical Synthesis of Purine Locked Nucleic Acid Nucleoside-5'-O-Triphosphates

This article presents a simple, reliable, straight-forward, general, and efficient chemical method for the gram-scale synthesis of purine locked nucleic acid (LNA) nucleotides, such as LNA guanosine-5'-O-triphosphate (LNA-GTP) and LNA adenosine-5'-O-triphosphate (LNA-ATP), starting from the corresponding nucleoside. The reaction pathway employs an improved protection-free "one-pot, three-step" Ludwig synthetic strategy. The first step involves monophosphorylation of nucleoside with phosphorus oxychloride followed by reaction with tributylammonium pyrophosphate and subsequent hydrolysis of the resulting cyclic intermediate to furnish the corresponding LNA nucleotide in good yields. It is noteworthy that the reaction affords high-purity (>99.5%) LNA nucleotide after diethylaminoethyl Sepharose column purification. © 2022 Wiley Periodicals LLC. Basic Protocol: Synthesis of LNA nucleoside-5'-O-triphosphates.

An improved protection-free one-pot chemical synthesis of purine locked nucleic acid nucleoside-5'-triphosphates

A simple, reliable, straightforward, and efficient method for the gram-scale chemical synthesis of purine locked nucleic acid (LNA) nucleotides such as LNA-guanosine-5'-triphosphate (LNA-GTP) and LNA-adenosine-5'-triphosphate (LNA-ATP) starting from the corresponding nucleoside is described. The overall reaction utilizes an improved "one-pot, three-step" Ludwig synthetic strategy that involves the monophosphorylation of LNA nucleoside, followed by the reaction with tributylammonium pyrophosphate and subsequent hydrolysis of the resulting cyclic intermediate using water to furnish the corresponding purine LNA nucleotide in good yield with high purity (>99.5%).

Highly regioselective 1,3-dipolar cycloaddition of 3'-O-propargyl guanosine with nitrile oxide: An efficient method for the synthesis of guanosine containing isoxazole moiety

The 1,3-dipolar cycloaddition reaction of 3'-O-propargyl guanosine with various in-situ generated nitrile oxides in the presence of DMF as a solvent is described. It is noteworthy that the reaction is highly regioselective that affords biologically important guanosine containing isoxazole moiety in good yields with high purities.

Highly regioselective methylation of inosine nucleotide: an efficient synthesis of 7-methylinosine nucleotide

A facile, straightforward, reliable, and an efficient chemical synthesis of inosine nucleotides such as 7-methylinosine 5'-O-monophosphate, 7-methylinosine 5'-O-diphosphate, and 7-methylinosine 5'-O-triphosphate, starting from the corresponding inosine nucleotide is delineated. The present methylation reaction of inosine nucleotide utilizes dimethyl sulfate as a methylating agent and water as a solvent at room temperature. It is noteworthy that the present methylation reaction proceeds smoothly under aqueous conditions that is highly regioselective to afford exclusive 7-methylinosine nucleotide in good yields with high purity (>99.5%).

An efficient protection-free chemical synthesis of inosine 5'-nucleotides

A facile, straightforward, reliable, and efficient chemical synthesis of inosine nucleotides such as inosine-5'-monophosphate, inosine-5'-diphosphate, and inosine-5'-triphosphate, starting from inosine is delineated. The inosine-5'-monophosphate is achieved by the highly regioselective monophosphorylation of inosine using the Yoshikawa procedure. The inosine-5'-diphosphate is obtained by the coupling reaction of tributylammonium phosphate with an activated inosine-5'-monophosphate using zinc chloride as a catalyst. The inosine-5'-triphosphate is efficiently achieved by the improved "one-pot, three-step" Ludwig synthetic strategy. In all the cases, the resulting final product is isolated in good yields with high purity (>99.5%).

Gram-Scale Chemical Synthesis of Base-Modified Ribonucleoside-5'-O-Triphosphates

This unit delineates a simple, reliable, straight-forward, general, and efficient chemical method for the synthesis of modified nucleoside-5'-O-triphosphates such as 5-methylcytidine-5'-O-triphosphate (5-Me-CTP), pseudouridine-5'-O-triphosphate (pseudo-UTP), and N¹ -methylpseudouridine-5'-O-triphosphate (N¹ -methylpseudo-UTP), starting from the corresponding nucleoside. The reaction utilizes an improved protection-free "one-pot, three-step" Ludwig synthetic strategy that involves the monophosphorylation of the nucleoside with phosphorous oxychloride followed by reaction with tributylammonium pyrophosphate and subsequent hydrolysis of the resulting cyclic intermediate to furnish the corresponding ribonucleoside triphosphate (NTP) in moderate yields. It is noteworthy that the reaction affords high purity (>99.5%) NTPs after DEAE Sepharose column purification. © 2016 by John Wiley & Sons, Inc.

Recent Trends in Nucleotide Synthesis

Focusing on the recent literature (since 2000), this review outlines the main synthetic approaches for the preparation of 5'-mono-, 5'-di-, and 5'-triphosphorylated nucleosides, also known as nucleotides, as well as several derivatives, namely, cyclic nucleotides and dinucleotides, dinucleoside 5',5'-polyphosphates, sugar nucleotides, and nucleolipids. Endogenous nucleotides and their analogues can be obtained enzymatically, which is often restricted to natural substrates, or chemically. In chemical synthesis, protected or unprotected nucleosides can be used as the starting material, depending on the nature of the reagents selected from P(III) or P(V) species. Both solution-phase and solid-support syntheses have been developed and are reported here. Although a considerable amount of research has been conducted in this field, further work is required because chemists are still faced with the challenge of developing a universal methodology that is compatible with a large variety of nucleoside analogues.