Acid-Promoted Cyclization Reaction of the Guanine Base with 1,1,3,3-Tetramethoxypropane: A Method for the Preparation of M1 dG and its Derivatives.

Despite the importance of nucleosides and nucleotides for drug discovery, only a few practical methods to prepare tricyclic nucleosides have been reported. Here, we describe a synthetic strategy for late-stage functionalization of nucleosides and nucleotides via chemo- and site-selective acid-promoted intermolecular cyclization. The nucleoside analogs with an additional ring were obtained in moderate-to-high yields, including some antiviral drugs (acyclovir, ganciclovir, and penciclovir) derivatives, endogenous fused ring nucleoside (M1 dG) and its derivatives, and nucleotide derivatives. © 2023 Wiley Periodicals LLC. Basic Protocol 1: Synthesis of tricyclic acyclovir analogs (3a-3c) Basic Protocol 2: Synthesis of tricyclic nucleosides M1 dG (6) and M1 G (9) Basic Protocol 3: Synthesis of tricyclic nucleotide (12).

Synthesis of Nucleoside and Nucleotide Analogues by Cyclization of the Guanine Base with 1,1,3,3-Tetramethoxypropane.

3-(2-Deoxy-ß-d-erythropentofuranosyl)pyrimido[1,2-a]purin-10(3H)-one (M1dG) is an endogenous DNA adduct in bacterial and mammalian cells that could be explored as a biomarker for oxidative stress. Nonetheless, the lack of an efficient methodology for the preparation of M1dG hampers the deep investigation of its biosynthesis and biorelevant processes. In this project, we aimed to address this issue by developing a highly efficient method to synthesize M1dG and its analogues. This method has wide functional group tolerance, as various guanine-based nucleosides and nucleotides are suitable for the reaction. Furthermore, large-scale and derivatization reactions were carried out to showcase the possibility for biochemists to study DNA damage and repair processes in the future.

Degradation of bisphenol A in aqueous solution by H2O2-assisted photoelectrocatalytic oxidation.

A series of titanium dioxide (TiO(2)/Ti) film electrodes were prepared from titanium (Ti) metal mesh by an improved anodic oxidation process and were further modified by photochemically depositing gold (Au) on the TiO(2) film surface as Au-TiO(2)/Ti film electrodes. The morphological characteristics, crystal structure and photoelectroreactivity of both the TiO(2)/Ti and Au-TiO(2)/Ti electrodes were studied. The experiments confirmed that the gold modification of TiO(2) film could enhance the efficiency of e(-)/h(+) separation on the TiO(2) conduction band and resulted in the higher photocatalytic (PC) and photoelectrocatalytic (PEC) activity under UV or visible illumination. To further enhance the TiO(2) PEC reaction, a reticulated vitreous carbon (RVC) electrode was applied in the same reaction system as the cathode to electrically generate H(2)O(2) in the aqueous solution. The experiments demonstrated that such a H(2)O(2)-assisted TiO(2) PEC reaction system could achieve a much better performance of BPA degradation in aqueous solution due to an interactive effect among TiO(2), Au, and H(2)O(2). It may have good potential for application in water and wastewater treatment in the future.

Calculation method of quantum efficiency to TiO2 nanocrystal photocatalysis reaction.

The quantum yield is an important factor to evaluate the efficiency of photoreactor. This article gives an overall calculation method of the quantum efficiency(phi) and the apparent quantum efficiency(phi a) to the TiO2/UV photocatalysis system. Furthermore, for the immobility system (IS), the formulation of the faction of light absorbed by the TiO2 thin film is proposed so as to calculate the quantum efficiency by using the measured value and theoretic calculated value of transmissivity (T). For the suspension system(SS), due to the difficulty to obtain the absorption coefficient (alpha) of TiO2 particulates, the quantum efficiency is calculated by means of the relative photonic efficiency (zeta r) and the standard quantum yield (phi standard).