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S-Adenosyl-L-methionine (SAM)-mediated methylation of biomolecules controls their function and regulates numerous vital intracellular processes. Analogs of SAM with a reporter group in place of the S-methyl group are widely used to study these processes. However, many of these analogs are chemically unstable that largely limits their practical application. We have developed a new compound, SAM-Ph, which contains an H-phosphinic group (-P(O)(H)OH) instead of the SAM carboxylic group. SAM-PH is significantly more stable than SAM, retains functional activity in catechol-O-methyltransferase and methyltransferase WBSCR27 reactions. The last is associated with Williams-Beuren syndrome. Rac-SAM-PH was synthesized chemically, while (R,S)-SAM-PH and its analogs were prepared enzymatically either from H-phosphinic analogs of methionine (Met-PH) or H-phosphinic analog of S-adenosyl-L-homocysteine (SAH-Ph) using methionine adenosyltransferase 2A or halide methyltransferases, respectively. SAH-PH undergoes glycoside bond cleavage in the presence of methylthioadenosine nucleosidase like natural SAH. Thus, SAM-PH and its analogs are promising new tools for investigating methyltransferases and incorporating reporter groups into their substrates. [ABSTRACT FROM AUTHOR]

A novel, efficient, two-step approach to the synthesis of merocyanine dyes was developed. Initially, N-substituted picolinium salts were formylated with N,N-dimethylformamide dimethyl acetal to produce enamine derivatives. Then a series of merocyanine dyes were obtained by the high-yield reaction between the enamines and various active methylene compounds. The described reactions, carried out in mild conditions, provide access to the synthesis of a wide range of dyes. This innovative method enabled the synthesis of a number of new merocyanine dyes and increased the yields of the known compounds. [ABSTRACT FROM AUTHOR]

19 F MRI is a unique technique for tracking and quantifying the indicator ( 19 F-MRI label) in vivo without the use of ionizing radiation. Here we report new 19 F-MRI labels, which are compounds with perfluoro-tert-butyl groups: 1,2-bis(perfluoro-tert-butoxy)ethane (C 10 F 18 H 4 O 2 ) and 1,3-bis(perfluoro-tert-butyl)propane (C 11 F 18 H 6 ). Both substances contain 18 equivalent 19 F atoms, constituting 68.67 % and 71.25 % of the molecule, respectively. The emulsions with 19 F molecules were prepared and used in 19 F MRI studies in laboratory rats in vivo. The substances demonstrated high contrast properties, good biological inertness and the ability to be rapidly eliminated from the body. We showed that at a dose of 0.34 mg/g of body weight in rats, the time for complete elimination of C 10 F 18 H 4 O 2 and C 11 F 18 H 6 is ∼30 days. The results turned out to be promising for the use of the presented compounds in 19 F MRI applications, especially since they are quite easy to synthesize., (© 2023 Wiley-VCH GmbH.)