[The course and clinical manifestations of Peutz-Jeghers syndrome in the Russian population].

Background: Peutz-Jeghers syndrome (PJS) is a rare hereditary syndrome characterized by the growth of hamartomatous polyps in the gastrointestinal tract, perioral pigmentation and an increased risk of malignant neoplasms. The syndrome is caused by a pathogenic variant in the gene.

Aim: To assess the clinical picture and treatment of Russian patients with PJS.

Mechanistic Study of Diketopiperazine Formation during Solid-Phase Peptide Synthesis of Tirzepatide.

This study focused on investigating diketopiperazine (DKP) and the formation of associated double-amino-acid deletion impurities during linear solid-phase peptide synthesis (SPPS) of tirzepatide (TZP). We identified that the DKP formation primarily occurred during the Fmoc-deprotection reaction and post-coupling aging of the unstable Fmoc-Pro-Pro-Ser-resin active pharmaceutical ingredient (API) intermediate. Similar phenomena have also been observed for other TZP active pharmaceutical ingredient (API) intermediates that contain a penultimate proline amino acid, such as Fmoc-Ala-Pro-Pro-Pro-Ser-resin, Fmoc-Pro-Pro-Pro-Ser-resin, and Fmoc-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-resin, which are intermediates for both hybrid and linear synthesis approaches.

Liquid Phase Peptide Synthesis via One-Pot Nanostar Sieving (PEPSTAR).

Herein, a one-pot liquid phase peptide synthesis featuring iterative addition of amino acids to a "nanostar" support, with organic solvent nanofiltration (OSN) for isolation of the growing peptide after each synthesis cycle is reported. A cycle consists of coupling, Fmoc removal, then sieving out of the reaction by-products via nanofiltration in a reactor-separator, or synthesizer apparatus where no phase or material transfers are required between cycles. The three-armed and monodisperse nanostar facilitates both efficient nanofiltration and real-time reaction monitoring of each process cycle.

Isolation and Rationale for the Formation of Isomeric Decarbamoylmitomycin C- N-deoxyadenosine Adducts in DNA.

Mitomycin C (MC) is an anticancer agent that alkylates DNA to form monoadducts and interstrand cross-links. Decarbamoylmitomycin C (DMC) is an analogue of MC lacking the carbamate on C10. The major DNA adducts isolated from treatment of culture cells with MC and DMC are N-deoxyguanosine (dG) adducts and adopt an opposite stereochemical configuration at the dG-mitosene bond.