10.1021/ol0157813
The study presents a novel strategy for synthesizing polypeptides using recombinant proteins, which are nonprotected peptides, in conjunction with S-alkyl peptide thioesters as building blocks. The method involves oxidizing the N-terminal serine of a peptide to form an Nr-glyoxyloyl peptide, which then undergoes reductive amination with 4,5-dimethoxy-2-(triphenylmethylthio)benzylamine to attach a thiol linker. This results in an Nr-4,5-dimethoxy-2-mercaptobenzyl glycyl peptide, which can be condensed with a peptide thioester to form a peptide bond. The innovative aspect of this approach is the use of the 4,5-dimethoxy-2-mercaptobenzyl (Dmmb) group as a linker, which can be removed under acidic conditions, allowing for the synthesis of peptides with native peptide bonds. The study demonstrates this method using a model sequence and shows the successful preparation of a thiol linker-attached peptide for condensation with peptide thioesters, providing a useful method for peptide synthesis in a neutral aqueous environment without the need for protecting groups.
10.1016/j.ejmech.2015.04.028
The research focuses on the design, synthesis, and biological evaluation of quinazoline derivatives as potential anti-trypanosomatid and anti-plasmodial agents. The main content involves the rational design of these compounds based on docking studies of dihydrofolate reductase (DHFR) and pteridin reductase (PTR) structures from Trypanosoma cruzi, Leishmania major, and Plasmodium vivax. The synthesis of nine quinazoline derivatives (1e9) was achieved through a series of chemical reactions involving reagents such as guanidine hydrochloride, acetic anhydride, and sodium borohydride, among others. The synthesized compounds were then biologically evaluated for their in vitro activity against T. cruzi and L. mexicana, as well as for cytotoxicity using the Vero cell line. Additionally, in vivo assays were conducted on a Plasmodium berghei mouse model to assess antiplasmodial activity. The experiments included trypanocidal and antileishmanial assays, cytotoxicity studies, in vivo antimalarial assays, ABTS assays to measure antioxidant capacity, and DHFR inhibition studies. Analytical techniques used throughout the research comprised various spectroscopic methods (IR, NMR, MS), melting point determinations, and elemental analyses to confirm the structures and purities of the synthesized compounds.
10.1080/00397911.2013.807517
The research aimed to develop a simple, multicomponent, ecofriendly, and microwave-mediated route for the synthesis of antimicrobial 2-amino-6-aryl-4-(3H)-pyrimidinones. These compounds are known for their wide array of biological activities, including antimicrobial properties. The study successfully synthesized 10 such pyrimidinones in good chemical yields (44–67%), with four of them being new to the literature. The synthesized compounds were evaluated for their antimicrobial activity against Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus, with two of the compounds showing significant activity against P. aeruginosa and S. aureus, which are major pathogens in nosocomial infections. The chemicals used in the process included aromatic aldehydes, ethyl cyanoacetate, guanidine hydrochloride, and potassium carbonate, with the reactions being mediated by microwaves to accelerate the synthesis process. The study concluded that the microwave-mediated multicomponent strategy was effective in synthesizing these pyrimidinones, which have potential as broad-spectrum antimicrobial agents.
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