RESUMO
In this study, we report on the ability of DMTMM PF6 to improve the amidation reaction. The on-DNA amidation reaction using DMTMM PF6 demonstrates higher conversion rates than those using HATU or DMTMM Cl, particularly with challenging sterically hindered amines and carboxylic acids. The developed method enables the expansion of available building blocks and the efficient synthesis of high-purity DNA-encoded libraries.
RESUMO
[This corrects the article DOI: 10.1021/acsomega.3c03634.].
RESUMO
The first total synthesis of (+)-tanzawaic acid B, a natural polyketide bearing a pentadienoic ester and octalin moiety, has been accomplished. The synthetic improvement from previous synthetic conditions facilitated our gram-scale synthesis of the chiral octalin that possesses seven stereogenic centers and that is the core skeleton of almost all of the tanzawaic acid family.
RESUMO
A depsipeptidic analogue of FE399 was efficiently synthesized mainly through macrolactamization using 2-methyl-6-nitrobenzoic anhydride (MNBA), and a detailed investigation of the desired 16-membered macrolactam core of FE399 was performed. It was determined that the combination of MNBA and a catalytic amount of 4-(dimethylamino)pyridine N-oxide exhibits much higher activity than that of conventionally used coupling reagents such as hexafluorophosphate azabenzotriazole tetramethyl uronium and benzotriazol-1-yl-oxytripyrrolidinophosphonium hexafluorophosphate.
RESUMO
A novel stereoisomer of eushearilide, 23-demethyleushearilide, was synthesized, and the structure-activity relationships of this compound along with known eushearilide stereoisomers were investigated in order to design novel lead compounds for the treatment of fungal infections. It was discovered that all of these congeners, together with the natural product, exhibited a wide range of antimicrobial activity against not only fungi but also against bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE).
Assuntos
Macrolídeos/síntese química , Macrolídeos/farmacologia , Fosforilcolina/análogos & derivados , Anti-Infecciosos/síntese química , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Macrolídeos/química , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Fosforilcolina/síntese química , Fosforilcolina/química , Fosforilcolina/farmacologia , Estereoisomerismo , Resistência a Vancomicina , Enterococos Resistentes à Vancomicina/efeitos dos fármacosRESUMO
As promising antifungal agents, the eight stereoisomers of eushearilide, including the natural compound, were synthesized relying on an asymmetric Mukaiyama aldol reaction, Julia-Kocienski olefination, and Shiina macrolactonization. Moreover, their in vitro antimicrobial activities against some fungi and bacteria were evaluated by the disk-diffusion method, which revealed that not only natural eushearilide but also its stereoisomers exhibited significant antimicrobial activity against a variety of fungi and bacteria.
Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Macrolídeos/química , Macrolídeos/farmacologia , Fosforilcolina/análogos & derivados , Anti-Infecciosos/síntese química , Técnicas de Química Sintética , Ciclização , Macrolídeos/síntese química , Fosforilcolina/síntese química , Fosforilcolina/química , Fosforilcolina/farmacologia , EstereoisomerismoRESUMO
The asymmetric total synthesis of a newly proposed structure of (3S,16E,20E,23S)-(+)-eushearilide was achieved primarily through an asymmetric Mukaiyama aldol reaction, Schlosser-modified Wittig reaction and 2-methyl-6-nitrobenzoic anhydride-mediated macrolactonization. Based on detailed spectroscopic analyses, the obtained synthetic compound was found to be identical to natural eushearilide. Therefore, we were able to determine the true structure of eushearilide. Moreover, the synthetic compound was found to exhibit significant in vitro antifungal activity against various fungi and bacteria.