Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan.
Published: April 2022
AI Article Synopsis
Article Abstract
Thelepamide, an unique ketide-amino acid isolated from a marine annelid worm , has a unique oxazolidinone ring derived from cysteine, glycine and valine. Rareness in nature as well as promising bioactive possibility make the oxazolidinone ring an attractive synthetic target. The hydroxy oxazolidinone fragment of thelepamide was prepared by acid-catalysed ,-acetal formation between a ketoamide and formaldehyde. Lactone-carbonyl selective isopropyl addition to an oxazilidine-dione under Grignard conditions also forms the target compound.
The aim of this work was to provide a theoretical and scientific basis for the treatment, prevention, and control of clinical drug-resistant bacterial infections by studying the molecular epidemiology and horizontal transfer mechanism of -carrying linezolid-resistant strains (LREfs) that were clinically isolated in a tertiary hospital in Kunming, China. Non-repetitive LREfs retained in a tertiary A hospital in Kunming, China. The strains were identified by Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS).
Metalloenzymes are able to catalyze complex biochemical reactions in cellular (aqueous) media with high efficiency. In recent years, a variety of metal-containing single-chain nanoparticles (SCNPs) have been synthesized as simplified metalloenzyme-mimetic nano-objects. However, most of the metal-containing SCNPs reported so far contained complexed metal ions but not metal nanoclusters (NCs) with diameter <5 nm, which could be used as powerful, emerging catalysts.
The photoionisation and photofragmentation of the two cyclic dipetides cyclo(alanyl-glycine) cGA and cyclo(glycyl-glycine) cGG, have been studied combining experiments and simulations. State selected fragments from the ionized molecules are detected using photo-electron photo-ion coincidence (PEPICO) measurements and specific fragmentation paths are identified and characterized the use of ion-neutral coincidence maps. The simulations, performed using Quantum Chemistry methods, allow us to infer the fragmentation mechanisms of the ionized and excited molecules.
School of Pharmaceutical Sciences & Key Laboratory of Advanced Drug Preparation Technologies, Zhengzhou University, Zhengzhou, 450001, China. Electronic address:
Due to the long-term and widespread use of antibiotics in clinic, the problem of bacterial resistance is increasingly serious, and the development of new drugs to treat drug-resistant bacteria has gradually become the mainstream direction of antibiotic research. The oxazolidinone-containing drugs linezolid, tedizolid phosphate and contezolid have been approved to the market, which are effective against a variety of Gram-positive bacterium infections. Moreover, there are also many antibiotics containing oxazolidinone fragment under clinical investigation that show good pharmacokinetic and pharmacodynamic properties with unique mechanism of action against resistant bacteria.
The multidrug resistance gene mediates resistance to multiple antimicrobial agents, including linezolid. Plasmids are the preferred vector for the dissemination of . However, the presence and transmission of -carrying plasmids among staphylococci from humans and animals have rarely been studied.
