agents halogénés

Facilitating the charge separation of semiconductor photocatalysts to increase the photocatalytic CO 2 reduction activity has become a great challenge for sustainable energy conversion. Herein, the surface halogenation-modified defective Bi 2 WO 6 nanosheets have been successfully prepared to address aforementioned challenge. Importantly, the modification of surface halogenation atoms is beneficial to the adsorption and activation for CO 2 molecules, and the charge separation. These properties have collectively evidenced by experimental and theoretical results...

Resistant bacteria successfully evade the action of conventional antibiotic therapies during infection, often leading to significant illness and death. Our lab has discovered halogenated phenazine (HP) analogues which demonstrate potent antibacterial activities through a unique iron-starving mechanism. Herein, we describe synthetic efforts towards a stable cephalosporin-HP conjugate prodrug with the aim of translating HPs into useful clinical agents. Cephalosporin-antibiotic conjugates offer multiple advantages for antibacterial design, including the release of active agents through the targeting of intracellular cephalosporinase following selective ring-opening of the beta-lactam warhead...

We report a case of Xp21 deletion syndrome, a contiguous gene syndrome associating glycerol kinase deficiency, Duchenne muscular dystrophy, and congenital adrenal hypoplasia. This results in a contraindication to the use of all halogenated agents and of propofol. We used regional anesthesia combined with dexmedetomidine and ketamine. Previously, the patient had received inadvertently a propofol-based total intravenous anesthesia (TIVA) with no clinical side effects. We were unfortunately unable to document the metabolic consequences of this glycerol load...

Halogenated compounds are widely discovered in nature, and many of them exhibit biological activities, such as an important chlorinated natural product salinosporamide A serving as a potential anticancer agent. Compared with bromination, iodination and fluorination, chlorination is the mainly important modification. To shed light on the mechanism of SAM-dependent chlorinases, a recombinant chlorinase ClA1 was expressed in Escherichia coli and further purified for crystallization and X-ray diffraction experiments...

BACKGROUND: Searching for new cytotoxic agents with apoptosis induction may represent a viable strategy for cancer treatment to overcome the increased resistance to available anticancer agents. OBJECTIVE: The purpose of the current study aimed at preparation and anticancer evaluation of two new series of 2Hquinolinone and halogenated 2H-quinolinone derivatives against two cancer cell lines. METHODS: Two new series of 2Hquinolinone and halogenated 2H-quinolinone derivatives were prepared and screened for their cytotoxicity against breast MCF-7 and liver HepG-2 cancer cell lines as well as normal breast MCF-10a...

Interface strains and lattice distortion are inevitable issues during perovskite crystallization. Silane as a coupling agent is a popular connector to enhance the compatibility between inorganic and organic materials in semiconductor devices. Herein, a protonated amine silane coupling agent (PASCA-Br) interlayer between TiO2 and perovskite layers is adopted to directionally grasp both of them by forming the structural component of a lattice unit. The pillowy alkyl ammonium bromide terminals at the upper side of the interlayer provide well-matched growth sites for the perovskite, leading to mitigated interface strain and ensuing lattice distortion; meanwhile, its superior chemical compatibility presents an ideal effect on healing the under-coordinated Pb atoms and halogen vacancies of bare perovskite crystals...

Phenanthroimidazole derivatives containing phenanthroline and imidazole heterocyclic aromatic rings are effective agents to inhibit tumor cell growth. Herein, halogen element-modified imidazo[4,5f][1,10]phenanthroline derivatives 1-6 (1, 4-fluorophenyl; 2, 4-chlorophenyl; 3, 4-bromobenyl; 4, 2,3-dichlorophenyl; 5, 3,4-dichlorophenyl; and 6, 2,4-dichlorophenyl) were synthesized, and their antitumor activities were investigated. All of the compounds, especially 4, exhibited an excellent inhibitory effect against nasopharyngeal carcinoma CNE-1 cells...

Thyroid hormones (THs) elicit significant effects on numerous physiological processes, such as growth, development, and metabolism. A lack of thyroid hormones is not compatible with normal health. Most THs effects are mediated by two different thyroid hormone receptor (TR) isoforms, namely TRα and TRβ, with the TRβ isoform known to be responsible for the main beneficial effects of TH on liver. In brain, despite the crucial role of TRα isoform in neuronal development, TRβ has been proposed to play a role in the remyelination processes...

The synthesis of three water-soluble lactose-modified 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY)-based photosensitizers with tumor-targeting capabilities is reported, including an investigation into their photodynamic therapeutic activity on three distinct cancer cell lines (human hepatoma Huh7, cervical cancer HeLa, and breast cancer MCF-7 cell lines). The halogenated BODIPY dyes exhibited a decreased fluorescence quantum yield compared to their non-halogenated counterpart, and facilitated the efficient generation of singlet oxygen species...

In the light of recent lines of evidence, 5-HT6 R ligands are a promising tool for future treatment of memory impairment. Hence, this study has supplied highly potent 5-HT6 R agents with procognitive effects, which represent an original chemical class of 1,3,5-triazines, different from widely studied sulfone and indole-like 5-HT6 R ligands. The new compounds were rationally designed as modifications of lead, 4-(1-(2-chlorophenoxy)ethyl)-6-(4-methylpiperazin-1-yl)-1,3,5-triazin-2-amine (1), involving an introduction of: (i) two chlorines at benzene ring and (ii) varied linkers joining the triazine ring to aromatic ethers...

ConspectusEnolate chemistry is one of the most fundamental strategies for the formation of carbon-carbon and carbon-heteroatom bonds. Classically, this has been accomplished through the use of stoichiometric quantities of strong base and cryogenic reaction temperatures. However, these techniques present issues related to enolate regioselectivity and functional group tolerance. While more modern methods utilizing stoichiometric activating agents have overcome some of these limitations, these processes add additional steps and suffer from poor atom economy...

We report a diaryldiselenide catalyst for cross-dehydrogenative nucleophilic functionalization of hydrophosphoryl compounds. The proposed organocatalytic cycle closely resembles the mechanism of the Atherton-Todd reaction, with the catalyst serving as a recyclable analogue of the halogenating agent employed in the named reaction. Phosphorus and selenium NMR studies reveal the existence of a P-Se bond intermediate, and structural analyses indicate a stereospecific reaction.

A series of Sulfonamide-based Schiff bases (E)-4-(benzylideneamino)-N-(6-methoxypyridazin-3-yl) benzenesulfonamide (3a-r) targeting Urease Inhibition was synthesized from sulphamethoxy pyridazine and substituted aldehydes. The prepared compounds were characterized by various spectroscopic techniques including FTIR, 1 HNMR, 13 CNMR, and spectrometric HRMS analysis. The most active agent (3g) bearing halogens and OH groups gave IC50 value of 2.20 µM for urease inhibition against the standard Thiourea (IC50  = 20...

Xantholipin ( 1 ), a polycyclic xanthone antibiotic, exhibited strong antibacterial activities and showed potent cytotoxicity. The biosynthetic gene cluster of 1 has been identified in our previous work and the construction of xanthone nucleus has been well demonstrated. However, limited information of the halogenation involved in 1 biosynthesis is known. In this study, based on the genetic manipulation and biochemical assay, we characterized XanH as an indispensable FAD-dependent halogenase (FDH) for the biosynthesis of 1 XanH was found to be a bifunctional protein capable of flavin reduction and chlorination, and exclusively used the reduced nicotinamide adenine dinucleotide (NADH)...

We report a highly active single-site heterogeneous cobalt-catalyst based on a porous and robust pyridylimine-functionalized metal-organic frameworks (pyrim-MOF) for chemoselective borylation of arene and benzylic C-H bonds. The pyrim-MOF having UiO-68 topology, constructed from zirconium-cluster secondary building units and pyridylimine-functionalized dicarboxylate bridging linkers, was metalated with CoCl2 followed by treatment of NaEt3 BH to give the cobalt-functionalized MOF-catalyst (pyrim-MOF-Co). Pyrim-MOF-Co has a broad substrate scope, allowing the C-H borylation of halogen-, alkoxy-, alkyl-substituted arenes as well as heterocyclic ring systems using B2 pin2 or HBpin (pin = pinacolate) as the borylating agent to afford the corresponding arene- or alkyl-boronate esters in good yields...

The threat from deliberate or accidental exposure to halogen gases is increasing, as is their industrial applications and use as chemical warfare agents. Biomarkers that can identify halogen exposure, diagnose victims of exposure or predict injury severity, and enable appropriate treatment are lacking. We conducted these studies to determine and validate biomarkers of bromine (Br2 ) toxicity and correlate the symptoms and the extent of cardiopulmonary injuries. Unanesthetized rats were exposed to Br2 and monitored noninvasively for clinical scores and pulse oximetry...

Eighteen pyrrolidin-2-one linked benzothiazole, and benzimidazole derivatives (10-27) were designed and synthesized. The structure of the compounds was confirmed by elemental and spectral (IR, 1 H-NMR, and MS) data analysis. All the compounds were screened by human monoacylglycerol lipase (hMAGL) inhibition assay. Three benzimidazole compounds, 22 (4-Cl phenyl), 23 (3-Cl,4-F phenyl), and 25 (4-methoxy phenyl) were found to be the most potent, having an IC50 value of 8.6 nM, 8.0 nM and 9.4 nM, respectively. Among them, the halogen-substituted phenyl derivatives, compound 22 (4-Cl phenyl) and compound 23 (3-Cl,4-F phenyl), showed micromolar potency against fatty acid amide hydrolase (FAAH), having an IC50 value of 35 µM and 24 µM, respectively...

Volatile halogenated gases and nitrous oxide used as part of a balanced general anesthetic may contribute to global warming. By avoiding volatile inhalational agent use, regional anesthesia may reduce greenhouse gas emissions and help prevent global warming. We present a theoretical calculation of the potential benefits and a real-life example of how much regional anesthesia may reduce greenhouse gas emissions.

Pandemic coronavirus disease-2019 (COVID-19) gives ample reason to generally review coronavirus (CoV) containment. For establishing some preliminary views on decontamination and disinfection, surrogate CoVs have commonly been assessed. This review serves to examine the existing science in regard to CoV containment generically and then to translate these findings into timely applications for COVID-19. There is widespread dissemination of CoVs in the immediate patient environment, and CoVs can potentially be spread via respiratory secretions, urine, and stool...

Quinazolinone and its congeners are ubiquitous structural motifs found in numerous natural products due to their wide applications as anticancer, antiviral, anti-inflammatory, antifolate and antitumor agents etc. Previously, the synthetic community devoted their efforts towards synthetic approaches but recent years have also witnessed an upsurge in the diversification of this scaffold and its applications. Thus, this review (from 2011 to the beginning of 2020) comprehensively focuses on transition metal catalyzed C-H bond functionalization namely arylation, amination, acetoxylation, amidation, alkylation, alkenylation, alkynylation, halogenation, thiolation, trifluoroethylation etc...