Molecular Interaction Fields Describing Halogen Bond Formable Areas on Protein Surfaces.

Molecular interaction fields (MIFs) are three-dimensional interaction maps that describe the intermolecular interactions expected to be formed around target molecules. In this paper, a method for the fast computation of MIFs using the approximation functions of quantum mechanics-level MIFs of small model molecules is proposed. MIF functions of N-methylacetamide with chlorobenzene, bromobenzene, and iodobenzene probes were precisely approximated and used to calculate the MIFs on protein surfaces. This method appropriately reproduced halogen-bond-formable areas around the ligand-binding sites of proteins, where halogen bond formation was suggested in a previous study.

Potential Application of the Myocardial Scintigraphy Agent [123I]BMIPP in Colon Cancer Cell Imaging.

[123I]ß-methyl-p-iodophenyl-pentadecanoic acid ([123I]BMIPP), which is used for nuclear medicine imaging of myocardial fatty acid metabolism, accumulates in cancer cells. However, the mechanism of accumulation remains unknown. Therefore, this study aimed to elucidate the accumulation and accumulation mechanism of [123I]BMIPP in cancer cells. We compared the accumulation of [123I]BMIPP in cancer cells with that of [18F]FDG and found that [123I]BMIPP was a much higher accumulation than [18F]FDG. The accumulation of [123I]BMIPP was evaluated in the presence of sulfosuccinimidyl oleate (SSO), a CD36 inhibitor, and lipofermata, a fatty acid transport protein (FATP) inhibitor, under low-temperature conditions and in the presence of etomoxir, a carnitine palmitoyl transferase I (CPT1) inhibitor. The results showed that [123I]BMIPP accumulation was decreased in the presence of SSO and lipofermata in H441, LS180, and DLD-1 cells, suggesting that FATPs and CD36 are involved in [123I]BMIPP uptake in cancer cells. [123I]BMIPP accumulation in all cancer cell lines was significantly decreased at 4 °C compared to that at 37 °C and increased in the presence of etomoxir in all cancer cell lines, suggesting that the accumulation of [123I]BMIPP in cancer cells is metabolically dependent. In a biological distribution study conducted using tumor-bearing mice transplanted with LS180 cells, [123I]BMIPP highly accumulated in not only LS180 cells but also normal tissues and organs (including blood and muscle). The tumor-to-intestine or large intestine ratios of [123I]BMIPP were similar to those of [18F]FDG, and the tumor-to-large-intestine ratios exceeded 1.0 during 30 min after [123I]BMIPP administration in the in vivo study. [123I]BMIPP is taken up by cancer cells via CD36 and FATP and incorporated into mitochondria via CPT1. Therefore, [123I]BMIPP may be useful for imaging cancers with activated fatty acid metabolism, such as colon cancer. However, the development of novel imaging radiotracers based on the chemical structure analog of [123I]BMIPP is needed.

Oxidation of Aldehydes into Carboxylic Acids by a Mononuclear Manganese(III) Iodosylbenzene Complex through Electrophilic C-H Bond Activation.

The oxidation of aldehyde is one of the fundamental reactions in the biological system. Various synthetic procedures and catalysts have been developed to convert aldehydes into corresponding carboxylic acids efficiently under ambient conditions. In this work, we report the oxidation of aldehydes by a mononuclear manganese(III) iodosylbenzene complex, [MnIII(TBDAP)(OIPh)(OH)]2+ (1), with kinetic and mechanistic studies in detail. The reaction of 1 with aldehydes resulted in the formation of corresponding carboxylic acids via a pre-equilibrium state. Hammett plot and reaction rates of 1 with 1°-, 2°-, and 3°-aldehydes revealed the electrophilicity of 1 in the aldehyde oxidation. A kinetic isotope effect experiment and reactivity of 1 toward cyclohexanecarboxaldehyde (CCA) analogues indicate that the reaction of 1 with aldehyde occurs through the rate-determining C-H bond activation at the formyl group. The reaction rate of 1 with CCA is correlated to the bond dissociation energy of the formyl group plotting a linear correlation with other aliphatic C-H bonds. Density functional theory calculations found that 1 electrostatically interacts with CCA at the pre-equilibrium state in which the C-H bond activation of the formyl group is performed as the most feasible pathway. Surprisingly, the rate-determining step is characterized as hydride transfer from CCA to 1, affording an (oxo)methylium intermediate. At the fundamental level, it is revealed that the hydride transfer is composed of H atom abstraction followed by a fast electron transfer. Catalytic reactions of aldehydes by 1 are also presented with a broad substrate scope. This novel mechanistic study gives better insights into the metal oxygen chemistry and would be prominently valuable for development of transition metal catalysts.

Alkyl Levulinates and 2-Methyltetrahydrofuran: Possible Biomass-Based Solvents in Palladium-Catalyzed Aminocarbonylation.

In this research, ethyl levulinate, methyl levulinate, and 2-methyltetrahydrofuran as bio-derived hemicellulose-based solvents were applied as green alternatives in palladium-catalyzed aminocarbonylation reactions. Iodobenzene and morpholine were used in optimization reactions under different conditions, such as temperatures, pressures, and ligands. It was shown that the XantPhos ligand had a great influence on conversion (98%) and chemoselectivity (100% carboxamide), compared with the monodentate PPh3. Following this study, the optimized conditions were used to extend the scope of substrates with nineteen candidates (various para-, ortho-, and meta-substituted iodobenzene derivatives and iodo-heteroarenes), as well as eight different amine nucleophiles.

Electrochemical Metal Recycling: Recovery of Palladium from Solution and In Situ Fabrication of Palladium-Carbon Catalysts via Impact Electrochemistry.

Recycling of critical materials, regeneration of waste, and responsible catalyst manufacture have been repeatedly documented as essential for a sustainable future with respect to the environment and energy production. Electrochemical methods have become increasingly recognized as capable of achieving these goals, and "impact" electrochemistry, with the advantages associated with dynamic nanoelectrodes, has recently emerged as a prime candidate for the recovery of metals from solution. In this report, the nanoimpact technique is used to generate carbon-supported palladium catalysts from low-concentration palladium(II) chloride solutions (i.e., a waste stream mimic) as a proof of concept. Subsequently, the catalytic properties of this material in both synthesis (Suzuki coupling reaction) and electrocatalysis (hydrogen evolution) are demonstrated. Transient reductive impact signals are shown and analyzed at potentials negative of +0.4 V (vs SCE) corresponding to the onset of palladium deposition in traditional voltammetry. Direct evidence of Pd modification was obtained through characterization by environmental scanning electron microscopy/energy-dispersive X-ray spectroscopy, inductively coupled plasma mass spectrometry, X-ray photoelectron spectroscopy, transmission electron microscopy, and thermogravimetric analysis of impacted particles. This showed the formation of deposits of Pd0 partially covering the 50 nm carbon black particles with approximately 14% Pd (wt %) under the conditions used. This material was then used to demonstrate the conversion of iodobenzene into its biphenyl product (confirmed through nuclear magnetic resonance) and the successful production of hydrogen as an electrocatalyst under acidic conditions (under cyclic voltammetry).

Clinical significance of 123I-BMIPP washout rate in patients with uncertain chronic heart failure.

BACKGROUND: Recently, triglyceride deposit cardiomyovasculopathy (TGCV) with defective intracellular lipolysis was found to be a disease that causes heart failure. As a diagnostic criterion for TGCV, an Iodaine-123-ß-methyl iodophenyl-pentadecanoic acid washout rate (BMIPP WOR) of < 10% is used, but its clinical significance in patients with heart failure remains to be clarified. METHODS: In 62 hospitalized patients with chronic heart failure, 123I-BMIPP myocardial single-photon emission computed tomography (SPECT) was performed predischarge state. The prevalence of TGCV was investigated. Subsequently, follow-up was conducted for ≥ 90 days (mean: 724.6 ± 392.7 days), and the association between the BMIPP WOR and cardiac events was examined, establishing all-cause mortality and admission due to heart failure as endpoints. RESULTS: Of the 62 patients, the WOR was < 10% in 41 (66.1%). Of these, 26 (41.9%) were diagnosed with definite TGCV. Furthermore, cardiac events were noted in 12 patients (19.4%). Analysis with Cox proportional hazards models showed that the BMIPP WOR < 4.5% was a significant event-predicting factor [HR 4.29, 95% CI: 1.20-16.87; p = 0.0245]. On a Kaplan-Meier curve, the WOR was 4.5%; there was a significant difference in the incidence of events (p = 0.0298). CONCLUSION: In the predischarge state of heart failure, 123I-BMIPP myocardial SPECT was performed. In approximately 40% of the patients, a diagnosis of TGCV was made. The results suggested that the BMIPP WOR is useful for predicting the prognosis of chronic heart failure patients regardless of TGCV.

Influence of Substituents in the Benzene Ring on the Halogen Bond of Iodobenzene with Ammonia.

The effects on the C-I⋅⋅N halogen bond between iodobenzene and NH3 of placing various substituents on the phenyl ring are monitored by quantum calculations. Substituents R=N(CH3 )2 , NH2 , CH3 , OCH3 , COCH3 , Cl, F, COH, CN, and NO2 were each placed ortho, meta, and para to the I. The depth of the σ-hole on I is deepened as R becomes more electron-withdrawing which is reflected in a strengthening of the halogen bond, which varied between 3.3 and 5.5 kcal mol-1 . In most cases, the ortho placement yields the largest perturbation, followed by meta and then para, but this trend is not universal. Parallel to these substituent effects is a progressive lengthening of the covalent C-I bond. Formation of the halogen bond reduces the NMR chemical shielding of all three nuclei directly involved in the C-I⋅⋅N interaction. The deshielding of the electron donor N is most closely correlated with the strength of the bond, as is the coupling constant between I and N, so both have potential use as spectroscopic measures of halogen bond strength.

A near-infrared fluorescent long-chain fatty acid toward optical imaging of cardiac metabolism in living mice.

Non-invasive fatty acid (FA) metabolic imaging is crucial for the evaluation of cardiac function in the heart. Currently, single-photon emission computed tomography (SPECT) and positron emission tomography (PET) are widely employed for cardiac metabolic imaging both in pre-clinical and clinical studies. Although SPECT and PET enable highly sensitive cardiac metabolic imaging, there are several disadvantages such as the high cost of instruments and radioactive tracer synthesis. In contrast, near-infrared (NIR) optical imaging using fluorescent FAs provides a simple and useful platform for in vivo imaging of cardiac metabolism. In this work, we synthesized a NIR fluorescence labelled long-chain fatty acid (LCFA) for real-time imaging of cardiac metabolism in vivo. A NIR fluorescence labelled LCFA was designed as an analogue of ß-methyl [123I] iodophenyl-pentanedecanoic acid (123I-BMIPP), which is widely used for the diagnosis of heart diseases in clinical practice. As a NIR fluorescent label, we used an Alexa 680 fluorophore that emits over 700 nm. By conjugation of Alexa 680 to Amino-BMPP (15-(4-(3-aminopropyl)phenyl)-3-methylpentadecanoic acid), we prepared a NIR fluorescent BMIPP analogue, Alexa680-BMPP. NIR fluorescence imaging showed that Alexa680-BMPP is taken up by the mouse heart tissue after intravenous injection, showing that Alexa680-BMPP can act as a fluorescent LCFA analogue. Among Alexa680 conjugated FA analogues including short and middle chain NIR fluorescent FAs, Alexa680-BMPP was most efficiently taken up by heart tissues. For fasted and fed mice, the difference in the degree of the uptake of Alexa680-BMPP in their heart tissues was clearly observed by in vivo and ex vivo NIR fluorescence imaging. Herein, we present the synthesis of a NIR fluorescent LCFA, Alexa680-BMPP, and its capability for real-time optical imaging of cardiac metabolism in living mice.

Synthesis of fluorinated polycyclic dehydroaltenusin analogs through hypervalent iodine-catalyzed dearomatization.

We developed a method employing stoichiometric meta-chloroperbenzoic acid (m-CPBA) as an oxidant and hydrogen fluoride pyridine (pyr·HF) as a fluoride source with catalytic amounts of iodobenzene (PhI) for the cyclization and fluorination-dearomatization of phenols, leading to a range of fluorocyclohexa-dienones with yields of up to 94%. This reaction provides a convenient method to synthesize fluorine-containing dehydroaltenusin analogs under mild conditions, and without expensive reagents. These analogs have potential application as inhibitors of DNA polymerase.

HPLC Fluorescence Method for Eugenols in Basil Products Derivatized with DIBI.

Eugenols (Eugs) such as eugenol (Eug), methyleugenol (MeEug), and linalool (Lin) in basil product are the main bioactive components of basil products and have a terminal double-bond. A sensitive HPLC-fluorescence method for Eugs derivatized with 4-(4,5-diphenyl-1H-imidazol-2-yl)iodobenzene (DIBI) was developed. Good separation of DIB-Eugs was achieved within 20 min on an Atlantis T3 column (50 × 2.1 mm i.d., 3 µm) with a mobile phase of methanol-water. The calibration curves obtained with Eug standards showed good linearities in the range of 0.1-50 µM (r ≥ 0.999). The limits of detection at a signal-to-noise ratio (S/N) = 3 for Eug, MeEug, and Lin were 1.0, 6.0, and 4.8 nM, respectively. The limits of quantitation (S/N = 10) of the Eugs were lower than 19.9 nM. The accuracies for the Eugs were within 96.8-104.6%. The intra- and inter-day precisions as relative standard deviations for the Eugs were less than 1.2 and 9.6% (n = 3). The recoveries of Eug, MeEug, and Lin were 99.0 ± 0.1, 98.0 ± 0.2, and 96.0 ± 0.4% (n = 3), respectively. The DIB-Eugs were confirmed to be stable for 2 h (>90%) at room temperature and 24 h (>95%) at 4 °C. These parameters of the proposed method were useful for the simultaneous determination of Eugs in basil products. Therefore, the developed method may be a powerful tool for the quality evaluation of dried commercially available basil products.

Transanal ileal pouch-anal anastomosis for ulcerative colitis: a single-center comparative study.

BACKGROUND: Ileal pouch-anal anastomosis (IPAA) is the procedure of choice in patients with ulcerative colitis (UC) requiring surgery. Advantages of laparoscopic IPAA (lap-IPAA) compared to open surgery have been investigated. However, laparoscopic dissection in the pelvis is still a challenge. A transanal approach provides better access to lower pelvis and avoids multiple staple firings, which could reduce the risk of anastomotic complications. The aim of this study was to compare short-term outcomes of transanal proctectomy with IPAA (ta-IPAA) with conventional lap-IPAA in patients with UC. METHODS: A single-center retrospective study was conducted on consecutive UC patients, treated at Copenhagen University Hospital, Hvidovre, undergoing either laparoscopic or transanal IPAA in the period between January 2013 and December 2020. Exclusion criteria were Crohn's disease, previous extensive abdominal surgery and impaired sphincter function. Primary outcomes were overall postoperative complications. Secondary outcomes were length of hospital stay and re-admissions. For comparison between ta-IPAA and lap-IPAA, the Mann-Whitney U test was used for continuous variables, and Chi-square and Fisher's exact test for categorical variables. RESULTS: A total of 65 patients with ta-IPAA (34 males, 31 females, median age 31 years [range 12-66 years]) and 70 patients with lap-IPAA (35 males, 35 females, median age 26 years [range 12-66 years]) were included. There was no difference between ta-IPAA and lap-IPAA regarding age, sex, body mass index or American Society of Anesthesiologists class. The primary colectomy procedure was performed laparoscopically in 95% of the ta-IPPA and 91% of the lap-IPAA patients (p = 0.493). The mean time between total colectomy and IPAA was 15 and 9 weeks for ta-IPAA and lap-IPAA, respectively (p = 0.048). A higher proportion of patients with ta-IPAA were treated with biologics preoperatively (98 vs. 82%; p = 0.002). Patients with ta-IPAA had a significantly higher mean operative time compared to lap-IPAA (277 min vs. 224 min; p = 0.001). There was no difference in the overall postoperative complication rate (ta-IPAA: 23% vs. lap-IPAA: 23%; p = 0.99). Pouch-related complications occurred in 13% of the ta-IPAA patients and 29% of lap-IPPA patients (p = 0.402). There was no difference in the anastomotic leakage rates. Readmission rates were similar in the ta-IPAA and lap-IPAA group (26 vs. 29%; p = 0.85), including IPAA-related readmissions. The mean follow-up time was 24 and 75 months for ta-IPAA and lap-IPAA, respectively (p = 0.001), and the ileostomy closure rate was similar in both groups of patients (p = 0.96). CONCLUSIONS: The ta-IPAA approach for UC is a safe procedure and offers acceptable short-time outcomes.

Comparison of BMIPP-SPECT/CT to 18FDG-PET/CT for Imaging Brown or Browning Fat in a Preclinical Model.

Obesity is a leading cause of preventable death and morbidity. To elucidate the mechanisms connecting metabolically active brown adipose tissue (BAT) and metabolic health may provide insights into methods of treatment for obesity-related conditions. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18FDG-PET/CT) is traditionally used to image human BAT activity. However, the primary energy source of BAT is derived from intracellular fatty acids and not glucose. Beta-methyl-p-iodophenylpentadecanoic acid (BMIPP) is a fatty acid analogue amenable to in vivo imaging by single photon emission computed tomography/CT (SPECT/CT) when radiolabeled with iodine isotopes. In this study, we compare the use of 18FDG-PET/CT and 125I-BMIPP-SPECT/CT for fat imaging to ascertain whether BMIPP is a more robust candidate for the non-invasive evaluation of metabolically active adipose depots. Interscapular BAT, inguinal white adipose tissue (iWAT), and gonadal white adipose tissue (gWAT) uptake of 18FDG and 125I-BMIPP was quantified in mice following treatment with the BAT-stimulating drug CL-316,243 or saline vehicle control. After CL-316,243 treatment, uptake of both radiotracers increased in BAT and iWAT. The standard uptake value (SUVmean) for 18FDG and 125I-BMIPP significantly correlated in these depots, although uptake of 125I-BMIPP in BAT and iWAT more closely mimicked the fold-change in metabolic rate as measured by an extracellular flux analyzer. Herein, we find that imaging BAT with the radioiodinated fatty acid analogue BMIPP yields more physiologically relevant data than 18FDG-PET/CT, and its conventional use may be a pivotal tool for evaluating BAT in both mice and humans.

Catalytic and Stoichiometric Baeyer-Villiger Oxidation Mediated by Nonheme Peroxo-Diiron(III), Acylperoxo, and Iodosylbenzene Iron(III) Intermediates.

In this paper we describe a detailed mechanistic studies on the [FeII(PBO)2(CF3SO3)2] (1), [FeII(PBT)2(CF3SO3)2] (2), and [FeII(PBI)3](CF3SO3)2 (3)-catalyzed (PBO = 2-(2'-pyridyl)benzoxazole, PBT = 2-(2'-pyridyl)benzthiazole, PBI = 2-(2'-pyridyl)benzimidazole) Baeyer-Villiger oxidation of cycloketones by dioxygen with cooxidation of aldehydes and peroxycarboxylic acids, including the kinetics on the reactivity of (µ-1,2-peroxo)diiron(III), acylperoxo- and iodosylbenzene-iron(III) species as key intermediates.

A Novel PIFA/KOH Promoted Approach to Synthesize C2-arylacylated Benzothiazoles as Potential Drug Scaffolds.

To discover an efficient and convenient method to synthesize C2-arylacylated benzothiazoles as potential drug scaffolds, a novel [bis(trifluoroacetoxy)iodo]benzene(PIFA)/KOH synergistically promoted direct ring-opening C2-arylacylation reaction of 2H-benzothiazoles with aryl methyl ketones has been developed. Various substrates were tolerated under optimized conditions affording the C2-arylacylation products in 70-95% yields for 38 examples. A plausible mechanism was also proposed based on a series of controlled experiments.

Palladium-Catalyzed Annulations of Strained Cyclic Allenes.

We report Pd-catalyzed annulations of in situ generated strained cyclic allenes. This methodology employs aryl halides and cyclic allene precursors as the reaction partners in order to generate fused heterocyclic products. The annulation proceeds via the formation of two new bonds and an sp3 center. Moreover, both diastereo- and enantioselective variants of this methodology are validated, with the latter ultimately enabling the rapid enantioselective synthesis of a complex hexacyclic product. Studies leveraging transition metal catalysis to intercept cyclic allenes represent a departure from the more common, historical modes of cyclic allene trapping that rely on nucleophiles or cycloaddition partners. As such, this study is expected to fuel the development of reactions that strategically merge transition metal catalysis and transient strained intermediate chemistry for the synthesis of complex scaffolds.

Iodosobenzene-Mediated Three-Component Selenofunctionalization of Olefins.

A three-component reaction of olefin, diselenide and water, alcohols, phenol, carboxylic acid, or amine by a commercially available hypervalent iodine(III) reagent, PhIO, was developed. This method provides access to a wide range of vicinally functionalized selenoderivatives under ambient conditions with mostly excellent yields and high diastereoselectivity. The developed reaction displays high levels of functional group compatibility and is suitable for the late-stage functionalization of styrene-functionalized biomolecules. Preliminary investigations on the mechanism of the reaction are also presented.

Feasibility of simultaneous 99mTc-tetrofosmin and 123I-BMIPP dual-tracer imaging with cadmium-zinc-telluride detectors in patients undergoing primary coronary intervention for acute myocardial infarction.

BACKGROUND: Simultaneous dual-tracer imaging using isotopes with close photo-peaks may benefit from improved properties of cadmium-zinc-telluride (CZT)-based scanners. METHODS: Thirty patients having undergone primary percutaneous coronary intervention for acute myocardial infarction underwent single-(99mTc-tetrofosmin (TF) or 123I-BMIPP first) followed by simultaneous 99mTc-TF /123I-BMIPP dual-tracer imaging using a Discovery NM/CT 670 CZT. The values for the quantitative gated-SPECT (QGS) and the quantitative perfusion SPECT (QPS) were assessed. RESULTS: The intra-class correlation (ICC) coefficients between the single- and dual-tracer imaging were high in all the QGS and QPS data (Summed motion score: 0.95, summed thickening score: 0.94, ejection fraction: 0.98, SRS for 99mTc-TF: 0.97/ for 123I-BMIPP: 0.95). Wall motion, wall thickening and rest scores per coronary-territory-based regions were also comparable between the single- and dual imaging (ICC coefficient > 0.91). The interrater concordance in the visual analysis for the infarction and perfusion-metabolism mismatch was significant for the global and regional left ventricle (P < 0.001). CONCLUSION: The quantitative/semi-quantitative values for global and regional left-ventricular function, perfusion, and fatty acid metabolism were closely comparable between the dual-tracer imaging and the single-tracer mode. These data suggests the feasibility of the novel CZT-based scanner for the simultaneous 99mTc-TF /123I-BMIPP dual-tracer acquisitions in clinical settings.

Prognosis and recurrence in cardiac sarcoidosis: Serial assessment of BMIPP SPECT and FDG-PET.

BACKGROUND: We analyzed 18F-Fludeoxyglucose positron emission tomography (FDG-PET) and 123I-betamethyl-p-iodophenyl-pentadecanoic acid (BMIPP) single-photon emission computed tomography (SPECT) performed for cardiac sarcoidosis (CS) patients taking prednisolone, identified recurrence by FDG-PET, and investigated BMIPP as a recurrence and prognostic factor in CS. METHODS AND RESULTS: CS patients who underwent BMIPP and FDG-PET within 2 months were enrolled. The recurrence-free group included patients with standardized uptake value (SUVmax) < 4 in the myocardium consecutively for ≥ 2 years. The total BMIPP SPECT defect score (BDS) was used to estimate myocardial damage. The predictability of the initial BDS and SUVmax for major adverse cardiac events (MACE) was analyzed using Kaplan-Meier analysis. Overall, 73 patients and 250 BMIPP and FDG-PET sets were analyzed retrospectively (mean follow-up, 3.5 years). The BDS was significantly greater for the recurrence group (N = 21) vs recurrence-free group (20 ± 13 vs 14 ± 12, P = 0.041). Patients with BDS ≥16 had a significantly higher MACE rate than patients with BDS < 16 (log-rank test, P = 0.016). However, MACE occurrence was comparable between patients with SUVmax ≥ 4 and < 4. CONCLUSIONS: BDS is a predictive marker of recurrence and MACE. SUV is not related to MACE. Recurrence, defined by prednisolone treatment-induced SUV variability, was observed in approximately 30% of CS patients.

PhI(OAc)2 and iodine-mediated synthesis of N-alkyl sulfonamides derived from polycyclic aromatic hydrocarbon scaffolds and determination of their antibacterial and cytotoxic activities.

The development of new approaches toward chemo- and regioselective functionalization of polycyclic aromatic hydrocarbon (PAH) scaffolds will provide opportunities for the synthesis of novel biologically active small molecules that exploit the high degree of lipophilicity imparted by the PAH unit. Herein, we report a new synthetic method for C-X bond substitution that is speculated to operate via a N-centered radical (NCR) mechanism according to experimental observations. A series of PAH sulfonamides have been synthesized and their biological activity has been evaluated against Gram-negative and Gram-positive bacterial strains (using a BacTiter-Glo assay) along with a series of mammalian cell lines (using CellTiter-Blue and CellTiter-Glo assays). The viability assays have resulted in the discovery of a number of bactericidal compounds that exhibit potency similar to other well-known antibacterials such as kanamycin and tetracycline, along with the discovery of a luciferase inhibitor. Additionally, the physicochemical and drug-likeness properties of the compounds were determined experimentally and using in silico approaches and the results are presented and discussed within.

Detection of enrofloxacin by flow injection chemiluminescence immunoassay based on cobalt hydroxide nanozyme.

The emergence and development of low-cost and high-efficiency nanozymes are promising to replace natural enzymes promoting the application of chemiluminescence immunoassays. Herein, a rapid and highly sensitive flow injection chemiluminescence immunoassay based on cobalt hydroxide (Co(OH)2) nanozyme was established to detect enrofloxacin (ENR) residues in food. In this system, Co(OH)2 nanosheets act as nanozymes to catalyze and amplify the chemiluminescence signal of the luminol-PIP-H2O2 system, as well as a carrier for immobilizing antibodies to form stable immunoprobes. In addition, carboxyl resin beads with good stability and biocompatibility were used as the base of the immunosensor to carry more coating antigens, based on the principle of competitive immunity and to achieve the rapid detection of ENR. Under optimal conditions, the linear working range is 0.0001 ~ 1000 ng/mL, and the limit of detection (LOD) is 0.041 pg/mL (S/N = 3). The method has been successfully applied to the analysis of aquatic products and poultry food. A non-enzyme immunosensor using Co(OH)2 nanosheets as antibody-conjugated carriers and peroxidase mimics for catalytic amplification of the chemiluminescence signal of luminol and using carboxyl resin beads as platform was designed to detect ENR residues in food.