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A facile one-pot four-component domino protocol has been successfully developed for the combinatorial synthesis of novel ...N-methyl-3-nitro-4-aryl-4H-pyrano2′,3′:4,5imidazo1,2-apyridine-2-amine 7 and 2-amino-4-aryl-4H-pyrano2′,3′:4,5imidazo1,2-apyridine-3-carbonitrile 8. The protocol employs readily available starting materials, leading to high yields of the products (83–89%). The transformation involves a domino Knoevenagel-intramolecular Michael reaction sequence, enabling the formation of three new bonds (two CC, two CN, and one CO) and two rings in a single step. Notably, this reaction exhibits several remarkable features, including short reaction time, eliminating the need for extensive workup and column chromatographic purification. Additionally, the reaction demonstrates good scalability, producing satisfactory yields even on a gram-scale.
A facile synthetic method for depositing copper(I) oxide (Cu2O) shell on Au nanocube (AuNC) core with different core–shell ratios (1:1, 1:5, 1:10, and 1:20) is reported. An innovative approach of ...tuning the Cu2O nanoshell for utilizing the catalytic activity of the AuNC@Cu2O core–shell nanostructures is investigated. N-3-(trimethoxysilyl)propyldiethylenetriamine (TPDT) silane played a dual role in the formation and stabilization of the Cu2O shell on the AuNC core. The optimal concentration of TPDT silane required for forming a stable Cu2O shell is studied systematically and deployed for fabricating AuNC@Cu2O core–shell nanostructures with various core-to-shell ratios. UV–vis absorption spectroscopy, high-resolution electron transmission microscopy analyses, scanning electron microscopy coupled with line scan energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and inductively coupled plasma mass spectrometry techniques were used to characterize the prepared AuNC@Cu2O core–shell nanostructures. High-angle annular dark-field scanning transmission electron microscopy–energy-dispersive X-ray spectroscopy mapping images–line scan image and scanning electron microscopy coupled with line scan energy-dispersive X-ray spectroscopy were recorded to understand the core–shell nature of AuNC@Cu2O nanostructures. The electrocatalytic activity of AuNC@Cu2O core–shell nanostructures with different Cu2O shell thicknesses toward nitrite detection was investigated using the cyclic voltammetry technique. The TPDT-stabilized AuNC@Cu2O nanostructure with the core–shell ratio of 1:10 showed the best electrocatalytic activity, and the estimated detection limit of nitrite concentration was found to be as low as 14.7 nM.
We have developed two different methods for synthesis of two distinct polysubstituted pyrroles. The first method proceeds by the reaction of N,S‐acetal, arylglyoxals and malononitrile in the presence ...of H2O / PEG400 to the synthesis of 2‐(2‐argio‐1‐methyl‐5‐(methylthio)‐4‐nitro‐1H‐pyrrol‐3‐yl)‐2‐cyanoacetamide (4a‐4p). The second method for the synthesis of other divergent pyrroles 2‐(2‐argio‐1‐methyl‐5‐(methylthio)‐4‐nitro‐1H‐pyrrol‐3‐yl)acetonitrile (6a‐6f) under solvent free at thermal condition using methylcyanoacetate instead of malononitrile by decarboxylative elimination. Among the pyrroles 2‐(4‐methoxyphenyl) (4c), 2‐(4‐fluorophenyl) (4d) 2‐(4‐chlorophenyl) (4e), 2‐(2,4‐dichlorophenyl) (4f), 2‐(3‐chloro‐4‐fluorophenyl) (4g), 2‐(2‐bromo‐4‐chlorophenyl) (4h), (2‐(3‐bromophenyl) (4i), 2‐(4‐bromophenyl) (4j), (2‐(4‐hydroxyphenyl) (4l), and 2‐(3‐nitrophenyl) (4m) displayed moderate to good clot lysis. The cytotoxicity studies were also carried out on L929 cells for selected compounds. The test derivatives 4 c, 4 d, 4 g and 4 h showed good cell viability at lower concentration. The compound 4 f showed mild to non‐toxicity at higher and lower concentration. The density functional theory calculations (DFT) were carried out for the possible configurations of 6a‐argio‐2‐imino‐6‐methyl‐5‐(methylthio)‐4‐nitro‐3,3a,6,6a‐tetrahydro‐2H‐furo2,3‐b pyrrole‐3‐carbonitrile (D), 2‐amino‐6a‐argio‐6‐methyl‐5‐(methylthio)‐4‐nitro‐3a,6a‐dihydro‐6H‐furo2,3‐bpyrrole‐3‐carbonitrile (E) and 4c.
The simple and direct synthesis of two distinct Pentasubstituted pyrroles were achieved in good yield by two different methods. The reaction of nitro ketene N,S‐acetal, arylglyoxals and malononitrile in H2O / PEG400 gave the pyrroles with acetamide. The other substituted pyrroles obtained by decarboxylative elimination under solvent free at thermal condition using methyl cyanoacetate instead of malononitrile. The pyrroles were evaluated for their in‐vitro anti‐thrombotic activity and cytotoxicity on L929 cells. This reaction proceeds via a 6,6a‐dihydrofuro2, 3‐b‐pyrrole as key Intermediate.
Various types of metal layer shells such as mono‐, bi‐, and alloy layer using gold and silver on preformed gold spherical nanoparticles core were synthesizing using sodium borohydride as reducing ...agent. UV‐vis absorption spectroscopy, transmission electron microscopy images, and X‐ray diffraction techniques were used to characterize the prepared pristine gold spherical nanoparticles and various core‐shell metal nanoparticles. High‐angle annular dark field scanning transmission electron microscopy‐energy dispersive X‐ray spectroscopy mapping images were recorded for the alloy and bilayer shell coated core‐shell nanoparticles. Catalytic reduction of 4‐nitroaniline in the presence of sodium borohydride was taken to study the catalytic activity of the prepared core‐shell nanostructures. Interestingly, the alloy shell coated gold spherical nanoparticles (AuNP@AgAu) showed the best catalytic activity (higher rate constant; 21.61×10−3 s−1) than that of mono‐, and bilayer core‐shell and pristine gold spherical nanoparticles.
A detailed study was achieved towards the catalytic effect of different metal layer shell such as mono‐, bi‐, and ally layer shell on gold spherical nanoparticles core and checked their catalytic activity towards the catalytic chemical reduction of 4‐nitroaniline and alloy shell coated gold nanoparticles showed best catalytic activity than that of pristine gold nanoparticles, mono‐, and bilayer shell coated gold nanoparticles core.
The iminopyrans were synthesized by the CuAAC‐MCR approach, the coupling of enaminones, phenyl acetylenes, and sulfonyl, under microwave treatment. The mechanism of the formation of iminopyrans along ...with amidine has been studied in detail. Experiments to minimize amidine formation were explored, and unfortunately, these experiments were unsuccessful. Molar equivalents of enaminones, phenyl acetylenes, and sulfonyl were optimized to increase the yield of iminopyran. Fluorescent properties of iminopyrans were characterized using Frontier molecular orbital analysis, UV absorption, and emission studies.
Novel method to synthesis a series of iminopyrans and styryl iminopyrans was developed under microwave conditions in one‐pot manner using substituted enaminones/styryl enaminones, substituted arynes, and tosyl azide. Further, the photophysical behavior of selected derivatives were studied and found highly fluorescent in nature
An efficient protocol has been developed for the synthesis of a novel fluorescent probe, 1,2-disubstituted-indeno1,2,3- gh phenanthridine, derived from a series of α-oxo-ketene dithioacetals (OKDTAs) ...and indenoquinoline under essential conditions via a 4+2 annulation in excellent yield. All the synthesized indenophenathridine derivatives were well characterized by NMR and mass spectrometry. One of the synthesized indenophenanthridine derivatives, 4b, has been involved in acidochromism studies, selectively sensing Fe 3+ ions in non-aqueous solution with a low detection limit (7.5 × 10 −7 M) applied in live-cell bio-imaging.
An efficient protocol has been developed for the synthesis of a novel fluorescent probe, 1,2-disubstituted-indeno1,2,3-
gh
phenanthridine, derived from a series of α-oxo-ketene dithioacetals (OKDTAs) ...and indenoquinoline under essential conditions
via
a 4+2 annulation in excellent yield. All the synthesized indenophenathridine derivatives were well characterized by NMR and mass spectrometry. One of the synthesized indenophenanthridine derivatives, 4b, has been involved in acidochromism studies, selectively sensing Fe
3+
ions in non-aqueous solution with a low detection limit (7.5 10
−7
M) applied in live-cell bio-imaging.
An efficient protocol has been developed for the synthesis of a novel fluorescent probe, 1,2-disubstituted-indeno1,2,3-
gh
phenanthridine, derived from a series of α-oxo-ketene dithioacetals (OKDTAs) and indenoquinoline under essential conditions
via
a 4+2 annulation in excellent yield.
An efficient route for the synthesis of novel thioether containing dihydropyrano2,3- c pyrazoles has been accomplished via a solvent-free, catalyst-free, one-pot, five component domino strategy. This ...synthetic approach offers several advantages such as an easy work-up, no need for purification techniques and a short reaction time with good atom economy and high yields of the products (81–86%).
Abstract
Background
Microbial translocation is a known characteristic of pulmonary tuberculosis (PTB). Whether microbial translocation is also a biomarker of recurrence in PTB is not known.
Methods
...We examined the presence of microbial translocation in a cohort of newly diagnosed, sputum smear, and culture positive individuals with drug-sensitive PTB. Participants were followed up for a year following the end of anti-tuberculosis treatment. They were classified as cases (in the event of recurrence, n = 30) and compared to age and gender matched controls (in the event of successful, recurrence free cure; n = 51). Plasma samples were used to measure the circulating microbial translocation markers. All the enrolled study participants were treatment naïve, HIV negative and with or without diabetes mellitus.
Results
Baseline levels of lipopolysaccharide (LPS) (P = .0002), sCD14 (P = .0191), and LPS-binding protein (LBP) (P < .0001) were significantly higher in recurrence than controls and were associated with increased risk for recurrence, whereas intestinal fatty acid binding protein (I-FABP) and Endocab showed no association. Receiver operating characteristic (ROC) curve analysis demonstrated the utility of these individual microbial markers in discriminating recurrence from cure with high sensitivity, specificity, and area under the curve (AUC).
Conclusions
Recurrence following microbiological cure in PTB is characterized by heightened baseline microbial translocation. These markers can be used as a rapid prognostic tool for predicting recurrence in PTB.
Findings from our cohort revealed that microbial translocation markers (MTM) are a good prognostic tool for predicting recurrence in pulmonary tuberculosis (PTB) and in addition these MTMs showed high sensitivity and specificity in differentiating recurrent from cured TB patients.
Polyheteroaryl pyridinium-based indenophenanthridine is synthesized using the conventional method. The synthesized pyridinium core indenophenanthridine detects cyanide ion (CN
−
) in a ratiometric ...manner with an excellent detection limit (1.2 nM). The CN
−
sensing ability of the probe was treated for practical applications in food extracts, water samples, and U87 cell lines. The probe successfully detected the CN
−
anion in real samples and cell lines.
Pyridinium based indenophenanthiride (Me-INDP) has been synthesized
via
conventional method which en route detection of CN
−
ion in a non-aqueous medium. The sensing behavior of Me-INDP to detection of CN
−
ion in a biological system was investigated using U87 cell lines.
