: Isatin is an endogenous and a significant category of fused heterocyclic component, widely been a part of several potential biologically useful synthetics. Since its discovery, tons of research work has been conducted with respect to the synthesis, chemical properties, and biological and industrial applications. It contains indole nucleus having both lactam and keto moiety which while being a part of a molecular framework exerted several biological effects, viz.; antimicrobial, antitubercular, anticonvulsant, anticancer etc. Isatin derivatives are synthetically significant substrates, which can be utilized for the synthesis of huge diversified chemical entities of which few members emerged to be a drug. The reason for this review is to provide extensive information pertaining to the chemistry and its significance in altering several pathological states of isatin and its derivatives. A Structure Activity Relationships study thus developed through a gamut of scientific information indicates the importance of mostly electron withdrawing groups, halogens, nitro, alkoxy and to a minor extent groups with positive inductive effects, such as methyl at position 1, 5, 6 and 7 of isatin in alleviating several clinical conditions. It is also observed from the survey that the presence of two oxo groups at position 2 and 3 sometimes become insignificant as fusion with a heterocycle at those position resulted in a biologically relevant compound.

The use of inexpensive K2S2O8 in water at room temperature for synthesis of bis(indolyl)methanes (BIMs) from simple indoles and alcohols is reported. The key step involves the conversion of alcohols...

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Hypoxia is a condition caused by a decrease in oxygen and is often seen in cases of cardiac ischemia, solid tumors, inflammation, and other diseases. Tumor hypoxia can result in cancer invasion, metastasis, decreased apoptosis, and resistance to various therapies (chemotherapy, immunotherapy, and radiotherapy), ultimately reducing overall survival rates. These effects of hypoxia underline the need to monitor hypoxia‐associated specific markers for more effective therapeutic intervention. Nitroreductase (NTR) is a common biomarker of hypoxia, via its reduction activity with nitroaromatic compounds to corresponding amino derivatives using NADH and NADPH as cofactor. The NTR expression level can be correlated to cellular hypoxia. Therefore, developing a diagnostic tool for measuring NTR activity is of immense importance for improving treatment efficacies. To leverage NTR activity as a proxy of hypoxia, small molecule based fluorescent probes have been developed as quantifiable probes. To date, several NTR‐sensitive fluorescent probes have been reported. This review is focuses on the advances in these fluorescent NTR probes over the last five years.

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An efficient and regioselective trifluoromethylation method of indole at the C2 position with ecologically-sound Langlois' reagent (CF 3 SO 2 Na) under metal-free conditions is described. K 2 S 2 O 8 in presence of glucose at room temperature has been utilized for the generation of CF 3 radicals from CF 3 SO 2 Na. The desired product can be obtained in good to excellent yields with a wide scope of substrate variability and gram scalability.

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Sulfite (SO 3 2−) is considered a highly toxic anion for living organisms. Herein, we report the synthesis of copper immobilized over a 2D hexagonally ordered mesoporous silica material CuMS as an electrochemical and colorimetric dual-technique-based sensing platform for sulfite detection. The immobilization of copper on silica was achieved through the bis[3-(triethoxysilyl)propyl]tetrasulfide (TEPTS) ligand. Morphological and physical properties of the material were confirmed by several characterization techniques, including scanning electron microscopy, transmission electron microscopy, X-ray diffraction, N 2 sorption, and X-ray photoelectron spectroscopy. The CuMS material retained mesoporosity with a narrow pore size distribution (D ≈ 5.4 nm) and a high Brunauer−Emmett−Teller surface area of 682 m 2 g −1 after the immobilization of copper. The prepared catalyst shows promising electrocatalytic activity toward sulfite oxidation. A linear variation in the peak current was obtained for SO 3 2− oxidation in the 0.2−15 mM range with a high sensitivity of 62.08 μA cm −2 , under optimum experimental conditions. The limit of detection (LOD) was found to be 1.14 nM. CuMS also shows excellent activity toward colorimetric detection of sulfite anions with an LOD of 0.4 nM. The proposed sensor shows high selectivity toward the sulfite anion, even in the presence of common interferents. The detection of sulfite in white wine with excellent recovery demonstrates the practical applicability of this sensor.