Highly sensitive AIEE active fluorescent probe for detection of deferasirox: extensive experimental and theoretical studies.

High concentrations of deferasirox (DFX) in living organisms cause hepatic, gastric and renal malfunctions. Therefore, it is significant to establish an accurate and efficient approach for the detection of deferasirox (DFX) to protect public health. Herein, we synthesized a thiourea-based diphenylacetamide probe MPT for the effective sensing of deferasirox through the fluorescence quenching phenomenon. The designed probe MPT shows a fluorescence quenching response toward deferasirox (DFX) through photo-induced electron transfer (PET). Furthermore, DFT studies were performed to support the experimental results. 1H-NMR titration experiment was used to explore the interaction type between probe MPT and DFX. The existence of non-covalent interactions was verified with spectroscopic studies that were assisted by NCI studies, QTAIM and SAPT0 analysis. Dynamic light scattering (DLS) analysis and scanning electron microscopy (SEM) were used to investigate the complexation of probe MPT with DFX. Moreover, the on-site solution phase and solid-state detection of DFX by probe MPT are executed. Additionally, the practical applications of probe MPT to sense DFX were also revealed in human plasma as well as in artificial urine samples.

Cu-MOF loaded chitosan based freeze-dried highly porous dressings with anti-biofilm and pro-angiogenic activities accelerated Pseudomonas aeruginosa infected wounds healing in rats.

Metal-organic frameworks (MOFs)-based therapy opens a new area for antibiotic-drug free infections treatment. In the present study, chitosan membranes (CS) loaded with two concentrations of copper-MOF 10 mg/20 ml (Cu-MOF10/CS) & 20 mg/20 ml (Cu-MOF20/CS) were prepared by a simple lyophilization procedure. FTIR spectra of Cu-MOF10/CS and Cu-MOF20/CS dressings confirmed absence of any undesirable chemical changes after loading Cu-MOF. The SEM images of the synthesized materials (CS, Cu-MOF10/CS & Cu-MOF20/CS) showed interconnected porous structures. Cytocompatibility of the materials was confirmed by fibroblasts cells culturing and the materials were hemocompatible, with blood clotting index <5 %. Cu-MOF20/CS showed comparatively higher effective antibacterial activity against the tested strains; E. coli (149.2 %), P. aeruginosa (165 %) S. aureus (117.8 %) and MRSA (142 %) as compared to Amikacin, CS and Cu-MOF10/CS membranes. Similarly, Cu-MOF20/CS dressing significantly eradicated the biofilms; P. aeruginosa (37 %) and MRSA (52 %) respectively. In full thickness infected wound rat model, on day 23, Cu-MOF10/CS and Cu-MOF20/CS promoted wound healing up to 87.7 % and 82 % respectively. H&E staining of wounded tissues treated with Cu-MOF10/CS & Cu-MOF20/CS demonstrated enhanced neovascularization and re-epithelization along-with reduced inflammation, while trichrome staining exhibited increased collagen deposition. Overall, this study declares Cu-MOFs loaded chitosan dressings a multifunctional platform for the healing of infected wounds.

A combined experimental and theoretical approach for doxycycline sensing using simple fluorescent probe with distinct fluorescence change in wide range of interferences.

Overuse of doxycycline (DOXY) can cause serious problems to human health, environment and food quality. So, it is essential to develop a new sensing methodology that is both sensitive and selective for the quantitative detection of DOXY. In our current research, we synthesized a simple fluorescent probe 4,4'-bis(benzyloxy)-1,1'-biphenyl (BBP) for the highly selective detection of doxycycline by through fluorescence spectroscopy. The probe BBP displayed ultra-sensitivity towards doxycycline due to Forster resonance energy transfer (FRET). Fluorescence spectroscopy, density functional theory (DFT), 1H NMR titration, UV-Vis, and Job's plot were used to confirm the sensing mechanism. The charge transfer between the probe and analyte was further examined qualitatively by electron density differences (EDD) and quantitively by natural bond orbital (NBO) analyses. Whereas the non-covalent nature of probe BBP towards DOXY was verified by theoretical non-covalent interaction (NCI) analysis as along with Bader's quantum theory of atoms in molecules (QTAIM) analysis. Furthermore, probe BBP was also practically employed for the detection of doxycycline in fish samples, pharmaceutical wastewater and blood samples.

Extensive optical and DFT studies on novel AIE active fluorescent sensor for Colorimetric and fluorometric detection of nitrobenzene in Solid, solution and vapor phase.

An electron rich isophthalamide based sensor IPA has been synthesized through a simple two-step reaction, containing noteworthy aggregation induced emission (AIE) properties. Considering the significant emission with λmax at 438 nm, sensor IPA has been employed for the sensing of nitrobenzene (NB) in solid, solution and vapor state with high sensitivity and selectivity. Sensor IPA showed noteworthy colorimetric and fluorometric quenching in fluorescence emission when exposed to NB. Small size of NB and involvement of photoinduced electron transfer (PET) lead to detection of NB down to 60 nM. IPA-NB interaction was studied through UV-Vis. spectroscopic studies along with fluorescence spectroscopy. Moreover, 1H and 13C NMR titration experiments provided additional support for determination of interaction type. Furthermore, by using density functional theory (DFT) calculations, thermodynamic stability was studied. Additionally, non-covalent interactions (NCI), frontier molecular orbitals (FMO), density of states (DOS), were investigated for providing further evidence of nitrobenzene sensing and its interaction with sensor. Natural bond orbital (NBO) analysis was carried out for charge transfer studies. Quantum theory of atom in molecule (QTAIM) and SAPT0 studies provided information about interaction points and binding energy. Additionally, IPA was investigated for NB sensing in real water samples, and its effective participation in solid state on-site detection as well as in solution phase was brought to light along with logic gate construction.

Novel amodiaquine analogues to treat cervical cancer and microbial infection in the future.

Aim: To synthesize and explore the therapeutic potential of amodiaquine analogues. Methodology: New promising analogues were synthesized by nucleophilic substitution at the 4-amino position and were characterized using 1H NMR, 13C NMR and FT-IR spectroscopic techniques. Results: Antibacterial and cytotoxic screening revealed the high potency of these compounds; analogue AS1 had an 34.3 ± 0.18 mm zone of inhibition against Pseudomonas aeruginosa. Excellent activity against fungal strains, that is, Candida albicans (39.6 ± 0.23 mm) was shown by analogue AS2. Analogue AS1 had an IC50 = 4.2 µg/ml against the HeLa cell line (cervical cancer) and binding energy against 5GWK (-8.32688 kcal/mol), 1PFK (-6.4780 kcal/mol) and 1TUP (-6.5279 kcal/mol) in the docking study. Conclusion: The obtained results reveal that these analogues exhibit potent antimicrobial and cytotoxic potential.

Bioactivity-Guided Synthesis: In Silico and In Vitro Studies of ß-Glucosidase Inhibitors to Cope with Hepatic Cytotoxicity.

The major cause of hyperglycemia can generally be attributed to ß-glucosidase as per its involvement in non-alcoholic fatty liver disease. This clinical condition leads to liver carcinoma (HepG2 cancer). The phthalimides and phthalamic acid classes possess inhibitory potential against glucosidase, forming the basis for designing new phthalimide and phthalamic acid analogs to test their ability as potent inhibitors of ß-glucosidase. The study also covers in silico (molecular docking and MD simulations) and in vitro (ß-glucosidase and HepG2 cancer cell line assays) analyses. The phthalimide and phthalamic acid derivatives were synthesized, followed by spectroscopic characterization. The mechanistic complexities associated with ß-glucosidase inhibition were identified via the docking of the synthesized compounds inside the active site of the protein, and the results were analyzed in terms of the best binding energy and appropriate docking pose. The top-ranked compounds were subjected to extensive MD simulation studies to understand the mode of interaction of the synthesized compounds and binding energies, as well as the contribution of individual residues towards binding affinities. Lower RMSD/RMSF values were observed for 2c and 3c, respectively, in the active site, confirming more stabilized, ligand-bound complexes when compared to the free state. An anisotropic network model was used to unravel the role of loop fluctuation in the context of ligand binding and the dynamics that are distinct to the bound and free states, supported by a 3D surface plot. An in vitro study revealed that 1c (IC50 = 1.26 µM) is far better than standard acarbose (2.15 µM), confirming the potential of this compound against the target protein. Given the appreciable potential of the candidate compounds against ß-glucosidase, the synthesized compounds were further tested for their cytotoxic activity against hepatic carcinoma on HepG2 cancer cell lines. The cytotoxicity profile of the synthesized compounds was performed against HepG2 cancer cell lines. The resultant IC50 value (0.048 µM) for 3c is better than the standard (thalidomide: IC50 0.053 µM). The results promise the hypothesis that the synthesized compounds might become potential drug candidates, given the fact that the ß-glucosidase inhibition of 1c is 40% better than the standard, whereas compound 3c holds more anti-tumor activity (greater than 9%) against the HepG2 cell line than the known drug.

Triazine based fluorescent sensor for sequential detection of Hg2+ and L-Cysteine in real samples and application in logic Gate: A combination of Extensive experimental and theoretical analysis.

Triazine based fluorescent sensor TBT was rationally designed and synthesized to achieve sequential detection of Hg2+ and L-cysteine based on the presence of sulfur moiety and suitable cavity in the molecule. Sensor TBT exhibited excellent sensing potential for the selective detection of Hg2+ ions and L-cysteine (Cys) in real samples. Upon addition of Hg2+ to sensor TBT, enhancement in emission intensity of sensor TBT was observed which was accredited to the presence of sulfur moiety and size of cavity in the sensor. Upon interaction with Hg2+ blockage of intramolecular charge transfer (ICT) along with chelation-enhanced fluorescence (CHEF) resulted in the increase in fluorescence emission intensity of sensor TBT. Further, TBT-Hg2+ complex was employed for the selective detection of Cys through fluorescence quenching mechanism. This was attributed to the significantly stronger interaction of Cys with Hg2+, which resulted in the formation of Cys-Hg2+ complex and subsequently sensor TBT was released from TBT-Hg2+ complex. The nature of interaction between TBT-Hg2+ and Cys-Hg2+ complex was evaluated through 1H NMR titration experimentations. Extensive DFT studies were also carried out which include thermodynamic stability, frontier molecular orbitals (FMO), density of states (DOS), non-covalent interaction (NCI), quantum theory of atom in molecule (QTAIM), electron density differences (EDD) and natural bond orbital (NBO) analyses. All the studies supported the non-covalent type of interaction between analytes and sensor TBT. The limit of detection for Hg2+ ions was found to be as low as 61.9 nM. Sensor TBT was also employed for the quantitative detection of Hg2+ and Cys in real samples. Additionally, logic gate was fabricated by using sequential detection strategy.

New fluorescent probe for sensing of mefenamic acid in aqueous medium: An integrated experimental and theoretical analysis.

Abnormal levels of mefenamic acid (MFA) in living organisms can result in hepatic necrosis, liver, and gastrointestinal diseases. Therefore, development of accurate and effective method for detection of MFA is of great significance for the protection of public health. Herein, we designed a stilbene based sensor ECO for the sensitive and selective detection of mefenamic acid by employing fluorescence spectroscopy for the first time. The developed sensor ECO displayed fluorescence turn-off response towards MFA based on PET (photoinduced electron transfer) and hydrogen bonding. The sensing mechanism of MFA was investigated through 1H NMR titration experiment and density functional theory (DFT) calculations. The presence of non-covalent interaction was confirmed through spectroscopic analysis and was further supported by non-covalent interaction (NCI) analysis and Bader's quantum theory of atoms in molecules (QTAIM) analysis. Additionally, the sensor ECO coated test strips were fabricated for on-site detection of mefenamic acid. Furthermore, the practical applicability of sensor ECO to detect MFA was also explored in human blood and artificial urine samples.

Theoretical and experimental studies on mechanochromic triphenylamine based fluorescent "ON-OFF-ON" sensor for sequential detection of Fe3+ and deferasirox.

A novel triphenylamine (TPA) based sensor TTU was rationally designed and synthesized that exhibited reversible mechanochromic and aggregation induced emission enhancement (AIEE) properties. The AIEE active sensor was employed for fluorometric detection of Fe3+ in aqueous medium, with distinguished selectivity. The sensor showed a highly selective quenching response towards Fe3+ that is ascribed to complex formation with paramagnetic Fe3+. Subsequently, TTU-Fe3+ complex acted as a fluorescence sensor for the detection of deferasirox (DFX). The subsequent addition of DFX to TTU-Fe3+ complex led to the recovery of fluorescence emission intensity of sensor TTU that was attributed to the displacement of Fe3+ by DFX and release of sensor TTU. The proposed sensing mechanisms for Fe3+ and DFX was confirmed through 1H NMR titration experiment and DFT calculations. Frontier molecular orbitals (FMO), density of states (DOS), natural bond orbital (NBO), non-covalent interaction (NCI) and electron density difference (EDD) analysis were performed using DFT calculations to support the experimental results. Moreover, sensor TTU displayed colorimetric detection of Fe3+. Further, the sensor was employed for the detection of Fe3+ and DFX in real water samples. Finally, logic gate was fabricated by using sequential detection strategy.

Highly sensitive fluorescent probes for selective detection of hypochlorite: Applications in blood serum and cell imaging.

Being one of the vital reactive oxygen species (ROS), abnormal level of hypochlorite ion (ClO-) may pose detrimental threats to living organisms. Therefore, highly selective, and rapid monitoring of ClO- in living system is of prime importance to protect living organisms from its harmful effects. In this regard, design of synthetic fluorescent probes for ClO- has garnered considerable attention. However less fluorescence emission in aggregated state and less photostability of several existing probes for ClO- inspired us to design aggregation induced emission (AIE) active fluorescent probes SH1 and SH2. Probes were rationally designed by introducing thiourea moiety that selectively reacted through desulfurization reaction and resulted in highly selective detection of ClO-. Hypochlorite induced desulfurization reaction was validated through 1H NMR titration and DFT studies. Fine tuning of probes SH1 and SH2 prompted highly sensitive nanoscale (55 nM and 77 nM) and rapid (15 and 35 sec) detection of ClO-. Probe SH1 displayed less cytotoxic effect to live cells before it was successfully applied for bioimaging of ClO- in live MCF-7 cells. Moreover, probes displayed excellent sensing potential for ClO- in blood serum and real water samples. Advantageously, probe coated portable fluorescent films were fabricated for the easy and fast monitoring of ClO-. Of note, this work offers excellent design strategy for highly selective detection of ClO- that may lead to clinical trials.

Ratiometric and colorimetric probes with large stokes shift for sensing of exogenous hypochlorite in potato sprouts and industrial effluents.

Being one of the important reactive oxygen species (ROS), hypochlorite ions (ClO-) are involved in the control of several pathological and physiological processes. However, overexpression of ClO- may prompt several disorders including cancer. Therefore, two fluorescein functionalized compounds with catechol (probe 1) and 2-naphthyl (probe 2) as substituents were synthesized through Schiff base reaction to recognize ClO- in food items and industrial samples. While probe 2 exhibited turn-off fluorescent response towards ClO- with limit of detection (LOD) of 86.7 nM, structurally alike probe 1 showed excellent ratiometric response with low detection limit (36.3 nM), large Stokes shift (353 nm), and 'fast' response time (15 s). 1H NMR titration experiments favored spiroring opening of probe 1 upon the reaction with ClO-. Probe 1 was successfully utilized for the monitoring of exogenous ClO- in industrial samples. Further, fabrication of probe coated fluorescent paper strips and recognition of ClO- in sprouting potato show diverse practical applicability of our probes.

AIEE active J-aggregates of naphthalimide based fluorescent probe for detection of Nitrobenzene: Combined experimental and theoretical approaches for Non-covalent interaction analysis.

A new naphthalimide-based fluorescent probe NS with exceptional J-aggregates based aggregation-induced emission enhancement (AIEE) properties was rationally synthesized through a single-step imidation reaction. Probe NS exhibited excellent AIEE properties in aqueous media through the formation of J-aggregates with remarkable red-shift. The AIEE active probe NS was used for selective and sensitive detection of nitrobenzene (NB) based on fluorescence quenching response. Formation of J-aggregates was assessed through fluorescence titration. These J-aggregates contributed significantly to produce favorable interaction between probe NS and NB. The highly selective fluorescence detection of NB was accredited to the adjustable smaller size of NB that can easily penetrate into interstitial spaces of probe molecules. Ability of sensor to detect NB in solid state was also accomplished through solid state fluorescence spectroscopy. Nature of interaction and sensitivity of probe NS for NB has also been investigated through 1H NMR titration and density functional theory (DFT) including non-covalent interaction (NCI), quantum theory of atom in molecule (QTAIM), electron density differences (EDD), frontier molecular orbitals (FMO) and density of states (DOS) analysis. Advantageously, probe exhibited colorimetric and vapor phase detection of NB. Moreover, probe was quite sensitive for the trace detection of NB in real samples.

Bentonite binding with mercury(II) ion through promotion of reactive oxygen species derived from manure-based dissolved organic matter.

This study reports the mercury binding by bentonite clay influenced by cattle manure-derived dissolved organic matter (DOM). The DOM (as total organic carbon; TOC) was reacted with bentonite at 5.2 pH to monitor the subsequent uptake of Hg2+ for 5 days. The binding kinetics of Hg2+ to the resulting composite was studied (metal = 350 µM/L, pH 5.2). Bentonite-DOM bound much more Hg2+ than original bentonite and accredited to the establishment of further binding sites. On the other hand, the presence of DOM was found to decrease the Hg2+ binding on the clay surface, specifically, the percent decrease of metal with increasing DOM concentration. Post to binding of DOM with bentonite resulted in increased particle size diameter (~ 33.37- ~ 87.67 nm) by inducing the mineral modification of the pore size distribution, thus increasing the binding sites. The XPS and FTIR results confirm the pronounced physico-chemical features of bentonite-DOM more than that of bentonite. Hydroxyl and oxygen vacancies on the surface were found actively involved in Hg2+ uptake by bentonite-DOM composite. Furthermore, DOM increased the content of Hg2+ binding by ~ 10% (pseudo-second-order qe = 90.9-100.0) through boosting up Fe3+ reduction with the DOM. The quenching experiment revealed that more oxygen functionalities were generated in bentonite-DOM, where hydroxyl was found to be dominant specie for Hg2+ binding. The findings of this study can be used as theoretical reference for mineral metal interaction under inhibitory or facilitating role of DOM, risk assessment, management, and mobilization/immobilization of mercury in organic matter-containing environment.

AIEE active sensors for fluorescence enhancement based detection of Ni2+ in living cells: Mechanofluorochromic and photochromic properties with reversible sensing of acid and base.

Stimuli responsive sensors QI 1 and QI 2 were rationally developed which exhibited diverse features of mutable mechanofluorochromism, reversible photochromism, solvatochromism, aggregation induced emission enhancement (AIEE), and metal ion sensing. After observing the exceptional structural property relationship, sensors were applied for reversible colorimetric and fluorometric determination of Ni2+ with low detection limits of 12 and 17 nM, respectively. Fluorescence emission enhancement based Ni2+ sensing was induced by chelation enhanced fluorescence (CHEF) mechanism. CHEF is triggered by the inhibition of excited state intramolecular proton transfer (ESIPT) and -C=N isomerization. The proposed Ni2+ sensing mechanism was investigated through 1H NMR, FT-IR titration, theoretical studies, and Jobs plots. Further, the developed sensors successfully demonstrated the selective acid-base induced absorption/emission switching through reversible ring-opening/closing and keto-enol tautomerization, evidenced by 1H NMR titration experiments. Additionally, the sensitivity of the sensor QI 1 towards Ni2+ was effectively mimicked in live MCF-7 cells and industrial effluents. Furthermore, monitoring of Ni2+ ions was also accessed through inexpensive and portable sensors' coated fluorescent films. Finally, an INHIBIT logic gate was fabricated imputing Ni2+ and EDTA as input signals to electronically scrutinize the targeted Ni2+.

Design, Synthesis, and Biological Evaluation of Novel Dihydropyridine and Pyridine Analogs as Potent Human Tissue Nonspecific Alkaline Phosphatase Inhibitors with Anticancer Activity: ROS and DNA Damage-Induced Apoptosis.

Small molecules with nitrogen-containing scaffolds have gained much attention due to their biological importance in the development of new anticancer agents. The present paper reports the synthesis of a library of new dihydropyridine and pyridine analogs with diverse pharmacophores. All compounds were tested against the human tissue nonspecific alkaline phosphatase (h-TNAP) enzyme. Most of the compounds showed excellent enzyme inhibition against h-TNAP, having IC50 values ranging from 0.49 ± 0.025 to 8.8 ± 0.53 µM, which is multi-fold higher than that of the standard inhibitor (levamisole = 22.65 ± 1.60 µM) of the h-TNAP enzyme. Furthermore, an MTT assay was carried out to evaluate cytotoxicity against the HeLa and MCF-7 cancer cell lines. Among the analogs, the most potent dihydropyridine-based compound 4d was selected to investigate pro-apoptotic behavior. The further analysis demonstrated that compound 4d played a significant role in inducing apoptosis through multiple mechanisms, including overproduction of reactive oxygen species, mitochondrial dysfunction, DNA damaging, and arrest of the cell cycle at the G1 phase by inhibiting CDK4/6. The apoptosis-inducing effect of compound 4d was studied through staining agents, microscopic, and flow cytometry techniques. Detailed structure-activity relationship (SAR) and molecular docking studies were carried out to identify the core structural features responsible for inhibiting the enzymatic activity of the h-TNAP enzyme. Moreover, fluorescence emission studies corroborated the binding interaction of compound 4d with DNA through a fluorescence titration experiment.

Isoxazole Derivatives against Carbonic Anhydrase: Synthesis, Molecular Docking, MD Simulations, and Free Energy Calculations Coupled with In Vitro Studies.

Heterocyclic compounds with a five-membered ring as a core, particularly those containing more than one heteroatom, have a wide spectrum of biological functions, especially in enzyme inhibition. In this study, we present the synthesis of five-membered heterocyclic isoxazole derivatives via sonication of ethyl butyrylacetate with aromatic aldehyde in the presence of a SnII-Mont K10 catalyst. The synthesized compounds were characterized using sophisticated spectroscopic methods. In vitro testing of the compounds reveals three derivatives with significant inhibitory action against carbonic anhydrase (CA) enzyme. The compound AC2 revealed the most promising inhibitory activity against CA among the entire series, with an IC50 = 112.3 ± 1.6 µM (%inh = 79.5) followed by AC3 with an IC50 = 228.4 ± 2.3 µM (%inh = 68.7) compared to the standard with 18.6 ± 0.5 µM (%inh = 87.0). Molecular docking (MD) study coupled with extensive MD simulations (400 ns) and MMPBSA study fully supported the in vitro enzyme inhibition results, evident from the computed ΔG bind (AC2 = -13.53 and AC3 = -12.49 kcal/mol). The in vitro and in silico studies are also augmented by a fluorescence-based enzymatic assay in which compounds AC2 and AC3 showed significant fluorescence enhancement. Therefore, on the basis of the present study, it is inferred that AC2 and AC3 may serve as a new framework for designing effective CA inhibitors.

Three New Acrylic Acid Derivatives from Achillea mellifolium as Potential Inhibitors of Urease from Jack Bean and α-Glucosidase from Saccharomyces cerevisiae.

(1) Background: Achillea mellifolium belongs to a highly reputed family of medicinal plants, with plant extract being used as medicine in indigenous system. However, limited data is available regarding the exploitation of the medicinal potential of isolated pure compounds from this family; (2) Methods: A whole plant extract was partitioned into fractions and on the basis of biological activity, an ethyl acetate fraction was selected for isolation of pure compounds. Isolated compounds were characterized using different spectroscopic techniques. The compounds isolated from this study were tested for their medicinal potential using in-vitro enzyme assay, coupled with in-silico studies; (3) Results: Three new acrylic acid derivatives (1-3) have been isolated from the ethyl acetate fraction of Achillea mellifolium. The characterization of these compounds (1-3) was carried out using UV/Vis, FT-IR, 1D and 2D-NMR spectroscopy (1H-NMR, 13C-NMR, HMBC, NOESY) and mass spectrometry. These acrylic acid derivatives were further evaluated for their enzyme inhibition potential against urease from jack bean and α glucosidase from Saccharomyces cerevisiae, using both in-silico and in-vitro approaches. In-vitro studies showed that compound 3 has the highest inhibition against urease enzyme (IC50 =10.46 ± 0.03 µΜ), followed by compound 1 and compound 2 with percent inhibition and IC50 value of 16.87 ± 0.02 c and 13.71 ± 0.07 µΜ, respectively, compared to the standard (thiourea-IC50 = 21.5 ± 0.01 µΜ). The investigated IC50 value of compound 3 against the urease enzyme is two times lower compared to thiourea, suggesting that this compound is twice as active compared to the standard drug. On the other hand, all three compounds (1-3) revealed mild inhibition potential against α-glucosidase. In-silico molecular docking studies, in combination with MD simulations and free energy, calculations were also performed to rationalize their time evolved mode of interaction inside the active pocket. Binding energies were computed using a MMPBSA approach, and the role of individual residues to overall binding of the inhibitors inside the active pockets were also computed; (4) Conclusions: Together, these studies confirm the inhibitory potential of isolated acrylic acid derivatives against both urease and α-glucosidase enzymes; however, their inhibition potential is better for urease enzyme even when compared to the standard.

Synthesis, Biological Evaluation, and In Silico Studies of Novel Coumarin-Based 4H,5H-pyrano[3,2-c]chromenes as Potent ß-Glucuronidase and Carbonic Anhydrase Inhibitors.

The search for novel heterocyclic compounds with a natural product skeleton as potent enzyme inhibitors against clinical hits is our prime concern in this study. Here, a simple and facile two-step strategy has been designed to synthesize a series of novel coumarin-based dihydropyranochromenes (12a-12m) in a basic moiety. The synthesized compounds were thus characterized through spectroscopic techniques and screened for inhibition potency against the cytosolic hCA II isoform and ß-glucuronidase. Few of these compounds were potent inhibitors of hCA II and ß-glucuronidase with varying IC50 values ranging from 4.55 ± 0.22 to 21.77 ± 3.32 µM and 440.1 ± 1.17 to 971.3 ± 0.05 µM, respectively. Among the stream of synthesized compounds, 12e and 12i were the most potent inhibitors of ß-glucuronidase, while 12h, 12i, and 12j showed greater potency against hCA II. In silico docking studies illustrated the significance of substituted groups on the pyranochromene skeleton and binding pattern of these highly potent compounds inside enzyme pockets.

Aggregation induced emission based fluorenes as dual-channel fluorescent probes for rapid detection of cyanide: applications of smartphones and logic gates.

Rational modification of molecular structure by incorporating electron donating groups can play a potential role for designing aggregation induced emission (AIE) active fluorescent probes. Based on this principle, fluorescent probes (1a-c) were synthesized, and they displayed excellent aggregation induced emission (AIE) behavior in a H2O/DMF (4 : 1, v/v) mixture due to restrictions in intramolecular charge transfer (ICT). As a comparison, probe 1d was synthesized by installing an electron withdrawing (-NO2) group that surprisingly quenched the aggregation behaviour. Additionally, AIE active probes 1a-c displayed a highly sensitive dual channel (fluorometric and colorimetric) response towards rapid detection of CN-, which is an active toxic material. Probes 1a-c showed selectively enhanced fluorescence emission behavior towards CN- with detection limits of 1.34 ppb, 1.38 ppb, and 1.54 ppb, respectively. The sensing mechanism involves Michael type adduct formation due to the nucleophilic addition reaction of cyanide with probes and was confirmed through 1H NMR titration experiments. In contrast, probe 1d containing an electron withdrawing moiety showed insensitivity towards CN-. Therefore, this study provides the efficient strategy to induce AIE character in fluorescent probes and expands the mechanistic approach toward the sensing of toxic CN-.

Development of AIEE active fluorescent and colorimetric probe for the solid, solution, and vapor phase detection of cyanide: smartphone and food applications.

Apart from environmental implications, the extreme toxicity of cyanide can lead to sudden human death upon prolonged exposure to it. Hence, rapid and low-level on-site detection of cyanide has earned paramount significance in the present era. Therefore, an AIEE active and piezofluorochromic Schiff base (probe 2) was synthesized which exhibited highly selective fluorescence enhancement based nanoscale (LOD; 6.17 nM) detection of CN-. The interaction mode was attributed to the deprotonation of the probe by the cyanide that was confirmed through 1H NMR titration, pH, theoretical studies, and switchable fluorescence response upon the addition of HCl. Advantageously, probe 2 displayed solid and vapor phase recognition of cyanide which is the first of its kind as far as we know. The excellent sensing potential of the probe was satisfactorily applied for the detection of cyanide in food, natural soil, and industrial wastewater. Additionally, probe 2 showed an immediate colorimetric response towards cyanide which was favorably integrated through a smartphone. Finally, the switchable fluorescence response of the probe was used to design an INHIBIT logic gate. Therefore, the multifunctional probe 2 displayed excellent practical potential for cyanide detection which was the ultimate goal of our work.