Multifunctional 58S Bioactive Glass/Silver/Cerium Oxide-Based Biocomposites with Effective Antibacterial, Cytocompatibility, and Mechanical Properties.

58S bioactive glass (BG) has effective biocompatibility and bioresorbable properties for bone tissue engineering; however, it has limitations regarding antibacterial, antioxidant, and mechanical properties. Therefore, we have developed BGAC biocomposites by reinforcing 58S BG with silver and ceria nanoparticles, which showed effective bactericidal properties by forming inhibited zones of 2.13 mm (against Escherichia coli) and 1.96 mm (against Staphylococcus aureus; evidenced by disc diffusion assay) and an increment in the antioxidant properties by 39.9%. Moreover, the elastic modulus, hardness, and fracture toughness were observed to be increased by ∼84.7% (∼51.9 GPa), ∼54.5% (∼3.4 GPa), and ∼160% (∼1.3 MPam1/2), whereas the specific wear rate was decreased by ∼55.2% (∼1.9 × 10-11 m3/Nm). X-ray diffraction, high-resolution transmission electron microscopy, and field emission scanning electron microscopy confirmed the fabrication of biocomposites and the uniform distribution of the nanomaterials in the BG matrix. The addition of silver nanoparticles in the 58S BG matrix (in BGA) increased mechanical properties by composite strengthening and bactericidal properties by damaging the cytoplasmic membrane of bacterial cells. The addition of nanoceria in 58S BG (BGC) increased the antioxidant properties by 44.5% (as evidenced by the 2,2-diphenyl-1-picrylhydrazyl assay). The resazurin reduction assay and MTT assay confirmed the effective cytocompatibility for BGAC biocomposites against mouse embryonic fibroblast cells (NIH3T3) and mouse bone marrow stromal cells. Overall, BGAC resulted in mechanical properties comparable to those of cancellous bone, and its effective antibacterial and cytocompatibility properties make it a good candidate for bone healing.

Preparation, characterization, and evaluation of ketoconazole-loaded pineapple cellulose green nanofiber gel.

The present study involves the isolation of cellulose nanofibers from pineapple crown waste by a combined alkali-acid treatment method. The extracted pineapple nanofibers were characterized by Fourier-transform infrared spectroscopy, differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, nuclear magnetic resonance, high-resolution transmission electron microscopy, and dynamic light scattering. The extracted pineapple nanofibers were then incorporated in Carbopol 934P containing ketoconazole to prepare a ketoconazole-loaded pineapple nanofibrous gel. The prepared gel formulation was evaluated for viscosity, spreadability, extrudibility, pH, drug content, and texture profile analysis. The anticipated gel formulation was further evaluated by in vitro drug release (98.57 ± 0.58 %), ex vivo drug permeation, cytotoxicity, and histopathological studies. The permeation of the drug through skin determined by the ex-vivo diffusion study was found to be 38.27 % with a flux rate of 4.06 ± 0.26 µg/cm2/h. Further, the cytotoxicity study of pineapple nanofiber and ketoconazole-loaded nanofiber gel displayed no cytotoxic on healthy vero cells in the concentration range from 10 to 80 µg/ml. The histopathological analysis exhibited no signs of distress and inflammation. In conclusion, ketoconazole-loaded pineapple nanofiber gel could be considered as a promising delivery system for topical applications.

Zinc(II)-MOF: A Versatile Luminescent Sensor for Selective Molecular Recognition of Flame Retardants and Antibiotics.

An exceptional Zinc(II)-organic framework with the formula [{Zn(L4-py)(bdc)}·DMF]n (Zn-MOF) has been constructed solvothermally using a novel linker L4-py {2,7-bis(3-(pyridin-4-ylethynyl)phenyl)benzo[lmn][3,8]phenanthroline-1,3,6,8(2H,7H)-tetraone}, coligand H2bdc (1,4-benzenedicarboxylic acid), and ZnBF4·xH2O. The ligand L4-py has been fabricated after functionalization of NDA (1,4,5,8-naphthalenetetracarboxylic dianhydride) core with 3-(pyridin-4-ylethynyl)phenyl group. The single-crystal X-ray analysis reveals that Zn-MOF exhibits a comprehensive three-dimensional (3D) framework architecture and features (4)-connected uninodal dia; 4/6/c1; sqc6 topology with point symbol {66} and two-dimensional (2D) + 2D, parallel polycatenation. Notably, Zn-MOF displayed excellent fluorescence phenomenon and stability in water as well as in methanol solvents and was harnessed as a versatile sensor, demonstrating selective and sensitive molecular recognition of flame retardants and antibiotics. Notably, Zn-MOF displayed 57 and 49.5% quenching efficiency for the flame-retardant pentabromophenol (PBP) and 3,3',5,5'-tetrabromobisphenol A (TBPA), respectively. Whereas an outstanding 90% quenching efficiency was observed for antibiotics, tetracycline (TC) and secnidazole (SD). The mechanistic investigations of this luminescence quenching suggest that this might be primarily occurring via the Fourier resonance energy transfer (FRET) and photoinduced electron transfer (PET) mechanisms, which might be assisted by the competitive absorption and host-guest interactions. The π-electron-rich framework structure of sensor Zn-MOF activates this mechanism.

Development and Validation of Reverse-Phase High-Performance Liquid Chromatography Method for Simultaneous Estimation of Doxorubicin and Clotrimazole.

A reverse-phase high-performance liquid chromatographic (RP-HPLC) method was developed to analyze the simultaneous estimation of doxorubicin and clotrimazole. The method was achieved by Nucleodur C18 column with dimension 250 × 4.6 mm (5 µm) using gradient elution. The mobile phase contained 0.2% formic acid (pH 3.2) and acetonitrile. The flow rate was kept at 1.0 mL/min and detection and quantitation of both drugs (doxorubicin and clotrimazole) were achieved using a photodiode array detector at 276 nm, which was the isosbestic point for both drugs. The proposed method was validated according to the current International Council for Harmonization of Technical Requirements of Pharmaceuticals for Human Use guidelines for specificity, linearity, accuracy, precision, and robustness. The developed method showed a linear response (R2 > 0.999), and was accurate (recoveries 97%-103%), precise (resolution ≤1.0%), sensitive, and specific. Thus, the developed RP-HPLC method for the simultaneous estimation of both drugs was successfully validated and can be utilized for the estimation of these drugs in the formulations being developed.

Drug synergy model for malignant diseases using deep learning.

Drug synergy has emerged as a viable treatment option for malignancy. Drug synergy reduces toxicity, improves therapeutic efficacy, and overcomes drug resistance when compared to single-drug doses. Thus, it has attained significant interest from academics and pharmaceutical organizations. Due to the enormous combinatorial search space, it is impossible to experimentally validate every conceivable combination for synergistic interaction. Due to advancement in artificial intelligence, the computational techniques are being utilized to identify synergistic drug combinations, whereas prior literature has focused on treating certain malignancies. As a result, high-order drug combinations have been given little consideration. Here, DrugSymby, a novel deep-learning model is proposed for predicting drug combinations. To achieve this objective, the data is collected from datasets that include information on anti-cancer drugs, gene expression profiles of malignant cell lines, and screening data against a wide range of malignant cell lines. The proposed model was developed using this data and achieved high performance with f1-score of 0.98, recall of 0.99, and precision of 0.98. The evaluation results of DrugSymby model utilizing drug combination screening data from the NCI-ALMANAC screening dataset indicate drug combination prediction is effective. The proposed model will be used to determine the most successful synergistic drug combinations, and also increase the possibilities of exploring new drug combinations.

Catalytic and antimicrobial potential of green synthesized Au and Au@Ag core-shell nanoparticles.

It has been a never-ending quest to design a safe, cost-effective, and environmentally acceptable technology for eliminating contaminants from water and countering antibiotic resistance. Herein, a waste leaf extract from the abundant and renewable plant, Brassica oleracea var. gongylodes, is introduced as a cost-effective and sustainable means to generate gold (Au) and Au@Ag core-shell nanoparticles (NPs). In comparison to the bare Au NPs, bimetallic NPs demonstrated improved catalytic and antibacterial capabilities. The reduction process conforms to the pseudo-first-order kinetic, and apparent rate constant (kapp) was calculated to be 0.46 min-1, according to the kinetic analysis. With both microbial pathogens, E. coli (Gram-negative) and B. subtilis (Gram-positive), an increment of Au and Au@Ag NPs lead to a considerable improvement in the zone of clearance. The present outcome is a step forward in the establishment of a viable and cost-effective catalytic and antibacterial platform based on bimetallic NPs that could be generated in an inexpensive and eco-friendly manner.

A systematic method for diagnosis of hepatitis disease using machine learning.

Hepatitis is among the deadliest diseases on the planet. Machine learning approaches can contribute toward diagnosing hepatitis disease based on a few characteristics. On the UCI dataset, authors assessed distinct classifiers' performance in order to develop a systematic strategy for hepatitis disease diagnosis. The classifiers used are support vector machine, logistic regression (LR), K-nearest neighbor, and random forest. The classifiers were employed without class balancing and in conjunction with class balancing using SMOTE strategy. Both studies, classification without class balancing and with class balancing, were compared in terms of different performance parameters. After adopting class balancing, the efficiency of classifiers improved significantly. LR with SMOTE provided the highest level of accuracy (93.18%).

Lycopene: Sojourn from kitchen to an effective therapy in Alzheimer's disease.

Reports on a significant positive correlation between consumption of carotenoid-rich food and prevention of Alzheimer's disease (AD) led to the investigation of carotenoids for the treatment and prevention of AD. More than 1100 types of carotenoids are found naturally, out of which only around 50 are absorbed and metabolized in human body. Lycopene is one of the most commonly ingested members of fat-soluble carotenoid family that gives vegetables and fruits their red, yellow, or orange color. Lycopene has established itself as a promising therapy for AD owing to its neuroprotective activities, including antioxidant, anti-inflammatory, and antiamyloidogenic properties. In this review, we highlight the various in vitro and preclinical studies demonstrating the neuroprotective effect of lycopene. Also, some epidemiological and interventional studies investigating the protective effect of lycopene in AD have been discussed. Diving deeper, we also discuss various significant mechanisms, through which lycopene exerts its remissive effects in AD. Finally, to overcome the issue of poor chemical stability and bioavailability of lycopene, some of the novel delivery systems developed for lycopene have also been briefly highlighted.

A comparative evaluation of the diagnostic accuracy of an infrared sensor device with standard mounting procedure in completely edentulous patients: A pilot clinical study.

STATEMENT OF PROBLEM: The conventional diagnostic mounting procedure in completely edentulous patients is time-consuming and increases the laboratory workload. Alternatives like optical scanners and jaw tracking devices have been documented but have their own shortcomings. PURPOSE: The purpose of this pilot clinical study was to assess the suitability of an infrared sensor scan device in procuring the diagnostic data parameters for completely edentulous patients. MATERIAL AND METHODS: Twelve completely edentulous participants were enrolled in the study. For each, the distance between the arches was measured by 2 clinical techniques at 3 common reference points, M1, M2, M3, for the maxillary arch and m1, m2, m3 for the mandibular arch. The control group measurements were recorded by using a standard diagnostic mounting procedure on a semi-adjustable articulator, and the experimental group measurements were recorded by using an infrared sensor scan device. To convert the analog infrared sensor output into digital data, the Arduino ADC software program was used. The data from both study groups were statistically compared by using the independent t test (α=.05). RESULTS: No significant difference in variation was found between the mean measurements of the device and diagnostic mounting (P>.05). The maximum variation recorded by the experimental device was 1.7 mm, whereas the minimum variation was 0.8 mm (mean 1.25 mm). CONCLUSIONS: The use of precisely calibrated infrared sensors may be a cost-effective option for diagnostic mounting.

A Primary Extracutaneous Presentation of Merkel Cell Carcinoma.

Merkel cell carcinoma (MCC) is a rare aggressive cutaneous neuroendocrine malignancy with a mortality rate of around 33%. The presence of advanced disease at the time of diagnosis is associated with poor prognosis. Twofold etiologies have been described in the pathogenesis of Merkel cell carcinoma: chronic exposure to ultraviolet (UV) light and Merkel cell polyomavirus (MCPvY). MCC usually affects sun-exposed skin areas, and the presence of cutaneous nodules is the hallmark of the disease. However, there have been case reports in the literature where the diagnosis of MCC was made in the absence of any cutaneous findings. We present a case report of Merkel cell carcinoma that is unique in its presentation because of the presence of pulmonary and hepatic nodules and the absence of cutaneous lesions.

Psoriasis: Interplay between dysbiosis and host immune system.

With advancement in human microbiome research, an increasing number of scientific evidences have endorsed the key role of both gut and skin microbiota in the pathogenesis of psoriasis. Microbiome dysbiosis, characterized by altered diversity and composition, as well as rise of pathobionts, have been identified as possible triggers for recurrent episodes of psoriasis. Mechanistically, gut dysbiosis leads to "leaky gut syndrome" via disruption of epithelial bilayer, thereby, resulting in translocation of bacteria and other endotoxins to systemic circulation, which in turn, results in inflammatory response. Similarly, skin dysbiosis disrupts the cutaneous homeostasis, leading to invasion of bacteria and other pathogens to deeper layers of skin or even systemic circulation further enhanced by injury caused by pruritus-induced scratching, and elicit innate and adaptive inflammation. The present review explores the correlation of both skin and gut microbiota dysbiosis with psoriasis. Also, the studies highlighting the potential of bacteriotherapeutic approaches including probiotics, prebiotics, metabiotics, and fecal microbiota transplantation for the management of psoriasis have been discussed.

Otological Assessment in Head Injury Patients: A Prospective Study and Review of Literature.

Head injuries constitute a tragic problem invariably in under-developed, developed and developing countries. The concomitant otological injuries often go unnoticed. The purpose of this study was to assess the various otological manifestations following head injuries. Prospective study with review of literature using PubMed database was done. All the patients were evaluated for their presenting symptoms and signs. Audiological investigations including PTA (Pure tone audiometry), OAE (Otoacoustic emission), Impedance-Audiometry and BERA were done. HRCT temporal bone was advised in cases of suspicion. Relevant literature was reviewed to calculate the pooled prevalence rates. Random-effects model to synthesize overall effects was used. Heterogeneity was evaluated with the I2 statistic. Of 53 patients enrolled in the study, RTA was the most common mode of injury. The audiometric findings showed SNHL, CHL and mixed HL in 34, 20 and 18% of patients respectively. HRCT showed Longitudinal fracture (n = 17; 53.12%); isolated mastoid bone fracture (n = 9; 28.12%), transverse (n = 3; 9.37%) and isolated EAC fracture in (n = 3; 9.37%) patients. The pooled prevalence (n = 1106 patients) of SNHL, CHL, Mixed HL and Normal hearing were-35% (95%CI, 18-55%; I2 = 95.20%; P < 0.00), 24% (95%CI, 16-33%; I2 = 80.01%; P < 0.00), 15%(95%CI, 9-23%; I2 = 79.64%; P < 0.00) and 30% (95%CI, 3-66%; I2 = 98.71%; P < 0.00) respectively. The pooled prevalence (n = 4191 patients) of longitudinal, Transverse, mixed and other fractures were-44% (95%CI, 3-66%;I2 = 99.48%; P < 0.00), 9% (95% CI, 4-16%; I2 = 95.95%; P < 0.00), 4% (95%CI, 1-8%; I2 = 94.13%; P < 0.00) and 1% (95%CI, 0-4%; I2 = 90.37%; P < 0.00) respectively. In patients with head injury coordination between the trauma-surgeon, neurosurgeon and otologist is must to improve the long-term outcomes.

Silver nanostructures prepared via novel green approach as an effective platform for biological and environmental applications.

Silver nanoparticles play a significant role in biomedical sciences due to their unique properties allowing for their use as an effective sensing and remediation platform Herein, the green synthesis of silver nanostructures (Ag NSs), prepared via aqueous extract of waste Brassica oleracea leaves in the presence of silver nitrate solution (10-4 M), is reported. The Ag NSs are fully characterized and their efficacy with respect to 4-nitrophenol reduction, glucose sensing, and microbes is determined. Visually, the color of silver nitrate containing solution altered from colorless to yellowish, then reddish grey, confirming the formation of Ag NSs. HRTEM and SEAD studies revealed the Ag NSs to have different morphologies (triangular, rod-shaped, hexagonal, etc., within a size range of 20-40 nm) with face-centered cubic (fcc) crystal structure. The Ag NSs possess high efficacy for nitrophenol reduction (<11 min and degradation efficiency of 98.2%), glucose sensing (LOD: 5.83 µM), and antimicrobial activity (E. coli and B. subtilis with clearance zones of 18.3 and 14 mm, respectively). Thus, the current study alludes towards the development of a cost-effective, sustainable, and efficient three-in-one platform for biomedical and environmental applications.

Metal-Organic Framework-Based Selective Molecular Recognition of Organic Amines and Fixation of CO2 into Cyclic Carbonates.

Synthesis and structural depiction of two new metal-organic frameworks (MOFs), namely, [{Zn(L)(oba)}·4H2O]α (Zn-MOF-1) and [{Cd1/2(L)1/2(nipa)1/2(H2O)1/2}·(DMF)1/2(H2O)]α (Cd-MOF-2) (where L = N2,N6-di(pyridin-4-yl)naphthalene-2,6-dicarboxamide, 4,4'-H2oba = 4,4'-oxybisbenzoic acid, and 5-H2nipa = 5-nitroisophthalic acid) are reported. Both Zn-MOF-1 and Cd-MOF-2 have been prepared by reacting ligand L and coligand 4,4'-H2oba or 5-H2nipa with the respective dihydrates of Zn(OAc)2 and Cd(OAc)2 (OAc = acetate). Crystal structure X-ray analysis discloses that Zn-MOF-1 displays an overall 2D → 3D interpenetrated framework structure. The topological analysis by ToposPro suggests a (4)-connected uninodal sql topology with a point symbol of {44·62} having 2D + 2D parallel polycatenation. However, crystal packing of Cd-MOF-2 adapted a porous framework architecture and was topologically simplified as (3,4)-connected binodal 2D net. In addition, both Zn-MOF-1 and Cd-MOF-2 were proved to be multifunctional materials for the recognition of organic amines and in the fixation of CO2 to cyclic carbonates. Remarkably, Zn-MOF-1 and Cd-MOF-2 showed very good fluorescence stability in aqueous media and have shown 98 and 97% quenching efficiencies, respectively, for 4-aminobenzoic acid (4-ABA), among all of the researched amines. The mechanistic study of organic amines recognition proposed that fluorescence quenching happened mainly through hydrogen-bonding and π-π stacking interactions. Additionally, cycloaddition of CO2 to epoxide in the presence of Zn-MOF-1 and Cd-MOF-2 afforded up to 96% of cyclic carbonate within 24 h. Both Zn-MOF-1 and Cd-MOF-2 exhibited recyclability for up to five cycles without noticing an appreciable loss in their sensing or catalytic efficiency.

Artificial intelligence techniques for prediction of drug synergy in malignant diseases: Past, present, and future.

In recent years, there has been a surge of interest in the application and acceptance of Artificial Intelligence for challenges involving development, design, and prediction. Artificial Intelligence has not only changed the way we see the world, but it has also offered up new avenues for solving problems. This has been made possible by advances in technology, the availability of large amounts of data generated in various formats, the availability of increasing computational capacity in the form of GPUs and TPUs, and the reduction of costs. The advantages of applying AI in medicine have long been recognized, backed up by ongoing research from numerous institutes, hospitals, and pharmaceutical companies. Drug synergy prediction in malignant diseases is one example of a problem domain that has benefited considerably from AI breakthroughs. Traditionally, finding synergistic drug combinations for malignant diseases by experimental methods has had little success, as promising outcomes may be obtained during trials but may not be achieved during actual treatment due to the development of drug resistance over time. Experimental techniques can only be used for a restricted number of drugs because they are time demanding and expensive. Screening all necessary drug combinations is impractical due to limited resources. The goal of this research is to look at the past, present, and future of AI applications, with an emphasis on drug synergy prediction in malignant diseases using deep learning models. The benefits of utilizing AI to forecast drug synergy are discussed in this paper, as well as future research directions and challenges for applying AI techniques.

Antimicrobial peptides: A plausible approach for COVID-19 treatment.

INTRODUCTION: Coronavirus disease 2019 (COVID-19), which emerged as a major public health threat, has affected >400 million people globally leading to >5 million mortalities to date. Treatments of COVID-19 are still to be developed as the available therapeutic approaches are not able to combat the virus causing the disease (severe acute respiratory syndrome coronavirus-2; SARS-CoV-2) satisfactorily. However, antiviral peptides (AVPs) have demonstrated prophylactic and therapeutic effects against many coronaviruses (CoVs). AREAS COVERED: This review critically discusses various types of AVPs evaluated for the treatment of COVID-19 along with their mechanisms of action. Furthermore, the peptides inhibiting the entry of the virus by targeting its binding to angiotensin-converting enzyme 2 (ACE2) or integrins, fusion mechanism as well as activation of proteolytic enzymes (cathepsin L, transmembrane serine protease 2 (TMPRSS2), or furin) are also discussed. EXPERT OPINION: Although extensively investigated, successful treatment of COVID-19 is still a challenge due to emergence of virus mutants. Antiviral peptides are anticipated to be blockbuster drugs for the management of this serious infection because of their formulation and therapeutic advantages. Although they may act on different pathways, AVPs having a multi-targeted approach are considered to have the upper hand in the management of this infection.

Orchestration of Obesolytic Activity of Microbiome: Metabiotics at Centre Stage.

Metabiotics have emerged as the safer alternatives to probiotics in last decade. Unlike probiotics that are live microbes, metabiotics are the low molecular weight bioactive metabolites produced by the gut microbiota. While offering a similar profile of health benefits as that of probiotics, metabiotics are free from the risks and uncertain responses associated with administration of live bacteria into the body. Metabiotics have demonstrated substantial effectiveness across the ethnicities, age, gender and nutritional habits in a number of metabolic disorders, including obesity. Obesity is attributed to the offsetting of the energy homeostasis of the body due to a number of genetic, endocrinological, and environmental factors leading to obesity. The obesogenic mechanisms are quite complicated as they result from a complex interplay among a number of factors. Owing to a variety of constituents exerting their action through different pathways, metabiotics offer a pragmatic option for treatment as well as prevention of obesity by addressing heterogeneous aspects of its aetiology. In this review, we categorize various components of metabiotics and discuss their cross-talk with host cells at the molecular level. We also discuss the challenges in understanding these interactions and their potential effects on obesity treatment and prevention strategies. Considering the alarming rise in obesity all over the world, metabiotics offer an attractive non-pharmacological approach to spearhead the strategies being designed to combat the challenges posed by the obesity epidemic.

Discovery and Development of Antibacterial Agents: Fortuitous and Designed.

Today, antibacterial drug resistance has turned into a significant public health issue. Repeated intake, suboptimal and/or unnecessary use of antibiotics, and, additionally, the transfer of resistance genes are the critical elements that make microorganisms resistant to conventional antibiotics. A substantial number of antibacterials that were successfully utilized earlier for prophylaxis and therapeutic purposes have been rendered inadequate due to this phenomenon. Therefore, the exploration of new molecules has become a continuous endeavour. Many such molecules are at various stages of the investigation. A surprisingly high number of new molecules are currently in the stage of phase 3 clinical trials. A few new agents have been commercialized in the last decade. These include solithromycin, plazomicin, lefamulin, omadacycline, eravacycline, delafloxacin, zabofloxacin, finafloxacin, nemonoxacin, gepotidacin, zoliflodacin, cefiderocol, BAL30072, avycaz, zerbaxa, vabomere, relebactam, tedizolid, cadazolid, sutezolid, triclosan, and afabiacin. This article aims to review the investigational and recently approved antibacterials with a focus on their structure, mechanisms of action/resistance, and spectrum of activity. Delving deep, their success or otherwise in various phases of clinical trials is also discussed while attributing the same to various causal factors.

Coordination Polymers as a Functional Material for the Selective Molecular Recognition of Nitroaromatics and ipso-Hydroxylation of Arylboronic Acids.

We report the synthesis and structural characterization of two coordination polymers (CPs), namely; [{Zn(L)(DMF)4 } ⋅ 2BF4 ]α (1) and [{Cd(L)2 (Cl)2 } ⋅ 2H2 O]α (2) (where L=N2 ,N6 -di(pyridin-4-yl)naphthalene-2,6-dicarboxamide). Crystal packing of 1 reveals the existence of channels running along the b- and c-axis filled by the ligated DMF and lattice anions, respectively. Whereas, crystal packing of 2 reveals that the metallacycles of each 1D chain are intercalating into the groove of adjacent metallacycles resulting in the stacking of 1D loop-chains to form a sheet-like architecture. In addition, both 1 and 2 were exploited as multifunctional materials for the detection of nitroaromatic compounds (NACs) as well as a catalyst in the ipso-hydroxylation of aryl/heteroarylboronic acids. Remarkably, 1 and 2 showed high fluorescence stability in an aqueous medium and displayed a maximum 88% and 97% quenching efficiency for 4-NPH, respectively among all the investigated NACs. The mechanistic investigation of NACs recognition suggested that the fluorescence quenching occurred via electron as well as energy transfer process. Furthermore, the ipso-hydroxylation of aryl/heteroarylboronic acids in presence of 1 and 2 gave up to 99% desired product yield within 15 min in our established protocol. In both cases, 1 and 2 are recyclable upto five cycles without any significant loss in their efficiency.

Synchronous Fluorescence Determination of Al3+ Using 3-Hydroxy-2-(4-Methoxy Phenyl)-4H-Chromen-4-One as a Fluorescent Probe.

A simple synchronous fluorescent chemosensor 3-hydroxy-2-(4-methoxyphenyl)-4H-chromen-4-one (3-HC) has been synthesized for the selective analysis of Al3+. On the addition of Al3+, 3-HC displayed a redshift with a change in wavelength of emission maximum from 436 to 465 nm along with enhancement in fluorescence intensity, which formed the basis for its sensitive detection. Under optimized conditions, 3-HC was applied for the determination of Al3+ in the concentration range of 1 × 10-7-1 × 10-6 M. The limit of detection (LOD) and limit of quantification (LOQ) values were found out to be 1.69 × 10-8 and 5.07 × 10-8 M respectively. Further, the developed method was applied for the analysis of Al3+ in real water samples (tap water, bottled water, and tube well water) which showed good recovery values in the range of 95-99.7% with RSD less than 4%.