ESI-mass Analysis Research Articles

Solvent-Directed Bioactive Supramolecular Zinc(II)-Metallogels: Exploring Semiconducting Aptitudes of Fabricating p-n Junction and Schottky Devices.

α-Ketoglutaric acid-based supramolecular Zn(II) metallogels in N,N'-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) solvent (i.e., Zn-α-Glu-DMF and Zn-α-Glu-DMSO) were successfully achieved. Zinc(II) acetate salt and α-ketoglutaric acid directed a three-dimensional noncovalent supramolecular network individually entrapped with N,N'-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) solvent to accomplish their respective semisolid flexible metallogel frameworks. The gel features of these synthesized materials were verified by rheological experiments such as amplitude sweep and frequency sweep measurements. The discrete morphological arrangements were analyzed for these metallogel samples through field emission scanning electron microscopic (FESEM) analysis. Highly stacked interconnected blocks of Zn-α-Glu-DMF with hierarchical arrays are found due to the occurrence of diverse noncovalent supramolecular interactions present in the metallogel framework. A distinct spherical shaped microstructure with interconnected hierarchical assembly has been observed for the FESEM pattern of Zn-α-Glu-DMSO. FTIR spectroscopic measurement was carried out to detect some important stretching vibrations of xerogel samples of different metallogels as well as gel-constructing chemical ingredients. A substantial amount of peak shifting of xerogel samples for both metallogels is observed in FTIR analysis, indicating the presence of different noncovalent interactions. ESI-mass analysis portrays a possible metallogel-constructing strategy. The antibacterial potentialities of both metallogels were investigated. These materials exhibited good antimicrobial efficacy toward Gram-positive and Gram-negative bacterial strains (including Escherichia coli, Bacillus cereus, Staphylococcus aureus, Listeria monocytogenes, and Salmonella typhimurium). Both synthesized metallogels were successfully implemented to fabricate the photoresponsive semiconducting diode. These materials offer excellent photodiode parameters including an ideality factor and rectification ratio (ON/OFF ratio). Synthesized metallogels are used to successfully fabricate photodiodes with an Al/p-Si/metallogel/Au structure. The ideality factors (η) for Zn-α-Glu-DMF and Zn-α-Glu-DMSO are found as 1.3 and 2.3, respectively, in dark conditions. The rectification ratios for Zn-α-Glu-DMF and Zn-α-Glu-DMSO metallogels are also determined, and these are found as 40 and 10, respectively.

Chromene Carbohydrazide- Schiff Base as a Highly Selective Turn-Off Fluorescence Chemosensor for In3+ Ion and its Application.

A new 7-(diethylamino)-2-oxo-2H-chromene-3-carbohydrazide design to synthesize a simple Schiff-base condition. The synthesized molecules' (probe L) photophysical properties were investigated in various solvent systems and solvent-poor-solvent assays. Probe L exhibits the absorbance band at 440nm and the emission band at 488nm in DMSO: H2O (7:3, v/v). Further, probe L shows selective turn-off emission recognition of In3+ ions in DMSO: H2O (7:3, pH = 7.4). By Job's plot and ESI mass analysis, probe L forms a 1:2 stoichiometry complex with an estimated association constant of 4.04 × 104 M- 2 with In3+ ions. Metal induces CHEQ (chelation-caused fluorescence quenching) to reduce the intensity of probe L's emission, and the estimated quenching constant was 4.52 × 104 M- 1. The limit of detection was found to be 5.93 nM; the time response of the sensor is instantaneous, and its reversible nature was confirmed using EDTA additions. Solid substrates (test strips) were designed and tested for fast, reliable, user-friendly, and real-time sensing of In3+ ions for on-site applications. The binding mechanism of probe L with In3+ ions was investigated using 1H NMR titration and DFT/TD-DFT studies.

Pd(II) based anticancer drug candidates with 1,2-Aminoethyl piperidine scaffold and sulfur donor ancillary: Their in vitro bio-activity, molecular docking and DFT study

A series of Pd(II) complexes Pd-1 to Pd-6; out of these [Pd(PIEAM)(LC)]+; Pd-3, [Pd(PIEAM)(NALC)]; Pd-4, [Pd(PIEAM)(GSH)]; Pd-5 and [Pd(PIEAM)(DL-meth)]2+; Pd-6 have been synthesized from water soluble stable diaqua complex [Pd(PIEAM)(OH2)2](NO3)2; Pd-2. The Pd-2 complex was obtained from hydrolysis of [Pd(PIEAM)Cl2]; Pd-1 (where, PIEAM = 1,2-Aminoethyl piperidine, a bidentate carrier ligand and with ancillary groups like; LC = L-cysteine, NALC = N-acetyl-L-cysteine, GSH = Glutathione, DL-meth = DL-methionine). All these Pd-1-Pd-6 complexes were characterized by different spectroscopic studies, like; UV–Vis, FT-IR, 1H NMR, and ESI Mass analyses. The bioactivity and drug-likeness properties of the complexes were assessed by PASS and ADME prediction software. The bioactivity of the complexes was experimentally investigated on DNA binding properties by gel electrophoresis, electronic, fluorescence, and viscometric methods. The binding constant values of Pd-3 complex with CT DNA bining in both absorption (Kb = 7.50 × 104M−1)and fluorosence titration (KSV = 35.10 × 103 M−1) was found greater than other Pd-1, Pd-2, Pd-4-Pd-6 complexes (Kb = (4.25–0.64) × 104 M−1; KSV = (13.57–1.11) × 103 M−1). The comparison in BSA bining of Pd(II) complexes also suggested the higher binding constant of Pd-3 complex in both spectroscopic method (Kb = 32 × 103M−1; KSV = 2.32 × 104 M−1) than other Pd(II) complexes (Kb = 16–2.4 × 103M−1; KSV = 1.99–1.53 × 104 M−1). A theoretical investigation of the structural property and TD-DFT of the complexes was executed by DFT calculations. The detailed BSA binding activity of the complexes was performed by fluorescence quenching, synchronous, and 3D-fluorescence spectroscopic methods. Molecular docking of the complexes with DNA and BSA was under study for their binding mode and different weak forces. Their cytotoxic behaviors, like; anticancer activity by MTT assay and ROS (Reactive Oxygen Species) generation by NBT (Nitro Blue Tetrazolium) assay, were investigated. The cytotoxicity of the complexes was under investigation on human lung adenocarcinoma cell A549, colorectal carcinoma cell HCT 116, and normal human embryonic kidney cell HEK 293.

Coordination of Distal Carboxylate Anion Alters Metal Ion Specific Binding in Imidazo[1,2-a]pyridine Congeners.

Imidazo[1,2-a]pyridine derivatives have excellent potential for chelation with transition metal ions. Two new imidazo[1,2-a]pyridine-8-carboxylates were synthesized and characterized by 1H NMR, 13C NMR, HRMS, andsingle crystal-XRD techniques. Methyl carboxylate (probe 1) turns on fluorescence upon coordination with Zn2+, while sodium carboxylate (probe 2) turns off its fluorescence upon coordination with Co2+ or Cu2+ ions present in aqueous acetonitrile medium. 13C NMR study revealed that the change in metal ion specific binding was due to the involvement of carboxylate anion in complex formation with Co2+ or Cu2+ ions. The carboxylate anion at 8-position also enhanced the sensitivity of detection of probe 2 by an order of magnitude (detection limits: 3.804 × 10-7M, probe 1/Zn2+; 0.420 × 10-7M, probe 2/Co2+ and 0.304 × 10-7M, probe 2/Cu2+). The detection limits of probes 1 and 2 comply well with the World Health Organization (WHO) and US Environmental Protection Agency (US-EPA) guidelines for detection of heavy metal ions present in drinking water and ground water. Both the probes form a 1:1 complex with Zn2+, Co2+ or Cu2+,and the stoichiometry was verified by Job plot and ESI-mass analysis. The sensing mechanism is explained using 13C NMR experiments, ESI-mass analytical data and theoretical DFT calculations. The suitability of probes 1 and 2 for on-site detection and quantitative determination of Zn2+, Co2+ and Cu2+ ions present in biological, environmental and industrial samples is demonstrated. In addition, both 1 and 2 are used for detection of intracellular contamination of Zn2+, Co2+ or Cu2+ ions in onion epidermal cells.

Pyridinecarbohydrazide-based fluorescent chemosensor for In3+ ions and its applications in water samples, live cells, and zebrafish imaging

Herein, we synthesized and characterized a new probe N',N'-bis((E)-2-hydroxy-3-methyl benzylidene)pyridine-2,6-dicarbohydrazide (L) for the detection and quantification of In3+ ions. Probe L exhibits a significant fluorescence ON upon the addition of In3+ in DMSO:H2O (2:8, v/v) media with a detection limit as low as 62.7 nM. The key sensing ability of L towards In3+ was attributed to the chelation-enhanced fluorescence (CHEF). The binding stoichiometry between L and In3+ was found to be 1:2 by Job’s plot, nuclear magnetic resonance (NMR), and mass analysis, with the calculated association constant of (Ka), 1.42 × 103 M−2 by Benesi-Hildebrand (BH) method. Various techniques such as 1H NMR, FTIR, ESI mass, and DFT analysis were used to determine the mechanism by which L binds to the In3+ ions. The detection of In3+ in water samples demonstrates that L might be used to detect In3+ ions in environmental samples. Notably, the bio-imaging revealed that L successfully detected In3+ ions in DrG cells and zebrafish larvae.

An NBD-based fluorescent and colorimetric chemosensor for detecting S2−: Practical application to zebrafish and water samples

A novel 7-nitro-1,2,3-benzoxadiazole (NBD)-based chemosensor BOP ((5-bromopyridin-2-yl)(4-(7-nitrobenzo[c][1,2,5]oxadiazol-4-yl)piperazin-1-yl)methanone) was synthesized. BOP could detect S2− through fluorescent quenching and colorimetric change. The detection limit was calculated to be 10.9 µM through fluorescence titration. The reaction mechanism of BOP towards S2− was estimated to be thiolysis of NBD amine, producing the cleavage products, NBD-S− and BP ((5-bromopyridin-2-yl)(piperazin-1-yl)methanone). The thiolysis was demonstrated by 1H NMR titrations, ESI-mass analysis and theoretical calculations. Importantly, BOP was able to successfully monitor S2− in zebrafish and water samples. Additionally, test strips coated with BOP were applied to the in-the-field measurements of S2−.

Dual anion colorimetric and fluorometric sensing of arsenite and cyanide ions involving MLCT and CHEF pathways

A newly designed quinoline acrylonitrile probe L was synthesized by reacting 6-methyl-2-oxo-1,2-dihydroquinoline-3-carbaldehyde with benzothiazole-2-acetonitrile and structurally characterized by various spectroscopic techniques. The sensing ability of probe L was studied with various anions by using visual, RGB tool, UV Visible, and spectrofluorometric methods. It shows a selective colorimetric response with AsO2− and turn-on emission fluorescent with CN− over other tested anions. The probe L exhibits a 1:1 complex formation with AsO2−and CN-. The probe L can work in the pH range of 2–10 and 3–8 with AsO2−and CN−respectively without interfering with other competing ions. The binding mechanism of L with AsO2− and CN− was characterized by using 1H NMR, ESI mass, and DFT analysis. It reveals that AsO2− and CN− ions are binding with L through metal-to-ligand charge transfer (MLCT) and chelation enhanced fluorescence (CHEF) respectively. The lowest detection limit (LOD) of AsO2− by using spectrophotometry and RGB color tool were found to be 24 ppb and 498 ppb respectively while CN− detection by spectrofluorimetry detected down to 1 ppb. Overall, probe L demonstrates a promising and potential for the detection of two toxic contaminates in the semi-aqueous phase.

Visible colorimetric sensing of Zn2+ and CN− by diaminomaleonitrile derived Schiff’s base and its applications to pharmaceutical and food sample analysis

A newly designed diaminomaleonitrile derived schiff’s base probe L was synthesized by reacting 2,3-diaminomaleonitrile with 3,5-tert-butyl-2-hydroxybenzaldehyde and structurally characterized by various spectroscopic techniques. The sensing ability of probe L was studied with various cations and anions by visual and UV visible techniques. It reveals that L is selectively interacting with Zn2+ and CN− ions resulted in distinct colour changes from yellow to grey and colourless respectively. The probe L exhibits 1:1 complex formation with these analytes and it can work in the pH range of 8–10 and 5–8 with Zn2+ and CN− respectively without interfering with other competing ions. The spectral response was used estimate the limit of detection of Zn2+ and CN− and it is found to be 0.58 μM and 0.33 μM respectively. Further, the probe L was applied for the quantification of analytes in real samples. The binding mechanism of L with Zn2+ was characterized by using 1H NMR, ESI mass, and DFT analysis. The frontier molecular orbital analysis (FMO) analysis reveals that that Zn2+ and CN− are exhibiting metal-to-ligand charge transfer (MLCT) and internal charge transitions (ICT) respectively. Overall, probe L demonstrates a promising and potential for the detection of Zn2+ and CN− in the semi-aqueous phase.

Electron Injection Process of Porphyrin Dye into a Heterogeneous TiO2/Re(I) Photocatalyst

We now report full details of the collisional ET process at the interface between the solvated porphyrin dye (a representative molecular dye) and heterogeneous TiO2 particles (a well-defined n-type semiconductor), which can be another major electron injection route in dye-sensitized photocatalytic (DSPC) systems based on TiO2 semiconductor besides the typical injection route by oxidative quenching of the TiO2-anchored dye. From temperature-dependent transient profiles of the reductively quenched porphyrin dye (porphyrin•–) with and without TiO2 particles, it was found that there exists a high activation energy (Ea = 57–58 kJ/mol, solvated dye → TiO2 particles) for the collisional electron transfer from the dissolved porphyrin•– to heterogeneous TiO2 semiconductor, which could originate from the low collisional probability between the solution-phase anionic dye and heterogeneous TiO2 particle. This quenching kinetic study provides the first quantitative results showing how the solution-phase dye radical anions transport their photoinduced electrons to the heterogeneous semiconductor side. In addition, the complex photosensitizing behaviors of photo-labile porphyrin dye were investigated with the preparation of the photomodified porphyrin species (ZnPAcet and ZnPEt), which are identified from in situ UV–vis spectroscopy and ESI-mass analysis of the dye solution after photolysis.

Synthesis and structure of mono and bis {1,3-bis(2- pyridylimino)isoindoline} supported 3d transition metal complexes

Series of homoleptic and heteroleptic 3d transition metal complexes were prepared in analytically pure form and high yield, by reacting appropriate metal precursors with 1,3-bis(2-pyridylimino)isoindolate (BPIH) ligand under suitable reaction conditions. The complexes were characterized by various spectro-analytical techniques, including IR, UV, NMR, ESI Mass and X-ray crystal analysis. A distorted octahedral structure containing two meridionally coordinating BPI ligands was assigned to all the homoleptic complexes. While, for the heteroleptic complexes, a highly distorted square pyramidal geometry, with a planar tridentate BPI ligand coordinating to the metal center along with chloro and aqua ligands was assigned. Considering the unique structural features of the complexes, potential catalytic applications are envisaged.

A multi-functional picolinohydrazide-based chemosensor for colorimetric detection of iron and dual responsive detection of hypochlorite.

A novel effective chemosensor HPHN, (E)-6-hydroxy-N'-((2-hydroxynaphthalen-1-yl)methylene) picolinohydrazide, was synthesized. HPHN sensed Fe3+/2+ with the changes of color from yellow to orange without obvious inhibition from other cations. In addition, HPHN could detect ClO- by both the color change from yellow to colorless and the fluorescence quenching. The binding modes of HPHN with Fe3+/2+ and ClO- were determined to be 1:1 with Job plot and ESI-mass analysis. HPHN displayed low detection limits of 0.29μM for Fe3+ and 0.77μM for Fe2+. For ClO-, the detection limit was 6.20μM by colorimetric method and 3.99μM by fluorescent one, respectively. Moreover, HPHN can be employed to quantify Fe3+ and ClO- in environmental samples and apply to cell imaging for ClO-.

Indole-fused spirochromenes as potential anti-tubercular agents: design, synthesis and in vitro evaluation.

As part of an ongoing effort to develop new anti-tubercular agents, a series of novel indole-fused spirochromene hybrids (7a-l) were efficiently synthesized in excellent yields by the popular 'Fisher-Indole synthesis' approach. The structure elucidation of the target compounds was carried out by different spectral techniques including 1H-NMR, 13C-NMR, ESI Mass, and FTIR analysis. Additionally, the proposed structure of 7i was proved by single-crystal X-ray analysis. These compounds (7a-l) were screened for in vitro anti-tubercular activity against Mycobacterium tuberculosis H37Rv (ATCC 27294) strain. The results showed that most of the targets exhibited promising antimycobacterial activity with MICs of 1.56-6.25μg/mL and weak cytotoxicity (19.93-32.16% at 50μg/mL). Among them, compound 7l was found to be the most active compound (MIC of 1.56μg/mL) with a good safety profile (32.16% at 50μg/mL).

Development of highly selective dual mode chromogenic and fluorogenic chemosensor for Bi3+ ions

A new dual mode chemosensor 8-methoxy-2-(thiophen-2-yl) quinolone (L) was synthesised for selective and sensitive detection of Bi3+ ions. The selective distinct colorimetric response and fluorescence quenching were observed upon interaction of L with Bi3+ in CH3CN:H2O (85:15, v/v) media. The sensor L could form 2:1 stoichiometric complex with Bi3+ with an association constant of 2.2 × 105 M−2 by using Benesi-Hilderbrand (BH) method. The fluorescence quenching constant estimated to be 9.3 × 108 M−1 by using Stern-Volmer (SV) plot. The lowest detection limit of Bi3+ by colorimetric and fluorimetric were found to be 1.78 μM and 0.057 μM respectively. The sensing mechanism of L with Bi3+ was studied using 1H NMR, ESI-mass analysis and theoretical calculations. Finally, the sensor L was applied for the detection of Bi3+ in various water and pharmaceutical drug samples.

A Novel Thiophene-Based Fluorescent Chemosensor for the Detection of Zn2+ and CN-: Imaging Applications in Live Cells and Zebrafish.

A novel fluorescent turn-on chemosensor DHADC ((E)-3-((4-(diethylamino)-2-hydroxybenzylidene)amino)-2,3-dihydrothiophene-2-carboxamide) has been developed and used to detect Zn2+ and CN−. Compound DHADC displayed a notable fluorescence increase with Zn2+. The limit of detection (2.55 ± 0.05 μM) for zinc ion was far below the standard (76 μM) of the WHO (World Health Organization). In particular, compound DHADC could be applied to determine Zn2+ in real samples, and to image Zn2+ in both HeLa cells and zebrafish. Additionally, DHADC could detect CN− through a fluorescence enhancement with little inhibition with the existence of other types of anions. The detection processes of compound DHADC for Zn2+ and CN− were demonstrated with various analytical methods like Job plots, 1H NMR titrations, and ESI-Mass analyses.

Two New Lignan Derivatives from Jatropha curcas

Two new lignan derivatives, jatrolignan A (1) and B (2), were isolated from the aerial parts of Jatropha curcas. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR experiments, as well as high-resolution ESI mass analysis.

Fluorescence “turn-on” sensor for highly selective recognition of Cu2+ ion and its application to living cell imaging

A new, bis-thiophene based Schiff base receptor A2 has been synthesized and rationally designed as rapid and highly selective fluorescence sensor for Cu2+ ion in a semi-aqueous medium. Structural characterization of A2 was confirmed by NMR, FT-IR and HRMS spectral techniques. The receptor A2 shows the colorimetric response from yellow to colorless and fluorescence “turn-on” with Cu2+ ions under visible and UV light. Both the UV–Vis and fluorescence studies were confirmed the formation of 1:1 stoichiometry complex with an estimated association constant of 1.07 × 10−5 M−1. The sensor could work in the pH range of 4.0–8.0 without interference in the presence of other interfering ions. The lowest detection limits by colorimetric and fluorescence techniques were found to be 1.18 × 10−7 M and 8.8 × 10−8 M respectively. Further, the probe was applied to image the intracellular Cu2+ ions in the HeLa cell line. The sensing mechanism was studied by ESI-mass analysis and DFT calculations.

One-step Separation and Purification of Four Phenolic Acids from Stenoloma chusanum (L.) Ching by Medium-pressure Liquid Chromatography and High-speed Counter-current Chromatography

Background:Stenoloma chusanum (L.) Ching is a Chinese traditional medicinal fern with high total flavonoid and total phenolic content. Traditionally, phenolic compounds were separated by using column chromatography, which is relatively inefficient. </P><P> Objective: This study aims to use an efficient method to separate natural products from S. chusanum by Medium-Pressure Liquid Chromatography (MPLC) and High-Speed Counter-Current Chromatography (HSCCC).Methods:In the present research, firstly, a sample (2.5 g) from the dichloromethane extract of S. chusanum was separated by MPLC. Next, fraction P5 was purified by HSCCC with a two-phase solvent system composed of hexane-ethyl acetate-methanol-water (HEMWat) at a volume ratio of 2:4:1:4 (v/v/v/v). </P><P> Result: Four phenolic acids were obtained and their structures were identified by means of NMR and ESI-mass analysis. They were identified as: 1) protocatechuic acid (34 mg, purity 90.1%), 2) syringic acid (66 mg, purity 99.0%), 3) p-hydroxybenzoic acid (5 mg, purity 91.2%) and 4) vanillic acid (6 mg, purity 99.3%).Conclusion:The combination of MPLC and HSCCC is a high-efficiency separation method for natural products. This is the first report with regard to the separation of four phenolic acids in one step by MPLC and HSCCC from S. chusanum (L.) Ching.

Highly selective turn-on fluorogenic chemosensor for Zn2+ based on chelation enhanced fluorescence

A new fluorescent zinc sensor was constructed based on cyclic and noncyclic Schiff's bases obtained by the condensation of 4‑(diethylamino) salicylaldehyde and 2‑aminobenzenethio under two different catalytic conditions such as sulphuric acid yields 2‑(benzo[d]thiazol‑2‑yl)‑5‑(diethylamino) phenol (L1) and acetic acid gives to (E)‑5‑(diethylamino)‑2‑(((2‑mercaptophenyl)imino)methyl) phenol (L2). Both L1 and L2 alone exhibits a week fluorescence in CH3OH/H2O (1:1, v/v) due to excited state intra-molecular change transfer (ESIPT) process but upon interaction with Zn2+ shows strong fluorescence due to chelation-enhanced fluorescence (CHEF) but with selected metal ions, there is no such a fluorescence change was observed. The Job's plot and B-H plot studies were revealed the formation of 2:1 and 1:1 stoichiometry with an estimated association constant (Ka) of 4.9 × 104 M−1 and 2.1 × 104 M−1 with L1 and L2 respectively. The detection limit of both sensors L1 and L2 were found to be 6.7 × 10−8 M and 3.6 × 10−7 M respectively. The fluorescence reversibility study was done by adding Zn2+ and EDTA sequentially to L1 and L2. Both sensors were successfully used for the determination of Zn2+ in the different water samples and pharmaceutical multivitamins tablet. The sensing mechanism was studied by 1H NMR, ESI-mass analysis as well as theoretical calculations using the Gaussian 09 program.

Synthesis of novel (E)-2-((anthracen-9-ylmethylene)amino)pyridin-3-ol and its transition metal complexes: Multispectral characterization, biological evaluation and computational studies

The synthesis and structural characterization of novel mixed ligand complexes derived from 9-anthraldehyde, 2-amino-3-hydroxy pyridine, 1,10-phenanthroline and metal chlorides are reported. The synthesized mixed ligand complexes are characterized by multispectral techniques such as UV‐Visible, FT-IR, EPR, NMR, ESI-mass analysis and other physicochemical analysis like elemental analysis, molar conductivity, magnetic susceptibility measurements. Moreover, the mixed ligand complexes have strived for their biological future. The biological studies involved are DNA interaction (binding and damage), antimicrobial, antiproliferative studies and free radical scavenging ability studies. The DNA interaction studies are accomplished by UV‐Visible absorption titration, viscosity measurement, which exposed that the synthesized compounds could interplay with CT-DNA through non-covalent interaction of phenanthroline co-ligand by the way of intercalative binding mode. Additionally, the antimicrobial assay specified that the mixed ligand complexes are excellent antimicrobial agents against various pathogens. The gel electrophoresis scrutiny clearly evinced that the prominent DNA cleavage activity of the mixed ligand complexes to divide the supercoiled pUC 19 DNA. The in-vitro antiproliferative activities of the mixed ligand complexes are explored on MCF-7, Hep G2, HBL-100 cell lines using an MTT assay. The morphological changes of the nucleus are explored using Hoechst 33258 staining apoptosis assay. The antioxidant possessions manifest that the mixed ligand complexes have desirable proficiency to scavenge the hydroxyl radical than the ligand. The prediction of in-silico ADMET property revealed that the Schiff base ligand possesses appreciable drug-likeness characters according to Lipinski's regulations. The prediction of PASS biological activity explains that the synthesized ligand holding the excellent biological potential against various diseases. Eventually, the molecular docking studies are achieved to comprehend the nature of binding of the synthesized ligand and mixed ligand complexes with COX-2 protein and DNA.

A novel benzophenone-based colorimetric chemosensor for detecting $$\hbox {Cu}^{2+ }$$ Cu 2 + and $$\hbox {F}^{-}$$ F -

A novel selective colorimetric chemosensor ANBP ((E)-(2-(((8-hydroxy-2,3,6,7-tetrahydro-1H,5H-pyrido[3,2,1-ij]quinolin-9-yl)methylene)amino)-5-nitrophenyl)(phenyl)methanone), based on the combination of benzophenone group and julolidine chromophore, was synthesized. Sensor ANBP showed rapid colorimetric responses toward $$\hbox {Cu}^{2+}$$ (pale orange to pink) and $$\hbox {F}^{-}$$ (orange to blue). The detection limit by ANBP to $$\hbox {Cu}^{2+}$$ (6.82 $$\upmu $$ M) was far below WHO guideline value (31.3 $$\upmu $$ M). Moreover, ANBP could quantify $$\hbox {Cu}^{2+}$$ in aqueous samples. 1:1 binding mode between ANBP and $$\hbox {Cu}^{2+}$$ or $$\hbox {F}^{-}$$ was proposed by ESI-mass analyses and Job plots. The remarkable color changes with $$\hbox {Cu}^{2+}$$ and $$\hbox {F}^{-}$$ resulted from the intramolecular charge transfer (ICT) effect, which was demonstrated by theoretical calculations. A novel selective colorimetric chemosensor ANBP, based on the combination of benzophenone group and julolidine chromophore, was designed and synthesized. Sensor ANBP showed rapid colorimetric responses toward $$\hbox {Cu}^{2+}$$ (pale orange to pink) and $$\hbox {F}^{-}$$ (orange to blue).