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Nanotechnology provides a very good chance to research and develop multipurpose nanomaterials because of their smaller size, larger surface area, low cost, and nanoscale materials, which are auspicious tools for many biological applications. The AgVO3 nanoparticle synthesis employing plant extract has offered an eco-friendly alternative for the industry. Literature survey shows that no research has been performed on AgVO3 using jackfruit; hence, we prepared AgVO3 using jackfruit extract as a reducing agent by a simple, easy, and eco-friendly precipitation method. The characterization techniques used for synthesized AgVO3 nanoparticles were x-ray diffraction analysis, which determines the monoclinic structure of synthesized AgVO3 nanoparticles; Fourier transform infrared spectroscopy, which shows the bonding of V–O–V; and scanning electron microscopy and energy dispersive spectra (EDS), which confirm the size, shape, purity, and elemental composition. Brunauer–Emmett–Teller analysis confirms the pore size, pore volume, and surface area of synthesized AgVO3 nanoparticles, Raman studies show the crystalline property, and UV–Vis studies give information about the material's formation and optical properties. The bandgap was calculated to be 2.54 eV. Furthermore, the photocatalytic studies show 98.14% degradation in 180 min using MB dye. We also performed scavenger studies for detection of OH· radicals and recyclability. Gram-negative (Klebsiella pneumonia and Pseudomonas aeruginosa) and gram-positive (Staphylococcus aureus and Bacillus subtilis) micro-organisms were used to determine the antimicrobial characteristics. The full analysis verifies AgVO3's antibacterial activity against both gram-negative and gram-positive bacteria, as well as its excellent photocatalytic activities for the degradation of the organic dye methylene blue with a high degree of recyclability. [ABSTRACT FROM AUTHOR]

Present work describes the UV–Visible and FT-IR spectral behavior of highly functionalized diarylmethanes via theoretical investigations. Analyses of both theoretical and experimental UV data were in good agreement with the assigned bands. In addition, calculations pertaining to natural bond orbitals (NBOs) and mapped molecular electrostatic potential surface (MEPS) were also performed, revealing that the strongest hyperconjugative intramolecular interactions involves the π ⟶ π∗, LP ⟶ σ∗ and n → π * transitions in the D and A rings. Further, the theoretical vibrational analysis revealed several characteristic vibrations that may be used as a diagnostic tool for other diarylmethanes and also indicated that the experimental bands related to the nitrile group occur in regions lower than usual, which confirms high conjugation of the triple bond with the aromatic system. Molecular dynamics (MD) and molecular docking calculations were performed in order to evaluate the behavior of such molecules in aqueous medium and the pharmacological potential. Another interesting observation in this study is the HOMO–LUMO analysis, which showed that the global reactivity values changed according to the type of substituent groups. [ABSTRACT FROM AUTHOR]

The emerging interest in the field of coordination chemistry and their biological applications has created a novel impact in the field of chemical biology. With this motivation, in this work we have synthesized a novel benzimidazole derived imine ligand, 2-((E)-((1H-benzo[d]-2-yl)methylimino)methyl)-4-fluorophenol (HBMF) and its Co(III) and Cu(II) complexes. The metal complexes (C1–C4) were synthesized in 2:1 (HBMF: metal ion) and 1:1:1 (HBMF: metal ion: 1,10-phen) ratios. Structural elucidations of all the synthesized compounds were performed using FT-IR, UV-Visible, NMR, Mass spectroscopy and elemental analysis techniques. A combination of first principles calculations and molecular dynamics simulations was applied to computationally investigate the structural, reactive, and spectroscopic properties of the newly synthesized HBMF ligand and its complexes with copper and cobalt metal ions. Quantum-mechanical calculations in this study were based on the density functional theory (DFT), while molecular dynamics (MD) simulations were based on the OPLS4 force field. The DFT calculations were used to obtain the reactive and spectroscopic properties of the ligand and its complexes, while molecular dynamics (MD) simulations were used to address the ligand's reactivity with water. Further, the in vitro anti-proliferative activity of the compounds was tested against the A549, Ehrlich–Lettre ascites carcinoma (EAC), SIHA and NIH3T3 cell lines. The biological results depicted that the compound C4, with molecular formula C27H23Cl2CoFN5O3 exhibited profound anti-proliferative activity against the EAC cell line with a significant IC50 value of 10 µm when compared to its parent ligand and other remaining metal complexes under study. Various assays of hematological parameters (alkaline phosphate, creatinine, urea, RBC and WBC) were performed, and significant results were obtained from the experiments. Furthermore, the effect of C4 on neovascularization was evaluated by stimulating the angiogenesis with rVEGF165, which was compared with non-tumor models. The EAC cells were cultured in vivo and administrated with 50 and 75 mg/kg of two doses and tumor parameters were evaluated. [ABSTRACT FROM AUTHOR]

Two novel oxidovanadium(IV) complexes with a new bidentate (O- and N-) imine-based ligand 2-((E)-(6-fluorobenzo[d]thiazol-2-ylimino)methyl)-6-methoxyphenol (HL) were synthesized under in situ experimental condition where VOSO4 acts as a kinetic template in the ratio 2 : 1 (L : M) and mixed ligand complex using 1,10-phenanthroline (phen) in 1 : 1 : 1 (L : M : phen) ratio. The synthesized compounds were structurally characterized by microanalysis, magnetic susceptibility, FTIR, electronic spectra, TG/DTA, ESR, and molar conductance studies. Based on the spectral studies, the complexes have the general composition [VO(L)2] (C1) and [VO(L)phen] (C2) in a square pyramid geometrical fashion. The synthesized compounds were primarily screened for their in vitro growth inhibiting activity against different strains of bacteria, namely, E. coli, B. subtilis, S. aureus, and P. aeruginosa by the disc diffusion method. Also, the antifungal activity was determined against C. albicans and A. niger by the Bateman poisoned technique. The in vitro antioxidant activity of all the compounds was determined by DPPH free radical-scavenging assay. Intercalative mode of DNA-binding properties of the oxidovanadium(IV) complexes with calf-thymus DNA (CT-DNA) was investigated using UV, fluorescence spectra, and viscosity measurements. [ABSTRACT FROM AUTHOR]

A bidentate (N- and O-) imine-based ligand (L1) and its metal complexes of types [CuII(L1)2] (C1), [CuII(L1)(Phen)] (C2), [CoIII(L1)2] (C3), and [CoIII(L1)(Phen)] (C4) (L1 = 2-((E)-(6-fluorobenzo[d]thiazol-2-ylimino)methyl)-4-chlorophenol and phen = 1,10-phenanthroline) were synthesized as potential chemotherapeutic drug candidates. The prepared complexes were structurally characterized by spectral techniques (NMR, FT-IR, LC-MS, EPR, and electronic absorption), thermogravimetric analysis (TGA/DTA), magnetic moment, and CHNO elemental analysis. Spectroscopic studies suggested the distorted octahedral structure for all complexes. In vitro bioassay studies include binding and nuclease activities of the ligand and its complexes with target calf thymus-(CT-) DNA were carried out by employing UV-Vis, fluorescence spectroscopy, viscosity, and gel electrophoresis techniques. The extent of binding propensity was determined quantitatively by Kb and Ksv values which revealed a higher binding affinity for C2 and C4 as compared to C1 and C3. In addition, the scavenging superoxide anion free radical (O∙−2) activity of metal complexes was determined by nitroblue tetrazolium (NBT) light reduction assay. Molecular docking studies with DNA and SOD enzyme were also carried out on these compounds. The antimicrobial study has shown that all the compounds are potential antibacterial agents against Gram-negative bacterial strains and better antifungal agents with respect to standard drugs used. [ABSTRACT FROM AUTHOR]

A simple, precise and accurate stability-indicating isocratic reverse phase ultra-performance liquid chromatographic (RP-UPLC) method was developed for the determination of lamotrigine (LMT) in bulk drug and in its tablets. The method was developed using Waters Aquity BEH C18 (100 mm × 2.1 mm, 1.7 µm) column with mobile phase consisting of a mixture of potassium dihydrogen phosphate buffer of pH 3.5 and an equal ratio of methanol and acetonitrile (50:50 v/v). The eluted compound was detected at 228 nm with a UV detector. The standard curve of mean peak area versus concentration showed an excellent linearity over a concentration range 1.0 . 75 µg/mL. Within-day and between-days RSD were less than 1.3% pronounces precision of the method. The accuracy of the method was further ascertained by recovery studies via standard addition procedure and the recoveries obtained were 98 - 100%. Forced degradation of the bulk sample was conducted in accordance with the ICH guidelines. Acidic, basic, hydrolytic, oxidative, thermal and photolytic degradation were used to assess the stability indicating power of the method. LMT was found to degrade significantly in acidic, basic and oxidative stress conditions and stable in thermal, hydrolytic and photolytic conditions. [ABSTRACT FROM AUTHOR]

Condensation of amine 1 with aldehyde 2 gives Schiff base, N-(4-((benzofuran-2-ylmethylene) amino)phenyl)acetamide 3. Schiff base on N-acylation with different substituted acid chlorides in the presence of triethylamine gives the corresponding benzamides, N-acetyl-N-(4-((benzofuran-2-ylmethylene)amino)phenyl)substitutedbenzamide (NABP) 5a-j. The structures of newly synthesized compounds were characterized by elemental analysis, ¹HNMR, 13CNMRFT-IR, and mass spectral studies. Compounds 3 and 5a-j have been screened for their antimicrobial activity using the disc diffusion and minimum inhibitory concentration (MIC) method against the selected bacterial and fungal strain. Compounds 5a, 5e, 5g, and 5h were found to be more active against all tested strains. The antioxidant properties were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radical scavenging methods. Compounds 5i and 5j showed predominant antioxidant activities among the synthesized analogues. The interaction between NABP and bovine serum albumin (BSA) was investigated using fluorescence and ultraviolet spectroscopic techniques at 298K under imitated physiological conditions. The results revealed that NABP caused the fluorescence quenching of BSA through a static quenching procedure. The binding constants and the number of binding sites were calculated. The binding distance between the donor (BSA) and acceptor (NABP) was determined based on Forster's theory. [ABSTRACT FROM AUTHOR]

The objective of the current study was the development of a simple, rapid, and accurate isocratic reverse-phase ultra-performance liquid chromatographic (RP-UPLC) method for the routine control analysis of imipramine hydrochloride (IMH) in bulk drug and in pharmaceutical formulations. This work was carried out in order to reduce analysis time and maintaining good efficiency which in turn is focused on high-speed chromatographic separations. The method was developed usingWaters Acquity BEH C18 column (100mm × 2.1 mm, 1.7 μm) with mobile phase consisting of a mixture of acetonitrile and ammoniumacetate buffer of pH-5 (80 : 20, v/v/v).UVdetection was performed at 220 nm for eluted compound. An excellent linearity was observed in the concentration range 0.2-3 μg/mL IMH with a regression coefficient (r2) value of 0.9999.The method developed was validated and forced degradation was performed as per ICH guidelines. The limit of detection (S/N = 3) was 0.2532 ng/mL and the limit of quantitation (S/N = 10) was found to be 0.7672 ng/mL. The drug IMH was subjected to hydrolytic, acidic, basic, thermal, photolytic, and oxidative stress conditions according to ICH regulations. IMH was found to be stable in basic, thermal, and photolytic conditions and degrades in acidic, hydrolytic, and oxidative stress conditions. [ABSTRACT FROM AUTHOR]

Two simple, selective, and rapid spectrophotometric methods are described for the determination of mycophenolate mofetil (MPM) in pure form and in tablets. Both methods are based on charge-transfer complexation reaction of MPM with p-chloranilic acid (p-CA) or 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) in dioxane-acetonitrile medium resulting in coloured product measurable at 520 nm (p-CA) or 580nm (DDQ). Beer's law is obeyed over the concentration ranges of 40-400 and 12-120 µgmL-1 MPM for p-CA and DDQ, respectively, with correlation coefficients (r) of 0.9995 and 0.9947. The apparent molar absorptivity values are calculated to be 1.06 × 10³ and 3.87 × 10³ Lmol-1 cm-1, respectively, and the corresponding Sandell's sensitivities are 0.4106 and 0.1119 µg cm-1. The limits of detection (LOD) and quantification (LOQ) are also reported for both methods. The described methods were successfully applied to the determination of MPM in tablets. Statistical comparison of the results with those of the reference method showed excellent agreement. No interference was observed from the common excipients present in tablets. Both methods were validated statistically for accuracy and precision. The accuracy and reliability of the methods were further ascertained by recovery studies via standard addition procedure. [ABSTRACT FROM AUTHOR]

A simple, accurate and sensitive visible spectrophotometric method for the determination of nimodipine (NMD) and nitrazepam (NTZ) is described. The method is based on the diazotization of reduced drugs with nitrous acid followed by coupling with resorcinol to form colored azo-dye in an alkaline medium. The resulting colored azo-dye exhibits maximum absorption peak at 480 nm for both NTZ and NMD. Beer's law was obeyed over the concentration ranges 0.5-10 and 1.0-40.0 μg/mL for NTZ and NMD, respectively. The calculated molar absorptivities are 1.84 × 104 and 0.67 × 10-4 L mol-1cm-1 for NTZ and NMD, respectively. All the variables such as effect of acid, alkali and reaction time were studied in order to optimize the reaction conditions. No interference from the excipients added to tablets was found. Statistical analysis of the results using Student's t-test for accuracy and F-test for precision revealed no significant difference between the proposed method and the literature method. The accuracy and validity of the methods were further established by recovery studies through the standard addition technique. [ABSTRACT FROM AUTHOR]

Three simple, sensitive, accurate and indirect visible spectrophotometric methods have been developed for the estimation of lamotrigine (LMT) in both pure and in pharmaceutical preparations. They are based on the oxidation of lamotrigine with a known excess of cerium(IV) in acid medium. The unreacted cerium(IV) oxidize leuco crystal violet to crystal violet colored dye (Method A), leuco malachite green to bluish-green malachite green dye (Method B), leuco xylene cyanol FF to xylene cyanol FF bluish dye (Method C) and exhibiting absorption maxima (λmax) at 580, 610 and 610 nm, respectively. In these methods, the amount of cerium(IV) reacted corresponds to the amount of LMT. The results of the three methods have been validated statistically and by recovery studies. The results obtained in the proposed methods were in good agreement with the label claim. [ABSTRACT FROM AUTHOR]

Two direct, simple, sensitive and rapid extraction-free spectrophotometric methods have been developed for the determination of lamotrigine (LMT) in pure form and in its dosage forms. The methods are based on formation of ion-pair complex between the drug and two sulphonthalein acidic dyes namely, bromothymol blue (method A) and bromocresol green (method B), followed by the measurement of absorbance at 410 nm in both the methods. Conformity to Beer's law enabled the assay of the drug in the range 1-12 μg mL-1 in both the methods with apparent molar absorptivities of 2.06 × 104 and 1.787 × 104 L mol-1cm-1 for method A and method B, respectively. The Sandell sensitivity values, limits of detection (LOD) and quantification (LOQ) values have also been reported for both the methods. The stoichiometry of the ion-pair complexes as evaluated by Job's continuous variations method was 1:1 and the conditional stability constant (log Kf) were calculated to be 7.05 and 8.24 for method A and method B, respectively. The accuracy and precision of the methods were evaluated on intra-day and inter-day basis; the relative error (%RE) was < 2.0% and the relative standard deviation (RSD) was < 1.60%. The methods were successfully applied to the determination of drug in tablets without interference by the common coformulated substances. Statistical comparison of the results with the reference method showed good agreement and indicated no significant difference in accuracy and precision. [ABSTRACT FROM AUTHOR]

A novel copper(II) complex of quinolin-4(3H)-one derived Schiff base ligand was synthesized and characterized by elemental analyses, IR, 1H-NMR, MS, UV-Vis, magnetic moments, conductance measurements and thermal studies. The DNA binding and nuclease activities of copper(II) complex was performed. [ABSTRACT FROM AUTHOR]

One titrimetric and two spectrophotometric methods which are simple, selective, sensitive, accurate, precise and economical for the determination of etamsylate (ETM) in bulk drug and in tablets employing permanganate as the oxidimetric reagent are described. In titrimetry, ETM is titrated directly with permanganate in sulphuric acid medium. A direct spectrophotometry (method A) involves treating the aqueous solution of the drug with permanganate in alkaline medium and measuring the bluish green product at 610 nm. In indirect spectrophotometry (method B), the drug solution was treated with a fixed concentration of permanganate in H2SO4 medium, and after a specified time, the unreacted permanganate was measured at 545 nm. The molar combining ratio in titrimetry and the optimum assay conditions were studied. Titrimetry is applicable over 1-10 mg range and the calculations are based on a 1:4 (ETM:KMnO4) molar ratio. In spectrophotometry, Beer's law is obeyed over 0.5- 5.0 and 1.5- -15 μg ml-1 for method A and B, respectively. The molar absorptivity values are calculated to be 2.79x104 and 4.17x104 l mol-1 cm-1 for method A and B, respectively and the corresponding sandell sensitivity values are 0.0094 and 0.0063 μg cm-2. The limits of detection (LOD) and quantification (LOQ) are also reported for spectrophotometric methods. The applicability of the developed methods was demonstrated by the determination of etamsylate in pure drug as well as in commercial dosage forms. [ABSTRACT FROM AUTHOR]

A new, simple, sensitive, and reliable method is presented for the rapid spectrophotometric determination of trace amounts of iron(III) using leuco Xylene cyanol FF. The method is based on the oxidation of leuco Xylene cyanol FF (LXCFF) to its blue form of xylene cyanol FF by iron(III) in sulfuric acid medium (pH 2.0–3.0), the absorbance of the formed dye is measured in an acetate buffer medium (pH2.8–4.4) at 615 nm. The method obeys Beer's law over a concentration range of 0.15–0.9 μg mL-1 iron, having a molar absorptivity of 5.6×104 L mol-1 cm-1 and a Sandell's sensitivity of 0.0001 μg cm-2. The optimum reaction conditions and other analytical parameters have been evaluated. The developed method has been successfully applied to the determination of iron in water, soil, industrial effluent, plant material, pharmaceutical preparations, synthetic mixtures, and aluminum alloys. [ABSTRACT FROM AUTHOR]

A new, simple, highly sensitive and rapid spectrophotometric method has been described for the determination of platinum(IV). The method is based on the oxidation of leuco xylene cyanol FF (LXCFF) to its blue form of xylene cyanol FF by platinum(IV) in sulfuric acid medium (pH 1.0–2.5), the formed dye shows an absorption maximum at 620 nm in acetate buffer medium (pH 3.0–4.5). The method obeys Beer's law over a concentration range of 0.3 to 2.6 µg mL–1 platinum, having molar absorptivity and Sandell's sensitivity of 5.1×104 L mol–1 cm–1 and 0.0038 µg cm–2, respectively. The optimum reaction conditions and other analytical parameters have been evaluated. The developed method has been successfully applied to the determination of platinum in pharmaceutical preparations, soil, natural water, plant material, platinum-containing catalyst, and synthetic alloy samples. [ABSTRACT FROM AUTHOR]

Acetyl acetone is introduced as a new coupling agent for the spectrophotometric determination of some chemotherapeutic agents, such as metoclopramide, dapsone, p-aminobenzoic acid, and cisapride in both pure and dosage forms. The method is based on the diazo-coupling reaction of these chemotherapeutic agents with a new coupling agent, acetyl acetone, in an alkaline medium. The optimum reaction conditions and other analytical parameters are evaluated. The influence of the substrates commonly employed as excipients with these chemotherapeutic agents has been studied. The method is simple, rapid, and sensitive. The results obtained compare favorably with those obtained with other reference methods. [ABSTRACT FROM AUTHOR]

Herein we describe the synthesis of Cu 2+ sensor, 2,2'-((1E,1'E)-((4-chloro-1,2-phenylene)bis(azaneylylidene))bis(methane-ylylidene))bis(4-bromophenol) (CPMB) and characterization using various spectral and analytical techniques. CPMB exhibited high selectivity towards Cu 2+ ions via fluorescence quenching mechanism, which combined the character of high selectivity towards Cu 2+ assay even in the presence of other common metal ions such as Cu 2+ , Al 3+ , Co 2+ , Ni 2+ , Mn 2+ , Zn 2+ Pb 2+ Cd 2+ , Fe 2+ , Hg 2+ , Mg 2+ and Fe 3+ (30 μM) ethanol-water (1:9 v/v) system. Upon the addition of the solution of Cu 2+ ions to CPMB, the complexation of Cu 2+ with CPMB leads to the immediate formation of light green color, indicating that CPMB can act as simple colorimetric sensor, particularly for Cu 2+ in the presence of most interfering metal ions in ethanol-water medium. More interestingly, the ability of sensing behavior of CPMB for Cu 2+ ion in the real water samples (tap water and lake water samples) was also investigated. Further, Job's plot confirmed that the complexation occurred in 1:1 ratio (ligand:metal). Furthermore, the fluorescence inhibiting factor showed a good linear relationship with the concentration of Cu 2+ with detection limit of 0.302 μM. The electronic transitions of the complex in ethanol were studied using DFT calculations., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Using Cu(I)-catalyzed cycloaddition of alkyne and azide reaction (CuAAC), a series of novel 1,2,3-triazole based imidazole derivatives (3a-e) have been synthesized. The synthesized molecules were characterized by spectroscopic techniques such as 1 H NMR, 13 C NMR, mass and elemental analysis. Antitubercular activity (anti-TB) against Mycobacterium tuberculosis H37Rv (Mtb) and cytotoxic activity against the mammalian Vero cell line was screened for the synthesized compounds. The compounds 3d and 3e displayed potent in vitro antitubercular activity and may serve as a lead for further optimization. Besides, the experimental findings were in line with the results of molecular docking. Also, the synthesized compounds have also been analyzed for ADME properties and the experimental finding facilitates the development of new and more potent anti-TB agents in this series in the future. Using fluorescence and UV-vis absorption spectroscopy, the binding interaction of compounds (3d and 3e) with human serum albumin (HSA) was investigated. The results showed that, as a result of HSA-compound complex, the fluorescence quenching of HSA by test compounds was a static quenching process. According to Forster's theory, energy transfer efficiency is calculated., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

In the title compound, C14H11Cl2N5O, the plane of the 1H-imidazo[4,5-c]pyridine ring system [r.m.s. deviation = 0.087 (19) Å] makes a dihedral angle of 4.87 (10)° with the terminal phenyl ring. An intra-molecular N-H⋯N hydrogen bond stabilizes the mol-ecular conformation. In the crystal, N-H⋯O hydrogen bonds link the mol-ecules into inversion dimers. These dimers are connected by π-π inter-actions between imidazole rings [shortest centroid-centroid distance = 3.4443 (14) Å].

A novel class of N-substituted glycosmicine derivatives was synthesized, and their anticonvulsant, antioxidant activity and interaction with bovine serum albumin (BSA) were evaluated. The synthesized compounds 4a-j were examined for anticonvulsant activity by maximal electroshock induced seizures (MESs) test and their neurotoxic effects were determined by rotorod test in mice. The structure-activity relationships (SARs) of these compounds were also investigated. Compounds 4d, 4g, 4i and 4j were found to have good protective effect from seizure. The in vitro antioxidant activity was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radical scavenging assay. The interaction between novel N-substituted methylquinazoline-2,4(1H,3H)-dione (NMQ) and BSA was analyzed by fluorescence and ultraviolet spectroscopy at 304K under simulative physiological conditions. BSA fluorescence quenched by NMQ is discussed according to the Stern-Volmer equation. The binding constant and binding sites of NMQ with BSA were calculated. According to Forster non-radiation energy transfer theory, the binding distance (r) between NMQ and BSA was calculated., (Copyright © 2013 Elsevier B.V. All rights reserved.)

In the title compound, C(23)H(26)FN(3)O(6)S, the two terminal aromatic rings form a dihedral angle of 49.26 (12)°. The cyclo-hexane ring adopts a chair conformation and the five-membered ring is essentially planar, with a maximum deviation from planarity of 0.0456 (19) Å. The dihedral angles between the five-membered ring and the meth-oxy-benzene and fluoro-benzene rings are 33.56 (11) and 81.94 (12)°, respectively. The crystal structure displays N-H⋯O hydrogen bonds as well as weak inter-molecular C-H⋯O inter-actions.

In the title compound, C(22)H(24)FN(3)O(4)S, the cyclo-hexane ring adopts a chair conformation and the five-membered ring is essentially planar, with a maximum deviation of 0.040 (2) Å. The dihedral angles between the five-membered ring and the tolyl and fluoro-benzene rings are 56.74 (12) and 89.88 (12)°, respectively. The two terminal benzene rings make a dihedral angle of 63.53 (12)°. The crystal structure displays inter-molecular C-H⋯O and N-H⋯O hydrogen bonds. An intra-molecular C-H⋯O hydrogen bond also occurs.

In the title compound, C(24)H(26)FN(3)O(4), the two aromatic rings form a dihedral angle of 88.81 (15)°. The cyclo-hexane ring adopts a chair conformation and the five-membered ring is essentially planar, with a maximum deviation from planarity of 0.041 (2) Å. The crystal structure displays inter-molecular C-H⋯O and N-H⋯O hydrogen bonds.

In the title compound, C(15)H(10)N(2)O(3), the isoindoline ring system is almost planar [maximum deviation = 0.020 (2) Å] and makes a dihedral angle of 1.57 (7)° with the benzene ring. Intra-molecular O-H⋯N and C-H⋯O hydrogen bonds are observed.

The asymmetric unit of the title salt, (C(16)H(20)N(3)S)(2)[Co(NCS)(4)], comprises one monovalent isothio-pendylium cation and one-half of a divalent thio-cyanatocobaltate(II) anion (2 symmetry). The central thia-zine ring of the cation is slightly twisted in a boat-like fashion, with r.m.s. deviations from the mean plane of 0.272 (1) and 0.2852 (8) Å for the N and S atoms. The mol-ecular structure of the cation is stabilized by an intra-molecular N-H⋯N hydrogen bond. Within the complex anion, the Co(II) atom is tetra-hedrally surrounded by four N atoms of the thio-cyanate ligands. π-π stacking, with a distance of 3.7615 (10) Å between the centroids of benzene and pyridine rings, helps to consolidate the packing.

A simple and sensitized spectrophotometric method for the determination of trace amounts of beryllium has been described. The method is based on the formation of a ternary complex by the reaction of beryllium with haematoxylin in the presence of micellar medium (cationic surfactant, cetyltrimethylammonium bromide). The ternary complex of beryllium has a maximum absorbance at 592 nm and showed an excellent sensitivity (molar absorption coefficient of 7.07 x 10(4)L mol(-1)cm(-1) and the Sandell's sensitivity being 1.27 x 10(-4) microg cm(-2)) and reproducibility (within-day precision: R.S.D.

A highly sensitive and selective spectrophotometric method was developed for the determination of trace amounts of chromium with leuco Xylene cynaol FF. The method is based on the oxidation of leuco Xylene cyanol FF (LXCFF) to its blue form of Xylene cyanol FF by chromium(VI) in sulphuric acid medium (pH 1.2-2.4), the absorbance of the formed dye is measured in an acetate buffer medium (pH 3.0-4.6) at 615 nm. The method obeys Beer's law in the concentration range of 0.05-0.45 mug ml(-l) chromium, having molar absorptivity and Sandell's sensitivity of 8.23x10(4) l mol(-1) cm(-l) and 0.00063 mug cm(-2), respectively. All the variables were studied in order to optimise the reaction conditions. The developed method has been successfully applied to the determination of chromium in steels, pharmaceutical samples, industrial effluents, natural water, and soil.

A simple, rapid, and sensitive spectrophotometric method has been developed for the determination of selenium in real samples of water, soil, plant materials, human hair, and synthetic cosmetic and in pharmaceutical preparations. The method is based on the reaction of selenium with potassium iodide in an acidic medium to liberate iodine. The liberated iodine bleaches the violet color of thionin, and which is measured at 600 nm. This decrease in absorbance is directly proportional to selenium concentration and obeys Beer's law in the range 1-5 micro g selenium in a final volume of 10 mL (0.1-0.5 microg mL(-1)). The molar absorptivity and Sandell's sensitivity of the method were found to be 7.33 x 10(4) L mol(-1) cm(-1) and 0.0011 microg cm(-2), respectively. The optimum reaction conditions and other analytical conditions were evaluated. The effect of interfering ions on the determination is described.

A rapid and sensitive spectrophotometric method is described for the determination of trace amounts of selenium using Variamine Blue (VB) as a chromogenic reagent. The proposed method is based on the reaction of selenium with potassium iodide in an acidic medium to liberate iodine, which oxidizes Variamine Blue to form a violet-colored species having an absorption maximum at 546 nm. Beer's law is obeyed in the range 2-20 g of selenium in a final volume of 10 ml. The molar absorptivity and Sandell's sensitivity were found to be 2.6 x 10(4) l mol-1 cm-1 and 0.003 microgram cm-2, respectively. The optimum reaction conditions and other analytical parameters were evaluated. The effect of interfering ions on the determination is described. The proposed method has been successfully applied to the determination of selenium in real samples of water, soil, plant materials, human hair, and synthetic samples of cosmetics and pharmaceutical preparations.

Two simple and sensitive spectrophotometric methods are described for the determination of ritodrine hydrochloride (RTH) in both pure and dosage forms. The methods are based on the interaction of diazotised p-nitroaniline (DPNA) and sulphanilic acid (DSNA) with RTH in an alkaline medium. The resulting azo dyes are measured at 480 nm (for the DPNA method) and at 440 nm (for the DSNA method) and are stable for more than 1 h. The optimum reaction conditions and other analytical parameters are evaluated. A study of the effect of commonly associated excipients and additives do not interfere with the determinations. Statistical analysis of results indicates that the methods are precise and accurate.

A rapid, sensitive and selective spectrophotometric method has been developed for the quantitative determination of metoclopramide hydrochloride (MCP) and dapsone (DAP) in both pure and dosage forms. The method is based on the diazo coupling reaction of the drugs with a new coupling agent, dibenzoyl methane in an alkaline medium. The resulting coloured azo dyes exhibit maximum absorption at 440 nm for MCP and at 470 nm for DAP with a molar absorptivity of 2.85x10(4) and 1.71x10(4) l mol(-1) cm(-1) for MCP and DAP, respectively. All variables have been optimized. No interferences were observed from excipients and the validity of the method was tested against reference method.

A simple, accurate, and rapid method for the quantitative determination of ritodrine hydrochloride (RTH) and isoxsuprine hydrochloride (ISH) in both pure and dosage forms, is described. The method is based on the development of pink colored product as a result of the condensation of 4-aminoantipyrine with phenols in the presence of an alkaline oxidizing agent. The resulting products are measured at 510 nm for both drugs, with molar absorptivities of 0.98 x 10(4) and 1.20 x 10(4) L/mol x cm for RTH and ISH, respectively. A study of the effect of commonly associated excipients revealed that they did not cause interference.

A sensitive spectrophotometric method for the determination of amitriptyline hydrochloride, nortriptyline hydrochloride and doxepin hydrochloride in pure and dosage forms, is described. The method is based on the oxidative coupling of the drugs with 3-methylbenzothiazolin-2-one hydrazone in the presence of iron(III) chloride in 1 M hydrochloric acid. The commonly encountered excipients and additives do not interfere with the determinations. Results of the present method are comparable with those of official methods. The new method offers the advantage of simplicity and rapidity.

A rapid and sensitive spectrophotometric method has been developed for the quantitative determination of some phenothiazine derivatives as the pure substances and in different dosage forms. The method is based on the formation of red coloured products with 1% iodic acid in sulphuric or phosphoric acid medium. The reaction involves oxidation of the phenothiazine nucleus into a semiquinonoid radical. The optimum reaction conditions and other analytical parameters are evaluated. The influence of the substrates commonly employed as excipients with phenothiazine drugs has been studied. Statistical comparison of the results with those of an official method shows excellent agreement and indicates no significant difference in precision.