Utility of <Emphasis Type="Italic">π</Emphasis>-acceptor reagents for spectrophotometric determination of sulphonamide drugs via charge-transfer complex formation

A simple, sensitive and accurate spectrophotometric method for the determination of sulphonamides (sulphamethoxazole (SMZ), sulphaguanidine (SGD), sulphaquinoxaline sodium (SQX), sulphametrole (SMR), and sulphadimidine sodium (SDD)) has been developed. The charge-transfer reactions between sulphonamides as n-electron donors and 7,7,8,8-tetracyanoquinodimethane (TCNQ), 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), and 2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone (chloranilic acid, p-CLA) as π-acceptors resulting in highly coloured complexes were studied. Experimental conditions for these CT reactions were carefully optimised. Beer’s law is valid over the concentration ranges from 4–280 μg mL⁻¹, 4–260 μg mL⁻¹, 4–200 μg mL⁻¹, and 4–200 μg mL⁻¹ of SMZ, SGD, SQX, and SDD using DDQ reagent, respectively. While the calibration curves are linear in the concentration ranges from 4–180 μg mL⁻¹, 4–80 μg mL⁻¹, 4–60 μg mL⁻¹, 4–180 μg mL⁻¹, and 4–60 μg mL⁻¹ of SMZ, SGD, SQX, SMR, and SDD, respectively, using TCNQ reagent and from 4–380 μg mL⁻¹ and 4–300 μg mL⁻¹ of SQX and SDD, respectively, using p-CLA reagent, respectively. Different analytical parameters, namely molar absorptivity (ε), standard deviation, relative standard deviation, correlation coefficient, limit of detection, and limit of quantification, were calculated. The results obtained by the proposed methods are in good agreement with those obtained by the official method as indicated by the percent recovery values.     

Are the eigenvalues of preconditioned banded symmetric Toeplitz matrices known in almost closed form?

The problem of computing oscillatory integrals with general oscillators is considered. We employ a Filon-type method, where the interpolation basis functions are chosen in such a way that the moments are in terms of elementary functions and the oscillator only. This allows us to evaluate the moments rapidly and easily without needing to engage hypergeometric functions. The proposed basis functions form a Chebyshev set for any oscillator function even if it has some stationary points in the integration interval. This property enables us to employ the Filon-type method without needing any information about the stationary points if any. Interpolation by the proposed basis functions at the Fekete points (which are known as nearly optimal interpolation points), when combined with the idea of splines, leads to a reliable convergent method for computing the oscillatory integrals. Our numerical experiments show that the proposed method is more efficient than the earlier ones with the same advantages.     

Thermalization of Fermionic Quantum Walkers

We consider the discrete time dynamics of an ensemble of fermionic quantum walkers moving on a finite discrete sample, interacting with a reservoir of infinitely many quantum particles on the one dimensional lattice. The reservoir is given by a fermionic quasifree state, with free discrete dynamics given by the shift, whereas the free dynamics of the non-interacting quantum walkers in the sample is defined by means of a unitary matrix. The reservoir and the sample exchange particles at specific sites by a unitary coupling and we study the discrete dynamics of the coupled system defined by the iteration of the free discrete dynamics acting on the unitary coupling, in a variety of situations. In particular, in absence of correlation within the particles of the reservoir and under natural assumptions on the sample’s dynamics, we prove that the one- and two-body reduced density matrices of the sample admit large times limits characterized by the state of the reservoir which are independent of the free dynamics of the quantum walkers and of the coupling strength. Moreover, the corresponding asymptotic density profile in the sample is flat and the correlations of number operators have no structure, a manifestation of thermalization.     

Design and Synthesis of Some New Analgesic Azole Derivatives Containing Tramadol Moiety

Some new triazole, thiadiazole, oxadiazole, thiazole, oxazole, and imidazole derivatives have been synthesized via the reaction of tramadol bearing a hydrazide, hydrazine carbodithioate, and/or acetic acid group with certain reagents. Molecular docking study had been carried out to demonstrate the reactivity of these synthetic compounds for interaction with Cytochrome P450 2D6 ( CYP2D6 ).     

Synthesis of Novel Substituted Tetrahydropyrimidine Derivatives and Evaluation of Their Pharmacological and Antimicrobial Activities

Tetrahydropyrimidine derivative 1 was employed as intermediate compound, which in turn was allowed to react with different electrophilic and nucleophilic reagents to synthesize new polyfunctionalized series of substituted pyrimidine‐2‐thione derivatives. Structures of the newly synthesized compounds have been elucidated by spectroscopic data and elemental analyses. The pharmacological and antimicrobial activities of synthesized products have been evaluated as drug candidates.     

Interaction of a Three-Level Atom and Field in a Squeezed Vacuum State with Added Photons: Quantum Phase and Nonclassical Properties

We present a detail study of the evolution of nonlocal correlations of an interacting quantum system comprising a three-level atom and a field mode initially prepared in a squeezed vacuum state with added photons. We compare the dynamical behavior of the quantum phase and entanglement by varying the number of photons added to the squeezed vacuum state. Furthermore, we examine the influence of the added-photon number and the squeeze parameter on the dynamical behavior of entanglement, quantum phase, and nonclassical properties of the field. Moreover, we explore the link between the quantum phase and the nonlocal correlation. Finally, we introduce an effective method to generate and maintain a high level of entanglement for this quantum system based on precise parameter ranges.     

Synthesis,antimicrobial, antiquorum-sensing and cytotoxic activities of new series of benzothiazole derivatives

New series of benzothiazole derivatives were designed and synthesized. The newly synthesized compounds were screened for their antibacterial activity against Escherichia coli, Staphylococcus aureus and Bacillus cereus. Compounds 6j and 6o showed the highest activity against E. coli and S. aureus. The antifungal activity of these compounds was also tested against Candida albicans and Aspergillus fumigatus293. Compounds 4c, 4g and 6j exhibited the highest activity against C. albicans. In addition, compounds4 a and 6j displayed promising activity against A. fumigatus 293. The same compounds were examined for their antiquorum-sensing activity against Chromobacterium violaceum ATCC 12472, whereas compounds4 a, 6j and 6p showed moderate activity. The in vitro cytotoxicity testing of the synthesized compounds was performed against cervical cancer(Hela) and kidney fibroblast cancer(COS-7) cell lines. Results indicated that all tested compounds have IC50 values 50 mmol/L against both cell lines. Molecular properties, toxicities, drug-likeness, and drug score profiles of compounds 4a–c, 5a, 6g,h, 6j, 6l, 6o and7 c,d were also assessed.     

Secondary Metabolite Profiling,Anti-Inflammatory and Hepatoprotective Activity of Neptunia triquetra (Vahl) Benth

The present study aimed to analyze the phytoconstituents of Neptunia triquetra (Vahl) Benth. Anti-inflammatory and hepatoprotective activities of ethanol (EE), chloroform (CE) and dichloromethane (DCME) of stem extracts were evaluated using in vivo experimental models. The extracts were analyzed for phytoconstituents using GC-HRMS. Anti-inflammatory activity of CE, EE and DCME was accessed using carrageenan-induced paw oedema, cotton pellet-induced granuloma and the carrageenan-induced air-pouch model in Wistar albino rats. The hepatotoxicity-induced animal models were investigated for the biochemical markers in serum (AST, ALT, ALP, GGT, total lipids and total protein) and liver (total protein, total lipids, GSH and wet liver weight). In the in vivo study, animals were divided into different groups (six in each group) for accessing the anti-inflammatory and hepatoprotective activity, respectively. GC-HRMS analysis revealed the presence of 102 compounds, among which 24 were active secondary metabolites. In vivo anti-inflammatory activity of stem extracts was found in the order: indomethacin > chloroform extract (CE) > dichloromethane extract (DCME) > ethanolic extract (EE), and hepatoprotective activity of stem extracts in the order: CE > silymarin > EE > DCME. The results indicate that N. triquetra stem has a higher hepatoprotective effect than silymarin, however the anti-inflammatory response was in accordance with or lower than indomethacin.     

Effect of Gamma Radiation-grafted Aramid Chopped Fibers as the Reinforcing Filler in Styrene–Butadiene Rubber Mixtures

Poly(p-phenylene-terephthalamide) PPTA chopped fibers, known as Kevlar 49 and related to aramid fibers, were subjected to graft copolymerization with styrene under the effect of gamma radiation. The effects of different parameters including irradiation dose, type of solvent and monomer concentration on the graft yield were studied. The surface-modified chopped fibers were introduced in styrene–butadiene rubber (SBR) mixtures. The properties of rubber mixtures and their corresponding vulcanizates were markedly affected depending on the fiber concentration. Grafting of styrene on to chopped PPTA fibers improves the mechanical properties of SBR–PPTA composites, especially in the presence of additional crosslining systems based on benzoyl peroxide EDMA (ethylene dimethacrylate) system. © 1997 John Wiley & Sons, Ltd.     

Immunoadjuvant and Humoral Immune Responses of Garlic (Allium sativum L.) Lectins upon Systemic and Mucosal Administration in BALB/c Mice

Dietary food components have the ability to affect immune function; following absorption, specifically orally ingested dietary food containing lectins can systemically modulate the immune cells and affect the response to self- and co-administered food antigens. The mannose-binding lectins from garlic (Allium sativum agglutinins; ASAs) were identified as immunodulatory proteins in vitro. The objective of the present study was to assess the immunogenicity and adjuvanticity of garlic agglutinins and to evaluate whether they have adjuvant properties in vivo for a weak antigen ovalbumin (OVA). Garlic lectins (ASA I and ASA II) were administered by intranasal (50 days duration) and intradermal (14 days duration) routes, and the anti-lectin and anti-OVA immune (IgG) responses in the control and test groups of the BALB/c mice were assessed for humoral immunogenicity. Lectins, co-administered with OVA, were examined for lectin-induced anti-OVA IgG response to assess their adjuvant properties. The splenic and thymic indices were evaluated as a measure of immunomodulatory functions. Intradermal administration of ASA I and ASA II had showed a four-fold and two-fold increase in anti-lectin IgG response, respectively, vs. the control on day 14. In the intranasal route, the increases were 3-fold and 2.4-fold for ASA I and ASA II, respectively, on day 50. No decrease in the body weights of animals was noticed; the increases in the spleen and thymus weights, as well as their indices, were significant in the lectin groups. In the adjuvanticity study by intranasal administration, ASA I co-administered with ovalbumin (OVA) induced a remarkable increase in anti-OVA IgG response (~six-fold; p < 0.001) compared to the control, and ASA II induced a four-fold increase vs. the control on day 50. The results indicated that ASA was a potent immunogen which induced mucosal immunogenicity to the antigens that were administered intranasally in BALB/c mice. The observations made of the in vivo study indicate that ASA I has the potential use as an oral and mucosal adjuvant to deliver candidate weak antigens. Further clinical studies in humans are required to confirm its applicability.