Optimized Degradation and Inhibition of α-glucosidase Activity by Gracilaria lemaneiformis Polysaccharide and Its Production In Vitro

Gracilaria lemaneiformis polysaccharide (GLP) exhibits good physiological activities, and it is more beneficial as it is degraded. After its degradation by hydrogen peroxide combined with vitamin C (H2O2-Vc) and optimized by Box–Behnken Design (BBD), a new product of GLP-HV will be generated. While using GLP as control, two products of GLP-H (H2O2-treated) and GLP-V (Vc-treated) were also produced. These products chemical characteristics (total sugar content, molecular weight, monosaccharide composition, UV spectrum, morphological structure, and hypolipidemic activity in vitro) were assessed. The results showed that the optimal conditions for H2O2-Vc degradation were as follows: H2O2-Vc concentration was 18.7 mM, reaction time was 0.5 h, and reaction temperature was 56 °C. The total sugar content of GLP and its degradation products (GLP-HV, GLP-H and GLP-V) were more than 97%, and their monosaccharides are mainly glucose and galactose. The SEM analysis demonstrated that H2O2-Vc made the structure loose and broken. Moreover, GLP, GLP-HV, GLP-H, and GLP-V had significantly inhibition effect on α-glucosidase, and their IC50 value were 3.957, 0.265, 1.651, and 1.923 mg/mL, respectively. GLP-HV had the best inhibition effect on α-glucosidase in a dose-dependent manner, which was the mixed type of competitive and non-competitive. It had a certain quenching effect on fluorescence of α-glucosidase, which may be dynamic quenching.

INVESTIGATION OF THE POSSIBILITY OF USING THE METHOD OF DIFFERENTIAL SPECTROPHOTOMETRY FOR THE ANALYSIS OF OVERLAPPING ABSORPTION BANDS OF TRITERPENE SAPONINS CHROMOPHORES AND THEIR QUANTITATIVE DETERMINATION IN AQUEOUS SOLUTIONS

A detailed analysis of the absorption spectra of mono- and bidesmoside triterpene glycosides was performed. It is suggested that the maximum in the region of 198–208 nm is attributed to the absorption of the double bond in the cyclohexene ring of the aglycone. The second less seen maximum at a wavelength of 280 nm is observed in the spectrum of saponin Quillaja Saponaria and is almost completely absent in the spectrum of saponin Mukorossi Sapindus. Identification of this maximum is extremely difficult, since its presence can be due to both the aldehyde group in the aglycone and the hydroxyl and carboxyl groups in the carbohydrate molecules. Using the method of differential spectrophotometry, a method for decomposing the UV spectrum of saponins into its constituent components is proposed and justified. A spectral analysis was performed, including the assignment of the absorption bands to the functional groups of the studied compounds. The possibility of estimating changes in the spectral properties of glycoside solutions with changes in the acidity of the medium is considered. The possibility of a bathochromic shift of the maximum absorption of the aglyconic part of saponin depending on the microenvironment (the structure of the carbohydrate part) and changes in the pH of the solution is established. It is shown that the bands at 274, 280.5 nm correspond to n-π* transitions of carbonyl and carboxyl groups and are determined only in the regions of high concentrations in Quillaja Saponaria saponin solutions. Based on the results obtained, calibration models for the quantitative determination of saponins in solutions are proposed. The regression analysis of the calibration equations is carried out, the main statistical indicators are calculated.

Studies on meropenem and cefixime metal ion complexes for antibacterial activity

Background The metal ion complexes of meropenem and cefixime with cadmium, silver, palladium, zinc, nickel, cobalt and copper were synthesized and characterized by UV, FTIR and H1-NMR spectrophotometry. The antibacterial effects of the complexes were studied using cup and plate method against S. aureus, B. subtilis, E. coli, P. aeruginosa and K. pneumoniae for normal and resistant strains of bacteria. The minimum inhibitory concentration of the metal ion complexes was determined by broth dilution method. Results UV spectroscopic studies suggested that meropenem ligand form complex with different metal ions and FTIR spectrum confirmed the proposed structure. Similarly, UV spectrum of cefixime metal ion complexes at λmax 202–295 nm and meropenem metal ion complexes at λmax 249–304 nm was observed in all the complexes. FTIR peaks for a proposed structure were observed in all the meropenem and cefixime metal ion, indicating the formation of complexes, and retained the functional groups of drugs. Meropenem as well as cefixime metal ion complexes exhibited more antibacterial activity against all the selected bacterial strains. Specifically, the lowest minimum inhibitory concentration against P. aeruginosa and K. pneumoniae was observed to be 100 and 150 μg/ml, respectively. Conclusion The present study concluded that the meropenem and cefixime metal complexes can exhibit the better treatment than individual drug on normal as well as resistant bacteria.

SDSS J1059+4251, a Highly Magnified z ∼ 2.8 Star-forming Galaxy: ESI Observations of the Rest-frame UV Spectrum

Detailed analyses of high-redshift galaxies are challenging because these galaxies are faint, but this difficulty can be overcome with gravitational lensing, in which the magnification of the flux enables spectroscopy with a high signal-to-noise ratio (S/N). We present the rest-frame ultraviolet (UV) Keck Echellette Spectrograph and Imager (ESI) spectrum of the newly discovered z = 2.79 lensed galaxy SDSS J1059+4251. With an observed magnitude F814W = 18.8 and a magnification factor μ = 31 ± 3, J1059+4251 is both highly magnified and intrinsically luminous, about two magnitudes brighter than M UV * at z ∼ 2–3. With a stellar mass M * = (3.22 ± 0.20) × 1010 M ⊙, star formation rate SFR = 50 ± 7 M⊙ yr−1, and stellar metallicity Z * ≃ 0.15–0.5 Z ⊙, J1059+4251 is typical of bright star-forming galaxies at similar redshifts. Thanks to the high S/N and the spectral resolution of the ESI spectrum, we are able to separate the interstellar and stellar features and derive properties that would be inaccessible without the aid of the lensing. We find evidence of a gas outflow with speeds up to −1000 km s−1, and of an inflow that is probably due to accreting material seen along a favorable line of sight. We measure relative elemental abundances from the interstellar absorption lines and find that α-capture elements are overabundant compared to iron-peak elements, suggestive of rapid star formation. However, this trend may also be affected by dust depletion. Thanks to the high data quality, our results represent a reliable step forward in the characterization of typical galaxies at early cosmic epochs.

Plastic mulches reduce adult and larval populations of Drosophila suzukii in fall-bearing raspberry

The invasive spotted-wing drosophila, Drosophila suzukii, is a major pest of fruit crops worldwide. Management of D. suzukii relies heavily on chemical control in both organic and conventional systems, and there is a need to develop more sustainable management practices. We evaluated the efficacy of three colors of plastic mulches at reducing populations of D. suzukii in fall-bearing raspberry and assessed the mulches’ impacts on canopy microclimate factors relevant to D. suzukii. Black, white, and metallic plastic mulches reduced adult D. suzukii populations by 42–51% and larval populations by 52–72% compared to the grower standard. The mulches did not change canopy temperature or relative humidity, but metallic mulches increased canopy light intensity compared to the black mulch. Radiance in the visible spectrum (401–680 nm) was higher for the white and metallic mulch plots, but the black mulch plots did not differ from the control. In the UV spectrum (380–400 nm), all three plastic mulches had higher radiance than the control plots. Future studies will determine whether changes in radiance are associated with the observed reduction in D. suzukii populations. Plastic mulches are a promising cultural practice for managing D. suzukii since they can reduce adult and larval populations and could be incorporated into an integrated pest management program in both organic and conventional systems.

Chromatographic Method for Quantification of Tenofovir in Pharmaceutical Formulations: Comparison with Spectrophotometric Method

Aims: An efficient therapeutic drug or antiviral agent to treat Covid-19 is still not available. But, previously licensed pharmaceuticals to treat other virus infections are usedon an off-label basis either alone or in combination. Tenofovir emerged as a promising treatment for Covid-19 in September 2020. It is an antiretroviral drug that is active against many viruses. This study explains the development and asessment of liquid chromatographic and UV spectrophotometric methods to quantify tenofovir in raw materials and tablets. Methods: HPLC analyzes were performed using a C18 column and a mobile phase composed of 20 mM KH2PO4, with a flow rate of 0.8 mLmin-1 and UV detection at 260 nm. For the spectrophotometric analyzes, ultra-pure water was used as a solvent. UV spectrum of standard and sample solution were recorded between 200 and400 nm and Tenofovir was detected using a wavelength of 260 nm. Both methods have been validated according to the procedures described in ICH guidelines Q2(R1) for the validation of analytical methods. Results: The results showed that both spectrophotometric and liquid chromatographic methods were linear, precise, accurate, rugged and robust with relative standard deviation R.S.D.% values less than 1%, and the recovery percentage was within standard limits (98-102%). Then a statistical comparison of these two analytical methods was performed, and the results of both methods showed no significant difference. It was found that both methods were not statistically significant with respect to each other in the 95% confidence interval (p<0.05). As a result, the proposed methods were found to be highly effective and could be used for routine analysis of tenofovir in pharmaceutical formulations.

Environmentally Benign Organic Dye Conversion under UV Light through TiO2-ZnO Nanocomposite

In this work, we developed a very simple and novel approach for synthesizing TiO2-ZnO nanocomposites via the urea-assisted thermal decomposition of titanium oxysulphate and zinc acetate at different weight ratios. The synthesized nanocomposite samples were studied by means of HR-TEM, XRD, STEM, UV–Vis DRS, PL and EDS. The observed results demonstrate that the TiO2-ZnO nanocomposite consists of an anatase crystal phase of TiO2 with a crystallite size of 10–15 nm. Combined characterization, including UV–Vis DRS, STEM, EDS and HR-TEM, revealed the successful formation of a heterojunction between TiO2 and ZnO and an improvement in UV spectrum absorption. The photocatalytic activity was explored using MO degradation under ultraviolet light illumination. The results of the optimized TiO2-ZnO nanocomposite show excellent photocatalytic activity and photostability over a number of degradation reaction cycles. In addition, the current approach has immense potential to be used as a proficient method for synthesizing mixed metal oxide nanocomposites.

Synthesis of Copper Nanoparticles Using Aspergillus Niger and Their Efficacy Against Pathogenic Staphylococcus Aureus

The attention has been paid in recent years to the biosynthesis of copper nanoparticles (CuNPs) and their important in medical applications. This study was conducted to synthesis of CuNPs using Aspergillus niger supernatant, study its characteristic and their antibacterial activity alone or with Ciprofloxacin against Staphylococcus aureus isolated from wounds infection. Then, its activity on the healing wounds was experimentally induced with Staphylococcus aureus using laboratory Hamster., followed by assaying of some blood parameters. The results indicated that Aspergillus niger supernatant was optimal for converting the CuNO3 to produce of CuNPs. The CuNPs were confirmed by UV spectrum, revealed an absorption at 225 nm, and the average size was by 20 nm after assay with the scanning electron microscopy (SEM). The mixing between CuNPs and ciprofloxacin had increased by 60% in the antibacterial activity against Staphylococcus aureus, more than for single inhibition activity of each treatment. The CuNPs or ciprofloxacin singly or in combination treated of induced experimentally contaminated wounds with Staphylococcus aureus appeared that synergism healing effects of the mixed treated with a short time compared with single treatments. The treatment of induced wounds with Staphylococcus aureus were significantly (p<0.05) increased in number of the WBCs and decreased of platelets number. While, the treatments with CuNPs or Ciprofloxacin singly or in combination were not significantly different with the same parameters in control group. Furthermore, the Hb, RBCs and PCV were not significantly different in all treatments. Furthermore, the values of urea and creatinine further of the IgG and IgA for all animals’ groups were reduced compared with the same values in infections animal group., GOT, GPT of liver enzymes values.were also showed a significant decreasing.

UV Spectrophotometric Method Development and Validation of Lignocaine Hydrochloride in Bulk and Semisolid Dosage Form

Objective: A new, simple, sensitive, precise and reproducible UV spectroscopic method was developed for the estimation of Lignocaine Hydrochloride in bulk and Semisolid Formulation. Methods: The UV spectrum of Lignocaine Hydrochloride in RO water showed λ max at 228.8nm. Beer’s law is valid in the concentration range of 20-100µg/ml. This method was validated for linearity, accuracy, precision, ruggedness and robustness. Results: The method has demonstrated excellent linearity over the range of 20-100µg/ml with regression equation y = 0.0097x + 0.023 and regression correlation coefficient r2= 0.9992. Moreover, the method was found to be highly sensitive with LOD (3.55μg/ml) and LOQ (10.75μg/ml). Conclusion: Depending on results the given method can be successfully applied for assay of Lignocaine Hydrochloride in Semisolid formulation.