Mitochondria are specifically vulnerable to 420nm light in drosophila which undermines their function and is associated with reduced fly mobility

Increased blue light exposure has become a matter of concern as it has a range of detrimental effects, but the mechanisms remain unclear. Mitochondria absorb short wavelength light but have a specific absorbance at 420nm at the lower end of the human visual range. This 420nm absorption is probably due to the presence of porphyrin. We examine the impact of 420nm exposure on drosophila melanogaster mitochondria and its impact on fly mobility. Daily 15 mins exposures for a week significantly reduced mitochondrial complex activities and increased mitochondrial inner membrane permeability, which is a key metric of mitochondrial health. Adenosine triphosphate (ATP) levels were not significantly reduced and mobility was unchanged. There are multiple options for energy/time exposure combinations, but we then applied single 420nm exposure of 3h to increase the probability of an effect on ATP and mobility, and both were significantly reduced. ATP and mitochondrial membrane permeability recovered and over corrected at 72h post exposure. However, despite this, normal mobility did not return. Hence, the effect of short wavelengths on mitochondrial function is to reduce complex activity and increasing membrane permeability, but light exposure to reduce ATP and to translate into reduced mobility needs to be sustained.

Quantitative Spectrophotometric Estimation of Prednisolone in Tablet Dosage Form Using Eco-friendly Green Solvent and by applying Beer-Lambert’s Law Mathematical Equation Method

Prednisolone is a widely used synthetic glucocorticoid drug used in the treatment of allergies, inflammatory conditions, auto-immune disorders, acute and chronic obstructive pulmonary disease, rheumatoid arthritis, systemic lupus erythematosus, dermatitis, eye inflammation, asthma and multiple sclerosis. A simple and economical method was developed using eco-friendly green solvent. In this developed method the eco-friendly green solvent used was ethanol which is available easily. The method was projected to quantitative estimation and assay of Prednisolone in Prednisolone dispersible tablet dosage form. The amount and percent label claim of Prednisolone in tablet dosage form was estimated using Beer-Lambert’s law. Specific absorbance (A1%1cm) of Prednisolone is 415 at lambda max of 243 nm. The method developed was validated as per ICH guidelines. The proposed method was found to be simple, accurate, sensitive, precise, linear and rugged. The method obeys Beer-Lambert’s Law in the concentration range of 2.5-20μg/mL, as the r2 value was found to be 1.000. The mean percent recovery was found to be within acceptable range as per ICH guidelines. Hence the developed method can be used in regular quantitative analysis. The developed method acquires only one green solvent, low cost analytical equipment and the percent label claim can be calculated in the assay of Prednisolone tablets without using any standards solution or standard graph by just employing specific absorbance value in Beer-Lambert’s law, thereby concentration of drug can be calculated. As this method is simple, economical and eco-friendly it can be used elegantly and routinely in analytical laboratories and industries for estimation of Prednisolone in tablet formulation.

The metrological parameters of diosmin quantitation in pharmaceutical dosage forms

Introduction. Pharmaceutical dosage forms with diosmin are allowed for medical use in Russian Federation. Simple and informative methods of diosmin quantitation for drug quality control are needed. Aim: determination of metrological parameters of diosmin quantitation in pharmaceutical dosage forms by UV-spectrophotometry. Matherials and methods. The study subjects Venarus, Detralex (tablets, suspension), Phlebopha. Diosmin were quantified by UV-spectrophotometry. The reference-specific absorbance values of diosmin at wavelengths of 268 and 370 nm by the parameters of calibration were determined. Statistical data processing was carried out by the methods of variation statistics, correlation, one-way analysis of variance using computer programs ChemMetr 1.0, ChemMetr Evaluation 1.0, Statistica 6.0 (Statsoft Inc., USA). Results. The range of diosmin quantitation by UV-spectrophotometry was revealed for the wavelength of 268 nm 0,0001-0,001%, 370 nm 0,0002-0,002%. The reference-specific absorbance values for diosmin at the wavelength of 268 and 370 nm in a sodium hydroxide solution 0,02M were 463,0 24,6 and 259,0 9,9 respectively. The mean errors of diosmin concentrations in pharmaceutical dosage forms were revealed for the wavelength of 268 nm 8-12% and for 370 nm 6-8%. Prognostic calculation of the sample preparation error (extraction) for diosmin was performed using the example of Detralex tablets. The sample preparation error was 8%. Conclusion. The values components of error for reference-specific absorbance value and sample preparation error for diosmin quantitation were determined (as exemplified by the study of Detralex tablets). Calculation algorithms can be used for error estimation of sample preparation for other multicomponent samples in drug quality control.

Determination of Specific Absorbance (A¦) for Six Psychoactive Drugs Encountered in Forensic Toxicology

Specific absorbance (A¦) is defined as the maximum absorbance of a 1% solution over a 1-cm path length measured via spectroscopy. Finding a reliable value for specific absorbance for a drug provides an important tool for the quantitative verification of concentration of analytical standards. Although many new drugs have emerged within the last ten years, many either do not have a reliable value for A¦, or a value simply has never been published. This work focused on determining the quantitative value of the specific absorbance of six psychoactive drugs using ultraviolet-visible spectroscopy, as well as comparing A¦ values of drugs purchased in 2017 to A¦ of their counterparts purchased in 2019. The drugs analyzed included Iloperidone, Risperidone, Aripiprazole, Vilazodone, Vortioxetine and Suvorexant.

Comprehensive Investigation of Thermal Degradation Characteristics and Properties Changes of Plant Edible Oils by FTIR-Spectroscopy

Structural characterization of edible oils after thermal treatment was made by (FTIR) spectroscopy. Olive, corn and sunflower oil samples were thermally treated at three consecutive cycles. Each cycle consisted of heating at the boiling point for 8 h, followed by cooling at room temperature for 16 h. At the end of each cycle the characteristics of oils were studied by FTIR spectroscopy and standard methods. Study of FTIR spectra of the treated oils revealed that the heating of oils caused significant changes in the intensities of their bands and produced shifts in the position of specific bands such as 3008 cm−1 and 1745 cm−1. The level of oil oxidation during different heating period was followed by the absorbance ratio at 3530/3472 cm−1. Additionally, the absorbance ratio 2853/3008 cm−1 was used as a measure of degree of unsaturation. The thermal heating of oils produced an initial decrease in the specific absorbance ratios which could be attributed to the reduction of unsaturated fatty acid content due to oxidation process. The results in this study demonstrated that FTIR could be used for assessment of the state of oils by using specific absorbance ratios as indicators.

Propolis as a potential alternative for the control of Dekkera bruxellensis in bioethanol fermentation

Dekkera bruxellensis is one of the most important contaminant yeasts of alcoholic fermentation. The use of propolis, which can selectively target contaminating yeasts without affecting the starter one, Saccharomyces cerevisiae, could be a useful nonconventional strategy for controlling the growth of contaminant yeasts. The objective of this research was to evaluate four samples of propolis produced by Apis mellifera honeybees from different regions of Argentina as antimicrobial agents against the growth of D. bruxellensis and S. cerevisiae. Hydroalcoholic extracts of propolis were prepared with ethanol:water (70:30 v/v), and the specific absorbance and final concentration of the samples were evaluated. A qualitative in vitro assay in solid medium was performed with different propolis concentrations, and the evaluation of yeast growth was based on a qualitative scale. A quantitative in vitro assay in liquid medium was also performed to assess the yeast cell number, using two different propolis concentrations. The cell number of D. bruxellensis decreased 1.52 and 1.85 log cycles with the two propolis extracts utilised at a concentration of 4.5 mg mL-1 while the cell number of S. cerevisiae decreased 0.48 and 0.76 log cycles with the same samples of propolis. The results from both assays demonstrated the selectivity of propolis use on the yeast species, leading to a higher inhibition of D. bruxellensis growth. This indicates a good potential for using propolis at the concentration of 4.5 mg mL-1, as a nonconventional strategy to control the growth of D. bruxellensis without significantly affecting S. cerevisiae, the yeast starter of ethanol fermentation.

Patterns of dissolved organic matter across the Patagonian landscape: a broad-scale survey of Chilean and Argentine lakes

Dissolved organic matter (DOM) is a complex mixture of carbon compounds from autochthonous and allochthonous sources. Dissolved organic carbon (DOC) concentrations and optical metrics of DOM provide clues as to the sources and processes affecting the DOM pool. Herein we provide the first broad-scale characterisation of DOM from Patagonian lakes across a strong west–east precipitation gradient. Fifty-eight lakes from Northern Patagonia (Argentina and Chile) plus six lakes from the Antarctic Peninsula were sampled during summer 2000–01. Six DOM metrics were evaluated: DOC absorbance at 254nm (a254) and 350nm (a350), DOC-specific absorbance at 254nm (a254/DOC) and 350nm (a350/DOC) and spectral slope between 275 and 295nm (S275–295). The DOM of Chilean maritime lakes and shallow (<15m) Andean lakes exhibited terrestrial signatures and a pattern of variation consistent with their occurrence across the longitudinal precipitation gradient (i.e. S275–295 increased, whereas a350/DOC decreased from west to east). The contribution of allochthonous DOM was smaller in deep (>15m) Andean lakes, which is consistent with their longer water retention time. Steppe lakes, mostly from endorheic basins, made up the most heterogeneous group with regard to DOM characteristics.

Determination of Lutein and Zeaxanthin Esters and Their Geometric Isomers in Carotenoid Ester Concentrates Used as Ingredients in Nutritional Supplements: Validation of a Combined Spectrophotometric-HPLC Method

A combined spectrophotometric-LC method is described for the determination of total lutein and zeaxanthin ester content in carotenoid ester concentrates, including their main geometrical isomers. The concept of composite-specific absorbance is introduced for this purpose. The method is applicable to carotenoid ester concentrates used as ingredients in oil suspensions and dosage forms. The sample is dissolved in a hexane–2-propanol mixture (95 + 5, v/v) for spectrophotometric measurement at a maximum absorption of ~445 nm. Subsequently, in parallel, a sample is saponified and chromatographed on a normal-phase HPLC column to determine the relative percentage profile of the main geometrical isomers of both carotenoid esters. This, in turn, is used to calculate the composite-specific absorbance of the sample for the final calculation of results. The method, which solely uses reference standards to validate chromatographic conditions, avoids the common error of applying the specific absorbance of only the trans isomer for the calculation of total carotenoid content when cis isomers are present.