Spectrophotometric Method Research Articles

In Vivo Evaluation of Innovative Gadolinium-Based Contrast Agents Designed for Bioimaging Applications.

The aim of this study was the investigation of biochemical and histological changes induced in different tissues, as a result of the subcutaneous administration of Gd nanohydrogels (GdDOTA⸦CS-TPP/HA) in a CD-1 mouse strain. The nanohydrogels were obtained by encapsulating contrast agents (GdDOTA) in a biocompatible polymer matrix composed of chitosan (CS) and hyaluronic acid (HA) through the ionic gelation process. The effects of Gd nanohydrogels on the redox status were evaluated by measuring specific activities of the antioxidant enzymes catalase (CAT), glutathione peroxidase (GPx), and superoxide dismutase (SOD), as well as oxidative stress markers, such as reduced glutathione (GSH), malondialdehyde (MDA), advanced oxidation protein products (AOPP), and protein-reactive carbonyl groups (PRCG), in the liver, kidney, and heart tissues. The nitrosylated proteins expression were analyzed with Western Blot and the serum biochemical markers were measured with spectrophotometric methods. Also, a histological analysis of CD-1 mouse tissues was investigated. These results indicated that Gd nanohydrogels could potentially be an alternative to current MRI contrast agents thanks to their low toxicity in vivo.

Study of the Fenton Oxidative Reaction on a Culture of Human Fibroblast Cells Incubated with Ablated CeO<sub>2</sub> Particles

Purpose. Study of the bioprotective properties of ablated cerium dioxide nanoparticles in relation to immortalized human fibroblasts under conditions of oxidative stress caused by the Fenton reaction.Methods. Cerium dioxide nanoparticles with pronounced antioxidant properties were obtained using laser ablation. The average maximum sizes of ablated particles of oxidized cerium in non-centrifuged and centrifuged at a speed of 1000 rpm nanodispersed aqueous solutions were revealed using the method of atomic force microscopy. The spectrophotometric method revealed that ablated cerium dioxide nanoparticles exhibit antioxidant properties and prevent the degradation of the methylene blue dye during the Fenton reaction. Cell culture samples were mapped using scanning electron microscopy using an energy-dispersive attachment after their incubation with ablated cerium dioxide nanoparticles. Using MTT analysis, the effect of ablated cerium dioxide nanoparticles on the survival of BJ TERT cell culture in the Fenton reaction was studied. Non-centrifuged and centrifuged at a speed of 1000 rpm nanodispersed solutions of oxidized cerium were used. The antioxidant activity of cerium dioxide nanoparticles after 6- and 24-hour incubation was studied.Results. The average limiting sizes of ablated cerium dioxide nanoparticles have been established, the values of which are (61,95±0,1) nm for a non-centrifuged aqueous solution and (56,59±0,1) nm for an aqueous solution centrifuged at a microcentrifuge speed of 1000 rpm. It was revealed that in the presence of ablated cerium dioxide nanoparticles, the degree of oxidative degradation of methylene blue during the Fenton reaction was significantly reduced. It was found that with an increase in the concentration of ablated cerium dioxide nanoparticles from 20 to 1000 mg/l, their antioxidant effect increased. From the obtained SEM images of cell cultures with ablated cerium dioxide nanoparticles, it follows that the nanoparticles are captured by cells during incubation and can have a significant effect on oxidative processes during the Fenton reaction. Statistical analysis based on the results of the MTT assay showed that 6-hour and 24-hour incubation with ablated cerium dioxide nanoparticles had a pronounced protective effect on the BJ TERT cell line.Conclusion. This work shows that during the Fenton reaction, cerium dioxide nanoparticles prevent the oxidative degradation of the methylene blue dye. When immortalized human fibroblasts are incubated, ablated cerium oxide nanoparticles are taken up by the cells and have a significant protective effect on them in the oxidative reaction. The high antioxidant activity of nanoparticles is determined by the high content of functional defects on the surface of nanoparticles obtained under sharply nonequilibrium conditions of laser ablation.

An eco-friendly spectrophotometric analysis tool with whiteness assessment to assay erythromycin in pharmaceutical formulation through metal complexation with Ni2+: application to the microbiological activity using agar diffusion method

A new, facile and eco-friendly spectrophotometric method for estimating erythromycin (ERY) in its dosage form has been proposed and validated. It depends on the formation of a complex between the drug and nickel at pH 7, using distilled water as a diluent, where the absorbance of the generated complex was measured at 228.5 nm. The formed complex followed a linear response over the concentration range of 80.0 to 300.0 µg/mL of ERY. The proposed method was fully validated according to international conference of harmonization (ICH) and was used to estimate the relevant concentration of the drug in its oral suspension formulation providing mean percentage recovery of 100.0±1.08 with a limit of detection and limit of quantification of 60 µg/mL and 80 µg/mL, respectively. the reaction stoichiometry was investigated and a reaction mechanism proposal was offered. Eventually, the antimicrobial effect of ERY and its metal complex with Ni2+ were compared using agar diffusion method, where no significant difference in their activities was observed.

Renoprotective effect of diacerein in rats with partial unilateral ureteral obstruction model

Abstract Objectives We aimed to analyze the effects of diacerein in a rat model of partial unilateral ureteral obstruction (PUUO). Methods We randomly divided 24 female rats into three groups. Control group, PUUO group and PUUO + diacerein group. The PUUO group was subjected to the PUUO model for seven days. The PUUO + diacerein group received oral diacerein (80 mg/kg) for seven days. Spectrophotometric methods were employed to measure oxidative stress parameters, including malondialdehyde (MDA), protein carbonyl (PC) and antioxidant enzyme levels, including glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD), while indicators of renal function, such as kidney injury molecule-1 (KIM-1) and neutrophil gelatinous-associated lipocalin (NGAL), along with inflammatory parameters interleukin-1 beta (IL-1beta), tumor necrosis factor-alpha (TNF-alpha), and interleukin-6 (IL-6), were assessed using the ELISA method. Inflammatory parameters were measured in blood samples, and other parameters were analyzed in kidney tissue. Hematoxylin-eosin method examinations were used for histological analyses. Results IL-1beta, TNF-alpha, and IL-6 levels were found to be significantly decreased in the PUUO + diacerein group compared to the PUUO group (p=0.006, p=0.002 and p=0.001, respectively). In the PUUO + diacerein group, GSH-Px and SOD activities increased compared with the PUUO group (p=0.031 and p=0.037, respectively). We also observed a significant improvement in renal function parameters, such as KIM-1 and NGAL levels in the PUUO + diacerein group compared to PUUO (p=0.002 and p=0.012, respectively). The PC and MDA levels were highest in the PUUO group (p<0.001). Similarly, the histopathologic tissue damage was the most prominent PUUO group (p<0.001). Conclusions Our study found that diacerein is a highly effective pharmacologic agent in alleviating oxidative damage in PUUO model rats.

Green Approach for Synthesis of Silver Nanoparticles with Antimicrobial and Antioxidant Properties from Grapevine Waste Extracts.

The present work aims to study the possibilities of developing silver nanoparticles using natural extracts of grape pomace wastes originating from the native variety of Fetească Neagră 6 Șt. This study focused on investigating the influence of grape pomace extract obtained by two different extraction methods (classical temperature extraction and microwave-assisted extraction) in the phytosynthesis process of metal nanoparticles. The total phenolic content of the extracts was assessed using the spectrophotometric method with the Folin-Ciocâlteu reagent, while the identification and quantification of specific components were conducted through high-performance liquid chromatography with a diode array detector (HPLC-DAD). The obtained nanoparticles were characterized by UV-Vis absorption spectroscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM), along with assessing their antioxidant and antimicrobial properties against Gram-positive bacteria. The data collected from the experiments indicated that the nanoparticles were formed in a relatively short period of time (96 h) and, for the experimental variant involving the use of a 1:1 ratio (v/v, grape pomace extract: silver nitrate) for the nanoparticle phytosynthesis, the smallest crystallite sizes (from X-ray diffraction-4.58 nm and 5.14 nm) as well as spherical or semispherical nanoparticles with the lowest average diameters were obtained (19.99-23 nm, from TEM analysis). The phytosynthesis process was shown to enhance the antioxidant properties (determined using the DPPH assay) and the antimicrobial potential (tested against Gram-positive strains) of the nanoparticles, as evidenced by comparing their properties with those of the parent extracts; at the same time, the nanoparticles exhibited a selectivity in action, being active against the Staphylococcus aureus strain while presenting no antimicrobial potential against the Enterococcus faecalis strain.

Spectrophotometric Determination of Selenium in Food Items

Selenium (Se) is an essential element that is obtained from food. To increase the level of selenium in the body, we should consume selenium-rich foods in our diet. The objective of this study was to develop a simple spectrophotometric method for the quantitative analysis of selenium present in food. This study included six food items such as broccoli, cabbage, red cabbage, fenugreek, garlic, and ginger. The new method is based on the yellow colour complex formed by the reaction between 2% potassium iodide and 0.2% pyridine in acidic medium with the selenium. Absorbance was measured at 400 nm against the reagent blank. The results of the above proposed method were compared with the reference method of using potassium iodide and starch as reagents. The selenium content in the examined food samples was determined from the regression equation of the calibration curve y= 0.0799x+0.3477 respectively. All the analyses were performed in triplicate, and the results are expressed as mean ± standard deviation. The highest mean selenium value was obtained in ginger and garlic 18.70 & 18.32 µg/g, respectively among all the studied samples, while the lowest value was in fenugreek seeds 7.38 µg/g. The proposed method is simple, rapid, sensitive, and obeys Beer–Lambert’s law. The proposed method was successfully applied to determine food items. Selenium has been quantitatively analysed for its potential to protect the body from many degenerative diseases. Selenium-rich food, as studied here, should be used as a supplement in the human diet.

Three new constituents from the stems of Knema globularia and their α-glucosidase inhibitory activity

Three new metabolites (1−3) were isolated from the stems of Knema globularia, along with five known compounds, including kaempferol (4), quercetin (5), isovanillic acid (6), protocatechuic acid (7), and gallic acid (8). Their structures were deduced using NMR spectroscopic, mass spectrometric analyses, and literature data. The absolute configurations of 1−3 were established by electronic circular dichroism (ECD) spectroscopy. α-Glucosidase inhibitory activities of those compounds were evaluated using a spectrophotometric method, compounds 1−3 showed very strong effects towards α-glucosidase with IC50 values 1.59, 0.58 and 1.37 µM, respectively (the positive control, acarbose, IC50 93.63 µM). Simultaneously, enzyme kinetics study indicated that 2 was a mix-type inhibitor. 2 interacted well in the active site of α-glucosidase enzyme, primarily through hydrogen bonds and hydrophobic interactions.

The study of antioxidant compounds in grape seeds

This paper uses spectrometric as well as chromatographic techniques to investigate the antioxidant properties of extracts from vine seeds (Vitis vinifera L.). For the study, ten vine varieties from the years 2015, 2016, along with 2017 were chosen. Four essentially distinct spectrophotometric methods were used to measure the antioxidant activity, whereas the Folin-Ciocalteu procedures were used to determine the level of total polyphenolic compounds. The composition of fourteen antioxidants was investigated in 2015. The study's findings indicate that grape seeds have a high level of antioxidant components, with variations in content between types and years. Grape seed extracts have potential applications in nutraceuticals, health supplements, as well as food product preservation.

Validation of UV–Vis spectrophotometric and colorimetric methods to quantify methotrexate in plasma and rat skin tissue: Application to in vitro release, ex vivo and in vivo studies from dissolving microarray patch loaded pH-sensitive nanoparticle

This research transformed MTX into smart nanoparticles that respond to the acidic conditions present in inflammation. These nanoparticles were then incorporated into a patch that dissolves over time, aiding their penetration. A method using UV–Vis spectrophotometry was validated to support the development of this new delivery system. This method was used to measure the quantity of MTX in the prepared patches in various scenarios: in laboratory solutions with pH 7.4 and pH 5.0, in skin tissue, and plasma. This validation was conducted in laboratory studies, tissue samples, and live subjects, adhering to established guidelines. The resulting calibration curve displayed a linear relationship (correlation coefficient 0.999) across these scenarios. The lowest quantity of MTX that could be accurately detected was 0.6 µg/mL in pH 7.4 solutions, 1.46 µg/mL in pH 5.0 solutions, 1.11 µg/mL in skin tissue, and 1.48 µg/mL in plasma. This validated method exhibited precision and accuracy and was not influenced by dilution effects. The method was effectively used to measure MTX levels in the developed patch in controlled lab settings and biological systems (in vitro, ex vivo, and in vivo). This showed consistent drug content in the patches, controlled release patterns over 24 h, and pharmacokinetic profiles spanning 48 h. However, additional analytical approaches were necessary for quantifying MTX in studies focused on the drug's effects on the body's functions.

ENDOTHELIAL DYSFUNCTION AND GASTROESOPHAGEAL REFLUX DISEASE: STUDY OF COMMON PATHOGENETIC MECHANISMS AND WAYS OF CORRECTION

The aim. To determine the role and place of endothelial dysfunction in the pathogenesis of comorbid gastroesophageal reflux disease (GERD) and obesity by studying the levels of nitric oxide (NO) metabolites in blood and urine. To evaluate the efficacy and benefits of the prescribed therapy, which included the additional inclusion of a peptide compound analogous to leu-enkephalin tyrosine-2-alanine-glycine-phenylalanine-leucyl-arginine diacetate (Dalargin).
 Materials and methods. Clinical manifestations were assessed using the GERD-HRQL questionnaire, levels of stable nitric oxide metabolites NO2 and total metabolites NO2 + NO3 were determined by spectrophotometric method, leptin levels were determined by enzyme-linked immunosorbent assay, pH-metry and motor function was studied by ultrasound. 130 patients were examined, including 70 patients with GERD with comorbid obesity of the first degree, 40 patients with GERD without concomitant pathology and 20 healthy individuals. The study was divided into 3 groups.
 Results. It was determined that the levels of stable metabolites NO2, NO2 + NO3 in blood and urine in the group of GERD with obesity are significantly lower than in the group of isolated GERD (p<0.001). A direct correlation between the level of nitric oxide metabolites in blood and urine and acidity in the stomach and oesophagus was established; an inverse relationship between NO metabolites and the degree of gastrointestinal motor and functional disorders, the severity of clinical manifestations, and the level of hormonal secretion by adipocytes. The supplemental inclusion of Dalargin improved the effectiveness and quality of pathogenetic therapy and achieved a more positive disease dynamics and is recommended for prescription in practice.
 Conclusions. Obesity is a predictor of a more severe course of GERD and more severe endothelial dysfunction. There is a correlation between the severity of endothelial dysfunction and the degree of functional, motor and secretory disorders of the stomach and oesophagus.

Green chemometric-assisted UV-spectrophotometric methods for the determination of favipiravir, cefixime and moxifloxacin hydrochloride as an effective therapeutic combination for COVID-19; application in pharmaceutical form and spiked human plasma

As pharmaceutical analysis progresses towards environmental sustainability, there is a growing need to enhance the safety and health conditions for analysts. Consequently, the incorporation of chemometrics into environmentally friendly analytical methods represents a promising approach. Favipiravir, cefixime, and moxifloxacin hydrochloride have been currently used in COVID-19 treatment. In this study, we develop spectrophotometric methods depending on chemometric based models to measure the levels of favipiravir, cefixime, and moxifloxacin hydrochloride in pharmaceutical preparations and spiked human plasma. It is challenging to determine favipiravir, cefixime, and moxifloxacin simultaneously because of overlap in their UV absorption spectra. Two advanced chemometric models, partial least square (PLS) and genetic algorithm (GA), have been developed to provide better predictive abilities in spectrophotometric determination of the drugs under study. The described models were created using a five-level, three-factor experimental design. The outcomes of the models have been thoroughly assessed and interpreted, and a statistical comparison with recognized values has been taken into consideration. The analytical eco-scale and the green analytical procedure index (GAPI) evaluation methods were also utilized to determine how environmentally friendly the mentioned models were. The outcomes demonstrated how well the models described complied with the environmental requirements.

In vitro and split-faced placebo-controlled in vivo study on the skin rejuvenating effects of cream loaded with bioactive extract of Indigofera argentea Burm.f.

The bioactive extracts of traditional medicinal plants are rich in polyphenols and help to rejuvenate skin. The study was designed to assess the skin rejuvenating effects of a stable cream enriched with 4% I. argentea (IaMe) extract. The quantity of polyphenols by spectrophotometric methods was TPC, 101.55 ± 0.03mg GAE/g and total flavonoid content; 77.14 ± 0.13mg QE/g, while HPLC-PDA revealed gallic acid; 4.91, chlorogenic acid 48.12, p-coumaric acid 0.43, and rutin 14.23μg/g. The significant results of biological activities were observed as DPPH; 81.81% ± 0.05%, tyrosinase; 72% ± 0.23% compared to ascorbic acid (92.43% ± 0.03%), and kojic acid (78.80% ± 0.19%) respectively. Moreover, the promising sun protection effects Sun protection factor of extract (20.53) and formulation (10.59) were observed. The active cream formulation (w/o emulsion) was developed with liquid paraffin, beeswax, IaMe extract, and ABIL EM 90, which was stable for 90 days as shown by various stability parameters. The rheological results demonstrated the active formulation's non-Newtonian and pseudo-plastic characteristics and nearly spherical globules by SEM. The IaMe loaded cream was further investigated on human trial subjects for skin rejuvenating effects and visualized in 3D skin images. Herein, the results were significant compared to placebo. IaMe formulation causes a substantial drop in skin melanin from -1.70% (2 weeks) to -10.8% (12 weeks). Furthermore, it showed a significant increase in skin moisture and elasticity index from 7.7% to 39.15% and 2%-30%, respectively. According to the findings, Indigofera argentea extract has promising bioactivities and skin rejuvenating properties, rationalizing the traditional use and encouraging its exploitation for effective and economical cosmeceuticals.

Biochemical and biological characterization of the venoms of Naja kaouthia and Naja mandalayensis from Myanmar and neutralization effects of BPI cobra antivenom

Snakebite is a neglected public health issue, with many scientific and medical issues to be solved. Cobras are among the most common venomous snakes in Myanmar and are responsible for a considerable number of severe snakebite envenoming. There are three species of cobra (Naja kaouthia, Naja mandalayensis and Ophiophagus hannah) in Myanmar. The study aims to characterize the N. kaouthia and N. mandalayensis venoms and to investigate the efficacy of anti-cobra antivenom (BPI) against the two venoms. Protein components and fibrinogenolytic activity were determined by SDS-PAGE. Enzymatic activities for PLA2, protease and acetylcholinesterase were determined by spectrophotometric method. Anticoagulant activity was determined by recalcification time of citrated human plasma. Myotoxicity, necrotizing activity, median lethal dose (LD50) and median effective dose (ED50) were determined by WHO recommended methods. The SDS-PAGE displayed the proteins and enzymes containing in two venoms were different. N. kaouthia venom exhibited more in PLA2, acetylcholinesterase, anticoagulant, fibrinogenolytic and necrotizing activities than N. mandalayensis venom. N. mandalayensis venom had more protease activity and myotoxicity than N. kaouthia venom. The median lethal dose (LD50) of N. kaouthia and N. mandalayensis venom was 4.33 μg/mouse and 5.04 μg/mouse respectively. Both venoms induced fibrinogen Aα chain degradation in 30 min (N. kaouthia) and in 6 h (N. mandalayensis). The same median effective dose (ED50) (19.56 μg/mouse) showed that anti-NK antivenom can neutralize against lethal effect of N. mandalayensis venom. It can also neutralize the protease activity, anticoagulant activity and fibrinogenolytic activity of both venoms. Immunodiffusion and immunoblotting studies showed that the antivenom recognized its homologous venom (N. kaouthia) and cross-reacted against the heterologous venom (N. mandalayensis). The anti-NK antivenom is suitable to use for N. mandalayensis bite if monospecific antivenom is not available.

Simultaneous biosorption of acid violet and reactive yellow dyes by Cladosporium cladosporioides

AbstractThe synthetic dye mixture of Acid Violet 90 and Reactive Yellow 145 was treated with dead Cladosporium cladosporioides biomass. The individual concentrations were calculated with the first-order derivative spectrophotometric method. The calibration curves were plotted at wavelengths of 578.4 nm and 318.2 nm in the derivative spectrum for Acid Violet 90 and Reactive Yellow 145, respectively. The calculated limit of quantitation value is ~ 2.5 mg/L for Acid Violet 90 and ~ 1.5 mg/L for Reactive Yellow 145. The achieved mean recovery percentage values are around 100%. The highest removal efficiency (100%) was obtained for both dyes at pH 4 using 0.25 g biomass and 50 mg/L of each dye in 60 min reaction time with 150 rpm shaking speed. The hydrochloric acid solution was used for biomass regeneration, and the removal efficiencies remained at 99% and 89% for Acid Violet 90 and Reactive Yellow 145 in the third cycle. Graphical abstract

Smart green versatile spectrophotometric and HPTLC techniques for the investigation of ambroxol, doxycycline, in presence of ambroxol precursor and impurity: Appraisal and comparison with various green metrics

Recently, Countless people have become affected as a result of the Covid-19 crisis. Even after recovery, COVID-19 can lead to respiratory difficulties and lung impairment consequently; bacterial infections have a good possibility of infiltrating our respiratory system due to reduction in respiratory immunity. Therefore, the importance of the chosen mixture of doxycycline and ambroxol becomes clear here curing bacterial illnesses invade respiratory tract. The ternary blend of (DOX) doxycycline hyclate, (AMB) ambroxol hydrochloride, (IMP) chemical ambroxol precursor, and pharmacopeial impurity was quantified using four contemporary, selective, and straightforward methods. Method (I) was area under the curve spectrophotometric method (AUC), where zero order absorption spectra were used for calculating the area under the curve of AMB, IMP, and DOX in ranges of 205–219, 222–245, and 264–290 nm, respectively. Each component's absorptivity values (a) at the chosen area were computed. Method (II) was differential dual wavelength (DDW), where upon collecting the first derivative spectra of AMB, IMP, and DOX, amplitudes at 252–263.4, 236–246.6, and 388.8–420 nm were subtracted, consecutively. Method (III) the mean centering of ratio spectra spectrophotometric method (MCR), peak to peak amplitudes on these resulted spectra were measured at (258.2 and 258.4 nm) for AMB, (264.4 and 264.6 nm) for IMP, and at (230.4 and 230.6 nm) for DOX. In addition, method (IV) HPTLC using a stationary phase made of silica gel HPTLC plates that had been pre-treated with 0.27 M di-sodium-EDTA (pH 9 with 21 % sodium hydroxide). The platform is developed using the eluent of ethyl acetate, acetone, distilled water, and acetic acid (9:2:0.7:0.55, by volume) and scanning by employing ultraviolet light regarding AMB and IMP at 254 nm while DOX at 380 nm. For validating the developed procedures, ICH principles were adhered to. The proposed methods were successful in studying dosage form containing investigated substances. The developed techniques' greenness features were assessed using a variety of greenness parameters, and an environmental evaluation comparison between the current methods and the reported one was done. Obtained methods' statistical analyses were also performed.

Verification of bile acid determination method and establishing reference intervals for biochemical and haematological parameters in third-trimester pregnant women.

The aims of this study were to verify the bile acids (BA) method and to establish reference intervals (RIs) for bile acids (BA) and biochemical and haematological parameters in Croatian pregnant women. BA spectrophotometric method verification was performed on Siemens Atellica Solution CH 930 automated analyser using Sentinel reagent. Stability, precision, trueness, linearity, and RIs, as well as lipemia interference were tested according to CLSI guidelines. BA, biochemical, and haematological parameters were measured in serum (BA, biochemical) and whole blood (haematological) samples of fasting healthy third-trimester pregnant women from Croatia (n=121). The establishment of the RIs was done a priori according to the CLSI EP28-A3C:2010 guideline. Selected reference individuals' data were analysed using parametric, non-parametric, and robust methods. Stability study showed that BA are stable in serum samples for 2days at 20 °C, 14days at 4-8 °C, and 22days at-20 °C. The precision study and adult RIs verification met the criteria. Linearity was verified for the concentration range of 3.5-172.1 μmol/L whereas the lipemia interference test showed a positive bias (%) in BA concentration. The determined reference limits generally exhibited better precision for haematological parameters, being lower than the upper recommended value 0.2, unlike biochemical parameters. Haematological parameters showed notable differences between pregnant and non-pregnant women, while many biochemical parameters' RIs remained similar. Only ALT and GGT showed lower non-comparable RI upper limits in the population pregnant women. Spectrophotometric BA method showed satisfactory performance and all examined parameters were within the set criteria. Moreover, RIs for key biochemical and haematological parameters, including BAs, have been established for the first time in the population of Croatian pregnant women.

Comparative Analysis of Pigments, Phenolics, and Bioactivities of Three Camellia Species Growing in Vietnam

Objective/Background: Camellia L. , belonging to the Theaceae family, is a diverse group of plant species native to various regions of Asia. Methods: Chlorophyll and carotenoid contents in leaves of three Camellia species, namely Camellia quephongensis, Camellia yokdonensis, and Camellia longii, were determined using a spectrophotometric method. Phenolic compounds of the leaf extracts were quantified using high-performance liquid chromatography. Additionally, antioxidant activity, anti-α-amylase and in vitro antiinflammatory properties of the extracts were evaluated. Results: The total carotenoid content in C. longii was the highest, whereas the total chlorophyll content in this species was the lowest. Most of the phenolic compounds in C. quephongensis were found at the greatest concentrations compared to the other species. The extract from C. quephongensis exhibited the strongest antioxidant properties estimated by ABTS and DPPH free radical scavenging assays. This activity was shown to be comparable with that of ascorbic acid. All the Camellia extracts may possess a much less potent anti-α-amylase activity in comparison with acarbose. They could also be weaker than diclofenac with respect to in vitro anti-inflammatory activity evaluated by albumin denaturation inhibition assay. Conclusions: The findings of this investigation provide the initial insights into pigments and phenolics present in the various Camellia species and pave the way for the development of functional foods that could potentially offer a range of health benefits.

Studying the acids and amino acid composition of horse chestnut flowers

Introduction. Currently, there is an increasing trend towards assessing the full spectrum of chemical compounds in plant materials. One of the first steps in the formation of secondary metabolites of complex structure, participating in biochemical processes in the plant body, which have their own effect on the human and animal body, are organic acids (OA) and amino acids (AA). However, due attention is not always given to these compounds when studying the component composition of plant raw materials.Aim. The purpose of the work was to study the profile and quantitative assessment of the content of organic acids and amino acids of Aesculus hippocastanum L. flowers.Materials and methods. The object of the study were horse chestnut flowers, collected during flowering in the Voronezh region in 2021 and dried by air-shade method. Quantitative assessment of the amount of TC in terms of malic acid and ascorbic acid was carried out titrimetrically according to the methods presented in the State Pharmacopoeia of the Russian Federation, XIV edition. The composition of the OA and AA profiles of horse chestnut flowers was determined using the capillary electrophoresis method ("Kapel®-105/105M", Group of Companies "Lumex", Russia).Results and discussion. The method of capillary electrophoresis revealed the presence of 12 compounds of the OA group in a total amount of 4.7 % (in terms of absolutely dry raw materials). The rationality of recalculating the content of the sum of OA to the major component – citric acid, which amounted to 1.65 ± 0.04 %, was shown. The content of ascorbic acid was low (0.033 ± 0.007) %. Using the TLC method, the presence of 5 zones of compounds belonging to the AA class was established in the aqueous extract of horse chestnut flowers. The quantitative content of the sum of free AA in terms of glutamine, determined by the spectrophotometric method, was 2.25 ± 0.07 % (n = 5). The presence of 17 AA was determined by capillary electrophoresis, which amounted to 7.13 %. Glutamic acid is present in the greatest quantity in horse chestnut flowers (1.19 %). Essential amino acids amounted to 2.27 %; leucine was present in the predominant amount (0.58 %).Conclusion. A study was carried out of the qualitative composition and quantitative content of organic acids and amino acids of horse chestnut flowers. The composition of the profile and the quantitative content of organic acids and amino acids have been established. It was revealed that citric acid prevails in the total organic acids; glutamic, aspartic acid, arginine and proline are found in greater quantities in the total amino acids.

طريقة القياس الطيفي المتزامن لتقدير كل من سيبروفلوكساسين وسيفاليكسين باستخدام طريقة H - point للاضافة المعيارية

طريقة سهلة وبسيطة ودقيقة لتقدير السبروفلوكساسين في وجود السيفاليكسين او العكس بالعكس في خليط منهما. طبقت الطريقة المقترحة بطريقة الاضافة القياسية لنقطة بنجاح في تقدير السبروفلوكساسين بوجود السيفاليكسين كمتداخل عند الاطوال الموجية 240-272.3 نانوميتر وبتراكيز مختلفة من السبروفلوكساسين 4-18 مايكروغرام . مل-1 وكذلك تقدير السيفاليكسين بوجود السبروفلوكساسين الذي يتداخل باطوال موجية 262-285.7 نانوميتر وبتراكيز مختلفة من السيفاليكسين 6-18 مايكروغرام . مل-1 في مزيج لهما. اظهرت النتائج عدم وجود اي تداخلات من قبل المواد المضافة التي تحتويها الادوية على هذه المركبات وضمن حدود كشف السبروفلوكساسين يساوي 0.1732 مايكروغرام . مل-1 وعقارالسيفاليكسين يساوي 0.4620 مايكروغرام . مل-1 . الانحراف القياسي النسبي المئوي اقل من 2% . تم تطبيق الطريقة بنجاح لتقدير العقارين في بعض المستحضرات الصيدلانية. تعتبر الطريقة المقترحة من الطرق القليلة التكلفة وعدم حاجتها الى ادخال الادوية في سلسلة من التفاعلات وتثبيت لظروف التفاعل لغرض تقديرها وانما تتم عن طريق تقدير الدواء بعد اذابته مباشرة في الماء المقطر بوجود العقار الاخر معه في مزيج وتعتبر من الطرق الناجحة في التقدير خاصة للادوية المتقاربة في طيف الامتصاص لها والتي من غير الممكن ايجاد طرق لفصل الدوائين وتقديرهما بصورة ادق من هذه الطريقة المقترحة دون التداخل وتاثير احدهما على الاخر. الطريقة المقترحة في هذا البحث كانت ناجحة في تقدير كل من السبروفلوكساسين والسيفاليكسين في مزيج لهما دون تداخل دواء مع الاخر.

A New Visible Spectrophotometric Approach for Determination of Methyldopa in Pharmaceuticals

الهدف من البحث هو تطوير طريقة طيفية جديدة لتقدير عقار الميثيل دوبا بشكليه النقي والصيدلاني تعتمد الطريقة المقترحة على التفاعل بين المثيل دوبا و كاشف الانسدين بوجود نيتروبروسيد البوتاسيوم وهيدروكسيد الصوديوم لتكوين ناتج ملون تم دراسة تأثير العديد من العوامل المؤثرة على ناتج التفاعل تتضمن تركيز الكاشف و زمن التفاعل و استقرارية الناتج الملون مع ضبط هذه العوامل. متابعة التفاعل تمت بقياس الامتصاص عند 597 نانومتر للناتج الملون. في مدى من التركيز من (0.50 إلى 80.0) ميكروغرام.مل -1 كانت حساسية ساندل 0.0218 مايكروغرام.سم-1 و حد الكشف 0.0353 مايكروغرام.مل-1 و الحد الكمي 0.2691 مايكروغرام.مل-1. تم تطبيق الطريقة المقترحة بنجاح لتقدير المثيل دوبا في المستحضرات الصيدلانية.