Spectrophotometric Method Research Articles

Winemaking Technologies for the Production of Cabernet Sauvignon and Feteasca Neagra Wines Enriched with Antioxidant Active Principles Due to the Addition of Melatonin.

In recent years, various studies have been carried out to increase the concentration of antioxidant active principles in red wines as a consequence of the effects of winemaking techniques on the polyphenols content. In this study, in order to obtain the most optimal wine in terms of content and efficiency of antioxidant activity, various winemaking technologies (punching-down and pumping-over maceration) were tried with diverse gradations (Feteasca Neagra and Cabernet Sauvignon wines) and the addition of different concentrations of melatonin in must. Suitable HPLC and spectrophotometric methods were used to follow the evolution of the antioxidant compounds from wines during aging (for 12 months). After comparing the acquired results, an increase was observed in the antioxidant compound concentrations, particularly in resveratrol (85%), peonidin-3-glucoside (100%) or cyanidin-3-glucoside (100%), and antioxidant activity (10-40%). The most enriched wine was obtained in the case of Feteasca Neagra by the addition of 0.5 mg of melatonin per 1 kg of must using the punch-down technology and, in the case of Cabernet Sauvignon, by the addition of 0.05 mg of melatonin per 1 kg of must using the pumping-over technique. This study can provide winemakers with an approach to enhance red wines with antioxidant compounds.

Laboratory Puzzle of Oxidative Stress, Parameters of Hemostasis and Inflammation in Hospitalized Patients with COVID-19.

Bearing in mind that coronavirus disease (COVID-19) is associated with a wide range of laboratory abnormalities, the aim of this study was to examine the importance of determining the parameters of oxidative stress and antioxidant protection as well as markers of inflammation and hemostasis in hospitalized patients with COVID-19. The study population included 105 patients with severe COVID-19 and 65 healthy control subjects. The parameters of oxidative stress and the activity of enzymes of the antioxidant system were determined from the obtained samples using spectrophotometric methods. Standard laboratory methods were performed for the determination of the biochemical and hematological parameters. Patients with COVID-19 showed a significantly higher level of pro-oxidative parameters (hydrogen peroxide (H2O2) and the index of lipid peroxidation in the form of thiobarbituric acid-reactive substances (TBARSs)) and a significantly lower activity of the antioxidant system (catalase (CAT)). Patients with COVID-19 had significantly higher values of inflammation parameters (C-reactive protein (CRP), procalcitonin (PCT), ratio of the number of neutrophils to lymphocytes (NLR), and ratio of the number of platelets to lymphocytes (PLR)) and parameters of hemostasis (activated partial thromboplastin time (aPTT), prothrombin time (PT), D-dimer, fibrinogen) than the control healthy subjects. In addition, changes in hemostatic parameters correlated positively with inflammatory markers in the group of patients with COVID-19. The early determination of hemostasis parameters and the parameters of inflammation can help in the prediction of poor prognosis in COVID-19 patients.

Formation and characterization of charge transfer complex between alectinib and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone: Application to development of microwell spectrophotometric method

Alectinib (ALC) is a novel highly selective anaplastic lymphoma kinase (ALK) inhibitor that is effective in the treatment of patients with advanced ALK-positive non-small cell lung cancer and lymphomas. This study, describes, for the first time, the formation of a charge transfer complex (CTC) between ALC with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The CTC was characterized using different spectrophotometric and computational techniques. UV–visible spectrophotometry ascertained the formation of the CTC in methanol via the formation of a new broad absorption band with a maximum absorption peak (λmax) at 505 nm. The molar absorptivity (ε) of the complex was 2.72 × 103 L mol−1 cm−1 and its band gap energy was 1.94 eV. The stoichiometric ratio of ALC:DDQ was found to be 1:1. The association constant of the complex was 9.6 × 102 L mol−1, and its standard free energy was −16.98 J mol−1. Computational calculations were conducted using different calculation tools. The computed geometrical parameters, specifically bond lengths, exhibited variations in the CTC compared to the individual reactants (ALC and DDQ). The Mulliken atomic charge analysis indicated increased values for DDQ (the acceptor) and decreased values for ALC (the donor) in the CTC, confirming the formation of a CTC. The reaction was employed as a basis for a novel microwell spectrophotometric method for the quantification of ALC in its bulk form, capsule content, and uniformity testing. This greenness and high throughput of the method was documented. The method represents a valuable tool for routine use in quality control laboratories for analysis of ALC's bulk form and capsules.

Aloe vera gel confers therapeutic effect by reducing pyroptosis in ethanol-induced gastric ulcer rat model: Role of NLRP3/GSDMD signaling pathway

BackgroundGastric ulcer (GU) is a common gastrointestinal tract illness. Aloe vera has anti-inflammatory, antioxidant, and healing characteristics. This research sought to explore the therapeutic impact of Aloe vera gel on ethanol-provoked GU in rats and to elucidate the underlying mechanisms involved.MethodsAn ethanol-induced GU rat model was constructed using forty male Wistar rats distributed at random into four groups: control, ulcer, pantoprazole, and Aloe vera. Gross evaluation of the stomach, ulcer index (UI), inhibition index, and gastric pH estimation were analyzed. Gastric malondialdehyde (MDA) and reduced glutathione (GSH) were determined using the spectrophotometric method, and serum gastrin level was measured by an enzyme-linked immunosorbent assay. Gastric nucleotide-binding domain, leucine-rich repeat, and pyrin domain PYD containing protein 3 (NLRP3) and gasdermin D (GSDMD) mRNA expression levels were estimated by quantitative real-time PCR. Finally, the histopathological examination of the glandular part of stomach tissue was done.ResultsThe ulcer group revealed a significant increase in MDA, gastrin, NLRP3, and GSDMD and a decrease in gastric pH and GSH compared to the control group. Gross investigations of the ulcer group revealed a hemorrhagic lesion in the stomach and an increase in UI. Also, histopathological results for this group showed severe epithelial loss, haemorrhage, inflammatory cell infiltration, and blood vessel congestion. However, Aloe vera treatment improved the gross, biochemical, molecular, and histopathological alterations induced by ethanol when compared to the ulcer group.ConclusionsAloe vera exerted antiulcer activities through modulation of oxidant/antioxidant status, anti-secretory properties, and mitigation of pyroptosis.

Bioanalytical Method Development and Validation of UV Spectrophotometric Method for Estimation of Sitagliptin in Urine sample

Bioanalytical Method Development and Validation of UV Spectrophotometric Method for Estimation of Sitagliptin in Urine sample

A comparative analysis of univariate versus multivariate eco-friendly spectrophotometric manipulations for resolving severely overlapped spectra of vonoprazan and amoxicillin new combination

Vonoprazan and amoxicillin are pharmacological combinations that demonstrate synergistic effects in treating Helicobacter pylori (H. pylori), a global public health concern associated with peptic ulcer disease and gastric cancer. Four spectrophotometric methods were developed, including two univariate techniques (Fourier self-deconvolution and ratio difference) and two multivariate chemometric approaches (partial least squares and principal component regression). These methods provide innovative solutions for effectively resolving and accurately quantifying the overlapping spectra of vonoprazan and amoxicillin. The concentration ranges covered were 3–60 μg ml−1 for vonoprazan and 5–140 μg ml−1 for amoxicillin. To assess the environmental sustainability of the methodologies, various measures such as the Green Analytical Procedure Index (GAPI), National Environmental Method Index (NEMI), Analytical GREEnness Calculator, and Analytical Eco-scale, as well as RGB12 and hexagon toll were implemented. The validation of the developed techniques was carried out in compliance with ICH standards. The present study is highly significant because it is the first time that the mixture has been determined using the current approaches. The comparative analysis demonstrated no significant difference in terms of accuracy and precision compared to reference HPLC method (p = 0.05). The established spectrophotometric methods offer a straightforward, rapid, and cost-effective alternative to complex analytical techniques for determining the vonoprazan and amoxicillin mixture. They show potential for routine analysis in research laboratories and pharmaceutical industries.

Spider chart, greenness and whiteness assessment of experimentally designed multivariate models for simultaneous determination of three drugs used as a combinatory antibiotic regimen in critical care units: Comparative study

In this study, five earth-friendly spectrophotometric methods using multivariate techniques were developed to analyze levofloxacin, linezolid, and meropenem, which are utilized in critical care units as combination therapies. These techniques were used to determine the mentioned medications in laboratory-prepared mixtures, pharmaceutical products and spiked human plasma that had not been separated before handling. These methods were named classical least squares (CLS), principal component regression (PCR), partial least squares (PLS), genetic algorithm partial least squares (GA-PLS), and artificial neural network (ANN). The methods used a five-level, three-factor experimental design to make different concentrations of the antibiotics mentioned (based on how much of them are found in the plasma of critical care patients and their linearity ranges). The approaches used for levofloxacin, linezolid, and meropenem were in the ranges of 3–15, 8–20, and 5–25 µg/mL, respectively. Several analytical tools were used to test the proposed methods' performance. These included the root mean square error of prediction, the root mean square error of cross-validation, percentage recoveries, standard deviations, and correlation coefficients. The outcome was highly satisfactory. The study found that the root mean square errors of prediction for levofloxacin were 0.090, 0.079, 0.065, 0.027, and 0.001 for the CLS, PCR, PLS, GA-PLS, and ANN models, respectively. The corresponding values for linezolid were 0.127, 0.122, 0.108, 0.05, and 0.114, respectively. For meropenem, the values were 0.230, 0.222, 0.179, 0.097, and 0.099 for the same models, respectively. These results indicate that the developed models were highly accurate and precise. This study compared the efficiency of artificial neural networks and classical chemometric models in enhancing spectral data selectivity for quickly identifying three antimicrobials. The results from these five models were subjected to statistical analysis and compared with each other and with the previously published ones. Finally, the whiteness of the methods was assessed by the recently published white analytical chemistry (WAC) RGB 12, and the greenness of the proposed methods was assessed using AGREE, GAPI, NEMI, Raynie and Driver, and eco-scale, which showed that the suggested approaches had the least negative environmental impact. Furthermore, to demonstrate solvent sustainability, a greenness index using a spider chart methodology was employed.

Application of smart chemometric models for spectra resolution and determination of challenging multi-action quaternary mixture: statistical comparison with greenness assessment

A multivariate spectrophotometric method is a potential approach that enables discrimination of spectra of components in complex matrices (e.g., pharmaceutical formulation) serving as a substitution method for chromatography. Four green smart multivariate spectrophotometric models were proposed and validated, including principal component regression (PCR), partial least-squares (PLS), multivariate curve resolution-alternating least squares (MCR-ALS), and artificial neural networks (ANN). The developed chemometric models were compared to resolve highly overlapping spectra of Paracetamol (PARA), Chlorpheniramine maleate (CPM), Caffeine (CAF), and Ascorbic acid (ASC). The four multivariate calibration models were assessed via recoveries percent, and root mean square error of prediction. Hence, the proposed models were efficiently applied with no need for any preliminary separation step. The models were utilized to analyze the studied components in their combined pharmaceutical formulation (Grippostad® C capsules). Analytical GREEnness Metric Approach (AGREE) and eco-scale tools were applied to assess the greenness of the established models and found to be 0.77 and 85, respectively. Moreover, the proposed models have been compared to official ones showing no considerable variations in accuracy and precision. Therefore, these models can be highly advantageous for conducting standard pharmaceutical analysis of the substances researched within product testing laboratories.

Determination of vitamin c in raw fruit and vegetable homogenates: dietary exposure and health effects of excess intake in adults and children.

The aim of the study was to determine Vitamin C content in some fruits and vegetables (FAV) including apple, banana, orange, pineapple, watermelon, carrot and cucumber, sold in the local markets in Awka, Anambra State, Nigeria as well as Vitamin C content in two-component and three-component homogenates FAV. The work was also designed to investigate the dietary exposure and health effects of excess vitamin C intake in adults and children. Vitamin C as total ascorbic acid (AA) after reduction of dehydroascorbic acid was analyzed using both titrimetric and spectrophotometric methods. The titrimetric method involved iodometric back-titration while the spectrophotometric method was done at an absorbance of 530 nm. The dietary exposure was evaluated as the total FAV intake multiplied by chemical concentration in the FAV whereas the health effect of excess vitamin C intake was conducted using the hazard quotient (HQ). The results revealed that Vitamin C for single fruits ranged from 11.76 - 41.17 mg/L for spectroscopic method and 16.9 - 31.84 mg/L for titrimetric method. Fruit homogenates showed Vitamin C concentrations of 14.70 - 220.58 mg/L and 17.23 - 209.09 mg/L for two-components homogenates: 29.41-132.35 mg/L and 31.05-113.10 mg/L for tri-components homogenates for spectrophotometric and titrimetric methods respectively. The results of dietary exposure and the health effects of excess vitamin C intake showed that children are more susceptible to health issues than adults in illnesses such as nausea, gastrointestinal pains, increased kidney stones and hyperactivity. There is therefore the need for a national recommended dietary allowance for total ascorbic acid (AA) in FAV homogenates from a stakeholder point of view in Nigeria.

Quantitative analysis of rutin in flavonoid-rich plant raw material by HPTLC

Introduction. Due to the increasing requirements for the quality of pharmaceutical products, the requirements for standardization of herbal medicines are also growing, which in turn necessitates the development of approaches to quality control of medicinal plant raw materials. The use of such an advanced method as high-performance thin-layer chromatography (HPTLC) will improve the quality of drug standardization, which is associated with the advantages of this method: minimized sample preparation, parallel determination of small volumes, elution time, high sensitivity, efficiency and speed. Objective. Quantitative determination of rutin by high-performance thin-layer chromatography, as well as comparison of the results of quantitative determination of the amount of flavonoids in terms of rutin by the spectrophotometric method. Material and methods. Medicinal plant raw materials – violet herb – were subjected to extraction using a developed method with 70 and 96% ethanol. Quantitative determination of rutin in extracts was carried out by HPTLC and spectrophotometry. Results. The developed method for the quantitative determination of rutin was validated in terms of linearity, specificity and accuracy. The difference in the extractive ability of the solvents used was shown. The percentage of rutin determined using the HPTLC method in an ethanol (96%) extract (3 µl) is 3.0826%, in an ethanol (70%) extract (3 µl) – 1.5911%. The percentage of rutin determined using the HPTLC method in an ethanol (96%) extract (5 µl) is 3.0894%, in an ethanol (70%) extract (5 µl) – 1.6064%. The percentage of total flavonoids in terms of rutin determined using the spectrophotometric method in the ethanol (96%) extract is 3.4289%, in the ethanol (70%) extract – 2.4176%. Conclusion. As a result of the study, a method for the quantitative determination of rutin was developed and validated, which can be used in the standardization of violet herb.

Water Resource Impacts of Irrigation: The Case of the Main Irrigation Canal from the M’Pourie Plain to Rosso in Mauritania

An important factor in determining agricultural production is the availability of irrigation water in the main canal of the M’Pourie plain. This factor affects both the intensification of crops and the size of the irrigation areas. The main Senegal River canal in Rosso, Mauritania, runs across the Plaine of M’Pourie. This study aims to assess the physicochemical quality of the water used for irrigation and agriculture in the main irrigation canal on the M’Pourie plain. The measurements were made from 2021 to 2022, and the following physical and chemical parameters were monitored: pH, temperature, electrical conductivity, salt content, calcium, magnesium, sodium, and potassium; ammonium bicarbonate; chloride; nitrite; nitrate; nitrogen; sulfate; and sodium adsorption ratio (SAR). These measurements were analyzed using volumetric, spectroscopic, and spectrophotometric methods. After conducting statistical analysis and comparing the results with Moroccan quality standards for surface water utilized in irrigation, it has been discovered that the average pH value is 7.51, indicating a neutral state. However, the average nitrite and ammonium values exceed Moroccan standards at 5.16 mg.L-1 and 0.41 mg.L-1, respectively. The water’s low mineralization is attributed to its low electrical conductivity, with an average of 52.2 μS.cm-1. Based on the analysis of the Senegal River water used for irrigation in the M’Pourie plain, it has been determined that its sodium adsorption ratio and electrical conductivity classify it as belonging to class C1S1. This indicates that the water has low salinity and is excellent for irrigation, with a low risk of alkalinization.

Accessibilité et qualité de l’eau dans la commune de Mboro (Sénégal) : étude exploratoire

In a context of demographic growth in coastal areas, access to drinking water remains a major challenge. The aim of this work is to contribute to the study of the population's perception of the accessibility and quality of water, as well as the hydro-chemical characterisation of water samples from the commune of Mboro. A questionnaire was administered to a sample of 150 households out of 3,455 for the perception survey. Two borehole water samples (MBORO F1 and MBORO F2), one from a traditional well (PUITS TRAD) and one from a pond (THI) were analysed using volumetric, electrothermal and spectrophotometric methods. The results show that the pH values of the water samples comply with WHO standards, and that the conductivity values and chloride, sodium, sulphate, magnesium, calcium, bicarbonate and potassium levels are below the regulatory thresholds. However, the PUITS TRAD (185.7 mg/l) and THI (117.5 mg/l) samples had nitrate concentrations above the guide value (50 mg/l). The iron content of the PUITS TRAD and THI samples is equal to the guide value (0.2 mg/l). The survey on the supply of drinking water revealed that 67% of households have domestic taps, 4% use standpipes, 16% draw water from their neighbours and 13% of the population use water from wells. 77% of the population say they have easy access to a water source. However, 47% of households are not satisfied with the management and operation of the commune's water facilities. This work shows that the commune of Mboro is facing difficulties in supplying quality water. Concerted, sustainable action is therefore needed to improve the situation for the local population.

Synthesis and Application of 3-[3-Phenylpyrazylazo]-2,7-Naphthalendiol for Improved Palladium Determination in Environmental Samples and Enhanced ZnO Nanoparticle Performance

In this study, a spectrophotometric method for the determination of low levels of palladium (II) was developed by forming a complex with the new reagent 3-(3-phenyl pyrazyl azo)-2,7-naphthalendiol (3PPAN). The complex showed maximum absorption at 612 nm with a maximum molar absorptivity of 4.911?104 L/mol/cm, and a linear correlation was established between absorbance and concentration. The accuracy and repeatability of the method were evaluated and found to be precise (RSD 1.22%) and accurate (relative error 0.157%). The method?s selectivity was also tested by evaluating the effect of various ions. The stability constant of the complex was determined to be 2.759?107 L/mol. The method was successfully applied to the determination of Pd (II) ions in environmental samples of water and soil. In addition, the new ligand (3PPAN) was used to improve the properties of nano ZnO through a ligand exchange reaction on nanoparticles.. KEYWORDS :Azo, Palladium, Spectrophotometric, ZnO nanoparticles.

First electrochemical investigation and determination of non-steroidal anti-inflammatory drug etofenamate using disposable pencil graphite electrode with voltammetric techniques

In this study, the electrochemical properties of etofenamate, an active ingredient belonging to the non-steroidal anti-inflammatory drug group, were investigated using cyclic voltammetry (CV) and square wave voltammetry (SW) techniques on a disposable pencil graphite electrode (PGE). With the CV technique, reversible voltammetric waves of around +0.470 V and irreversible voltammetric waves of around +1.02 V were produced on the PGE. An environmentally friendly, selective and highly sensitive SW voltammetric method was developed using disposable PGE. This voltammetric method gave very good analytical working range on PGE in PBS (pH = 3.0) medium at concentrations ranging from 0.017 μM to 0.306 μM. The LOD value of this analytical method in PBS (pH = 3.0) medium was calculated as 0.0011 μM (0.406 μg L−1). The developed voltammetric method was successfully applied to urine and drug samples. The results of the voltammetric method were compared with the results of the spectrophotometric method. The results were found to be compatible with each other.

Initial Investigation of the Potential of Robusta Coffee, Arabica Coffee, and Caffeine in Asthma Treatment through the Evaluation of 5-Lipoxygenase Inhibition Activity

Numerous studies have documented the potential of coffee to aid in asthma prevention. Nevertheless, research into how coffee influences asthma management has not been available. One known mechanism by which asthma medications work involves inhibiting 5-lipoxygenase (5-LOX) activity. This study aims to determine the potency of Coffea canephora var. Robusta extract (CRE), Coffea arabica extract (CAE), and caffeine are the primary isolates against 5-LOX activity. Extraction was performed by a reflux procedure using 96% ethanol with a sample-total solvent ratio of 1 : 10, an extraction time of 1 hour, and the extraction was conducted in triplicate. Fractionation was carried out by liquid-liquid partition using a chloroform-water system. Caffeine further purification was performed by the sublimation method, and the inhibition of 5-LOX activity was evaluated using the spectrophotometric method at λ = 234 nm. Apigenin was used as a positive control. From the experiment conducted, the IC50 of the CRE, CAE, caffeine, and apigenin against 5-LOX was 32.2 ± 1.4, 42.1 ± 2.3, 14.3 ± 1.6, and 7.4 ± 1.7 µg/mL, respectively. Continued efforts to isolate bioactive compounds from coffee extract led to the discovery of caffeine, which exhibited a more potent inhibitory effect on 5-LOX. The inhibition of 5-LOX activity by caffeine occurs in a non-competitive manner.

Smartphone-Based Spectrophotometer for Facile and Fast Determination of Lipid Peroxidation in Local Fried Food

During lipid peroxidation in foods, deterioration rancidity occurred, and a toxic by-product also accumulated. The well-known marker of lipid peroxidation in food is malondialdehyde (MDA), suspected to be carcinogenic and mutagenic in humans. MDA level is determined using thiobarbituric acid (TBA) assay. The pink color of the MDA-TBA2 complex after the reaction can be measured spectrophotometrically at 530-540 nm. Several analytical methods, including smartphone-based methods, have been used to determine the MDA-TBA2 complex, such as UV-Vis spectrophotometry and HPLC-DAD. Therefore, this research aimed to determine lipid peroxidation in fried food using a simple smartphone-based spectrophotometer. The device was established using a paper box, LED lamps, and a test tube. Various concentrations of MDA were reacted with TBA reagent and then submitted to the device. RGB intensity data were converted to absorbance values and used to construct linear regression. Results showed that the G value from the smartphone-based spectrophotometer provided consistent results with R2 of 0.9869, including 0.93 and 95.17% precision and accuracy, respectively. Then, the developed device was finally used to determine the MDA in local fried food samples. The concentration of MDA in fried foods was successfully determined with high precision (0.96) and accuracy (88.33 %) compared to the traditional UV-Vis spectrophotometric method. Thus, this study provides a practical guideline for developing quick and easy accessibility, portability, and low-cost spectrophotometer for lipid peroxidation assessment in fried food and other future food matrices.

Determination of Catechin Content in Green and Black Tea (Camellia sinensis L.) by UV-Vis Spectrophotometric Method

Tea is one of the most commonly consumed beverages around the world. The chemical compounds contained in tea have a good effect on health because they contain polyphenolic compounds, catechins. This study examined the catechin compound content of black tea and green tea from Karanganyar (A) and Malang (B). This research aims to determine the differences in catechin levels in black and green tea types in Malang, East Java, and Karanganyar, Central Java plantations. The research method used was experimental. Identification of catechin content was done using UV-Vis Spectrophotometry method. Tea is extracted by brewing, 4 grams of green tea is brewed using distilled water for 6 minutes, while 5.6 grams of black tea is brewed using distilled water for 10 minutes with the comparison used is pure catechin solution. The results obtained for green tea Karanganyar (A) had a catechin content of 3.61±0.083%, green tea Malang (B) had a level of 2.97±0.037%, black tea Karanganyar (A) had a level of 3.14±0.065%, and black tea Malang (B) had a level of 1.60±0.009%. It is concluded that the catechin content of green tea is higher than black tea, and of the two samples, the high catechin content comes from Karanganyar (A). Keywords: catechins, green tea, black tea, malang, karanganyar

Development of the spectrophotometric method for the determination of meldonium in capsules by using alizarine

The aim of the work was to develop a simple, rapid, economic spectrophotometric method for the determination of meldonium in capsules based on the reaction with alizarin.
 Materials and methods. Analytical equipment: double-beam UV-visible spectrophotometer Shimadzu UV 1800 (Japan), a pair of 1 cm matched quartz cells, software UV-Probe 2.62, laboratory electronic balance RAD WAG AS 200/C, pH-meter И-160МИ. Pharmacopoeial standard sample (CRS) of meldonium dihydrate (Sigma-Aldrich, (≥ 98 %, HPLC)), alizarin (Synbias), capsules Metamax (Darnytsia) 250 mg, Vasopro (Farmak) 500 mg, Mildronate (Grindex) 500 mg, dimethylformamide (“Honeywell Riedel-de Haen”).
 Results and discussion. A spectrophotometric method for determining meldonium in capsules by reaction with alizarine has been developed. The absorption maximum of the formed complex in dimethylformamide was at a wavelength of 517 nm. Stoichiometric ratios of reactive components «meldonium- alizarin» were 1:1. Validation of the developed analytical method for the determination of meldonium in medicines was carried out in accordance with the requirements of the SPhU. The optimal conditions for performing the quantitative determination of meldonium have been established: concentration of alizarin solution – 0.8 %, volume 0.8 % alizarin solution – 0.5 ml, heating time – 20 min, temperature – 95+/- 2 °C. Linearity has been in the concentration range of 0.0402- 0.1073 mg/mL, the limit of detection - 2.84 μg/mL, and the limit of quantification – 8.59 μg/mL. The eco-friendliness of the developed analytical method was carried out using the analytical eco-scale, AGREE, and GAPI methods.
 Conclusions. The developed method can be used as an arbitration method for the routine analysis of meldonium capsules

Indole acetic acid (IAA) production by endophytic bacterial isolate Agrobacterium tumefaciens BE-1 from roots of Musa acuminata

We have screened 23 endophytic isolates to estimate the production of indole acetic acid (IAA) from the root of the banana (Musa spp) by using Salkowski’s reagent spectrophotometric method with and without L- tryptophan supplement. Amongst 23 isolates only eight isolates, showed the ability to produce IAA. It is observed that one isolates out of eight produced maximum amount of IAA supplemented with and without L-tryptophan in medium. Based on morphological, cultural, biochemical and 16s rRNA gene sequencing method, this promising endophytic bacterial isolate (BE 1) was identified as Agrobacterium tumefaciens. IAA production of BE-1 was further confirmed by Thin-layer chromatography as well as by High-Performance Liquid Chromatography with and without L-tryptophan in medium. Statistical analysis was carried out using paired t-test to test whether the production of IAA significantly increased by using L-tryptophan in medium.

Fortification of Shrimp Shell Flour as a Source of Calcium on the Preference Level of Bread

This research aim was to find the most preferred percentage of shrimp shell flour fortification on white bread. This research used an experimental method with 20 semi-trained panelists and 5 treatments of shrimp shell flour percentages which were 0%; 2,5%; 5%; 7,5%; and 10%. The parameters in this research were yield of shrimp shells, bread volume development, and calcium content which were analyzed with a comparative descriptive method; and preference level which was analyzed using the Friedman test. Fisheries Product Processing Laboratory, Faculty of Fisheries and Marine Science and Test Service Laboratory, Faculty of Agro-Industrial Technology, Padjadjaran University, between January and June 2023. Yield and volume development were tested by the ratio of the mass of shrimp shells flour and shrimp shells (yield test) and dough volume and white bread loaf (volume development test) times 100%. The Preference test used an organoleptic test with each panelist being given a test sheet to test 5 treatments of white bread fortified with shrimp shell flour and to test their preference level on 4 characteristics; which were color, aroma, texture, and taste. Calcium content was tested using the atomic absorption spectrophotometer method on the control treatment (0%) and the most preferred treatment. Yield result from shrimp shell flour was 27.8% (139 gr) from its initial mass (500 gr). Volume development of white bread showed decreases in volume with each treatment from 136.433% to 111.504%. The most preferred fortification of shrimp shell flour on white bread was treatment 2.5% with an alternative value of 7.22 and characteristic value of color 9, aroma 7, taste 7, and texture 7, which means overall still preferred. The calcium content within treatment 2.5% was 30.095 mg/100gr which is significantly higher than the calcium of treatment 0% (1.465 mg/100gr) and could assist humans meet their calcium needs.