Visible Spectrophotometric Method Research Articles

Development and validation of visible spectrophotometric method for determination of ferrous bisglycinate in bulk and formulation

This study aims to develop a simple, precise, and cost-effective visible spectrophotometric method to quantify ferrous bisglycinate in its bulk and dosage form. Ferrous bisglycinate, an iron chelate used in dietary supplements and food fortification, treats iron deficiency anemia with fewer side effects than other iron formulations. Despite numerous analytical methods available for iron analysis, no visible spectrophotometric techniques have been reported for ferrous bisglycinate. The method was validated according to ICH Q2 (R1) guidelines. The method development involved determining the wavelength of maximum absorption (λmax) at 510 nm. A linear calibration curve was established for ferrous bisglycinate in the concentration range of 1.0–5.0 µg/ml, with a high correlation coefficient (r2 = 0.9943). The method demonstrated high accuracy, with recovery rates between 98.54 and 99.98%, and precision, with %RSD values below 2% for intra-day and inter-day studies. The limits of detection (LOD) and quantification (LOQ) were determined to be 0.42 µg/ml and 0.60 µg/ml, respectively, indicating high sensitivity. Repeatability and ruggedness studies confirmed the method’s reliability and consistency across different analysts and experimental conditions. The method was successfully applied to the analysis of ferrous bisglycinate in marketed tablets, with results showing a % assay between 98.24 and 100.43%. Overall, this validated visible spectrophotometric method offers a reliable and efficient approach for the quantitative analysis of ferrous bisglycinate in bulk and pharmaceutical formulations.

Smartphone-integrated inkjet-printed paper sensor and UV/Vis spectrophotometric method for on-site detection of As3+ and L-cysteine in food samples using novel AMTPP-functionalized silver nanoparticles

The increasing prevalence of arsenic (As3+) in water and its health impacts necessitate advanced detection methods. Similarly, monitoring L-Cysteine, a vital thiol-containing amino acid, is crucial for assessing physiological processes and disorders. This study presents a novel method for detecting As3+ and L-Cysteine in food samples using 4-amino-3-(D-galactopentitol-1-yl)-5-mercapto-1,2,4-triazole (AMTPP) functionalized silver nanoparticles (AMTPP-AgNPs) by UV/Vis spectrophotometric method and smartphone-assisted inkjet-printed paper-based sensors. AMTPP-AgNPs, synthesized through a detailed process, show exceptional selectivity and sensitivity to As3+ and L-Cysteine, undisturbed by other metal ions and amino acids. Characterization techniques like FTIR, DLS, Zeta Potential, AFM, and SEM detailed their morphological and interaction properties. Optimizing detection parameters, such as response time, pH, and temperature, improved sensitivity and achieved low detection limits. The limits of detection (LODs) were 0.0052 μM for L-cysteine and 0.0092 μM for As3+, as calculated using UV–Vis spectrophotometric methods. The method also demonstrated high recovery rates in spiked meat and corn samples. This research offers a cost-effective, rapid method for on-site food analysis, significantly aiding environmental and public health monitoring.

Simultaneous estimation of prasugrel and aspirin in bulk drugs by chemometric methods

A UV–Vis spectrophotometric method enhanced by chemometric techniques, specifically Principal Component Regression (PCR) and Partial Least Squares (PLS) regression, was developed and validated for the simultaneous quantification of prasugrel (PRA) and aspirin (ASP) in bulk drugs and pharmaceutical formulations. The method demonstrated high accuracy, precision, and robustness, achieving mean recoveries of 100.63% for PRA and 100.08% for ASP with relative standard deviations (RSD) below 3%. Both PCR and PLS models showed excellent predictive capabilities, with RMSEP values of 0.45–0.48 for PRA and 0.78–1.13 for ASP, indicating the models’ reliability. In line with green and white chemistry principles, the method minimizes environmental impact by reducing solvent consumption and waste generation compared to traditional chromatographic methods. The Analytical Eco-Scale score was 84, reflecting excellent compliance with green chemistry standards. The method’s simplicity, low energy consumption, and reduced chemical waste further support its alignment with sustainability goals. However, acetonitrile, a hazardous solvent, was still used in small quantities, and solvent recycling was not implemented, slightly affecting the eco-score. To evaluate the method’s greenness, the RGB12 algorithm was applied, achieving a high score of 94.4%, with the majority of parameters related to reagent consumption, waste production, energy efficiency, and safety scoring optimally. The method’s safety, cost-effectiveness, and minimal environmental footprint make it suitable for routine pharmaceutical analysis, particularly in quality control environments where resource efficiency and sustainability are prioritized. Thus, the developed method offers a sustainable, efficient, and environmentally friendly solution for the simultaneous analysis of prasugrel and aspirin in pharmaceutical formulations, making it a valuable tool for routine analysis in the pharmaceutical industry.

Quantitative Estimation of Gallic Acid in Triphala Tablets by UV Spectrophotometric Method

A rapid, simple, selective and precise UV Visible spectrophotometric method has been developed for the determination of Gallic acid in Triphala tablet. The spectrophotometric detection carried out at an absorption maximum of 258 nm using distilled water as solvent. The method was validated for specificity, Linearity, accuracy, precision, robustness and ruggedness. The detector response for the Gallic acid was linear over the selected concentration 5- 25 µg/mL with a correlation coefficient of 0. 995.The accuracy was found to be between 99.1-101.3%. The % RSD for intra and inter day precision was found to be less than 2%. The LOD and LOQ was found to be 0.338µg/mL and 1.03µg/mL, respectively. The results demonstrated that the estimation of Gallic acid in the triphala tablets were found with this method and can be applied for routine analysis.

Orthogonal signal correction assisted multivariate regression approach for the estimation of uranium and acidity in PUREX process streams

A direct UV–Visible absorbance spectrophotometric method was developed for the simultaneous determination of uranium and nitric acid concentration in the PUREX process samples. The simulated system consisted of uranium and nitric acid in concentration range corresponding to reprocessing of spent nuclear fuel discharged from nuclear reactor was prepared. The absorbance of these samples was measured in the range of 400–470 nm at a scan speed of 100 nm/s and resultant spectra were recorded. The changes in wavelength maxima of U(VI) absorption spectrum at different nitric acid concentration was utilized to determine the concentration of uranium and nitric acid in the sample by orthogonal signal correction assisted principal component regression. After the principle component regression the RMSEP for test data (Uranium: 3–21 g/L and acidity: 2–12 M) were 0.7 g/L and 0.4 M respectively. This method is superior to conventional method being followed for routine analysis of plant control samples in view of minimizing the generation of radioactive analytical waste consisting other corrosive reagents and reducing radiation exposure to operators during analysis. This method is amenable for online monitoring also.

Analytical Method Development and Validation for Butylated Hydroxy Toluene by using UV- Visible Spectrophotometric Method

Upon utilizing the Prediction Activity Spectra of Substances (PASS) program, computer-aided predictions were conducted to assess the antioxidant activities. Compounds 1, 3, 4, and 5 underwent evaluation using 1,1-diphenyl-2- picrylhydrazyl (DPPH) and lipid peroxidation assays to confirm the predictions obtained from the PASS program. Notably, compounds 3 and 5 exhibited higher inhibition of the DPPH stable free radical at 10 M compared to the widely recognized standard antioxidant, butylated hydroxytoluene (BHT). Of particular interest, compound 5 demonstrated significant in vitro inhibition of Fe-induced lipid peroxidation in the lipid-rich medium of essential egg yolk (83.99%, IC50 16.07 ± 3.51 μM/mL) in contrast to α-tocopherol (α-ΤΟΗ, 84.6%, IC50 5.6 ± 1.09 μM/mL). Furthermore, the drug-likeness of these BHT analogues was assessed based on Lipinski's "rule-of-five" (RO5), revealing a violation of one parameter (Log P > 5) despite their solubility in protic solvents. The predictive polar surface area (PSA) and absorption percentage (% ABS) data imply a potential capacity for cell membrane penetration. Consequently, these new multipotent antioxidants (MPAOs) hold promise as effective agents for addressing oxidative stress and lipid peroxidation processes.

Dissecting the natural phytochemical diversity of carrot roots with its colour using high performance liquid chromatography and UV–Visible spectrophotometry

The research provides insights into the phytoconstituents of black, orange and red carrots (Daucus carota subsp. Sativus (Hoffm.) Schübl. & G. Martens), a highly nutritious food crop widely appreciated across age groups. Recognising carrots as a repository of health-promoting compounds, our study employs UV–Visible spectrophotometric and HPLC methods to discern significant variations in bioactive components among carrot varieties. Black carrots emerge as potent contenders, displaying the highest levels of total phenolics (2660 ± 2.29 mg GAE/100 g F W.), total flavonoids (831 ± 1.74 mg QE/100 g F W.), proanthocyanins (10910 ± 1.11 mg CE/100 g F W.), and tannins (713 ± 0.84 mg/100 g F W.). Red carrots, conversely, showcase higher anthocyanin content (6870 ± 1.85 mg CyGE/100 g F W.) by UV–Vis spectrophotometry. Additionally, orange carrots exhibit heightened β-carotene levels, confirmed at 0.03 μg/mg through HPLC. HPLC analysis unveils substantial chlorogenic acid variability (1.29 μg/mg) in black carrots, accompanied by the discovery of unique compounds such as cryptochlorogenic acid (0.05 μg/mg), caffeic acid (0.01 μg/mg), ferulic acid (0.11 μg/mg), methyl caffeate (0.01 μg/mg), and quercetin (0.02 μg/mg), marking the first detection of methyl caffeate in black carrots. The analytical methodology was meticulously validated encompassing optimal parameters such as linearity, precision, limit of detection, limit of quantification, accuracy, and robustness, within the range. In conclusion, our study underscores the health benefits of black carrots due to their rich polyphenolic content and endorses orange carrots for elevated β-carotene levels. These findings contribute to a deeper understanding of the diverse phytoconstituents in carrots, aid in informed dietary choices for improved health.

Determination of ionization/protonation constant values of some guanine derivative drugs by traditional/ green RPLC and UV–Vis spectrophotometric methods

In this study, the greenreverse-phase liquid chromatography (RPLC) method was used in addition to the traditional RPLC method to determine the ionization/protonation constants (pKa) of the guanine derivatives ganciclovir, valacyclovir, and valganciclovir. The determination of these values was carried out in binary acetonitrile–water mixtures (for the traditional RPLC method), ethanol–water binary mixtures (for the green RPLC method), and in aqueous solution of a micelle-forming surfactant (for pure micellar chromatography). The pKa values sspKa of the compounds were calculated using the linear solvation energy relationship (LSER) method in the studied hydro-organic and micellar solvent-free mixtures. Moreover, the UV–Vis spectrophotometric method was used to compare the sspKa values of ganciclovir, valaciclovir, and valganciclovir obtained in a acetonitrile–water medium using another method. The pKa values ​​of the examined compounds in water were calculated using the linear relationship between the sspKa values ​​determined in hydroorganic mixtures and some macroscopic values ​​of acetonitrile and ethanol. Additionally, wwpKa values ​​were determined in the micellar solvent-free mobile phase. Subsequently, the wwpKa values calculated by these direct and indirect methods were compared and the agreement between them was excellent. By using the wwpKa value calculated for each compound, the ionization percentages were calculated at different pH (1–12) values with the Henderson-Hasselbalch equation. The environmental impact of the RPLC methods used in this study was assessed using the green metrics tools GAPI and AGREE. The result of the investigation was that the environmental suitability of the green methods is satisfactory.

Electrode modified with CO2 laser-reduced graphene oxide-silver nanoparticles for determination of nitrite in water

Intercalation of rGO with AgNPs was achieved photothermally through CO2-assisted laser irradiation of GO and Ag+ precursors in the solid state. A uniform distribution of AgNPs was anchored on rGO (LrGO-AgNPs). The LrGO-AgNPs nanocomposite was structurally and electrochemically characterized. The parameters for the fabrication of LrGO-AgNPs and electrochemical NO2− detection were optimized. Under optimal conditions, the glassy carbon electrode (GCE) modified with LrGO-AgNPs showed a high diffusion coefficient and electron transfer rate constant for NO2− oxidation. Aditionally, the modified electrode displayed outstanding electrocatalytic activity toward NO2− oxidation with a sensitivity of 114.6 μA μM−1 cm−2 and an estimated response time of 7 s. The linear concentration range, LOD, and LOQ were 0.1–10,000, 0.039, and 0.131 μM, respectively. The proposed amperometric sensor was applied to detect carcinogenic nitrite in water samples and obtained recoveries between 93 ± 3 % and 103.3 ± 0.3 %. The results of the proposed method and the UV–vis spectrophotometric method showed no significant differences, indicating the potential of the proposed sensor for wider applications.

Greener spectrophotometric and HPLC investigation of CNS agent pregabalin: Taguchi model and box-behnken design for method parameters optimization

In the current study, two analytical methods are developed using spectrophotometry and high performance liquid chromatography for the determination of pregabalin in pharmaceutical preparations. Box-Behnken Design model was adopted to ease the optimization process. The visible spectrophotometric method is based on the reaction of potassium ferricyanide and ferric chloride in an acidic medium and measured absorbed at 700 nm. The HPLC method utilizes ammonium formate buffer solution and RP18 base deactivated silica (BDS) column for the quantitative analysis of pregabalin. The calibration plot was found to be linear in the range of 1.5–26.2 and 0.4–17.6 µg/mL for spectrophotometric and HPLC methods. BBD is a powerful statistical experiment design for optimizing reaction conditions that minimize the number of experiments and the cost of the method. Response Surface Methodology (RSM) via Box–Behnken design (BBD) optimized the chromatographic procedure. The Greenness of the methods were also evaluated by considering the Analytical Greenness Metric Approach. Method I attained a score of 0.74, while method II scored 0.59, suggesting an excellent and considerable level of eco-friendliness. Moreover, it is economical, consumes a minimum amount of organic solvent, and has good accuracy and precision.

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.

Tea (Camellia sinensis) cultivated in three agro-ecological regions of Bangladesh: Unveiling the variability of methylxanthine, bioactive phenolic compound, and antioxidant activity

Tea (Camellia sinensis) is a widely consumed beverage known for its numerous health benefits, largely attributed to its rich content of quality determining secondary metabolites such as methylxanthine compounds and bioactive phenolic compounds. The goal of this study was to find out variations of the levels of methylxanthines, bioactive phenolic compounds, and antioxidant activity in methanolic and hot water extracts of 129 tea samples grown in three different ecological regions of Bangladesh named Panchagar, Sylhet, and Chattogram. Methylxanthine and bioactive phenolic compounds were determined by using HPLC-DAD, and the antioxidant profile was analysed by UV–vis spectrophotometric methods for methanol and hot water extracts of tea leaves. The IC50 values showed the trend as Panchagar > Sylhet > Chattogram and Sylhet > Chattogram > Panchagar for water and methanol extract, respectively. The results revealed significant (p < 0.05) variations in the levels of methylxanthines content: Panchagar > Chattogram > Sylhet. Caffeine was significantly higher (103.02 ± 5.55 mg/g of dry extract) in the methanolic extract of tea leaves of Panchagar district and lower (53.33 ± 4.30 mg/g of dry extract) in the hot water extract of Sylhet district. Panchagar and Chattogram possessed significantly (p < 0.05) higher catechin content for methanol (57.01 ± 5.50 mg/g dry extract) and hot water (55.23 ± 4.11 mg/g dry extract) extracts, respectively. The utilization of canonical discriminant functions yielded highly favorable outcomes in the classification of tea from three distinct cultivation origins in Bangladesh, relying on their inherent features. This study demonstrated the potential effects of geographical variations on the bioactive compounds and antioxidant properties of tea, emphasizing the importance of regional differences in tea cultivation for optimizing its health benefits as well as dispersing tea cultivation across the country.

Usability of simplified UV–Vis spectrophotometric methods for the determination of nitrate in the presence of organic matter and chloride as interfering factors

Abstract The presence of nitrate in groundwater and surface water in concentrations above levels suitable for human consumption is an increasingly common problem. This is mainly due to human activity, such as the excessive use of fertilizers and the inadequate deactivation of pits. Water analysis laboratories very often carry out analyses to determine nitrate to control the presence of this anion in water intended for human consumption. One of the most commonly used methods is spectrophotometry, both with commercially available kits and by direct measurement of specific wavelengths. However, in these methods, the presence of organic matter and chloride can influence the results obtained. Thus, in this study, the applicability of the simplification (without acidification) of two methods for the determination of nitrate in water by ultraviolet–visible absorbance was verified in the presence of the above-mentioned interfering factors, and it was found that the absorbance method at 220 nm corrected for the absorbance at 275 nm, in its simplified form without acidification, can be used with concentrations of organic matter of 20 mg L−1 for high nitrate concentrations (10 mg L−1 NO3-N).

Spectrophotometric quantification of amitriptyline hydrochloride in pharmaceutical tablets: method development and validation

The development and validation of two uncomplicated, selective, and non-extraction-based visible spectrophotometric methods was carried out for the quantification of a tricyclic antidepressant amitriptyline hydrochloride as pharmaceutical tablets as well as in its pure form. The methods rely on the formation of ion pair complexes between amitriptyline base and two acidic dyes, bromothymol blue and bromocresol purple, which were subsequently measured at 410 and 400 nm, respectively. The developed methods included numerous reaction variables that were examined and improved. Beer's law is applicable under optimal conditions for the bromothymol blue and bromocresol purple methods, respectively, over concentrations from 0.5 to 12.5 μg mL−1 and from 0.5 to 10.0 μg mL−1 amitriptyline hydrochloride. The computed values of molar absorptivity were 1.79 × 104 and 2.32 × 104 L.mol−1.cm−1 for bromothymol blue and bromocresol purple methods, respectively, with Sandell’s sensitivity values of 0.0155 and 0.0119 μg cm−2. Both detection limits and quantification limits were computed and determined to be 0.55 and 1.67 μg mL−1 for bromothymol blue method, and 0.49 and 1.49 μg mL−1 for bromocresol purple method, respectively. The developed methods were successfully applied to estimate the concentration of amitriptyline hydrochloride in bulk form and commercial pills. Therefore, these methods demonstrate promising potential for testing this drug in labs for quality control.Graphical abstractSpectrophotometric quantification of amitriptyline hydrochloride in pharmaceutical tablets: method development and validation

Heterometallic bridged Pt(II)‐Zn(II) complexes: Influence of the substituent in 4′‐position in inert terpy ligand on antigenotoxicity, potential antitumor activity and mechanism of interactions of the complexes with biomolecules

The synthesis and characterization of novel hetrometallic complexes [{cis‐PtCl(NH3)2(μ‐4,4′‐bipyridyl)ZnCl(terpy‐Cl)}](ClO4)2 (C1a), [{trans‐PtCl(NH3)2(μ‐4,4′‐bipyridyl)ZnCl(terpy)}](ClO4)2 (C2a), [{cis‐PtCl(NH3)2(μ‐pyrazine)ZnCl(terpy‐Cl)}](ClO4)2 (C3a) and [{trans‐PtCl(NH3)2(μ‐pyrazine)ZnCl(terpy‐Cl)}](ClO4)2 (C4a) (where terpy‐Cl = 4′‐chloro‐2,2′:6′,2′′‐terpyridine) was done. Acid–base titrations were performed by UV–Vis spectrophotometric method to evaluate the pKa values of corresponding aqua complexes. Interactions between complexes and important biomolecules, guanosine‐5′‐monophosphate (5′‐GMP) and glutathione (GSH) were examined by 1H NMR spectroscopy. The chloride substituent at the 4′ position on the middle pyridine ring of terpyridine ligand significantly affects the coordination of biomolecules, as well as overall stability of complexes. The complexes were evaluated in vitro for the antioxidant prevention of DNA damages. All tested novel complexes demonstrated a significant reduction in DNA damage against oxidative modifications of DNA caused by the hydroxyl and peroxyl radicals. Also, cytotoxicity evaluation showed that significant cytotoxicity occurs only after long‐term effect of C1a, C2a and C3a, complexes in HCT‐116 cells. Molecular docking studies predict results in agreement with experimental research.

Physical and Chemical Scrutiny of Obizi River in Awka South Local Government Area of Anambra State, Nigeria for Domestic Consumption

The Obizi River in the Awka South Local Government Area of Anambra State was examined physically and chemically to evaluate its contamination level and suitability for home use. It is important for recreational, fishing, cooking, drinking, and other applications. Its typical applications for drinking, cooking, fishing, recreational activities and other uses are limited since it flows through a canal that might be contaminated by industrial, agricultural, and other human activities. Nitrate mg/l, nitrite mg/l, magnesium mg/l, zinc mg/l, total dissolved solid (TDS) mg/l, hardness mg/l, sulphate mg/l, phosphate mg/l, alkalinity mg/l, acidity mg/l, sodium mg/l, biological oxygen demand (BOD) mg/l, chemical oxygen demand (COD) mg/l, total suspended solid (TSS) mg/l, TS mg/l, oxygen demand (OD) mg/l, and potassium mg/l are among the parameters that were evaluated. Total dissolved solids (TSS) were calculated as the difference between total solids and total dissolved solids. The zinc and nitrate elements within the samples were measured using the ultraviolet (UV) VIS spectrophotometric method. Sulphate was determined turbidimetrically by the absorption spectrophotometry. Magnesium content, total hardness, and alkalinity were measured through titration. TDS (mg/L) was measured with a Multi-Meter (HI 991300, Hanna Equipments, Romania), potassium and sodium ions were assessed by flame photometric technique, chemical oxygen demand (COD) was identified photometrically using the SpectroQuant Nova 60 COD cell test (Merck) in the range of 10 – 150 mg/L. Biological oxygen demand (BOD) was determined using the OxiDirect BOD system and total suspended solids (TSS) was calculated as the difference between total solids and total dissolved solids. Phosphates were measured using the ascorbic acid method, total solids were estimated gravimetrically, and oxygen demand (OD) was measured on-site using a dissolved oxygen meter JENWAY-3405 (Manufacturer: Barloworld Scientific Ltd., England). To find out if the results were significant or not, the parameters were subjected to an ANOVA single factor analysis. The analysis's conclusion was that the data were statistically not significant. Since nitrate and OD were above the World Health Organization's (WHO) limit while most other physicochemical parameters were below it, the ANOVA result showed that there was no significant difference between the physicochemical characteristics of the water samples. With the exception of nitrite and OD, which are above the WHO limit for domestic drinking water and other purposes, it was discovered that the majority of the physicochemical parameters fell within the organization's water quality standards for these purposes. As a result, the water quality is not good and should not be drunk unless treated.

A colorimetric detection of creatinine based-on EDTA capped-gold nanoparticles (EDTA-AuNPs): Digital Image Colorimetry

A colorimetric sensor based on EDTA-modified gold nanoparticles (EDTA-AuNPs) has been developed for the sensitive and selective detection of creatinine using UV–vis spectrophotometer and digital image method. The presence of creatinine in EDTA-AuNPs results in a decrease in the absorbance peak at 524 nm and the appearance of an absorbance peak at 700 nm in the UV–vis spectrum. Creatinine induces the aggregation of EDTA-AuNPs, resulting in a color change from wine red to blue, which is easily observable with the naked eye. Color changes in colloids of EDTA-AuNPs can be further developed using digital image methods based on red, green, and blue colors to detect creatinine. The UV–vis spectrophotometer method demonstrated a linear relationship between the absorbance ratio at A700/A524 nm in the range of 0.0–5.0 mM, with a regression coefficient of 0.9906 and a detection limit of 0.125 mM. Meanwhile, the digital image method demonstrates a linear relationship between red color intensity (R) and creatinine concentration, with a high regression coefficient of 0.996 and a low detection limit of 0.050 mM. Creatinine testing conducted on artificial urine samples demonstrated a recovery rate between 97.5 % and 101.7 %, with a relative standard deviation (RSD) ranging from 0.28 % to 0.74 %. These results indicate good measurement accuracy and precision for the creatinine testing method.

The Effect of Extraction Method on Total Flavonoid Content of Ageratum conyzoides Ethanol Extract

This research is a type of comparative research using a quantitative approach. The study population was the population of Bandotan plants in the Kudus and Jepara regions. The organ parts taken from the plant were leaves, while the stems, roots and flowers were not extracted in this study. The extraction method used maceration and soxhletation with 96% ethanol solvent. Furthermore, to determine the total flavonoid content of &lt;em&gt;Ageratum conyzoides &lt;/em&gt;leaf extraction results using the UV Vis Spectrophotometric method, it is known that &lt;em&gt;Ageratum conyzoides &lt;/em&gt;leaf extract using the Soxhletation method has a higher total flavonoid content (0.32% b/v) compared to the Maceration method (0.22% b/v). The results of the total flavonoid test were then analyzed using the &lt;em&gt;Mann Whitney U Test. &lt;/em&gt;Based on the &lt;em&gt;Mann Whitney U Test &lt;/em&gt;shows that the value of Asymp. Sig. (2- tailed) of 0.102 &amp;gt; 0.05. Therefore, it can be concluded that there is no significant difference between maceration and soxhletation extraction methods on total flavonoids of &lt;em&gt;Ageratum conyzoides &lt;/em&gt;extract.

Extraction and Comparison of Anthocyanin Content in Seeds of Different Black Rice Varieties Using Water Bath Solution Extraction Method

Black rice, rare colored rice, is rich in anthocyanins. Black rice anthocyanin is a kind of natural plant pigment, which has the important effects of anti-oxidation, anti-inflammation and anti-cancer, protecting eyesight and promoting cardiovascular health. Fifteen representative black rice seeds in Southern Henan were used as test materials, and were determined and analyzed by using rice huller, visible light spectrophotometer and water bath solution extraction method and microwave assisted extraction method. The results showed that the anthocyanin content of different varieties of black rice varies greatly, among which the anthocyanin content of black fragrant glutinous rice No. 2 was the highest (0.4258%), and that of black fragrant glutinous rice No.4 was the lowest (0.0207%). The average content of anthocyanin in seeds of black rice varieties tested in Southern Henan Province was 0.1925%. Therefore, the above research results provide important clues for the genetic breeding and improvement of high-quality black rice varieties in Southern Henan. At the same time, varieties with higher anthocyanin content in black rice can be considered as backbone parents for new breeding high-quality black rice.

In vitro biodistribution studies on clinically approved FGFR inhibitors ponatinib, nintedanib, erlotinib and the investigational inhibitor KP2692

Binding towards human serum albumin (HSA) and α1-acid glycoprotein (AGP) of three approved fibroblast growth factor receptor (FGFR) inhibitors ponatinib (PON), nintedanib (NIN) and erdafitinib (ERD), as well as the experimental drug KP2692 was studied by means of spectrofluorometric and UV–visible spectrophotometric methods. Additionally, proton dissociation processes, lipophilicity, and fluorescence properties of these four molecules were investigated in detail. The FGFR inhibitors were predominantly presented in their single protonated form (HL+) at pH 7.4 (at blood pH). At gastric pH (pH 1–2) the protonated forms (+1 – +3) are present, which provide relatively good aqueous solubility of the drugs. All of the four inhibitors are highly or extremely lipophilic at pH 7.4 (logD7.4 ≥ 2.7). At acidic pH 2.0 PON and ERD are rather lipophilic, NIN is amphiphilic, while KP2692 is highly hydrophilic. All four compounds bind to HSA and AGP. Moderate binding of PON, KP2692 and NIN was found towards albumin (logK’ = 4.5–4.7), while their affinity for AGP was about one order of magnitude higher (logK’ = 5.2–5.7). ERD shows a larger affinity for both proteins (logK’HSA ≈ 5.2, logK’AGP ≈ 7.0). The computed constants were used to model the distribution of the FGFR inhibitors in blood plasma under physiological and pathological (acute phase) conditions. The changing levels of the two proteins under pathological conditions compensate each other for PON and NIN, so that the free drug fractions do not change considerably. In the case of ERD the higher AGP levels distinctly reduce the free available fraction of the drug. Comparison with clinical pharmacokinetic data indicates that the here presented solution distribution studies can very well predict the conditions in cancer patients.