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Marine microalgae are emerging as promising sources of polyphenols, renowned for their health-promoting benefits. Recovering polyphenols from microalgae requires suitable treatment and extraction techniques to ensure their release from the biomass and analytical methodologies to assess their efficiency. This review provides a comprehensive comparison of traditional and cutting-edge extraction and analytical procedures applied for polyphenolic characterization in marine microalgae over the past 26 years, with a unique perspective on optimizing their recovery and identification. It addresses (I) cell disruption techniques, including bead milling, high-speed homogenization, pulsed electric field, ultrasonication, microwave, freeze-thawing, and enzymatic/chemical hydrolysis; (II) extraction techniques, such as solid–liquid extraction, ultrasound and microwave-assisted extraction, pressurized-liquid extraction, and supercritical CO2; (III) analytical methods, including total phenolic and flavonoid content assays and advanced chromatographic techniques like GC-MS, HPLC-DAD, and HPLC-MS. Key findings showed bead milling and chemical hydrolysis as effective cell disruption techniques, pressurized-liquid extraction and microwave-assisted extraction as promising efficient extraction methods, and HPLC-MS as the finest alternative for precise phenolic characterization. Unlike previous reviews, this study uniquely integrates both extractive and analytical approaches in one work, focusing exclusively on marine microalgae, a relatively underexplored area compared to freshwater species, offering actionable insights to guide future research and industrial applications.

Five sustainable and validated UV spectrophotometric methods were developed for analyzing chloramphenicol (CHL) and dexamethasone sodium phosphate (DSP) in pure and ophthalmic dosage forms. CHL was detected by zero order spectra method at 292.0 nm in the range 2.00–32.00 µg/mL with limits of detection (LOD) and quantification (LOQ) of 0.96 and 2.88, respectively. DSP was analyzed using the following four techniques: Induce dual wavelength (IDW), fourier self-deconvolution (FSD), ratio difference (RD), and derivative ratio (DD 1 ). The IDW method used at 239.0 and 254.0 nm with a linearity range of 4.00–40.00 µg/mL with LOD and LOQ values were 0.93 and 2.79, respectively. The FSD approach used at 242.0 nm, with a linearity range of 2.00–32.00 µg/mL and 0.65, 1.95 as values of LOD and LOQ, respectively. In the linearity range of 4.00–32.00 µg/mL, RD and DD 1 are applied. RD is utilized at 225.0–240.0 nm, while DD 1 is carried out at 249.0 nm. Values of LOD and LOQ for RD were 0.70 and 2.10 while for DD 1 were 0.80 and 2.40, respectively. These methods were evaluated for their environmental sustainability and validated according to ICH guidelines, overcoming challenges like spectral overlap and collinearity. Statistical comparisons with published methods revealed no significant differences.

Differential pulse voltammetry (DPV) and spectrophotometric methods were used to evaluate the antioxidant capacity (AC) in strawberry and orange juice, soluble coffee, rosemary extract, red wine, and sparkling white wine. The AC through spectrophotometric methods showed the following trend in solid foods, coffee > rosemary extract, and red wine > strawberry juice > orange juice > sparkling white wine in liquid samples. Charge measurements by DPV, presented in equivalent units of Trolox and gallic acid, showed the same trend in liquid samples; however, for solid samples, the AC of rosemary extract was greater than that of coffee. The charge expressed in equivalent units showed a high, positive, and significant correlation ( p  < 0.001) with total phenols (0.7919), FRAP (0.8875), and ABTS (0.8366). The proposed electrochemical technique proves to be a fast, reliable, and environmentally friendly alternative or complement to evaluate antioxidant capacity in food, which is not affected by the turbidity or color of the samples. Graphical abstract

Two simple, sensitive, precise and specific UV spectrophotometric methods for simultaneous estimation of tolperisone hydrochloride and diclofenac sodium in bulk and combined tablet dosage form have been developed using distilled water as solvent. Determination using the simultaneous equation method was at wavelength 261 nm and 276 nm. The Q –absorbance ratio method involved the formation of equation at 293.5 nm (isoabsorptive point) and at 261 nm (λmax of tolperisone hydrochloride). The linearity ranges for tolperisone hydrochloride and diclofenac sodium were 621 μg/ml and 2–7 μg/ml respectively. The accuracy of the methods was assessed by recovery studies and was found to be 100.28 ± 0.32 and 99.46 ± 0.31 for simultaneous equation method and 100.44 ± 0.18 and 99.44 ± 0.16 for Q absorbance ratio method for tolperisone hydrochloride and diclofenac sodium, respectively. Results of marketed formulation shows that these methods can be applied successfully to marketed formulation.

This paper presents the results of testing the content of 5-hydroxymethylfurfural (HMF) in honey from Greater Poland. The production of honey from this area of Poland, its processing, and its consumption are closely related to the sustainable development of this region. It is created in the process of the production, storage, and transport of honey, especially during its thermal processing. Therefore, it can be an indicator in the analysis of sustainable development throughout the life cycle of honey and its products. The aim of this research was to determine the HMF content in Greater Poland’s honey available on the Polish market using three different methods and to compare the obtained results. The methodology used was as follows: two spectrophotometric methods (White and Winkler) and an HMF determination method based on the LC-MS/MS technique developed especially for this study. The determined HMF content in all tested honey samples did not exceed the applicable standard. The determined HMF values in all honey samples ranged from 0 to 28.5 mg HMF/kg honey. All results fell within the scope of European Council Directive 2001/110/EC of 20 December 2001, i.e., they did not exceed the HMF content in honey, which is 40 mg/kg. The results will encourage modifications to the universal honey testing procedures to be developed for the agri-food sector. In the study, seven honeys of different origins and types were selected; three HMF detection methods were selected; a comparative procedure was developed; and the content of the reference ingredient in honey was determined.

Schiff bases are bioactive compounds that have been synthesized by many researchers in recent years. They may also exhibit strong antimicrobial activities against various pathogenic microorganisms in both medicine and veterinary applications. The synthesis of new Schiff base-derived compounds remains of interest due to the increasing problem of antibiotic-resistance in clinical practice. Seven new Schiff base derivatives were synthesized, and their chemical structures were characterized using FT-IR, 1H/13C NMR, and LCMS-MS analyses. The antimicrobial activities of thesyntesized compounds against various pathogenic bacteria, yeasts, and fungi were evaluated using the disk-diffusion method, and their MIC values were also determined. In addition, one representative microorganisms from each class were selected for molecular docking studies. IFD analyses were performed for the 4f and 4g ligands using the dihydrofolate reductase enzyme. Spectroscopic analyses confirmed the structures of the synthesized compounds, revealing the presence of characteristic imine functionalities and validating the integrity of the molecular frameworks. Antimicrobial assays demonstrated that several derivatives exhibited measurable activity, with compounds 4f and 4g showing the most potent effects, displaying MIC values of 32 µg/mL against B. cereus and E. faecalis, respectively. Molecular docking studies further indicated that both 4f and 4g bind efficiently to the DHFR active site. These findings indicate that among the synthesized Schiff base derivatives, compounds 4f and 4g exhibit particularly promising antimicrobial activity, warranting further pharmacological evaluation and medicinal chemistry optimization.

Environmentally benign and straightforward spectrophotometric methods were developed and validated for the simultaneous determination of saxagliptin (SAX), metformin (MET), and the pharmacopeial impurity of MET, melamine (MEL), in bulk powder and pharmaceutical formulations. These proposed approaches provide reliable, low-cost, and accessible alternatives to conventional chromatographic techniques, which often require complex instrumentation, extended analysis times, and significant solvent consumption. Two complementary spectrophotometric methods were established. Method A, the ratio-difference approach, utilized MEL as a divisor for the quantification of SAX, while SAX served as a divisor for determining MET and MEL. Method B, based on the first derivative of ratio spectra, applied MEL as a divisor under optimized conditions (scaling factor = 10, Δλ = 4 nm). However, MEL could not be quantified by Method B because its derivative ratio signals in the selected spectral region were too weak and overlapped extensively with those of SAX and MET, preventing the establishment of a reliable linear calibration curve for this impurity. The methods exhibited linearity over the ranges of 5–90 µg/mL for SAX, 1–40 µg/mL for MET, and 0.5–10 µg/mL for MEL. Validation in accordance with ICH Q2(R1) guidelines confirmed their accuracy, precision, selectivity, and specificity. The results obtained by the proposed methods were statistically compared with those of a reported RP‑HPLC method, confirming the reliability of the proposed procedures. The environmental impact was assessed using the principles of green analytical chemistry (GAC), which incorporates sustainability by promoting methods that limit hazardous reagents, reduce energy consumption, and minimize waste while maintaining suitable analytical performance. Holistic evaluation tools such as the analytical greenness metric (AGREE), the green analytical procedure index (GAPI), the national environmental methods index (NEMI), the blue applicability grade index (BAGI), and the RGB 12 model enable simultaneous assessment of analytical quality, environmental impact, and practical applicability. These tools foster the development of “white” analytical chemistry and complement emerging indices like the environmental and practical performance index (EPPI).Overall, these spectrophotometric approaches represent sustainable, efficient, and accessible analytical alternatives for the routine quality control of Saxagliptin and Metformin in combined pharmaceutical formulations.

A stability indicating UV spectrophotometric method has been developed and validated for the estimation of voglibose in pharmaceutical preperation. The proposed method utilized 0.1 N NaOH as solvent and detection was carried out at 214.5nm. Experiments were designed for determining linearity, limit of detection and quantitation, accuracy, precision and specificity of this analytical method. The stability studies of voglibose was carried out under acid, alkaline, thermal, oxidative and photolytic. The responses were linear in the concentration range of 5-25µg/ml with correlation coefficient of 0.9997. The % RSD for both inter-day and intra-day precision were less than 2%. The recovery of drug from sample was found to be 99.6-100.4%. Although the degradation products of stress condition had not been identified, the method had been able to detect the changes due to stress condition. The stated method can be used as stability indicating method with high degree of linearity, accuracy and precision for assay of voglibose in routine pharmaceutical analysis of tablet formulation. The method was found to be simple and cost effective. Hence this method can be successfully used to study stress degradation behavior of voglibose in small industry where high end instruments are not available.

Bilastine binds with H1 receptor and prevents the activation of H1 receptor by histamine. [...]it acts as an antagonist for histamine. [...]it is useful for treating patients suffering with renal/ hepatic dysfunction 6. First set of stock solutions were diluted with 0.1M NaOH, second set with phosphate buffer (pH 2.0) and the third set with distilled water upto the mark. Three simple, fast, accurate, precise, economic and sensitive UV-spectrophotometric methods were developed for the estimation of Bilastine in both bulk and pharmaceutical formulation. [...]the methods can be successfully employed for routine analysis of Bilastine in QC laboratories.