Propolis is a natural product with very important properties and its chemical composition was investigated by many researchers. In the present study the polyphenols and flavonoid content was ...investigated for 10 Romanian propolis samples. Extracts were obtained by using ethanol of different concentrations. The investigation was done spectrophotometrically. Flavonoids content was determined using chrysin as internal standard and zirconium oxychloride as reagent. The second method uses aluminium chloride and 2,4-dinitorphenylhydrazine and as internal standards galangin and pinocembrin.
Bovine cattle milk lactoferrin is industrially produced from cow’s milk and used in a variety of functional products, including baby food, nutritional supplements, dairy products, and veterinary ...drugs. The possibility of obtaining lactoferrin from lactic acid milk wheyrises a particular interest. The purpose of this study is to assess the possibility of using and adapting existing spectrophotometric methods for determining the concentration of total protein and an electrophoretic method for analyzing the protein composition of whey fractions and lactoferrin substances. A comparative study of two methods for determining the total protein in whey fractions and lactoferrin preparations biuret and Bradford method was carried out. The validation parameters of both methods were defined. An analytical range from 30 μg / ml to 1000 μg / ml characterizes the linearity of the Bradford method. The electrophoretic profile of milk, milk whey, whey fractions and substances of lactoferrinwere analyzed. The results obtained indicate a high information content of the electrophoretic method for characterizing the purification efficiency of whey fractions.
Determination of Free Proline in Plants Sena, Florencia; Monza, Jorge; Signorelli, Santiago
Methods in molecular biology (Clifton, N.J.),
2024, Volume:
2798
Journal Article
Proline metabolism has been associated with the induction of reactive oxygen species (ROS), antioxidant enzymes, and the control of cellular redox status. Moreover, proline accumulation is a highly ...evolutionarily conserved response to diverse abiotic stresses in plants. Thus, proline quantification has been helpful in abiotic stress research as a stress marker. The need for a reliable, fast, and simple method to detect proline in plant tissues is a powerful resource to imply the physiological status of plants under abiotic stress. This chapter summarizes the main strategies for proline extraction and quantification, highlighting their limitations and advantages, and recommends and details a specific protocol for proline extraction and quantification. The chapter provides a friendly version of this protocol with notes useful for researchers to perform the protocol.
Lesinurad is a novel selective uric acid reabsorption inhibitor which has been recently approved for the treatment of the chronic gout. Four simple mathematical spectrophotometric methods have been ...developed for the quantitative and selective determination of lesinurad in the presence of its oxidative degradation product. Complete oxidative degradation of lesinurad to its degradation product has been done. The developed methods namely, ratio difference spectrophotometric, first derivative of the ratio spectra, mean centering of the ratio spectra and continuous wavelet transform spectrophotometric methods. These methods have been developed and optimized to resolve the existed overlapping between the zero order UV absorption spectra of lesinurad and its oxidative degradation product. The described spectrophotometric methods have achieved selective determination of lesinurad without any interference from the oxidative degradation product. Also, they have been validated and applied for quantitative analysis of the studied drug in its new pharmaceutical preparation.
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•The contents of fluconazole (FLC) and riparin B (RIP) in lipid nanoparticles were simultaneously determined.•Four spectrophotometric methods were applied and validated (P-factor, AS, ...MAS and fourth-order derivative).•All the methods proposed are simple, precise and accurate.•Validated methods were applied in ex vivo nail retention studies of lipid nanoparticles FLC and RIP.
Fluconazole (FLC) has been used in the clinic for almost thirty years as a treatment for fungal infections, but its widespread use has led to the emergence of resistant strains. In this context, synthetic analogues of riparins, phytocompounds isolated from Aniba riparia (Nees) Mez (Lauraceae), such as Riparin B (RIP), stand out as an important agent for modulating antimicrobial resistance, potentially useful for treating superficial mycoses resistant to conventional antifungals. Onychomycosis is one of the main fungal infections affecting the nails. Its local treatment is desirable but has limited efficacy due to poor drug permeation. The use of nanoparticles and permeation promoters can increase permeability and improve treatment. Therefore, nanostructured lipid carriers coated with β-cyclodextrin (MNLC) were developed for the topical application of FLC and RIP on nails. To support the formulation, four spectrophotometric methods (amplitude factor, amplitude subtraction, modified amplitude subtraction, and fourth-order derivative), based on derivative spectroscopy and simple mathematical manipulations, were validated, in accordance with the International Conference on Harmonization (ICH), for simultaneous determination of FLC and RIP in the MNLC and in in vitro characterization studies of the formulation. In addition, the methods were applied to quantify drug retention in porcine hooves using an optimized extraction process. All the methods developed were found to be linear (r > 0.999), precise (RSD < 5 %), and accurate (92.33 to 108.86 %) without being affected by the components of the formulation or the biological matrix. The methods developed made it possible to determine the encapsulation efficiency and sustained release profile of the drugs. In addition, successive extractions revealed the amount of FLC and RIP retained in the superficial and deeper regions of porcine hooves. Thus, the results indicated that FLC and RIP can be determined simultaneously, quickly, simply, and economically, using any of the proposed methods, in complex MNLC samples and the biological matrix of porcine hooves.
Due to the versatile usage and applications of chromium compounds in the industry worldwide, the chromium ions are present in the major effluents from a broad range of industries. Cr(VI) which is ...highly hazardous and carcinogenic poses a serious threat to the our ecosystem and human health even at very low concentration limits. Cr(III) ions are also toxic to aquatic life, but they are less harmful than Cr(VI) ions. Therefore, detection and analysis of the toxic Cr(VI) and Cr(III) ionic species in waste water are an utmost important area of research. Various chemical reagents and the different methods which require expensive instrumentation used in the past for detection and determination of the non-biodegradable Cr(VI) ions suffer from serious limitations. The present review summarises the use of spectrophotometric methods of determination of Cr(VI) and Cr(III) ions from aqueous solutions with high sensitivity, selectivity, accuracy and at lesser costs. The use of chemical reagents such as diphenylcarbazide (DPC) and several other dye-based reagents for spectrophotometric determination of hazardous Cr ions in water samples is discussed. Additionally, the use of DPC reagent in developing advanced technologies such as microfluidic detection system, microfluidic paper-based analytical devices (µPADs) and 3D printed device with online spectrophotometric detection system for onsite monitoring of water samples is elucidated. Different methods for selective speciation and preconcentration of Cr(VI) ions prior to spectrophotometric determination in water samples with very low concentrations (as low as ppb) of Cr ions are also described. The emerging trends in detection and determination of carcinogenic Cr(VI) ions involving the use of novel and innovative technologies and different categories of nanomaterials are also elucidated in the present review.
In this work, we have developed simple, sensitive and inexpensive methods for the spectrophotometric determination of urea in urine samples using silver nanoparticles (AgNPs). The standard addition ...and 2nd order derivative methods were adopted for this purpose. AgNPs were prepared by chemical reduction of AgNO3 with hydrazine using 1,3-di-(1H-imidazol-1-yl)-2-propanol (DIPO) as a stabilizing agent in aqueous medium. The proposed methods were based on the complexation of AgNPs with urea. Using this concept, urea in the urine samples was successfully determined spectrophotometric methods. The results showed high percent recovery with ±RSD. The recoveries of urea in the three urine samples by spectrophotometric standard addition were 99.2%±5.37, 96.3%±4.49, 104.88%±4.99 and that of spectrophotometric 2nd order derivative method were 115.3%±5.2, 103.4%±2.6, 105.93%±0.76. The results show that these methods can open doors for a potential role of AgNPs in the clinical determination of urea in urine, blood, biological, non-biological fluids.
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•Manner of sample preparation have a substantial impact on terpenoid content result.•Total terpenoids determination on dried material is repeatable.•Always consider all disadvantages when decide to ...work with dried plant material.•Sample microwaving is the worst you can do if measure terpenoid content.•Smaller amount of material to be analysed is needed than expected.
In ecological research, quantitative methods are often used to measure the total content of metabolites groups (i.e., phenols, carbohydrates). Until recently, there has been no simple and effective method to determine the total terpenoid content with satisfactory repeatability and sensitivity. The procedure proposed by Ghorai et al. (2012) requires the use of fresh plant material. That may be problematic when experimental units are located far from a laboratory. Our goals were to optimize the procedure, and to find the threshold of misestimation using the procedure adjusted to work with dried material. Needles of Pinus sylvestris were used to test the effect of changes in drying, grinding, storage, and extraction on determined total terpenoid content. All applied changes in material storage and grinding decreased the quantity of the terpenoids in needles. Only air-dried and ball-milled material produced similar results to those obtained with fresh material – can be recommended if the fresh material unattainable. Air-dried material may be stored for up to three months, but it resulted in greater variation and then greater sample size is needed. Lower sample mass and solvent volume have no impact on accuracy. Shorter extraction time, oven-drying or microwaving leads to unreliability of measurements.
Versatile, extraction-free univariate spectrophotometric methods have been modified to get effective spectral resolution of mixtures in accordance with their feature challenges. The proposed methods ...have been applied and validated for analyzing some antihypertensive medicines in their co-formulated medicinal products. Two mixtures have been used: the first one Mix I (OLM/ADB) is composed of Olmesartan medoxomil (OLM) and Amlodipine besylate (ADB) with partly-overlapped spectra while the second Mix II (TEL/HCT) is made up Telmisartan (TEL) and Hydrochlorothiazide (HCT) with total-overlapped spectra. Induced dual wavelength, absorbance correction and ratio subtraction coupled with constant multiplication methods were applied to Mix I (OLM/ADB), while dual wavelength, advanced absorbance subtraction and constant center coupled with spectrum subtraction methods were applied to Mix II (TEL/HCT). Calibration graphs were established with good correlation coefficients. The methods exhibit significant advantages as simplicity, sensitivity, minimal data manipulation besides optimum robustness. Selectivity was inspected using lab-mixtures with diverse ratios. Accuracy, precision and repeatability were found to be within the acceptable limits. The proposed methods are good enough to be used for co-assay of analytes in combined forms without any interfering from excipients. Moreover, all results were estimated in accordance with ICH criteria and successfully compared with those of the reported methods applying t-test and F-test at 95% confidence level. Generally, these methods can be used efficiently for routine quality control testing.
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•Versatile spectrophotometric methods are modified to get effective spectral resolution suiting mixture feature challenges.•The methods have been applied and validated for analysis of two antihypertensive binary blends formulated as tablets.•The methods provide high efficiency for potent spectral resolution of partly and totally overlapping blends.•They show significant advantages as simplicity, sensitivity, accuracy, optimum robustness besides cost saving.•They can be used successfully for routine QC analyte testing in combined formulations without any excipient interference.
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