Browsing by Subject "HPLC"

Now showing 1 - 5 of 5
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    A Fast and Accurate Method for the Quantification of Doxycycline in Goat Plasma and Milk by HPLC Using a Fluorescence Detector
    (2024-12-17) Martínez, José; Hernandis, Verónica; Badillo, Elena; Escudero, Elisa; Yuste Pérez, María Teresa; Galecio, Juan Sebastián; Marín, Pedro; Farmacología
    Doxycycline is an antimicrobial agent used in veterinary medicine to treat a variety of bacterial infections. To date, no analytical technique utilising HPLC with fl uorescence detection has been documented for the quantifi cation of doxycycline concentrations in goat plasma or milk. Consequently, the objective of the present study was to propose a rapid HPLC assay with fl uorescence detection for the quantifi cation of doxycycline in the aforementioned samples, thereby facilitating the conduct of pharmacokinetic studies and the detection of residues in diverse goat tissues. Proteins were precipitated with methanol and trifl uoroacetic acid in a single step. Doxycycline was separated on a XBRIDGE C18 column using an isocratic method. Sample volume injected into the HPLC system was 50 µl. Fluorescence detection was conducted with an excitation wavelength of 380 nm and an emission wavelength of 520 nm. The retention times of doxycycline and danofl oxacin (internal standard) were determined to be 8.0 and 5.5 minutes, respectively. The calibration curves for plasma and milk exhibited linearity over the concentration range of 0.1 to 2 μg/mL. The limit of detection was 0.065 μg/ mL, while the limit of quantifi cation was 0.1 μg/mL in both matrices. The accuracy and precision of the method were consistently within the limits of 10.9% for plasma and 10.5% for milk. The fi ndings of this study may be employed in the quantifi cation of doxycycline in goat plasma and milk, thus facilitating the conduct of pharmacokinetic studies.
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    Comparative study of metabolomic profile and antioxidant content of adult and In vitro leaves of Aristotelia chilensis
    (MDPI, 2021-12-23) Crisóstomo Ayala, Karina Andrea; Pérez Manríquez, Claudia; Ferreres, Federico; Gil-izquierdo, Ángel; Hernández de la Torre, Martha; Sánchez Olate, Manuel; Ríos Leal, Darcy Graciela; Pedreño García, María Ángeles; Sabater Jara, Ana Belén; Biología Vegetal
    This work aimed to identify the bioactive compounds present in adult maqui (Aristotelia chilensis) leaves from different stages of development and seasons of the year and compare them with leaves obtained from maqui plants grown in vitro. The qualitative and quantitative analysis of maqui leaf extracts by HPLC-DAD-ESI-MSn showed the presence of different polyphenolic compounds classified into galloyl and caffeoyl quinic acids, ellagitannins and ellagic acid- and flavonoid-derivatives. In general, the total phenolic content of the in vitro samples was higher than that of ex vitro samples, whereas the total flavonoid content was higher in winter basal leaves. Additionally, the analysis by HPLC-MS showed that the extract from spring basal leaves was enriched in quercetin, catechin, kaempferol and 3-caffeoyl quinic acids, while in the in vitro leaves extract, quercetin was not present. As regards lipophilic compounds identified by GC/MS, the samples of in vitro leaves showed a high presence of α-tocopherol and β-sitosterol. In contrast, the samples of adult leaves presented a hight level of linolenic and linoleic acids. These results suggest that maqui leaves could be an excellent source of antioxidants and lipophilic compounds for many industries, such as the nutraceutical and pharmaceutical industries.
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    Cuantificación del contenido de ácido indolacético (AIA) en un caldo de fermentación microbiana
    (Murcia: Universidad de Murcia, Servicio de Publicaciones, 2005) Castillo, Grolamys; Altuna, Beatriz; Michelena, Georgina; Sánchez Bravo, José; Acosta Echevarría, Manuel; Biología Vegetal; Facultad de Biología
    El Ácido indol acético (AIA) es una auxina natural presente en la ma yoría de las plantas. Las auxinas son hormonas vegetales que regu- lan diversos procesos del desarrollo vegetal, por lo que su aplicación en Agricultura es muy frecuente. Frente a la actual utilización de auxi- nas obtenidas por síntesis química, la síntesis microbiológica de estas sustancias resulta de gran importancia ya que la aplicación de caldos de fermentación que contienen auxinas, puede constituir una alterna tiva viable en el contexto de una agricultura ecológica. En este trabajo se muestra el estudio realizado para cuantificar el AIA presente en caldos de fermentación obtenidos a partir de la bacteria Rhyzobium sp. 3. Utilizando un procedimiento de análisis de fitohormonas mediante HPLC desarrollado previamente, se ha puesto a punto un método para cuantificar AIA usando Ácido indol propiónico (AIP) como estándar in terno. Se ha utilizado la técnica de supresión iónica que evita la nece- sidad de obtener un derivado del compuesto a analizar. La detección se realizó por fluorescencia a una sensibilidad baja. Las muestras de caldos analizados mostraron un valor medio de AIA en el extracto de 29,0 ± 1,3 mg/mL. El método utilizado resultó ser lineal, sensible, pre- ciso y exacto en el intervalo de concentración estudiado, por lo que se considera adecuado para la cuantificación de AIA a los niveles encon- trados en los caldos fermentados.
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    Effect of body size on plasma and tissue pharmacokinetics of danofloxacin in rainbow trout (Oncorhynchus mykiss)
    (MDPI, 2024-11-16) Uney, Kamil; Corum, Duygu Durna; Marin, Pedro; Coskun, Devran; Terzi, Ertugrul; Badillo Puerta, Elena; Corum, Orhan; Farmacología
    Danofloxacin is a fluoroquinolone antibiotic approved for use in fish. It can be used for bacterial infections in fish of all body sizes. However, physiological differences in fish depending on size may change the pharmacokinetics of danofloxacin and therefore its therapeutic efficacy. In this study, the change in the pharmacokinetics of danofloxacin in rainbow trout of various body sizes was revealed for the first time. The objective of this investigation was to compare the plasma and tissue pharmacokinetics of danofloxacin in rainbow trout of different body sizes. The study was conducted at 14 ± 0.5 ◦C in fish of small, medium, and large body size and danofloxacin was administered orally at a dose of 10 mg/kg. Concentrations of this antimicrobial in tissues and plasma were quantified by high performance liquid chromatography with ultraviolet detector. The plasma elimination half-life (t1/2Lz), volume of distribution (Vdarea/F), total clearance (CL/F), peak concentration (Cmax), and area under the plasma concentration–time curve (AUC0–last) were 27.42 h, 4.65 L/kg, 0.12 L/h/kg, 2.53 μg/mL, and 82.46 h·μg/mL, respectively. Plasma t1/2Lz, AUC0–last and Cmax increased concomitantly with trout growth, whereas CL/F and Vdarea/F decreased. Concentrations in liver, kidney, and muscle tissues were higher than in plasma. Cmax and AUC0–last were significantly higher in large sizes compared to small and medium sizes in all tissues. The scaling factor in small, medium, and large fish was 1.0 for bacteria with MIC thresholds of 0.57, 0.79, and 1.01 μg/mL, respectively. These results show that therapeutic efficacy increases with body size. However, since increases in danofloxacin concentration in tissues of large fish may affect withdrawal time, attention should be paid to the risk of tissue residue.
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    Trends in dithiocarbamates food research: A bibliometric vision
    (Elsevier, 2022-11-23) Veiga del Baño, José Manuel; Martínez López, Salvadora; Pérez Lucas, Gabriel; Andreo Martínez, Pedro; Química Agrícola, Geología y Edafología
    Dithiocarbamate Fungicides (DTFs) are widely analyzed and studied mainly due to the fact that they play an important role in the cultivation of fruits and vegetables. This manuscript aims to display the results of a bibliometric analysis based on the Web of Science© database, performed in the DTF and food research area. A total of 374 publications were examined. The most scientific production was concentrated between 2012 and 2021, showing a decrease of 32% over the last two years. The Journal of Agricultural and Food Chemistry, India, and Sardar Vallabhbhai National Institute of Technology were the most productive journal, country, and institution, respectively. Reference Publication Year Spectroscopy index showed a decrease of 95% in the last last years studied. Finally, current and future trends should focus on keywords such as individual DTF (Mancozeb, Thiram and Maneb), metabolites (Ethylenethiourea, Propilenthiourea) and a change in the analysis methodology: HPLC versus traditional GC.