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1.
Sci Rep ; 13(1): 21165, 2023 11 30.
Artículo en Inglés | MEDLINE | ID: mdl-38036656

RESUMEN

An abrupt outbreak of COVID-19 caused enormous global concerns. Although all countries around the world are severely affected, developing Asian countries faced more difficulties due to their low per capita GDP. The temperature was considered a leading variable in spreading viral diseases, including COVID-19. The present study aimed to assess the relationship between temperature and the spread of COVID-19, with a focus on developing Asian countries. In a few Asian countries, COVID-19 spread rapidly in the summer, while in some countries, there is an increase in winter. A linear correlation was developed between COVID-19 cases/deaths and temperature for the selected countries, which were very weak. A coefficient of determination of 0.334 and 0.365 was observed between cases and average monthly max/min temperatures. A correlation of R2 = 0.307 and 0.382 was found between deaths and average max/min monthly temperatures, respectively. There is no scientific reason to assume that COVID-19 is more dominant at low than high temperatures. Therefore, it is believed that the results may be helpful for the health department and decision-makers to understand the fast spread of COVID-19.


Asunto(s)
COVID-19 , Humanos , COVID-19/epidemiología , Temperatura , Asia/epidemiología , Brotes de Enfermedades
2.
Artículo en Inglés | MEDLINE | ID: mdl-37291774

RESUMEN

BACKGROUND: Tolfenamic acid (TA) belongs to the fenamates class of non-steroidal anti-inflammatory drugs. Insufficient information is available regarding the availa-bility of a reliable and validated stability-indicating method for the assay of TA. OBJECTIVE: A relatively simple, rapid, accurate, precise, economical, robust, and stability-indicating RP-HPLC method has been developed to determine TA in pure and tablet dosage forms. METHODS: The method was validated according to the ICH guideline, and parameters like linearity, range, selectivity, accuracy, precision, robustness, specificity, and solution stability were determined. TLC and FTIR spectrometry were used to ascertain the purity of TA. The specificity was determined with known impurities and after performing forced degradation, while the robustness was established by Plackett-Burman's experimental design. The mobile phase used for the analysis was acetonitrile and water (90:10, v/v) at pH 2.5. The detection of the active drug was made at 280 nm using a C18 column (tR = 4.3 min.). The method's ap-plicability was also checked for the yellow polymorphic form of TA. RESULTS: The results indicated that the method is highly accurate (99.39-100.80%), precise (<1.5% RSD), robust (<2% RSD), and statistically comparable to the British Pharmacopoeia method with better sensitivity and specificity. CONCLUSION: It was observed that the stress degradation studies do not affect the method's accuracy and specificity. Hence the proposed method can be used to assay TA and its tablet dosage form.

3.
RSC Adv ; 8(71): 41023-41031, 2018 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-35557936

RESUMEN

Triterpenoid glycosides are molecules widely distributed in plants and have shown a wide range of biological activities against various diseases. This paper describes the qualitative and quantitative analysis of triterpenoid glycoside (saponins) using a two-stage mass spectrometry approach in five samples of Fagonia indica collected from various parts of the country. In the first stage, triterpenoid glycosides were identified using liquid chromatography high-resolution mass spectrometry using UHPLC-QTOF-MS system. In the second stage, compounds were quantified using a multiple reaction monitoring (MRM) approach using an UHPLC-QQQ-MS system. Fagonia indica has shown a wide range of biological activities and found to be rich in saponin or triterpenoid glycoside constituents. A total of thirteen triterpenoid saponins were identified based on high-resolution analysis, MS/MS and database comparison, while six of them were simultaneously quantified using the multiple reaction monitoring (MRM) approach. The results indicate that the samples share a similar UHPLC pattern, however, the amount of these saponins in samples varies greatly. Compound 4i.e. nayabin D was the major constituent (1.4-3.8 µg g-1) among the six analyzed compounds. The results demonstrated that the developed multi-compound determination in combination with a fingerprint analysis method is rapid, accurate, precise and sensitive and can be utilized for quality control and high-throughput quantification of various saponins in Fagonia indica may be extended to other plant species.

4.
Biomed Chromatogr ; 31(10)2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28214376

RESUMEN

Diabetes is a major global health problem which requires new studies for its prevention and control. Scoparia dulcis, a herbal product, is widely used for treatment of diabetes. Recent studies demonstrate coixol as a potent and nontoxic insulin secretagog from S. dulcis. This study focuses on developing two quantitative methods of coixol in S. dulcis methanol-based extracts. Quantification of coixol was performed using high-performance liquid chromatography-tandem mass spectrometry (method 1) and high-performance liquid chromatography-ultraviolet detection (method 2) with limits of detection of 0.26 and 11.6 pg/µL, respectively, and limits of quantification of 0.78 and 35.5 pg/µL, respectively. S. dulcis is rich in coixol content with values of 255.5 ± 2.1 mg/kg (method 1) and 220.4 ± 2.9 mg/kg (method 2). Excellent linearity with determination coefficients >0.999 was achieved for calibration curves from 10 to 7500 ng/mL (method 1) and from 175 to 7500 ng/mL (method 2). Good accuracy (bias < -8.6%) and precision (RSD < 8.5%) were obtained for both methods. Thus, they can be employed to analyze coixol in plant extracts and herbal formulations.


Asunto(s)
Benzoxazoles/análisis , Cromatografía Líquida de Alta Presión/métodos , Extractos Vegetales/química , Scoparia/química , Espectrometría de Masas en Tándem/métodos , Insulina/análogos & derivados , Límite de Detección , Modelos Lineales , Reproducibilidad de los Resultados
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