Journal of Mathematical and Fundamental Sciences
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Anti-inflammatory Activities and Gastric Ulcer-inducing Properties of Tetraacetylquercetin and Tetrapivaloylquercetin
Get PDFQuercetin (3,3'4',5,7-pentahydroxyflavone) has been reported to show anti-inflammatory activity. However, its low oral bioavailability limits the application of quercetin in therapy. Ester derivatives of quercetin have been reported to have higher bioavailability than quercetin. This research aimed to study the anti-inflammatory activities and gastric ulcer-inducing properties of tetraacetylquercetinas well as tetrapivaloylquercetin. Synthesis of tetra-acyl derivatives of quercetin was conducted using acetic anhydride or pivaloyl chloride in the presence of pyridine and the structure was confirmed by 1H-NMR and 13C-NMR spectroscopy as well as elemental analysis. At a dose of 20 mg/kg bw, oral administration of quercetin only showed 20% inhibition activity on carragenan induced rat paw edema, while tetraacetyl and tetrapivaloyl derivatives at equimolar dose showed 11-33% and 5-15% inhibition activity respectively. Contrary to the gastric ulcer healing-promoting action of quercetin, tetraacetylquercetin caused mild gastric ulcers. However, no gastric ulcer was observed after administration of tetrapivaloylquercetin. It was concluded that acylation enhances the anti-inflammatory activity of quercetin but causes mild gastric ulcers in the case of tetraacetylation
Inclusion Properties on a Class of Meromorphic Functions Defined by a Linear Operator
Get PDFIn the present paper, we study a certain class of meromorphic univalent functions f(z) dened by the linear operator L(α,β) f (z). The aim of the present paper is to prove some properties for the class Σα,β,kλ;(h) to satisfy the certain subordination.AMS Subject Classication: 30C4
Robust Estimators for the Correlation Measure to Resist Outliers in Data
Get PDFThe objective of this research was to propose a composite correlation coefficient to estimate the rank correlation coefficient of two variables. A simulation study was conducted using 228 situations for a bivariate normal distribution to compare the robustness properties of the proposed rank correlation coefficient with three estimators, namely, Spearman's rho, Kendall's tau and Plantagenet's correlation coefficients when the data were contaminated with outliers. In both cases of non-outliers and outliers in the data, it was found that the composite correlation coefficient seemed to be the most robust estimator for all sample sizes, whatever the level of the correlation coefficient.
