The chemical components of Coreopsis tinctoria Nutt. and their antioxidant,antidiabetic and antibacterial activities

Abstract

Seventeen compounds were isolated from the capitula of Coreopsis tinctoria Nutt. with various column chromatographic methods and semi-preparative HPLC. Their structures were identified by the spectroscopic data and comparison with literatures as 2′-hydroxy-4,4′-dimethoxy-chalcone; (1), isoliquiritigenin (2), eriodictyol (3), naringenin (4), maritimetin (5), butin (6), taxifolin (7), luteolin (8), 7,3′,4′-trihydroxyflavone (9), 8,3′,4′-trihydroxyflavone-7-O-β-d-glucoside (10), quercetin (11), quercetagitin-7-O-β-d-glucoside (12), quercetin-7-O-β-d-glucoside (13), 3,4-dihydroxybenzoic acid (14), caffeic acid (15), coreoside B (16), and myo-inositol (17). Compounds 1, 4, 9, 10 and 17 were isolated from C. tinctoria Nutt. for the first time. Compounds 7 and 12 possessed the highest antioxidant activity (IC₅₀?=?64.37 and 32.86?µg/ml, respectively) among the tested compounds (IC₅₀ value of positive control was 5.34?µg/ml). Compound 7 exhibited potent PTP1B enzymatic inhibition with an IC₅₀ value of 7.73?μg/ml (IC₅₀ value of positive control is 1.46?µg/ml). Furthermore, compound 5 showed strong antibacterial activity against the Gram-positive bacterium, S. aureus.     

A Certain Inversion Problem for the Ray Transform with Incomplete Data

The problem is considered of reconstructing a function in three-dimensional space from its integrals over a family of straight lines that are generators of cones, i.e., an inversion problem for the ray transform with incomplete data. This problem is connected with an auxiliary problem of analytic continuation and is strongly ill-posed. A uniqueness theorem and conditional stability estimates for a solution are obtained.     

Calculation of systematic vertical. Drainage

In the reported studies of vertical drainage (for example, [1, 2]) a constant infiltration rate acts in the course of an entire year. Since infiltration arises as a result of irrigation or input from atmospheric water, it actually acts in certain seasons of the year and not all year long.We shall investigate how the motion parameters vary in cases with and without irrigation, and also the question of how well justified is the consideration of the infiltration rate as a function acting throughout the the course of the entire year.In conclusion I wish to thank P. Ya. Kochina for her interest in this investigation.