Search

A novel bioactive flavan glycoside was isolated by solvent extraction method with the help of Soxhlet apparatus from the methanolic extract of Tradescantia spathacea Sw. Flavan glycoside having molecular formula C20H22O10, melting point 175-1780C, molecular weight by ESI-MS m/z (M + H]+ 423, optical rotation was[α]21D-45.1(c 0.20 methanol). Its structure was determined (–)-epicatechin 7-O-alpha-L-arabinopyranoside. Various color reactions, chemical degradation (like acid hydrolysis, permethylation, and enzymatic hydrolysis), UV-Visible spectrophotometry, Fourier transforms infrared spectroscopy, electrospray ionization mass spectrometry, and nuclear magnetic resonance spectroscopy were used to establish the structure of compound (–)-(–)-epicatechin 7-O-alpha-L-arabinopyranoside.. A flavan glycoside was also tested with a DPPH assay method for antioxidant activity by using Ascorbic acid as standard. DPPH radical scavenging test data demonstrate that a flavan glycoside possesses potent antioxidant activity so this flavan glycoside can be utilized as a potent antioxidant agent. [ABSTRACT FROM AUTHOR]

Here we are reporting a new bioactive flavanone glycoside. The compound having molecular formula C21H22O11, melting point 123-125°C, and ESI-MS m/z 451 was isolated from the methanolic extract of Tradescantia Spathacea Sw. Its characterization and structure elucidation was done with the help of various chemical degradation, color reactions, and spectral data like UV-Visible, FT-IR, electrospray ionization mass spectrometry technique, nuclear magnetic resonance spectroscopy, etc. It was recognized as 5,7,3'4'-tetrahydroxy flavanone 3'-O-D-mannopyranoside. This study was also designed to examine the efficacy of an isolated compound against various bacteria which are responsible for food spoilage and pathogens in humans. The organic flavanone glycoside of methanolic extract exhibited a promising antibacterial activity towards Escherichia coli (gram negative) MTCC 724, Bacillus subtilis MTCC 441, Staphylococcus aureus MTCC 737, Pseudomonas aerugenosa MTCC 424, and Salmonella typhimurium MTCC 3224. A new flavanone glycoside possesses potent anti-bacterial activity so it can be utilized as a potent source of antibacterial agents for food and pharmaceutical interest. [ABSTRACT FROM AUTHOR]

The relationship between the regression depth developed by Rousseeuw and Hubert and the usual norm of data fitting has been studied. The utility of the maximal regression depth in describing the linearity of a given dataset has also been examined. The conclusions obtained argue that additional properties of a given line must be coupled with the regression depth if the measure of fitness of regression problems is to be derived. The maximal regression depth is at its highest when the data are on the line while at its lowest when the data lie on a convex or concave curve. This suggests that themaximal value can be used in gauging the linearity of the data., 1. INTRODUCTION Rousseeuw and Hubert introduce the notion of depth in a regression setting. In particular, they study the properties of the deepest fit, which is a generalization of the [...]