Isolation and analyses of polymeric polyphenol fractions from black tea

Comparative studies on the physicochemical and antioxidant properties of different tea extracts

“…UVvisible characteristics and LC/MS/MS n data were given in Table 2. Based on the LC-MS data and the identity of tea polyphenols previously established (Del Rio et al 2004, Lee et al 2005, Krishnan and Maru 2006 were identified as gallic acid, 5-galloylquinic acid, (−)-gallocatechin, (+)-catechin, (−)-epigallocatechin, HHDP-galloylglucose, (−)-epigallocatechin-3-gallate, (−)-epicatechin, (−)-gallocatechin-3-gallate, (−)-epicatechin-3-gallate, respectively. Peaks 12 and 15 were the polymeric polyphenols which was identified as (−)-gallocatechin-3-gallate dimer and EGCG quinone dimer (Tanaka et al 2005).…”

Cytotoxic Activity of Biosynthesized Gold Nanoparticles with an Extract of the Red Seaweed Corallina officinalis on the MCF-7 Human Breast Cancer Cell Line

“…In the FT-IR analysis, the bands were tentatively identified on the basis of reference standards, and published FT-IR spectra in relation to specific molecular groups (Sigee et al, 2002;Krishnan and Maru, 2006;Xie et al, 2007). The results of this study confirm that the hydroxyl functional from polyphenols might be involved in the bioreduction of Au (III) ions into Au (0) and carbonyl group from proteins has stronger ability to bind metal so that the proteins or enzymes could most possibly cap the GNPs to prevent the agglomeration of the particles.…”

A Facile Green Synthesis of Silver Nanoparticles Using the Medicinal Plant Leucas Aspera and Their Antibacterial Activity

“…The peak at 1539 cm -1 may be assigned to symmetric stretching vibrations of -COO-(carboxyl ate ion) groups of amino acid residues with free carboxyl ate groups in the protein [14]. The peaks at 1000-1200 cm -1 indicate C-O single bond and peaks at 1620-1636 cm -1 represent carbonyl groups (C=O) from polyphenols such as catechin gallate, epicatechin gallate and theaflavin [15].…”