Flavonoids of Campanula alata and their antioxidant activity

The authors thank the DG/RSDT, MESRS, Algeria for financial support

Dimeric Coumarin and Other Constituents from Flowers of Matricaria pubescens

Dimer of herniarin (1) together with herniarin (2), scopoletin (3), and (2E,4E)-6-(2-thienyl)-2,4-hexadienisobutylamide (4) were isolated from the flowers of Matricaria pubescens. Their structures were established by spectroscopic data and by comparison with spectral data of known compounds. Compound 1 is reported for the first time in plant kingdom, and compound 3 is reported from M. pubescens for the first time.The authors wish to thank Dr. Youcef Hallis (laboratory of biochemistry, scientific and technical center for arid areas, Touggourt, Algeria) for the identification of the plant material.Peer reviewe

Actividad antioxidante de los polifenoles de HYPOGYMNIA TAVARESII D. HAWKSW. & P. JAMES

Lichen substances have more than one phenolic hydroxyl group attached to one or more benzene rings, thus qualifying them as polyphenols. The secondary metabolites isolated from the lichen H. tavaresii have been studied in a bid to find compounds protective against oxidative stress and free radical-induced damage. The compounds were identified based on their MS and 1H-NMR spectra as well as retention factors of TLC analysis. In addition to the previously described metabolites (atranorin, chloroatranorin, physodic and physodalic acids) of H. tavaresii, a further three were identified in its thalli: 2´-O-methylphysodone, isophysodic and ursolic acids. The newly identified compounds of H. tavaresii thalli may be useful in the chemotaxonomic classification of this species. Antioxidant effectiveness of the acetone extract's fractions was measured. The compounds of the active fractions were purified and exhibited 180-800 fold less radical scavenging activity than the reference substance α-(+)-tocopherol in a DPPH• model expressed by IC50 values