19611-22-4Relevant articles and documents
Phytotoxic and Antimicrobial Activities of Catechin Derivatives
Veluri, Ravikanth,Weir, Tiffany L.,Bais, Harsh Pal,Stermitz, Frank R.,Vivanco, Jorge M.
, p. 1077 - 1082 (2007/10/03)
(±)-Catechin is a potent phytotoxin, with the phytotoxicity due entirely to the (-)-catechin enantiomer. (+)-Catechin, but not the (-)-enantiomer, has antibacterial and antifungal activities. Tetramethoxy, pentaacetoxy, and cyclic derivatives of (±)-catechin retained phytotoxicity. The results indicate that antioxidant properties of catechins are not a determining factor for phytotoxicity. A similar conclusion was reached for the antimicrobial properties. Centaurea maculosa (spotted knapweed) exudes (±)-catechin from its roots, but the flavanol is not re-absorbed and hence the weed is not affected. The much less polar tetramethoxy derivative may, however, be absorbed and hence be able to cause toxicity. Because of the combination of phytotoxicity and antimicrobial activity, (±)-catechin could be a useful natural herbicide and antimicrobial.
Synthesis of Biflavonoids in which the Flavan Units are linked through Oxygen from C-2 to C-3 or C-4
Brown, Ben R.,Stuart, Ian A.,Tyrrell, A. William R.
, p. 2563 - 2572 (2007/10/02)
Flav-2-enes have been utilised via 2,3-cis-2-acetoxy-3-bromoflavans for the synthesis of C-2-O-C-3- and C-2-O-C-4-linked biflavonoids.For example, 2,3-cis-2-acetoxy-3-bromoflavans react with (+/-)-tetra-O-methylcatechin (18) to give
