Peroxidase-mediated transformation of hydroxy-9,10-anthraquinones.
A peroxidase (EC 1.11.1.7) has been isolated and purified from Senna angustifolia. The enzyme was purified by ion-exchange chromatography on high Q and high S columns. SDS-PAGE electrophoresis showed that the protein has a molecular mass of approximately 70 kDa. Hydroxy-anthraquinones and hydroxy-anthracenones were evaluated as substrate of S. angustifolia and horseradish peroxidases. Both peroxidases catalyzed the oxidation of alizarin and purpurin anthraquinones to the corresponding 3,3'-bializarin and the new compound 3,3'-bipurpurin, respectively, as well as the formation of 2,2'-biquinizarin from quinizarin anthracenone. The K(Mapp) and V(max) values for alizarin and purpurin were 97 and 95 microM, and 1.5 and 2.1 microM min(-1) mg prot(-1), respectively. The results suggest that peroxidase may participate in the biogenesis of anthraquinones.
Arrieta-Baez
Daniel
D
Facultad de Química, UNAM, Ciudad Universitaria, Coyoacán, D.F. 06860, CP 04510 Mexico.
Roman
Rosa
R
Vazquez-Duhalt
Rafael
R
Jiménez-Estrada
Manuel
M
D000873:Anthracenes / Q000378:metabolism; D000880:Anthraquinones / Q000378:metabolism*; D001711:Biotransformation / Q000502:physiology; D006735:Horseradish Peroxidase / Q000378:metabolism*; D007700:Kinetics; D037102:Lectins / Q000378:metabolism; D010084:Oxidation-Reduction; D010544:Peroxidases / Q000378:metabolism*; D037121:Plant Lectins; D029846:Senna Plant / Q000201:enzymology*
D000873:Anthracenes; D000880:Anthraquinones; D037102:Lectins; D037121:Plant Lectins; C010078:alizarin; D006735:Horseradish Peroxidase; D010544:Peroxidases; C511975:purpurin anthraquinone