The phytotoxic lichen metabolite, usnic acid, is a potent inhibitor of plant p‐hydroxyphenylpyruvate dioxygenase

FEBS Letters

Nanayakkara, N.P.Dhammika³  Romagni, Joanne G.²  Dayan, Franck E.²  Meazza, Giovanni¹ 

[1] Isagro Ricerca Srl, via G. Fauser, 4, 28100 Novara, Italy;USDA/ARS, Natural Products Utilization Research Unit, P.O. Box 8048, University of Mississippi, University, Lafayette Co, MS 38677, USA;National Center for Natural Products Research, School of Pharmacy, University of Mississippi, University, Lafayette Co, MS 38677, USA

关键词: Bleaching herbicide;    Lichen;    p-Hydroxyphenylpyruvate dioxygenase;    Phytotoxin;    Alectoria sarmentosa;   

DOI  :  10.1016/S0014-5793(00)01907-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The lichen secondary metabolite usnic acid exists as a (−) and a (+) enantiomer, indicating a α or β projection of the methyl group at position 9b, respectively. (−)-Usnic caused a dose-dependent bleaching of the cotyledonary tissues associated with a decrease of both chlorophylls and carotenoids in treated plants whereas no bleaching was observed with the (+) enantiomer. (−)-Usnic acid inhibited protophorphyrinogen oxidase activity (I ₅₀=3 μM), but did not lead to protoporphyrin IX accumulation. Bleaching appears to be caused by irreversible inhibition of the enzyme 4-hydroxyphenylpyruvate dioxygenase by (−)-usnic acid (apparent IC₅₀=50 nM).

【 授权许可】

Unknown