Herbicidal indolizine-5,8-diones: photosystem I redox mediators.
6,7-Disubstituted indolizine-5,8-diones showed activity as herbicides, giving rapid desiccation symptomology in whole-plant tests and bleaching in leaf-disc assays. In isolated chloroplasts, such compounds initiated rapid uptake of oxygen in Photosystem I. A redox mediator mode of action was further supported by electrochemical studies. Several compounds described had low photostability, high volatility, hydrolytic instability or reactivity with glutathione. The detrimental effects that these factors may have had on expression of herbicidal activity are discussed.
Smith
Stephen C
SC
Syngenta, Jealott's Hill International Research Centre, Bracknell, Berkshire RG42 6EY, United Kingdom. steve.smith@syngenta.com
Clarke
Eric D
ED
Ridley
Stuart M
SM
Bartlett
David
D
Greenhow
Daren T
DT
Glithro
Harry
H
Klong
Agnes Y
AY
Mitchell
Glynn
G
Mullier
Graham W
GW
D004355:Drug Stability; D006540:Herbicides / Q000138:chemical synthesis* / Q000494:pharmacology*; D007212:Indolizines / Q000138:chemical synthesis* / Q000494:pharmacology*; D008027:Light; D015394:Molecular Structure; D045331:Photosystem I Protein Complex / Q000187:drug effects*; D018515:Plant Leaves; D010944:Plants / Q000201:enzymology; D013329:Structure-Activity Relationship
D006540:Herbicides; D007212:Indolizines; D045331:Photosystem I Protein Complex