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A Nitroxide Diuron Analog as a Probe for the Mode of Action of Herbicides
- Siderer, Yona, Lavintman, Nelly, Gilon, Chaim, Ohad, Itzhak
- Zeitschrift für Naturforschung 2014 v.39 no.5 pp. 342-346
- diuron, electrons, mechanism of action, photosystem II, thylakoids, trypsin, urea
- A new spin label nitroxide which is also a herbicide of the urea family has been synthesized. The nitroxide spin label derivative of diuron (ditempuron, DTPU) inhibits electron flow at the site of diuron inhibition of photosystem II (PSII) activity, and it is also reduced by electron flow from one of the first acceptors of PSII. The reduction of the nitroxide group of DTPU is inhibited by diuron or by trypsin treatment of the thylakoids but not by DNP-INT or DBMIB. It is suggested that DTPU binds specifically to and accepts electrons at the Qв site.