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Updated: Jul 21, 2025
![[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)
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[DPEPhosbcpCu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst
Published on: May 21, 2019
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Probing the Influence of Novel Organometallic Copper(II) Complexes on Spinach PSII Photochemistry Using OJIP
Sergei K Zharmukhamedov1, Mehriban S Shabanova2, Irada M Huseynova2
1Institute of Basic Biological Problems, FRC PSCBR RAS, 142290 Pushchino, Russia.
Biomolecules
|July 29, 2023
Summary
A novel copper complex, [CuL2]Br2, acts as a herbicide by inhibiting photosynthesis in photosystem II (PSII). It exhibits dual binding sites, affecting both reaction centers and exhibiting diuron-like activity, offering potential for sustainable agriculture.
Area of Science:
- Biochemistry
- Plant Science
- Agricultural Chemistry
Background:
- Genetically modified crops require effective herbicides for weed control.
- There is a need for sustainable, biodegradable herbicides to reduce environmental impact.
- Photosystem II (PSII) is a key target for herbicide development.
Purpose of the Study:
- To investigate the herbicidal activity and mechanism of a novel copper complex, [CuL2]Br2.
- To explore the binding sites and effects of [CuL2]Br2 on PSII.
- To compare the action of [CuL2]Br2 with known PSII inhibitors like DCMU.
Main Methods:
- Utilized OJIP chlorophyll fluorescence transient measurements on PSII-containing membranes.
- Investigated the effects of [CuL2]Br2 in the presence and absence of DCMU.
- Analyzed the impact of [CuL2]Br2 on photosynthetic oxygen evolution and PSII fluorescence (Fv).
Main Results:
- The novel [CuL2]Br2 complex inhibits photosynthetic oxygen evolution at the micromolar level.
- [CuL2]Br2 significantly reduces Fv of PSII fluorescence, an effect not reversed by artificial electron donors.
- Observed two distinct effects of [CuL2]Br2: a primary decrease in fluorescence intensity and a secondary 'diuron-like' effect, suggesting dual binding sites with varying affinities.
Conclusions:
- The [CuL2]Br2 complex acts as a potent PSII inhibitor with a dual-site binding mechanism.
- High-affinity binding resembles PSII reaction center inhibition, while low-affinity binding mimics DCMU's effects.
- This novel copper complex shows promise as a new class of herbicides for sustainable agriculture.
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