Search results for "photor"
showing 10 items of 340 documents
Effect of Glufosinate (Phosphinothricin) and Inhibitors of Photorespiration on Photosynthesis and Ribulose-1,5-Bisphosphate Carboxylase Activity
1992
Summary Glufosinate (phosphinothricin) irreversibly inhibits glutamine synthetase and leads to a great decrease in the amino acids glutamine, glutamate, aspartate, serine, glycine and alanine. Due to the lack of glutamate and serine, the transamination of glyoxylate into glycine in the course of photorespiration cannot take place. The inhibition of this part of the photorespiratory process plays the essential role with respect to the photosynthesis inhibition caused by PPT under atmospheric conditions. After addition of different photorespiration or Calvin cycle intermediates to phosphinothricin no decrease in photosynthesis inhibition can be measured. This suggests that photosynthesis inhi…
Kinetics of 4-Methoxybenzyl Alcohol Oxidation in Aqueous Solution in a Fixed Bed Photocatalytic Reactor
2010
WOS: 000280384800004
Inhibitory Action of Glufosinate on Photosynthesis
1993
Glufosinate (phosphinothricin) irreversibly blocks the glutamine synthetase which subsequently gives rise to an accumulation of ammonium and to a strong decrease in some amino acids, especially glutamine and glutamate. Under atmospheric conditions (400 ppm CO2, 21% O2) glufosinate causes a rapid inhibition of photosynthesis, too. H ow ever, under non-photo respiratory conditions (1000 ppm CO2, 2% O2) only a slight inhibition of photosynthesis occurs with glufosinate. Since under both conditions an accumulation of ammonium occurs, it is concluded that inhibition of photosynthesis is not induced by the higher concentrations of ammonium. The results rather suggest that the absence of amino don…
A Photoredox-Catalyzed Four Component Reaction for the Atom-Efficient Synthesis of Complex Secondary Amines
2020
The one-pot sulfonylation/aminoalkylation of styrene derivatives furnishing highly substituted gamma-sulfonylamines was accomplished through a photoredox-catalyzed four-component reaction. Apart from one molecule of water and the sodium counterion of the sulfinate, all atoms of the starting materials are transferred to the final product, rendering this process highly atom-efficient. The operationally simple protocol allows for the simultaneous formation of three new single bonds (C–S, C–N, and C–C) and therefore grants rapid access to structurally diverse products. The reaction proceeds under mild conditions in aqueous acetonitrile and shows a broad scope, including natural products and dru…
The Effect of Bialaphos on Ammonium-Assimilation and Photosynthesis II. Effect on Photosynthesis and Photorespiration
1989
Abstract The application of bialaphos (phosphinothricyl-alanyl-alanine) effects a quick photosynthesis inhibition under atmospheric conditions (400 ppm CO2, 21% O2). However, under conditions (1000 ppm CO2, 2% O2) under which photorespiration cannot occur there is no photosynthesis inhibition. In the previous investigation it could be shown that bialaphos splits in plants into phosphinothricin and alanine. The inhibition of glutamine synthetase through freed phosphinothricin results in an NH4 +-accumulation and a decrease in glutamine. With the addition of glutamine, photosynthesis inhibition by bialaphos can be reduced. An NH4 +-accumulation takes place under atmospheric conditions as well…
Synthesis of methyl derivatives of linear and angular thienocoumarins and thiopyranocoumarins
1998
New linear and angular thienocoumarins and thiopyranocoumarins were synthesized. The key intermediates were appropriate methyl derivatives of 7-mercaptocoumarin, which were condensed with chloro-ketones or propargyl chloride. Thioethers were cyclized under various conditions in order to determine which methods produced the best yields of the desired thienocoumarins 15, 16, 17, 18, 22, 23, 24, 27 and thiopyranocoumarins 28 and 29.
Controlling Spin-Correlated Radical Pairs with Donor-Acceptor Dyads: A New Concept to Generate Reduced Metal Complexes for More Efficient Photocataly…
2021
Abstract One‐electron reduced metal complexes derived from photoactive ruthenium or iridium complexes are important intermediates for substrate activation steps in photoredox catalysis and for the photocatalytic generation of solar fuels. However, owing to the heavy atom effect, direct photochemical pathways to these key intermediates suffer from intrinsic efficiency problems resulting from rapid geminate recombination of radical pairs within the so‐called solvent cage. In this study, we prepared and investigated molecular dyads capable of producing reduced metal complexes via an indirect pathway relying on a sequence of energy and electron transfer processes between a Ru complex and a cova…
PCARE and WASF3 regulate ciliary F-actin assembly that is required for the initiation of photoreceptor outer segment disk formation
2020
Significance The photoreceptor outer segments are primary cilia, modified for phototransduction by incorporation of stacked opsin-loaded membrane disks that are continuously regenerated. This process is disrupted in several types of inherited retinal dystrophy, but the driving force remained unclear. We show that C2orf71/PCARE (photoreceptor cilium actin regulator), associated with inherited retinal dystrophy subtype RP54, efficiently recruits the Arp2/3 complex activator WASF3 to the cilium. This activates an actin dynamics-driven expansion of the ciliary tip, resembling membrane evagination in lamellipodia formation. Colocalization of this actin dynamics module to the base of the outer se…
Regio- and Stereoselective Chloro Sulfoximidations of Terminal Aryl Alkynes Enabled by Copper Catalysis and Visible Light
2021
Advanced synthesis & catalysis 2552-2556 (2021). doi:10.1002/adsc.202100162