Probing the Influence of Novel Organometallic Copper(II) Complexes on Spinach PSII Photochemistry Using OJIP Fluorescence Transient Measurements.

Modern agricultural cultivation relies heavily on genetically modified plants that survive after exposure to herbicides that kill weeds. Despite this biotechnology, there is a growing need for new sustainable, environmentally friendly, and biodegradable herbicides. We developed a novel [CuL]Br complex (L = bis{4H-1,3,5-triazino[2,1-b]benzothiazole-2-amine,4-(2-imidazole) that is active on PSII by inhibiting photosynthetic oxygen evolution on the micromolar level.

Effects of Novel Photosynthetic Inhibitor [CuL]Br Complex on Photosystem II Activity in Spinach.

The effects of the novel [CuL]Br complex (L = bis{4H-1,3,5-triazino [2,1-b]benzothiazole-2-amine,4-(2-imidazole)}copper(II) bromide complex) on the photosystem II (PSII) activity of PSII membranes isolated from spinach were studied. The absence of photosynthetic oxygen evolution by PSII membranes without artificial electron acceptors, but in the presence of [CuL]Br, has shown that it is not able to act as a PSII electron acceptor. In the presence of artificial electron acceptors, [CuL]Br inhibits photosynthetic oxygen evolution.

Evaluation of new Cu(II) complexes as a novel class of inhibitors against plant carbonic anhydrase, glutathione reductase, and photosynthetic activity in photosystem II.

Increasing inefficiency of production of important agricultural plants raises one of the biggest problems in the modern world. Herbicide application is still the best method of weed management. Traditional herbicides blocking only one of the plant metabolic pathways is ineffective due to the rapid growth of herbicide-resistant weeds.

Characterization of nineteen antimony(III) complexes as potent inhibitors of photosystem II, carbonic anhydrase, and glutathione reductase.

Nineteen antimony(III) complexes were obtained and examined as possible herbicides. Six of these were synthesized for the first time, and their structures were identified using elemental analyses, H-NMR, C-NMR, FTIR, LCMS, magnetic susceptibility, and conductivity measurement techniques. For the nineteen examined antimony(III) complexes their most-stable forms were determined by DFT/B3LYP/LanL2DZ calculation method.

Antimony(III) complexes with 2-amino-4,6-dimethoxypyrimidines: Synthesis, characterization and biological evaluation.

Novel pyrimidine compound bearing disulfide bridge, 5,5'-disulfanediylbis(2-amino-4,6-dimetoxypyrimidine) (3) was synthesized by reduction of 2-amino-4,6-dimethoxy-5-thiocyanatopyrimidine for the first time, and its structure was confirmed by X-ray crystallographic analysis. Novel binuclear antimony(III) compound of (3), {Sb[5,5'-disulfanediylbis(2-amino-4,6-dimetoxypyrimidine)]Cl3}2 (4) and mononuclear antimony(III) compounds, SbL2Cl3, [L: 2-amino-5-thiol-4,6-dimethoxy pyrimidine (2) and 2-amino-5-(1H-tetrazol-5-ylthio)-4,6-dimethoxypyrimidine (6)] were synthesized and characterized with the help of elemental analysis, molecular conductivity, FT-IR, (1)H-NMR and LC-MS techniques. The geometrical structures optimized by a DFT/B3LYP/LANL2DZ method of the compounds, indicated that monomeric compounds have square pyramidal shape.

DNA cleavage, antimicrobial studies and a DFT-based QSAR study of new antimony(III) complexes as glutathione reductase inhibitor.

New antimony(III) complexes, [Sb(2-aminopyridine)2Cl3] (1a), [Sb(2-aminopyridine)2Br3] (1b), [Sb(5-methyl-2-aminopyridine)2Cl3] (2a), [Sb(5-methyl-2-aminopyridine)2Br3] (2b), [Sb(2-aminopyrimidine)2Cl3] (3a), [Sb(2-aminopyrimidine)2Br3] (3b), [Sb(4,6-dimethoxy-2-aminopyrimidine)2Cl3] (4a), [Sb(4,6-dimethoxy-2-aminopyrimidine)2Br3] (4b), [Sb(2-amino-1,3,5-triazine)2Cl3] (5a), [Sb(2-amino-1,3,5-triazine)2Br3] (5b), [Sb(2-guanidinobenzimidazole) Cl3] (6a), [Sb(2-guanidinobenzimidazole)Br3] (6b) [Sb(2- benzyl-2-thiopseudeourea)2Cl3] (7a) and [Sb(2- benzyl-2-thiopseudeourea)2Br3] (7b) were synthesized. Their structures were characterized by elemental analysis, molecular conductivity, FT-IR, (1)H NMR, LC-MS techniques. Glutathione reductase inhibitor activity, antimicrobial activity and DNA cleavage studies of the complexes were determined.

Screening of novel chemical compounds as possible inhibitors of carbonic anhydrase and photosynthetic activity of photosystem II.

Thirty novel chemical compounds were designed and synthesized expecting that they would be possible inhibitors. From this number eleven were organic bases, twenty-four were their organic derivatives and fourteen were metal complexes. Screening of these chemicals by their action on photosynthetic electron transfer (PET) and carbonic anhydrase (CA) activity (CAA) of photosystem II (PSII), α-CA, as well as β-CA was done.

Quantitative structure-activity relationship analysis of perfluoroiso-propyldinitrobenzene derivatives known as photosystem II electron transfer inhibitors.

Quantitative structure-activity relationship (QSAR) analysis of the twenty-six perfluoroisopropyl-dinitrobenzene (PFIPDNB) derivatives was performed to explain their ability to suppress photochemical activity of the plants photosystem II using chloroplasts and subchloroplast thylakoid membranes enriched in photosystem II, called DT-20. Compounds were optimized by semi-empirical PM3 and DFT/B3LYP/6-31G methods. The Heuristic and the Best Multi-Linear Regression (BMLR) method in CODESSA were used to select the most appropriate molecular descriptors and to develop a linear QSAR model between experimental pI(50) values and the most significant set of the descriptors.

Simultaneous preconcentration and removal of iron, chromium, nickel with N,N'-etylenebis-(ethane sulfonamide) ligand on activated carbon in aqueous solution and determination by ICP-OES.

In this study, Fe, Cr and Ni have been preconcentrated and removed by using N,N'-ethylenebis (ethane sulfonamide), (ESEN) ligand on activated carbon (AC) in aqueous solution. For this purpose, complexes between these metals and ligands have been investigated and used in preconcentration and removal studies. Factors which have affected adsorption of metals on activated carbon have been optimized.