Regulation of photosynthetic electron transport and photophosphorylation in intact chloroplasts and leaves of Spinacia oleracea L.

Planta ◽  
1978 ◽  
Vol 143 (1) ◽  
pp. 41-49 ◽  
Author(s):  
U. Heber ◽  
H. Egneus ◽  
U. Hanck ◽  
M. Jensen ◽  
S. K�ster
Keyword(s):  
Electron Transport ◽  
Spinacia Oleracea ◽  
Photosynthetic Electron Transport ◽  
Spinacia Oleracea L ◽  
Intact Chloroplasts

scholarly journals Preparation and Photosynthesis-Inhibiting Activity of Novel Dihalogenated 3-Hydroxynaphthalene-2-carboxanilides

Proceedings ◽  
2019 ◽  
Vol 41 (1) ◽  
pp. 30
Author(s):  
Jiri Kos ◽  
Tomas Gonec ◽  
Tomas Strharsky ◽  
Michal Oravec ◽  
Josef Jampilek
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Spinacia Oleracea ◽  
Photosynthetic Electron Transport ◽  
Microwave Assisted Synthesis ◽  
Inhibiting Activity ◽  
Microwave Assisted ◽  
Spinacia Oleracea L ◽  
Wide Range

In this study, a series of nine 3-hydroxynaphthalene-2-carboxanilides, disubstituted on the anilide ring by fluorine, chlorine and bromine in various positions, was prepared by microwave-assisted synthesis and characterized. The compounds were tested for their activity related to the inhibition of photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. The PET-inhibiting activity of the compounds was within a wide range, but rather moderate; the highest activity within the series of the compounds was observed for N-(3,5-difluorophenyl)-3-hydroxynaphthalene-2-carboxamide (IC50 = 9.8 µM). The compounds were found to inhibit PET in photosystem II.

scholarly journals Photosynthesis-Inhibiting Activity of N-(Disubstituted-phenyl)-3-hydroxynaphthalene-2-carboxamides

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4336
Author(s):  
Jiri Kos ◽  
Tomas Gonec ◽  
Michal Oravec ◽  
Izabela Jendrzejewska ◽  
Josef Jampilek
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Spinacia Oleracea ◽  
Photosynthetic Electron Transport ◽  
Inhibiting Activity ◽  
Spinacia Oleracea L ◽  
The Individual

A set of twenty-four 3-hydroxynaphthalene-2-carboxanilides, disubstituted on the anilide ring by combinations of methoxy/methyl/fluoro/chloro/bromo and ditrifluoromethyl groups at different positions, was prepared. The compounds were tested for their ability to inhibit photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. N-(3,5-Difluorophenyl)-, N-(3,5-dimethylphenyl)-, N-(2,5-difluorophenyl)- and N-(2,5-dimethylphenyl)-3-hydroxynaphthalene-2-carboxamides showed the highest PET-inhibiting activity (IC50 ~ 10 µM) within the series. These compounds were able to inhibit PET in photosystem II. It has been found that PET-inhibiting activity strongly depends on the position of the individual substituents on the anilide ring and on the lipophilicity of the compounds. The electron-withdrawing properties of the substituents contribute towards the PET activity of these compounds.

scholarly journals The effects of high concentrations of salts on photosynthetic electron transport in spinach (Spinacia oleracea) chloroplasts

1982 ◽  
Vol 204 (3) ◽  
pp. 705-712 ◽  
Author(s):  
A C Stewart
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Photosystem I ◽  
Spinacia Oleracea ◽  
Photosynthetic Electron Transport ◽  
Potassium Citrate ◽  
O2 Evolution ◽  
Hofmeister Series ◽  
Reaction Centre ◽  
High Concentrations

1. Photosynthetic electron transport from water to lipophilic Photosystem II acceptors was stimulated 3-5-fold by high concentrations (greater than or equal to 1 M) of salts containing anions such as citrate, succinate and phosphate that are high in the Hofmeister series. 2. In trypsin-treated chloroplasts, K3Fe(CN)6 reduction insensitive to 3-(3,4-dichlorophenyl)-1,1-dimethylurea was strongly stimulated by high concentrations of potassium citrate, but there was much less stimulation of 2,6-dichloroindophenol reduction in Tris-treated chloroplasts supplied with 1,5-diphenylcarbazide as artificial donor. The results suggest that the main site of action of citrate was the O2-evolving complex of Photosystem II. 3. Photosystem I partial reactions were also stimulated by intermediate concentrations of citrate (up to 2-fold stimulation by 0.6-0.8 M-citrate), but were inhibited at the highest concentrations. The observed stimulation may have been caused by stabilizaton of plastocyanin that was complexed with the Photosystem I reaction centre, 4. At 1 M, potassium citrate protected O2 evolution against denaturation by heat or by the chaotropic agent NaNO3. 5. It is suggested that anions high in the Hofmeister series stimulated and stabilized electron transport by enhancing water structure around the protein complexes in the thylakoid membrane.

Regulation of photosystem II by metabolic and environmental factors

1989 ◽  
Vol 323 (1216) ◽  
pp. 269-279 ◽  
Keyword(s):  
Electron Transport ◽  
Higher Plants ◽  
Photosynthetic Electron Transport ◽  
Thylakoid Membranes ◽  
Internal Factors ◽  
Regulatory Processes ◽  
Quenching Analysis ◽  
Intact Chloroplasts ◽  
Rate Of Dissipation

The thylakoid membranes of higher plants possess several mechanisms that control both the distribution and rate of dissipation of absorbed light. These mechanisms, which allow regulation of photosynthetic electron transport in response to alteration in external and internal factors, can be observed as the various processes that quench chlorophyll fluorescence. By using the 'light-doubling techniques’, together with analysis of quenching relaxation, it is possible to assess quantitatively the extents of these regulatory processes and to allow their interrelations to be studied. These techniques can be applied to in vitro systems or to leaves, and can be particularly useful when applied with electron-transport measurements and when models are used to aid interpretation. Results of quenching analysis at different light intensities in isolated thylakoids, intact chloroplasts, protoplasts, algae and leaves of a variety of species are presented.

scholarly journals Synthesis and Spectrum of Biological Activities of Novel N-arylcinnamamides

2018 ◽  
Vol 19 (8) ◽  
pp. 2318 ◽  
Author(s):  
Sarka Pospisilova ◽  
Jiri Kos ◽  
Hana Michnova ◽  
Iva Kapustikova ◽  
Tomas Strharsky ◽  
...  
Keyword(s):  
Spinacia Oleracea ◽  
Biological Activities ◽  
Cell Metabolism ◽  
Photosynthetic Electron Transport ◽  
Lethal Effect ◽  
Bipolaris Sorokiniana ◽  
Spinacia Oleracea L ◽  
Inhibitor Compounds

: A series of sixteen ring-substituted N-arylcinnamamides was prepared and characterized. Primary in vitro screening of all the synthesized compounds was performed against Staphylococcus aureus, three methicillin-resistant S. aureus strains, Mycobacterium tuberculosis H37Ra, Fusarium avenaceum, and Bipolaris sorokiniana. Several of the tested compounds showed antistaphylococcal, antitubercular, and antifungal activities comparable with or higher than those of ampicillin, isoniazid, and benomyl. (2E)-N-[3,5-bis(trifluoromethyl)phenyl]-3-phenylprop-2-enamide and (2E)-3-phenyl-N-[3-(trifluoromethyl)phenyl]prop-2-enamide showed the highest activities (MICs = 22.27 and 27.47 µM, respectively) against all four staphylococcal strains and against M. tuberculosis. These compounds showed an activity against biofilm formation of S. aureus ATCC 29213 in concentrations close to MICs and an ability to increase the activity of clinically used antibiotics with different mechanisms of action (vancomycin, ciprofloxacin, and tetracycline). In time-kill studies, a decrease of CFU/mL of >99% after 8 h from the beginning of incubation was observed. (2E)-N-(3,5-Dichlorophenyl)- and (2E)-N-(3,4-dichlorophenyl)-3-phenylprop-2-enamide had a MIC = 27.38 µM against M. tuberculosis, while a significant decrease (22.65%) of mycobacterial cell metabolism determined by the MTT assay was observed for the 3,5-dichlorophenyl derivative. (2E)-N-(3-Fluorophenyl)- and (2E)-N-(3-methylphenyl)-3-phenylprop-2-enamide exhibited MICs = 16.58 and 33.71 µM, respectively, against B. sorokiniana. The screening of the cytotoxicity of the most effective antimicrobial compounds was performed using THP-1 cells, and these chosen compounds did not shown any significant lethal effect. The compounds were also evaluated for their activity related to the inhibition of photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. (2E)-N-(3,5-dichlorophenyl)-3-phenylprop-2-enamide (IC50 = 5.1 µM) was the most active PET inhibitor. Compounds with fungicide potency did not show any in vivo toxicity against Nicotiana tabacum var. Samsun. The structure–activity relationships are discussed.

scholarly journals Synthesis and Biological Evaluation of 2-Hydroxy-3-[(2-aryloxyethyl)amino]propyl 4-[(Alkoxycarbonyl)amino]benzoates

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Jan Tengler ◽  
Iva Kapustíková ◽  
Matúš Peško ◽  
Rodney Govender ◽  
Stanislava Keltošová ◽  
...  
Keyword(s):  
Electron Transport ◽  
Conformational Changes ◽  
Spinacia Oleracea ◽  
Photosynthetic Electron Transport ◽  
Thylakoid Membranes ◽  
Biological Evaluation ◽  
Mycobacterial Species ◽  
Monocytic Leukaemia ◽  
Synthesis And Biological Evaluation

A series of twenty substituted 2-hydroxy-3-[(2-aryloxyethyl)amino]propyl 4-[(alkoxycarbonyl)amino]benzoates were prepared and characterized. As similar compounds have been described as potential antimycobacterials, primaryin vitroscreening of the synthesized carbamates was also performed against two mycobacterial species. 2-Hydroxy-3-[2-(2,6-dimethoxyphenoxy)ethylamino]-propyl 4-(butoxycarbonylamino)benzoate hydrochloride, 2-hydroxy-3-[2-(4-methoxyphenoxy)ethylamino]-propyl 4-(butoxycarbonylamino)benzoate hydrochloride, and 2-hydroxy-3-[2-(2-methoxyphenoxy)ethylamino]-propyl 4-(butoxycarbonylamino)benzoate hydrochloride showed higher activity againstM. aviumsubsp.paratuberculosisandM. intracellularethan the standards ciprofloxacin, isoniazid, or pyrazinamide. Cytotoxicity assay of effective compounds was performed using the human monocytic leukaemia THP-1 cell line. Compounds with predicted amphiphilic properties were also tested for their effects on the rate of photosynthetic electron transport (PET) in spinach (Spinacia oleraceaL.) chloroplasts. All butyl derivatives significantly stimulated the rate of PET, indicating that the compounds can induce conformational changes in thylakoid membranes resulting in an increase of their permeability and so causing uncoupling of phosphorylation from electron transport.

Enhancement of Chloroplast Photooxidations with Photosynthesis-Inhibiting Herbicides and Protection with NADH or NADPH

Weed Science ◽  
1978 ◽  
Vol 26 (5) ◽  
pp. 440-443 ◽  
Author(s):  
C. N. Giannopolitis ◽  
G. S. Ayers
Keyword(s):  
Lipid Peroxidation ◽  
Electron Transport ◽  
Hordeum Vulgare ◽  
Photosynthetic Electron Transport ◽  
Intact Chloroplasts ◽  
Chlorophyll Bleaching ◽  
Additional Support ◽  
Reducing Potential

Representative herbicides of the substituted ureas, uracils,s-triazines, benzonitriles, and bipyridyls, which are potent inhibitors of photosynthetic electron transport, markedly accelerated photooxidations (chlorophyll bleaching and lipid peroxidation) normally occurring in isolated intact chloroplasts. Other herbicides, which are not potent inhibitors of photosynthesis, did not accelerate photooxidations. The photooxidations, whether in the presence or absence of herbicides, were completely prevented by exogenously supplied NADH or NADPH but not by sucrose or mannitol. Herbicide-induced injury to barley(Hordeum vulgareL.) seedlings treated with paraquat (1,1′-dimethyl-4,4′-bipyridinium ion) was diminished by allowing the seedlings to absorb NADPH. These results provide additional support to the hypothesis that depletion of the source of reducing potential (NADPH) is responsible for chloroplast photooxidations and plant death following treatment with photosynthesis-inhibiting herbicides.

scholarly journals Synthesis and Antimycobacterial and Photosynthesis-Inhibiting Evaluation of 2-[(E)-2-Substituted-ethenyl]-1,3-benzoxazoles

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Ales Imramovsky ◽  
Jan Kozic ◽  
Matus Pesko ◽  
Jirina Stolarikova ◽  
Jarmila Vinsova ◽  
...  
Keyword(s):  
Electron Transport ◽  
Photosystem Ii ◽  
Inhibitory Action ◽  
Spinacia Oleracea ◽  
Photosynthetic Electron Transport ◽  
Inhibiting Activity ◽  
Donor Side ◽  
Structure Activity Relationships ◽  
Structure Activity

A series of twelve 2-[(E)-2-substituted-ethenyl]-1,3-benzoxazoles was designed. All the synthesized compounds were tested against three mycobacterial strains. The compounds were also evaluated for their ability to inhibit photosynthetic electron transport (PET) in spinach (Spinacia oleraceaL.) chloroplasts. 2-[(E)-2-(4-Methoxyphenyl)ethenyl]-1,3-benzoxazole, 2-[(E)-2-(2,3-dihydro-1-benzofuran-5-yl)ethenyl]-1,3-benzoxazole and 2-{(E)-2-[4-(methylsulfanyl)phenyl]ethenyl}-1,3-benzoxazole showed the highest activity againstM. tuberculosis,M. kansasii,andM. avium, and they demonstrated significantly higher activity againstM. aviumandM. kansasiithan isoniazid. The PET-inhibiting activity of the most activeortho-substituted compound 2-[(E)-2-(2-methoxyphenyl)ethenyl]-1,3-benzoxazole was IC50= 76.3 μmol/L, while the PET-inhibiting activity ofpara-substituted compounds was significantly lower. The site of inhibitory action of tested compounds is situated on the donor side of photosystem II. The structure-activity relationships are discussed.

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