Quantitative Structure–Enhancement Relationship and the Microenvironment of the Enhancer Site of Action

Author(s):  
S. Kevin Li ◽  
William I. Higuchi
1979 ◽  
Vol 34 (11) ◽  
pp. 1028-1031 ◽  
Author(s):  
G. P. Brugnoni ◽  
P. Moser ◽  
A. Trebst

Abstract Substituted phenyl-hydroxy pyrrolone derivatives are potential herbicides and are found to be effective inhibitors of photosynthetic electron flow in chloroplasts. Their site of inhibition is localized at the acceptor side of photosystem II similar to DCMU. They have no effect on photophosphoryla­tion. The correlation of photosynthetic acitivity to chemical structure is studied by comparing 36 derivatives. A clear dependence of inhibitory activity on lipophilicity is found. The dependence of herbicidal activity on chemical structure is more complex.


1966 ◽  
Vol 118 (2) ◽  
pp. 117-122 ◽  
Author(s):  
W. J. Flanigan

1992 ◽  
Vol 5 (4) ◽  
pp. 299-305 ◽  
Author(s):  
lonan Marigómez ◽  
Manu Soto ◽  
Eduardo Angulo

1972 ◽  
Vol 27 (01) ◽  
pp. 063-071
Author(s):  
S. G Iatridis ◽  
P. G Iatridis

SummaryThe present investigation deals with in vivo studies of possible relations of active Hageman factor (HFa) to the problems of thrombolysis. The study is based upon animal experimentation in which 40 normal, 5 dicumarolized and 5 heparinized rabbits each received ellagic acid (Elac 10-2 M) by intravenous continuous infusion at a rate of 1 ml/min for a period of 25 min. The data suggest that the Elac infusion induced in vivo activation of HF. Streptokinase (SK) injection 25 min from the start of Elac i. v. infusion failed to induce clot lysis in blood drawn one min after its injection. The phenomenon was more prominent with low (SK 250 U or 500 U) concentrations of SK. With higher concentrations, SK-induced clot lysis activity was not affected by Elac infusion.In dicumarolized and heparinized rabbits Elac infusion still counteracted the fibrinolysis activating effect of low concentration of SK. The possibility that the above described phenomenon was due to either hypercoagulability or to a non-specific inhibitory effect of Elac upon SK was explored and excluded.It is concluded that HFa and SK have the same site of action. Thus it seems that HFa may block the precursor upon which SK acts by forming a complex with it. It is stressed that activation of this precursor by HFa requires a suitable surface.


2020 ◽  
Vol 3 (4) ◽  
pp. 558-576
Author(s):  
Seithikurippu R Pandi-Perumal ◽  
Daniel P Cardinali ◽  
Russel J Reiter ◽  
Gregory M Brown

That the pineal gland is a source of melatonin is widely known; however, by comparison, few know of the much larger pool of extrapineal melatonin. That pool is widely distributed in all animals, including those that do not have a pineal gland, e.g., insects.  Extrapineal melatonin is not released into the blood but is used locally to function as an antioxidant, anti-inflammatory agent, etc. A major site of action of peripherally-produced melatonin is the mitochondria where it neutralizes reactive oxygen species (ROS) that are generated during oxidative phosphorylation. Its role also includes major actions as an immune modulator reducing overreactions to foreign agents while simultaneously boosting immune processes. During a pandemic such as coronavirus disease 2019 (COVID-19), caused by the virus SARS-CoV-2, melatonin is capable of suppressing the damage inflicted by the cytokine storm. The implications of melatonin in susceptibility and treatment of COVID-19 disease are discussed. 


2019 ◽  
Vol 48 (3) ◽  
pp. 417-425
Author(s):  
Md Khayrul Alam Bhuiyan ◽  
Md Akhter Hossain ◽  
Abdul Kadir Ibne Kamal ◽  
Mohammed Kamal Hossain ◽  
Mohammed Jashimuddin ◽  
...  

A study was conducted by using 5m × 5m sized 179 quadrates following multistage random sampling method for comparative regenerating tree species, quantitative structure, diversity, similarity and climate resilience in the degraded natural forests and plantations of Cox's Bazar North and South Forest Divisions. A total of 70 regenerating tree species were recorded representing maximum (47 species) from degraded natural forests followed by 43 species from 0.5 year 39 species from 1.5 year and 29 species from 2.5 year old plantations. Quantitative structure relating to ecological dominance indicated dominance of Acacia auriculiformis, Grewia nervosa and Lithocarpus elegans seedlings in the plantations whereas seedlings of Aporosa wallichii, Suregada multiflora and Grewia nervosa in degraded natural forests. The degraded natural forests possess higher natural regeneration potential as showed by different diversity indices. The dominance-based cluster analysis showed 2 major cluster of species under one of which multiple sub-clusters of species exists. Poor plant diversity and presence of regenerating exotic species in the plantations indicated poor climate resilience of forest ecosystem in terms of natural regeneration.


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