Activity correlations

We consider first some experimental observations. In general, the initial heats of adsorption on metals tend to follow a common pattern, similar for such common adsorbates as hydrogen, nitrogen, ammonia, carbon monoxide, and ethylene. The usual order of decreasing Q values is Ta > W > Cr > Fe > Ni > Rh > Cu > Au a traditional illustration may be found in Refs. 81, 84, and 165. It appears, first, that transition metals are the most active ones in chemisorption and, second, that the activity correlates with the percent of d character in the metallic bond. What appears to be involved is the ability of a metal to use d orbitals in forming an adsorption bond. An old but still illustrative example is shown in Fig. XVIII-17, for the case of ethylene hydrogenation. 

The activity coefficient (y) based corrector is calculated using any applicable activity correlating equation such as the van Laar (slightly polar) or Wilson (more polar) equations. The average absolute error is 20 percent. 

Balaban, A. T., Motoc, I., Bonchev, D., and Mekenyan, O. Topilogical Indices for Structure-Activity Correlations, 114, 21-55 (1983). 

The hierarchical order of El, E2 and E3 activity correlates with an increase in enzymatic specificity which ensures selective ubiquitin modification of distinct... 

Struve, I., Weber, A., Liittge, U., Ball, E. Smith, J.A.C. (1985). Increased vacuolar ATPase activity correlated with CAM induction in Mesembryanthemum crystallinum and Kalanchoe blossfeldiana cv. Tom Thumb. Journal of Plant Physiology, 117, 451-68. 

Hermann RB. Structure-activity correlations in the cephalosporin C series using extended Htickel theory and CNDO/2.1 Antibiot 1973 26 223-7. 

Hansch C, Lien EJ, Helmer F. Strnctnre-activity correlations in the metabolism of drngs. Arch Biochem Biophys 1968 128 319-30. 

Kawasaki M. 1980. Experiences with the test scheme under the chemical control law of Japan An approach to structure-activity correlations. Ecotoxicol Environ Safety 4 444-454. 

Figure 6.8 ACh release and cortical activity. Correlation between acetylcholine release and EEG activity after injections of leptazol (LEPmgkg intravenously) into the urethane anaesthetised rat. ACh was collected in a cortical cup incorporating EEG recording electrodes. Mean values SE, n — 6 (unpublished data, but see Gardner and Webster 1977)...

Pence, B.C. and Reiners, J.J. (1987). Murine epidermal xanthine oxidase activity correlation with degree of hyperplasia induced by tumor promoters. Cancer Res. 47, 6388-6392. 

P.N. Craig, Comparison of the Hansch and Free-Wilson approaches to structure-activity correlation, In Biological Correlations — The Hansch Approach (R.F. Gould, Ed.). Advances in Chemistry Series, No. 114. American Chemical Society, Washington DC, 1972, pp. 115-129. P.N. Craig, Interdependence between physical parameters and selection of substituent groups for correlation studies. J. Med. Chem., 14 (1971) 680-684. 

XIII. Biological Activity Correlation with Structure. 127... 

The concept that different structural domains on the heparin chains are principally involved for optimal activity in the foregoing interactions could not be perceived in early work on structure-activity correlations, because the activity of heparin has been most frequently evaluated only with whole-blood-clotting tests (such as the U.S.P. assay). Development of assays for specific clotting-factors (especially Factor Xa and thrombin) has permitted a better insight into the mechanism of action of heparin at different levels of the coagulation cascade. 

Increases in ALAS activity have been observed in lead workers (Meredith et al. 1978). Leukocyte ALAS was stimulated at a PbB level of 87 pg/dL (Meredith et al. 1978), a level at which ALAD activity is already significantly inhibited. ALAD activity correlated inversely with PbB levels in occupationally exposed individuals (Alessio et al. 1976 Wada et al. 1973), as has been seen in subjects with no occupational exposure (Secchi et al. 1974). Erythrocyte ALAD and hepatic ALAD activities were correlated directly with each other and correlated inversely with PbB levels in the range of 12-56 pg/dL (Secchi etal. 1974). 

Ha JH, Shin SM, Lee SK, et al. In vitro effects of hydroxybenzaldehydes from Gastro-dia elata and their analogues on GABAergic neurotransmission, and a structure -activity correlation. Planta Med 2001 67 877-880. 

Hameed.A., Montini.T., Gombac, V.,and Fomasiero, P. (2008) Surface phases and photocatalytic activity correlation of Bi203/Bi204 x nanocomposite. Journal of the American Chemical Society, 130 (30), 9658-9659. 

Politzer, P., P. R. Laurence, and K. Jayasuriya. 1985. Structure-Activity Correlation in Mechanism Studies and Prediction Toxicology. Env. Health Persp. 61, 191. 

Leo, A.J. (1975) Calculation of partition coefficients useful in the evaluation of relative hazards of various chemicals in the environment. In Symposium on Structure-Activity Correlations in Studies of Toxicity and Bioconcentration with Aquatic Organisms. G.D. Veith and D.E. Konasewich, Editors, International Joint Commission, Ontario, Canada. 

Since plastomeric polypropylenes were insufficiently investigated, further improvement of catalyst activity correlated with an easy synthetic approach was required. Therefore, the two asymmetric hafnocene dichloride complexes, each bearing a 2,5,7- and 2,4,6-trimethyl substituted indenyl moiety (4a, 4b) were developed. 

Casida, J.E. and LJ. Lawrence. 1985. Structure-activity correlations for interactions of bicyclophosphorus esters and some polychlorocycloalkane and pyrethroid insecticides with the brain-specific t-butylcyclo-phosphorothionate receptor. Environ. Health Perspec. 61 123-132. 

Sediments and biota collected from the Hersey River, Michigan, in 1978, were heavily contaminated with phenanthrene, benz[a]anthracene, and benzo[a]pyrene when compared to a control site. Elevated PAH concentrations were recorded in sediments, whole insect larvae, crayfish muscle, and flesh of lampreys (family Petromyzontidae), brown trout (Salmo trutta), and white suckers (Catostomus commersoni), in that general order (Black et al. 1981). The polluted collection locale was the former site of a creosote wood preservation facility between 1902 and 1949, and, at the time of the study, received Reed City wastewater treatment plant effluent, described as an oily material with a naphthalene-like odor (Black et al. 1981). In San Francisco Bay, elevated PAH concentrations in fish livers reflected elevated sediment PAH concentrations (Stehr et al. 1997). In Chesapeake Bay, spot (Leiostomus xanthurus) collected from a PAH-contaminated tributary (up to 96 mg PAHs/kg DW sediment) had elevated cytochrome P-450 and EROD activity in liver and intestine microsomes (Van Veld et al. 1990). Intestinal P-450 activity was 80 to 100 times higher in fish from highly contaminated sites than in conspecifics from reference sites intestinal EROD activity had a similar trend. Liver P-450 and EROD activity was about 8 times higher in spot from the contaminated sites when compared to the reference sites. Liver P-450 activity correlated positively with sediment PAH, but intestinal P-450 activity seemed to reflect dietary exposure (Van Veld et al. 1990). The poor correlation between hepatic concentrations of PAHs and P-4501A is attributed to the rapid metabolism of these compounds (van der Weiden et al. 1994). 

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