Green Inhibitors

Fig. 12.47. Corrosion inhibition by n-alkyl-triethyl- and -trimethylammonium bromides in 1 W-H2S04 at 20 °C. (Reprinted from W. P. Singh, Relationships between the Structure of organic Compounds and Corrosion Inhibition, in Green Inhibitor Consortium, Texas A M University, 1997.)...

As is common with any industry environmental concerns have led to intense activity in the development of green inhibitors. The biological oxygen demand (BOD) is the time duration over which the inhibitor persists in the environment. Inhibitors should be nontoxic and the BOD is at least 60%. Toxicity is expressed as LC50 which is the concentration of the inhibitor needed to kill 50% of the test species. Some typical data are given in Table 1.26. 

Sharma, S.K., Mudhoo, A., and Khamis, E. 2009a. Adsorption studies, modeling and use of green inhibitors in corrosion inhibition An overview of recent research. The Journal of Corrosion Science and Engineering, 11 1-24. (Available at http //www.jcse.org/view-paper.php vol=l l pap=14.)... 

Figure 8. Stereoview of renin inhibitors extracted from the X-ray crystal structures of three different aspartic proteases. The yellow inhibitor, 20, is from an HIV-1 protease structure (unpublished), the cyan inhibitor is from an endothiapepsin structure [17] and the green inhibitor is from a renin structure [43],...

M.B. Valcarce, M. Vazquez, Phosphate ions used as green inhibitor against copper corrosion in tap water, Corros. Sci. 52 (2010) 1413-1420. 

E. Khamis, N.A. Landis (2002). Herbs as new type of green inhibitors for acidic corrosion of steel. Materialwissenschaft und Werkstoffiechnik 33(9), pp. 550-554. 

Toxicity issues will continue to be some of the most important aspects of corrosion inhibitor technology, and meeting the demands for less toxic inhibitors will consume a large portion of the funds available to develop new formulations. Other issues such as flash point and presence of heavy metals will limit the palette available to the inhibitor formulator. A comprehensive review of "green" inhibitor technology was presented at the 2000 Ferrara, Italy inhibitor conference. ... 

Gupta DVS (2004), Green inhibitors - where are we NACE Corrosion 2004, Paper 04406. 

Deacon, G.B., Forsyth, C.M., Behrsing, X, Konstas, K., and Forsyth, M., Heterometalhc Ce-lll-Fe-in-salicylate networks models for corrosion mitigation of steel surfaces by the Green inhibitor, Ce(sahcylate)(3). Chemical Communications, 2002. 23 2820-2821. 

Campazzi, E., Villatte, M., Druez, C., Senani, S., and Barbe, C. (2013) Alternatives to chromate systems for corrosion protection in aerospace study of Green -inhibitor loaded spheres in model sol-gel coatings. 9th Coatings Science International 2013, (une 24-28, 2013, Noordwijk, The Netherlands. 

Muthukumar, N. Maruthamuthu, S. Palaniswamy, N. (2007). Green inhibitors for petroleum product pipelines. Electrochemistry, 75, 50-53, ISSN. 1344-3542. 

Figure 4.12 Schematic diagram illustrating the role of the conserved leucine residues (green) in the leucine-rich motif in stabilizing the P-loop-(x structural module. In the ribonuclease inhibitor, leucine residues 2, 5, and 7 from the P strand pack against leucine residues 17, 20, and 24 from the a helix as well as leucine residue 12 from the loop to form a hydrophobic core between the P strand and the a helix.

Figure 5.24 Space-filling model (green) of the sialic acid binding domain of hemagglutinin with a bound inhibitor (red) Illustrating the different binding grooves. The sialic acid moiety of the Inhibitor binds in the central groove. A large hydrophobic substituent, Ri, at the Cz position of sialic acid binds in a hydrophobic channel that runs from the central groove to the bottom of the domain. (Adapted from S.J. Watowich et al.. Structure 2 719-731, 1994.)...

The C-terminal part is green. The catalytic triad Asp 32, His 64, and Ser 221 as well as Asn 15S, which forms part of the oxyanion hole are shown in purple. The main chain of part of a polypeptide Inhibitor is shown in red. Main-chain residues around 101 and 127 (orange circles) form the nonspecific binding regions of peptide substrates. 

FIGURE 16.29 (left) HIV-1 protease com-plexed with the inhibitor Crixivan (red) made by Merck. The flaps (residues 46-55 from each snbnnit) covering the active site are shown in green and the active site aspartate residues involved in catalysis are shown in white. 

External coil problems White calcium carbonate CaC03 Phosphate scale from threshold agents. Blue/green/black copper phosphate trihydrate Cu3(P04)2 3H20 Dirt pockets due to low level of coil. BW sludgei settles on external fins. Gasket weeping from inhibitor. Color stains from inhibitor dyes. 

Fig. 6 Superimposition of inhibitors and key active site residues from crystal structures of oseltamivir carboxylate 18 brown carbons, PDB - 2qwk) and Neu5Ac2en 4 (green carbons, PDB - IfSb) in complex with influenza A virus siaMdase. Note the alternative conformations of the...

Smith PW, Sollis SL, Howes PD, Cherry PC, Starkey ID, Cobley KN, Weston H, Scicinski J, Merritt A, Whittington A, Wyatt P, Taylor N, Green D, BetheU R, Madar S, Fenton RJ, Motley PJ, Pateman T, Beresford A (1998) Dihydropyrancarboxamides related to zanamivir a new series of inhibitors of influenza virus sialidases. 1. Discovery, synthesis, biological activity, and structure-activity relationships of 4-guanidino- and 4-amino H-pyran-6-carboxamides. J Med Chem 41 787-797... 

Oberdorster, E. and McClellan-Green, P. (2002). Mechanisms of imposex induction in the mud snail, Ilyanassa obsoleta TBT as a neurotoxin and aromatase inhibitor. Marine Environmental Research 54, 715-718. 

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