Structure SAR

Eldred DV, Jurs PC. Prediction of acute mammalian toxicity of organophosphorus pesticide compounds from molecular structure. SAR QSAR Environ Res 1999 10 75-99. 

Sakuratani Y, Sato S, Nishikawa S, Yamada J, Maekawa A, Hayashi M (2008) Category analysis of the substituted anilines studied in a 28-day repeat-dose toxicity test conducted on rats correlation between toxicity and chemical structure. SAR QSAR Environ Res 19, 681-96. 

The major role of TOF-SARS and SARIS is as surface structure analysis teclmiques which are capable of probing the positions of all elements with an accuracy of <0.1 A. They are sensitive to short-range order, i.e. individual interatomic spacings that are <10 A. They provide a direct measure of the interatomic distances in the first and subsurface layers and a measure of surface periodicity in real space. One of its most important applications is the direct determination of hydrogen adsorption sites by recoiling spectrometry [12, 4T ]. Most other surface structure teclmiques do not detect hydrogen, with the possible exception of He atom scattering and vibrational spectroscopy. 

Masson F and Rabalais J W 1991 Time-of-flight scattering and recoiling spectrometry (TOF-SARS) analysis of Pt 110. I. Quantitative structure study of the clean (1 x 2) surface Surf. Sc/. 253 245-57... 

This is the domain of establishing Structure-Property or Structure-Activity Relationships (SPR or SAR), or even of finding such relationships in a quantitative manner (QSPR or QSAR). 

The fundamental assumption of SAR and QSAR (Structure-Activity Relationships and Quantitative Structure-Activity Relationships) is that the activity of a compound is related to its structural and/or physicochemical properties. In a classic article Corwin Hansch formulated Eq. (15) as a linear frcc-cncrgy related model for the biological activity (e.g.. toxicity) of a group of congeneric chemicals [37, in which the inverse of C, the concentration effect of the toxicant, is related to a hy-drophobidty term, FI, an electronic term, a (the Hammett substituent constant). Stcric terms can be added to this equation (typically Taft s steric parameter, E,). 

B and W J Howe 1991. Computer Design of Bioactive Molecules - A Method for Receptor-Based Novo Ligand Design. Proteins Structure, Function and Genetics 11 314-328. i H L 1965. The Generation of a Unique Machine Description for Chemical Structures - A hnique Developed at Chemical Abstracts Service. Journal of Chemical Documentation 5 107-113. J 1995. Computer-aided Estimation of Symthetic Accessibility. PhD thesis. University of Leeds, itan R, N Bauman, J S Dixon and R Venkataraghavan 1987. Topological Torsion A New )lecular Descriptor for SAR Applications. Comparison with Other Descriptors. Journal of emical Information and Computer Science 27 82-85. 

M. G. J. Beets, SAR Structure—Activity Relationships in Human Chemoreception, AppHed Science Pubhshers, London, 1978. 

Fig. 14. Structure of cyclosporin A where MeBmt = 4-(2-butenyl)-4, A-dimethylthreonine Sar = sarcosine MeLeu = A-methylleucine ...

The elementary building block of the zeolite crystal is a unit cell. The unit cell size (UCS) is the distance between the repeating cells in the zeolite structure. One unit cell in a typical fresh Y-zeolite lathee contains 192 framework atomic positions 55 atoms of aluminum and 1atoms of silicon. This corresponds to a silica (SiOj) to alumina (AI.O,) molal ratio (SAR) of 5. The UCS is an important parameter in characterizing the zeolite structure. 

The structure activity relationships ( SAR) of newly synthesized analogues of nucleosides, xanthine heterocycles, and nonxanthine heterocycles have been explored at the ARs. Potent and selective AR antagonists have been prepared for all four subtypes [3, 4], and selective agonists are known for three subtypes [1]. Thus, numerous pharmacological tools are available for in vitro and in vivo use (Table 2). Potent and selective A2b AR agonists are yet to be repotted, although several research groups have identified lead compounds. 

Anand K, Ziebuhr J, Wadhwani P, Masters JR, Hilgenfeld R (2003). Coronavirus main proteinase (3CLpro) structure basis for design of anti-SARS drugs. Science (New York, N.Y 300 1763-1767... 

Crystal structures of the NS5B polymerase alone and in complexes with nucleotide substrates have been solved and applied to discovery programs (Ago et al. 1999 Bressanelli et al. 2002 Bressanelli et al. 1999 Lesburg et al. 1999 O Farrell et al. 2003). From these studies, HCV polymerase reveals a three-dimensional structure that resembles aright hand with characteristic fingers, palm, and thumb domain, similar to the architectures of the RNA polymerases of other viruses. However, none of these experimental structures contained the ternary initiation complex with nu-cleotide/primer/template, as obtained with HIV RT. Accordingly, HCV initiation models have been built using data from other viral systems in efforts to explain SAR (Kozlov et al. 2006 Yan et al. 2007). 

Lee TW, Chemey MM, Huitema C, Liu J, James KE, Powers JC, Eltis LD, James MN (2005) Crystal structures of the main peptidase from the SARS coronavirus inhibited by a substrate-fike aza-peptide epoxide. J Mol Biol 353 1137-1151 Liang PH (2006) Characterization and inhibition of SARS-coronavirus main protease. Curr Top Med Chem 6 361-376... 

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