Solving structural problems, strategy

Strategy As noted in Practice Problem 13.2, it s best to begin solving structural problems by calculating a molecule s degree of unsaturation. In the present instance, a formula of C.5H]20 corresponds to a saturated, open-chain molecule, either an alcohol or an ether. 

Most chemists need to be able to solve structure problems What compound will fit the spectral data A proper attitude toward this type of problem solving is needed, and nobody has said it better than Sherlock Holmes It is a capital mistake to theorize before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. Strategies are definitely needed. Generate possibilities, then select the best one that fits the data. If none fit, generate more possibilities and examine your assumptions. 

The only information provided is the molecular composition and selected NMR properties, but it is possible to solve virtually all the structures unambiguously where this is not the case, the problem clearly says so. We discuss below an outline strategy for solving structures using spectroscopic data. 

There is no completely rational or reliable strategy for solving structures from spectroscopic data. The precise route to a structure will depend on how much background and spectroscopic information is available about the molecule, and on which of the spectra appear most useful. Nevertheless, there are some useful rules and guidelines about the right way to tackle such a problem. Further details will be found in Chapter 5 of our main book. 

Nature has solved the problem of protein design through the mechanism of Darwinian evolution. Every one of the proteins in our cells, from enzymes and receptors to structural proteins, has arisen by this process. As the examples presented here with chor-ismate mutase amply demonstrate, evolutionary strategies can also be successfully exploited in the laboratory to study the structure and function of existing proteins and to engineer new ones. 

The peptide mass mapping strategy using trypsin and V8 protease was applied to solve structural identification problems of the variants. The comparison of the trypsin and V8 protease digest of the native GM-CSF (VO) and... 

Luger GF. Artificial intelligence Structures and strategies for complex problem solving, 5th Edition. Boston Addison-Wesley, 2005. 

The last decade has shown that purely chemical strategies like combinatorial chemistry cannot solve the problem of identifying new lead structures possessing high biological activity and selectivity, and at the same time exhibiting low toxicity. 

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