Thursday, January 28, 2016

Chemical synthesis as a tool for “exploring the unknown”

Why do chemists make molecules? Major reasons include, among others, foreseen usefulness of synthesized molecules, refining synthetic strategies, and training for the next generation of chemists [reviewed in (1)].
Whereby known or predicted usefulness of the synthesized molecules is lately a major driving factor dictating whether chemical synthesis projects are financed or not by funding bodies, often overseen consideration is that generation of new chemical molecules might also lead to a following discovery of physical, chemical, or biological properties that are not possible to be predicted in advance. Therefore, new structure synthesis could also be seen as a tool for exploring the unknown, which might later lead to unpredictable but very beneficial expansion of existing knowledge. In the context of drug discovery, for example, screening approaches can lead to the discovery of new pharmacological activities of chemical structures that were previously generated without knowledge for possible effects on the biological target molecules that are later found to be affected [e.g. (2,3)].

References

(1) Ball P. Chemistry: Why synthesize? Nature. 2015 Dec 17;528(7582):327-9. doi: 10.1038/528327a. PubMed PMID: 26672538.
(2) Huang XP, Karpiak J, Kroeze WK, Zhu H, Chen X, Moy SS, Saddoris KA, Nikolova VD, Farrell MS, Wang S, Mangano TJ, Deshpande DA, Jiang A, Penn RB, Jin J, Koller BH, Kenakin T, Shoichet BK, Roth BL. Allosteric ligands for the pharmacologically dark receptors GPR68 and GPR65. Nature. 2015 Nov 26;527(7579):477-83. doi: 10.1038/nature15699. Epub 2015 Nov 9. PubMed PMID: 26550826.
(3) Letso RR, Stockwell BR. Chemical biology: renewing embryonic stem cells. Nature. 2006 Dec 7;444(7120):692-3. PubMed PMID: 17151647.


Synthesis of galanthamine: an example of a natural compound synthesis strategy developed due to known in advance pharmaceutical usefulness of the molecule (inhibition the enzyme acetylcholinesterase leading to alleviation of the symptoms of Alzheimer's disease). The colors indicate: blue (skeletal atoms/bonds: carbon/oxygen/nitrogen framework), and red (installed non-skeletal atoms/bonds). The figure is taken from “Discovery and resupply of pharmacologically active plant-derived natural products: A review”: http://www.ncbi.nlm.nih.gov/pubmed/26281720