The Cambridge Structural Database (CSD) System incorporates a suite of search and analysis tools enabling chemical knowledge to be extracted from raw crystallographic data. Information derived from small-molecule crystal structures is vital to pharmaceutical drug discovery, materials design, drug development and formulation. There are clear indications that this knowledge will be equally vital in the development of future materials, such as gas-storage systems, and will play a key part in the development of nano and green technologies.
Dr Colin Groom, Executive Director of the CCDC, says that ‘the determination of 500,000 crystal structures is a remarkable achievement. However, the scientific community is hungry for the next 500,000 and the knowledge these will undoubtedly bring. As the CSD grows both in size and in the complexity of structures it contains, the database not only helps us to answer our questions about molecular structure and interactions, but tells us what those questions should be’.
The CSD’s 500,000th structure is the anti-convulsant drug Lamotrigine, published in Acta Crystallographica by Balasubramanian Sridhar and Krishnan Ravikumar of the Indian Institute of Chemical Technology in Hyderabad. The CSD reference code for the structure is EFEMUX01. Lamotrigine (Lamictal®) was discovered by GlaxoSmithKline and approved by the US FDA for the treatment of epilepsy in 1994 and, additionally, for the treatment of bipolar I disorder in 2003. Lamotrigine is chemically unrelated to other anticonvulsant or mood-regulating medications and is distinguished by its relatively benign side-effects. It is frequently effective in patients who have not responded to antidepressants or other mood stabilizers. The CSD contains chemical structure information on several close variants of the compound, all of which – when used together – provide information to the life sciences community in their quest to optimize the efficacy of such medicines.
The development of X-ray crystallography has been rapid, and since the diffraction of X-rays by crystals was discovered by von Laue in 1912, the technique has attracted 24 Nobel Prizes. Indeed, crystal structure analysis is now central to modern chemistry – it is the method of choice for the characterization of newly discovered compounds, and in the words of Professor Chet Raymo in the Boston Globe, ‘Crystals are windows on the world of atoms’.
Today, the CCDC archives approximately 150 new experimentally determined structures each working day. Each structure is checked and validated by chemists and crystallographers, and entries are further enriched with chemical data. As the world’s output of crystal structures continues to accelerate, the CSD has doubled in size in the past nine years and now contains a fully retrospective collection of half a million entries. Notable examples include the structures of amino acids, steroids, alkaloids, antibiotics including penicillin, ferrocenes, fullerenes, catalysts, and so on. Within this massive structural diversity, normal molecules are abundant and unusual molecules are commonplace.
Further reading
Sridhar, B. and Ravikumar, K. (2009) Lamotrigine, an antiepileptic drug, and its chloride and nitrate salts. Acta Cryst. C65, o460–o464