Human identity revolves around names and making a name for oneself is a lifetime goal for many. Chemicals are no different - many have become an integral part of human culture and some are upcoming stars. Chemicals not only have names like humans do, but some may also look like them [Figure 1] or resemble some part of our lives - for example, Buckminsterfullerene resembles a football [Figure 2] while Olympicene was inspired by Olympic rings [Figure 3]. In fact unusual chemical names, makes chemistry an exciting area of research, and an interesting subject to learn.
Figure 1 : Structure of Valproic acid
Figure 2 : Structure of Buckminsterfullerene (C60). Source : Wiki
Figure 3 : Structure of Olympicene. Source : Wiki
Chemicals may be referred by common names, trade names, systematic names, semi-systematic names, non-systematic names, abbreviations, anaphoras, identifiers. IUPAC nomenclature is the most commonly used systematic nomenclature for chemicals. In order to identify chemicals unambiguously several registration systems and identifiers have been devised.
Chemical names not only refer to chemicals but some of them also describe their corresponding structures. For example, InChI identifiers can be calculated from structures. InChIkey is a compact version of InChI meant to facilitate web search of chemical structures. Two different molecules having different InChIs may have same InChIkey. Line notations/identifiers like SMILES and InChI though human readable, require ample practice to gain reasonable level of familiarity.
Some examples of different types of chemical names are given below :
1. Vitamin C (common name)
other name : Ascorbic acid
Systematic/IUPAC name : (5R)-[(1S)-1,2-dihydroxyethyl]-3,4-dihydroxyfuran-2(5H)-one OR
2-oxo-L-threo-hexono-1,4- lactone-2,3-enediol
2. Aspirin (trade name)
Systematic/IUPAC name : 2-acetoxybenzoic acid
CAS Registry Number : 50-78-2
PubChem ID : CID 2244
ChemSpider ID : 2157
ChEMBL : CHEMBL25
InChI : InChI=1S/C9H8O4/c1-6(10)13-8-5-3-2-4-7(8)9(11)12/h2-5H,1H3,(H,11,12)
InChI key : BSYNRYMUTXBXSQ-UHFFFAOYSA-N
SMILES : O=C(Oc1ccccc1C(=O)O)C
3. benzene-1,3,5-triacetic acid (Semi-systematic name)
IUPAC name : 2-[3,5-Bis(carboxymethyl)phenyl]acetic acid
4. TNT (abbreviation for trinitrotoluene)
IUPAC name : 2-methyl-1,3,5-trinitrobenzene
5. It (Anaphora)
"10 ml of acetic acid was taken from a bottle and it was added to ...."
Here it refers to acetic acid and is an anaphora.
Multiple naming conventions makes it challenging to handle chemical information. In fact obtaining better nomenclature/identifiers for chemical names is an active area of research in cheminformatics. For example, InChI is under active development and is being extended to handle Markush structures, electronic states, organometallics, inorganics, biopolymers, tautomers, interlocking structures and extended stereochemistry.
Naming problems have been addressed in knowledgebases to a certain extent by assigning a unique registry ID to each chemical. These knowledgebases have smart search capabilities aided by large dictionaries to find a chemical by multiple names.
Explosion of chemical information has led to the emergence of text mining technologies which can be used to rapidly identify chemical entities in a large number of documents, even with optical character recognition (OCR) errors.
Growth of mobile devices has given an interesting twist to the problem of multiple chemical names. Typing is not easy on mobile devices, hence, shorter chemical names are preferable as text input for chemical information search on mobile devices. Voice based search technology may help in getting rid of the typing problem and one would expect shorter names to have a better probability of being recognized than longer ones. Of course autosuggest in search forms can also help in dealing with typing issue to some extent. In the near future, voice based search of chemical names could become mainstream, provided underlying algorithm is trained regularly using an ever expanding dictionary of chemical names.
All in all new chemicals continue to be synthesized, named and made a part of our lives as life saving drugs, household chemicals and much more.
