CASMI 2016: A manual approach for dereplication of natural products using tandem mass spectrometry

The Critical Assessment of Small Molecule Identification (CASMI) contest is an initiative designed as an unbiased test of manual and automated strategies for the identification of small molecules from raw mass spectrometric data. In this contest, the participants are provided a set of high resolution MS and MS/MS data and asked to identify the unknown structure. CASMI 2016 is the fourth round of this contest in which the author participated in Category 1: Best Identification of Natural Products using a manual approach. The provided high resolution mass spectrometric data were interpreted manually using a combination of fragment and neutral loss analysis, literature consultation, manual database searches, deductive logic and experience. Out of 18 challenges, the author submitted correct structures as lead candidates for 14 challenges and 2 ranked candidate for four challenges and was declared the winner of this category Pitfalls and challenges encountered during data interpretation are discussed.