from the GNU version of the Collaborative International Dictionary of English
- n. the process of testing samples of mixtures which are active in a screening process, so as to recognize and eliminate from consideration those active substances already studied; -- a stage subsequent to the preliminary screening in the process of discovery of new pharmacologically active substances in mixtures of natural products; -- also called counterscreening. See screening.
Sorry, no etymologies found.
Second, the researchers created "dereplication" tools for moving the other direction: taking the chemical structures of known NRPs and other related information and determining what the data signature would look like if a mass spectrometer had blown the compound part.
Bruker's dedicated MALDI Biotyper solution enables molecular identification, taxonomical classification or dereplication of microorganisms like bacteria, yeasts and fungi.
With dereplication, researchers can leverage known information and are not forced to start from scratch each time a new compound needs to be identified.
Though I believe there are other uses too, for example, in between sample alignment, the recovery of a full mass spectrum is particularly important for metabolite identification of new, yet unknown compounds (yes, even dereplication is already non-trivial, because of the lack of free (open data preferably), machine accessible (open standards!) database of mass spectra (using different ionization methods).