An Automated Chemical structure Elucidation System (ACES) for mass spectrometry/mass spectrometry data

Abstract

Interpretation of the large quantities of multidimensional data produced by modern analytical instrumentation represents a continuing challenge to chemists. Recent developments in computer architecture, speed and memory and advances in artificial intelligence and pattern recognition have allowed the development of expert systems capable of meeting this challenge. The Automated Chemical structure Elucidation System (ACES) consists of several software tools including MAPS (Method for Analyzing Patterns in Spectra), MFG (Molecular Formula Generator), GENOA (a structure generator) and IC (Intelligent Controller). Substructure identification rules are provided by the MAPS software. This software correlates the spectral features found in the mass/mass (MS/MS) spectra of known compounds with the substructures known to be present in these compounds. The rules can then be applied to the MS/MS spectra of unknown compounds. Molecular formula determination can be accomplished by several methods which include the use of the elemental composition of substructures found to be present in the unknown compound by the MAPS rules and ratio measurements of peaks in the daughter spectrum of the M + 1 ion. GENOA is then used to create a list of candidate structures which are consistent with the molecular formula and substructure constraints. This entire process will be automated through the intelligent controller. The intelligent controller will also use MAPS rules generated using MS/MS data acquired under different experimental conditions to infer ancillary experiments which could further resolve the identity of an unknown.