MASSIS: a mass spectrum simulation system. 2: Procedures and performance.
The use of the mass spectral simulation system, MASSIS, is reported and its performance has been evaluated. The search for substructures matching with fragments stored in four pivot databases was realised using the Ullmann algorithm. Special cleavage rules, such as the McLafferty rearrangement, the retro-Diels-Alder reaction, elimination of a neutral small molecule and oxygen migration, are processed through shortest path and depth-first search algorithms. For a search in the database of small fragments, the key step is to determine the tautomeric fragments; then a match can be obtained using a subgraph isomorphism algorithm. A string match is used to determine peak intensity. If the limited environment of an atom is the same as that found in the database of relationships between fragment and intensity, this intensity value is assigned to the query atom. Performance in a set of tests is very important in evaluating the system performance. A comparison of peaks with an intensity greater than 5% (relative) shows that our system has a very high performance figure (> 90% ) for routine organic compounds.
Chen
HaiFeng
H
ITODYS, CNRS UMR 7086, Université Paris 7, 1 rue Guy de la Brosse, 75005 Paris, France.
Fan
BoTao
B
Petitjean
Michel
M
Panaye
Annick
A
Doucet
Jean-Pierre
JP
Li
Feng
F
Xia
HaiRong
H
Yuan
ShenGang
S
D000465:Algorithms; D003198:Computer Simulation; D016208:Databases, Factual; D013058:Mass Spectrometry / Q000379:methods*; D008956:Models, Chemical; D015203:Reproducibility of Results