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Internet Electronic Journal of Molecular Design - IEJMD, ISSN 1538-6414, CODEN IEJMAT
| ABSTRACT - Internet Electron. J. Mol. Des. February 2005, Volume 4, Number 2, 173-180 |
Computer-aided Identification of Chemical Constituents Isolated
from Cybistax antisyphilitica
Maria Paula P. Ramos, Marcelo J. P. Ferreira, Lousã Lopes, and Vicente P. Emerenciano
Internet Electron. J. Mol. Des. 2005, 4, 173-180
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Abstract:
Natural products are substances generally obtained in mixtures
from natural sources. For identification and structure
determination it is necessary to isolate each compound present in
the mixture through chromatographic methods. This procedure is
frequently used due to the great diversity and the structural
complexity of the compounds found within the mixtures, and
usually demands time. So, trying to reduce the time spent during
this process, we developed an expert system able to analyze
complex mixtures of compounds. SISCONST program was
developed to aid the process of structural determination of
organic compounds by means of analysis of chemical shifts and
multiplicities obtained from the 13C NMR DEPT spectra. The
program may predict the most probable skeleton type for a
compound under analysis and suggests several substructures
from the signals assigned in 13C NMR. In this study, we have
used the program to identify the individual components present
in a mixture from the 13C NMR data. The program was evaluated
with a mixture of triterpenes isolated from
Cybistax antisyphilitica. The results show that the program was able to
propose all components present in the mixture, including a
triterpene not reported yet in the literature. The method described
in this study allowed us to achieve the correct identification of
the substances present in the mixture. The procedure can
therefore be applied as a tool for analysis of compounds whose
separation through chromatographic methods is very difficult.
One of the advantages of this method is to detect the presence of
new compounds in mixtures.
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