Post-doctoral Project Work at Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa (Since 2004)
Title: Comparing the chemical spaces of metabolites and available chemicals: models of metabolite-likeness
Summary: The chemical space covered by compounds involved in metabolic reactions was compared with that of a random
dataset of purchasable compounds. The comparison was based on 3D structure, 2D structure+charges, or descriptors of global properties, by means of
self-organizing maps, random forest and classification trees. The most discriminatory features of metabolites and non-metabolites were number of OH
groups, presence of aromatic systems and molecular weight. A relationship between metabolite-likeness and ready biodegradability was observed
Title: QSAR analysis of antioxidant compounds using MOLMAP descriptors of local properties
Summary: MOLecular Maps of Atom-level Properties MOLMAPs were developed to represent the diversity of chemical bonds existing in
a molecule. The MOLMAP descriptors were used to establish QSAR of the antioxidant activity of naturally occurring antioxidant compounds related to caffeic acid and cinnamic acid.
The counterpropagation neural network s and random forest allowed identification of bonds and substructures that are mostly responsible for antioxidant activity.
Title: Quantitative estimation of retention factor in chiral HPLC separations
Summary: The chromatographic retention factors were predicted for a series of amino acid and peptide enantiomers (or derivatives) in an HPLC multimodal chiral
stationary phase based on ristocetin A. Conformation-dependent chirality codes were used for structure representation, and counterpropagation neural networks
were trained to predict retention factors in two mobile phases - methanol/water and acetonitrile/water. The networks were then used to predict the retention factors of a new set of enantiomers, not
used during the training.
The publications
and presentations related to post-doctoral work are:
- The 232ndACS National Meeting, San Francisco, CA, 10-14 September, 2006 (Aires-de-Sousa, J.*, Gupta, S., Latino, D.A.R.S. and Zhang, Q.Y. – Classification of organic and bio-organic reactions with MOLMAP physicochemical descriptors.)
- 6thEuropean Conference on Computational Chemistry, Tale (Low Tatras - Brezno), Slovakia, 03-07 September 2006 (POSTER PRESENTATION
- Gupta, S. and Aires-de-Sousa, J. - Comparing the chemical spaces of metabolites and available chemicals: models of metabolite-likeness.)
- Gupta, S., Mathew, S., Abreu, P.M. and Aires-de-Sousa , J., (2006) QSAR analysis of phenolic antioxidants using MOLMAP descriptors of local properties.
Bioorg. Med. Chem.14, 1199-1206 .
- Computer Chemistry Center, University of Erlangen - Nurnberg , Germany,
March, 2005 (GUEST TALK - Gupta, S. and Aires-de-Sousa , J. - Descriptors of chemical reactivity and QSAR applications)
- Symposium on Computer Applications and Chemometrics in Analytical Chemistry, Lake Balaton, Hungary, 31 August – 3 September 2004
(KEY-NOTE LECTURE - Gupta, S.* and Aires-de-Sousa, J. Quantitative estimation of retention factor in chiral HPLC separations.)
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