Modeling chromatographic parameters by a novel graph theoretical sub-structural approach.

E Estrada; Y Gutierrez

doi:10.1016/s0021-9673(99)00808-0

Home/Archive/PubMed

PubMed · 10551351

Modeling chromatographic parameters by a novel graph theoretical sub-structural approach.

E Estrada·Y Gutierrez

View original source ↗Export metadata ↓

Abstract

A novel approach to the study of quantitative relationships between chromatographic parameters and the chemical structure is introduced. It is based on the computation of the spectral moments of the topological bond matrix by using different weights as diagonal entries of this matrix. The main advantage of the present approach is that the quantitative contributions of the structural fragments of molecules to the chromatographic parameters studied can be obtained explicitly. By using this approach we study two data sets: one composed of 156 alkanes and the other of 81 oxygen-containing organic molecules. In both cases excellent quantitative structure-chromatographic retention relationships were obtained. The contributions of the different fragments to the chromatographic retention were generated obtaining tables of additive contributions to the properties studied. The physicochemical interpretation of the results on the basis of the retention mechanisms is also analyzed in light of this new approach.

Explore related subjects

Chromatography Models, Theoretical Molecular Structure Journal Article

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

E Estrada, Y Gutierrez. 1999-10-15. Modeling chromatographic parameters by a novel graph theoretical sub-structural approach.. https://doi.org/10.1016/s0021-9673(99)00808-0

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2007

Sequence-specific purification of DNA oligomers in hydrophobic interaction chromatography using peptide nucleic acid amphiphiles: extended dynamic range.

We present improvements on a previously reported method (Vernille JP, Schneider JW. 2004. Biotechnol Prog 20(6):1776-1782) to purify DNA oligomers by attachment of peptide nucleic acid amphiphiles (PNAA) to particular sequences on the oligomers, followed by their separation from unbound oligomers using hydrophobic interaction chromatography (HIC). Use of alkyl-modified HIC media (butyl and octyl sepharose) over phenyl-modified media (phenyl sepharose) reduced the elution time of unbound DNA while not affecting the elution time of the PNAA/DNA complex. Modifying the alkane tail length for PNAA from C(12) to C(18) increased slightly the retention of PNAA/DNA duplexes. By combining these two refinements, we show that sequence-specific purifications of DNA oligomers 60 bases in length or more can be achieved with high resolution, even when the PNAA alkane is attached to the center of the target strand. The insensitivity of the PNAA/DNA duplex binding to choice of HIC media appears to be due to a surface-induced aggregation phenomenon that does not occur in the case of untagged DNA. We also report on the use of batch HIC as an adequate predictor of elution profiles in linear gradient HIC, and its potential to considerably reduce purification times by applying step gradients.

Chromatography↗

PubMed2006

Improved photostability indicating ion-pair chromatography method for pergolide analysis in tablets and in the presence of cyclodextrins.

Pergolide (PG) a semi-synthetic ergot alkaloid derivative used mainly for the treatment of Parkinson's disease is known to be a photosensitive drug substance. The major photodegradation products are PG sulphoxide (SX) and PG sulphone (SN), which are also the main impurities of the bulk drug substance. It is widely metabolized to more than 10 metabolites including SX and SN. In this work an improved photostability indicating ion-pair chromatography method for PG mesilate was developed. The method can be applied in the determination of PG and impurities in aqueous solutions and in tablets for routine analysis. This new method is appropriate for the quantitative determination of PG in the presence of its impurities and photodegradation products and can also be used for PG complexes with cyclodextrins (commonly used as photostabilizing agents). Furthermore it is suitable for the quantitation of its impurities and its thermal or photo-induced decomposition products. Separation was achieved on a ThermoQuest C(18) BDS column and Sodium octanosulphonate was used as ion-pairing agent. Analysis was performed at 223 nm. Validation parameters included: specificity, linearity, precision and accuracy, limit of quantitation and suitability. The method was found to be specific and linear for PG, as well as for SX and, SN impurities. The recovery was 100.83+/-0.46% for PG, 99.86+/-0.33% for SX and 99.77+/-1.84% for SN. Finally the photodegradation profile of PG mesilate was studied in different initial sample concentration. The obtained result revealed that: PG photolysis is catalyzed by its degradation products and that decrease of initial sample concentration reduces the rate of PG photoinduced degradation.

Chromatography↗

PubMed2006

JUICE: a data management system that facilitates the analysis of large volumes of information in an EST project workflow.

BACKGROUND: Expressed sequence tag (EST) analyses provide a rapid and economical means to identify candidate genes that may be involved in a particular biological process. These ESTs are useful in many Functional Genomics studies. However, the large quantity and complexity of the data generated during an EST sequencing project can make the analysis of this information a daunting task. RESULTS: In an attempt to make this task friendlier, we have developed JUICE, an open source data management system (Apache + PHP + MySQL on Linux), which enables the user to easily upload, organize, visualize and search the different types of data generated in an EST project pipeline. In contrast to other systems, the JUICE data management system allows a branched pipeline to be established, modified and expanded, during the course of an EST project. The web interfaces and tools in JUICE enable the users to visualize the information in a graphical, user-friendly manner. The user may browse or search for sequences and/or sequence information within all the branches of the pipeline. The user can search using terms associated with the sequence name, annotation or other characteristics stored in JUICE and associated with sequences or sequence groups. Groups of sequences can be created by the user, stored in a clipboard and/or downloaded for further analyses. Different user profiles restrict the access of each user depending upon their role in the project. The user may have access exclusively to visualize sequence information, access to annotate sequences and sequence information, or administrative access. CONCLUSION: JUICE is an open source data management system that has been developed to aid users in organizing and analyzing the large amount of data generated in an EST Project workflow. JUICE has been used in one of the first functional genomics projects in Chile, entitled "Functional Genomics in nectarines: Platform to potentiate the competitiveness of Chile in fruit exportation". However, due to its ability to organize and visualize data from external pipelines, JUICE is a flexible data management system that should be useful for other EST/Genome projects. The JUICE data management system is released under the Open Source GNU Lesser General Public License (LGPL). JUICE may be downloaded from http://genoma.unab.cl/juice_system/ or http://www.genomavegetal.cl/juice_system/.

Chromatography↗