1. Anal Chim Acta. 2009 Sep 1;649(1):24-32. Epub 2009 Jul 23.

Potential antioxidant compounds in Mallotus species fingerprints. Part I:
indication, using linear multivariate calibration techniques.

Tistaert C, Dejaegher B, Nguyen Hoai N, Chataigné G, Rivière C, Nguyen Thi Hong
V, Chau Van M, Quetin-Leclercq J, Vander Heyden Y.

Department of Analytical Chemistry and Pharmaceutical Technology, Vrije
Universiteit Brussel-VUB, Laarbeeklaan 103, B-1090 Brussels, Belgium.

Republished in:
    Anal Chim Acta. 2009 Oct 12;652(1-2):189-97.

Some Mallotus species are used in traditional medicine in Vietnam and China. Some
also show interesting activities, such as antioxidant and cytotoxic ones.
Combining fingerprint technology with data-handling techniques allows indicating 
the peaks potentially responsible for given activities. In this study it is
aspired to indicate from chromatographic fingerprints the peaks potentially
responsible for the antioxidant activity of several Mallotus species. Relevant
information was extracted using linear multivariate calibration techniques, both 
before and after alignment of the fingerprints with correlation optimized warping
(COW). From the studied techniques, Stepwise Multiple Linear Regression is least 
recommended as it made an inadequate variable selection. Principal Component
Regression theoretically can take largely varying variables uncorrelated to the
antioxidant activity into account. However, in practice in the actual case study 
this problem was limited. These problems in principle do not occur using Partial 
Least Squares (PLS) models. Of the tested PLS methods, Orthogonal Projections to 
Latent Structures was preferred because of its simplicity, reproducibility,
reduced model complexity and improved interpretability of the regression
coefficients, yielding a clearer view on the individual contribution of the
compounds. Furthermore, reducing analysis times from 60 min to 35 and 22.5 min
resulted in the same main compounds, indicated responsible for the antioxidant
activity. Models built after alignment by COW did not result in additional
information.

PMID: 19664459 [PubMed - indexed for MEDLINE]