3 research outputs found
Palynological study of the endemic woody sonchus from de Flora of Madeira.A morphological and molecular approach
info:eu-repo/semantics/publishedVersio
Flavonoids in phylloclades discriminate endemic Semele androgyna chemotypes from Madeira
Thirty-five randomly-collected Semele androgyna Kunth
samples were screened by RP-HPLC for their phenolic
composition. Fraction analysis allowed the detection of
17 different compounds. According to their retention
times and UV spectra obtained by diode array analysis,
these phenolics represent three classes: phenolic
acids, flavones and flavonols. Co-chromatography with
specific standards enabled identification of quercetin,
rutin and quercitrin in Semele tissues for the first time.
Polymorphism based on phenolic composition was
evaluated using multivariate analysis and showed four
distinct S. androgyna clusters. This polymorphism was
not associated with morphological diversity or different
in ambient light intensities. Biochemical differentiation
is thus present in this species. The application of
multivariate analysis techniques to RP-HPLC data has
allowed the classification of samples into two groups,
previously proposed on the basis of morphological and
cytotaxonomical information. Therefore, the use of
phenolics as chemotaxonomic markers in Semele is
highly recommended because of its diagnostic value,
even at a subspecies level. Discriminant canonical
analysis and Mahalanobis distances confirmed these
clusters as recognisable chemosystematic units.
However, these units do not support the separation of S.
pterygophora.The Portuguese Foundation for Science and
Technology (FCT) funded this work through the Centre of Macaronesian
Studies (CEM). The authors are grateful to the Madeiran Centre of
Science and Technology (CITMA), the Berardo Foundation and
European Social Funding for financial assistance given during execution
of this work. The assistance rendered by Mr Rog茅rio Correia during field
collection is gratefully acknowledged.info:eu-repo/semantics/publishedVersio