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Orientador(es)
Resumo(s)
Plants have been widely used worldwide for medicinal purposes, leading to the increased
consumption of herbal products, such as herbal infusions and plant food supplements. The growing
demand of these products leads, inevitably, to the global market growing of herbal products and,
consequently, to their adulteration. Ginkgo biloba is a Chinese tree whose leaves are extensively
used in herbal preparations, being a very popular phytomedicine with high economic value. It has
well-established therapeutic indications for the improvement of (age-associated) cognitive
impairment and of quality of life in mild dementia, and treatment of problems associated with the
peripheral circulation [1,2]. Ginkgo products have been adulteration targets through the addition of
pure flavonols/flavonol glycosides or substitution with other botanical species [2]. Therefore, this
work aims at proposing a new species-specific PCR approach to detect and quantify G. biloba to
assess the authenticity of products thereof.
Reference mixtures of known amounts (50% to 0.01%, w/w) of G. biloba leaves and Cammelia
sinensis leaves were prepared. DNA was extracted from referencemixtures and other plant species
using the Nucleospin Plant kit. Specific primers targeting the ITS1 region (Genbank: Y16892.1) were
designed to amplify a 175 bp fragment of G. biloba. A species-specific PCR assay was developed
and used to confirm the absence of cross-reactivity with other medicinal plant species. Afterwards,
a quantitative real-time PCR assay with EvaGreen dye for G. biloba was developed and applied to
binary mixtures of G. biloba in C. sinensis. A normalised calibration model was constructed based
on the parallel amplification of the ITS1 region of G. biloba and the 18S rRNA gene (reference for
eukaryotes). The normalised real-time PCR system allowed establishing a calibration curve covering
the dynamic range of 50-0.1% (w/w) of ginkgo in C. sinensis. Additionally, a sensitivity down to 2 pg
of ginkgo DNA was reached. The method exhibited adequate performance with values of
correlation (0.996) and PCR efficiency (84.3%) in agreement with the acceptance criteria for these
assays. The results showed that the proposed method could provide a species-specific quantitative
tool for the authentication of herbal products containing ginkgo.
Descrição
Palavras-chave
Plant food supplements Real-time PCR quantification Plant authentication Ginkgo biloba
Contexto Educativo
Citação
Grazina, L,; Amaral, J.S.; Costa, J.; Mafra, I. (2019). A novel quantitative real-time PCR approach for authenticity assessment of herbal products with Ginkgo biloba. In 9th International Symposium on Recent Advances in Food Analysis. Prague, Czech Republic. ISBN 978-80-7592-055-3