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Journal of Analytical Methods in Chemistry
Volume 2017, Article ID 3407312, 8 pages
https://doi.org/10.1155/2017/3407312
Research Article

Studies on Chemical Composition and Antioxidant Activity of Rudbeckia triloba

1Department of Analytical Chemistry, Faculty of Chemistry, University of Bucharest, 90–92 Panduri Av., 050663 Bucharest, Romania
2Department of Organic Chemistry, Biochemistry and Catalysis, Faculty of Chemistry, University of Bucharest, 90–92 Panduri Av., 050663 Bucharest, Romania

Correspondence should be addressed to Zenovia Moldovan; moc.oohay@navodlom_z

Received 8 June 2017; Accepted 30 October 2017; Published 27 November 2017

Academic Editor: Filomena Conforti

Copyright © 2017 Zenovia Moldovan et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The paper describes the physicochemical studies made on the decorative plant, Rudbeckia triloba (Asteraceae). For this purpose, essential oil, infusion, decoction, and hydroalcoholic macerate obtained from different aerial parts of Rudbeckia triloba were analyzed. The main phytochemical constituents identified by GC-MS analysis were found to be α-pinene (in dried leaves (46.0%) and flowers (40.1%)) and β-phellandrene (in essential oil of dried inflorescences (26.09%)). The Folin–Ciocalteu and quercetin assays revealed different values of total phenolic and flavonoid contents of petals, leaves, and seeds as a function of the solvent used and extraction procedure. The hydroalcoholic macerate of petals was found to present the maximum phenolic and flavonoid contents (130.29 ± 5.58 mg gallic acid equivalent/g dry vegetable material and 30.72 ± 1.35 mg quercetin equivalent/g dry vegetable material, resp.) and also exhibits the lower value of EC50 (0.32% (v/v)), obtained by applying the DPPH⋅ assay. Comparing the extraction methods applied, the maceration was found to be the most effective for phenolic compounds, most likely due to the solvent (70% ethanol). The use of water-alcohol mixture leads to an improvement of the extraction yield of phenolic compounds (including those with higher molecular weights) than by using water as extractive solvent, in the case of infusions and decocts.