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Phenolic Profile and Antioxidant Potential of Leaves from Selected Cotoneaster Medik. Species

The antioxidant efficiency of 70% aqueous methanolic extracts from the leaves of twelve selected Cotoneaster Medik. species was evaluated using four complementary in vitro tests based on SET- (single electron transfer) and HAT-type (hydrogen atom transfer) mechanisms (DPPH, FRAP, O(2)(•−) and H(2)O(...

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Detalles Bibliográficos
Autores principales: Kicel, Agnieszka, Michel, Piotr, Owczarek, Aleksandra, Marchelak, Anna, Żyżelewicz, Dorota, Budryn, Grażyna, Oracz, Joanna, Olszewska, Monika Anna
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6274135/
https://www.ncbi.nlm.nih.gov/pubmed/27240329
http://dx.doi.org/10.3390/molecules21060688
Descripción
Sumario:The antioxidant efficiency of 70% aqueous methanolic extracts from the leaves of twelve selected Cotoneaster Medik. species was evaluated using four complementary in vitro tests based on SET- (single electron transfer) and HAT-type (hydrogen atom transfer) mechanisms (DPPH, FRAP, O(2)(•−) and H(2)O(2) scavenging assays). The samples exhibited the dose-dependent responses in all assays with activity parameters of EC(50) = 18.5–34.5 µg/mL for DPPH; 0.9–3.8 mmol Fe(2+)/g for FRAP; SC(50) = 27.7–74.8 µg/mL for O(2)(•−); and SC(50) = 29.0–91.3 µg/mL for H(2)O(2). Significant linear correlations (|r| = 0.76–0.97, p < 0.01) between activity parameters and total contents of phenolics (5.2%–15.4% GAE) and proanthocyanidins (2.1%–15.0% CYE), with weak or no effects for chlorogenic acid isomers (0.69%–2.93%) and total flavonoids (0.28%–1.40%) suggested that among the listed polyphenols, proanthocyanidins are the most important determinants of the tested activity. UHPLC-PDA-ESI-QTOF-MS analyses led to detection of 34 polyphenols, of which 10 B-type procyanidins, 5 caffeoylquinic acids and 14 flavonoids were identified. After cluster analysis of the data matrix, the leaves of Cotoneaster zabelii, C. splendens, C. bullatus, C. divaricatus, C. hjelmqvistii and C. lucidus were selected as the most promising sources of natural antioxidants, exhibiting the highest phenolic levels and antioxidant capacities, and therefore the greatest potential for pharmaceutical applications.