Profiling of the Bioactive Compounds in Flowers, Leaves and Roots of Vinca sardoa

Abstract

Vinca sardoa (Stern) Pignatti (Apocynaceae) is largely distributed in Sardinia where it is considered a typical endemism. Since the plant is used in traditional folk medicine, the aim of the present work was to identify and quantify the polyphenolic metabolites, due to the well-known importance of polyphenolic compounds, as well as to evaluate antioxidant activity in different parts of the plant. The compounds were identified and determined in the methanol extracts of leaves, flowers, and roots by developing different LC-MS/MS methods. The obtained data show that leaves possess the highest amount of polyphenols, in particular quinic acid (3401 mg/100 g), chlorogenic acid (1082 mg/100 g), caffeoylquinic acid isomer 1 (190 mg/100 g), and robinin (633 mg/100 g). Likewise, antioxidant tests showed that leaves possess the main radical scavenging activities in both ABTS (49.19 ± 3.41 μg/mL, 30.88 ± 3.04 μg/mL at time zero and after 50 min, respectively) and DPPH assays (223.97 ± 30.81 μg/mL, 109.52 ± 12.89 μg/mL at time zero and after 30 min, respectively). Taking into account that leaves differed most from flowers and roots in the content of caffeoylquinic acid and chlorogenic acid, of which antioxidant properties are widely recognized, it is reasonable to assume that these two compounds are involved in the differences described. The relationship between the high polyphenolic content and interesting antioxidant activities, justifies its use in ethnobotany and may be suggest a use of this specie, after removal of the alkaloid fraction, in the pharmaceutical, phytotherapy, and cosmetic industries.