Quantitative Analysis of Rutin by HPTLC and In Vitro Antioxidant and Antibacterial Activities of Phenolic-Rich Extracts from Verbesina sphaerocephala.

Kathia Yanelly Rodríguez-Valdovinos,José Roberto Medina-Medrano,Ernesto Oregel-Zamudio,Luis Fernando Ceja-Torres,Monserrat Vázquez-Sánchez,Rafael Salgado-Garciglia,Dioselina Álvarez-Bernal

doi:10.3390/plants10030475

Abstract

Verbesina sphaerocephala A. Gray, like other wild plants of the genus Verbesina, has been used in herbal medicine. There is information for other species of the genus related to their phenolic content, antioxidant capacity, and isolation of bioactive compounds with antimicrobial activity. However, there are no reports for V. sphaerocephala, although it has an important presence in the state of Michoacán, México. In this study, the phenolic composition, quantification of rutin, and in vitro antioxidant and antibacterial activities of methanolic extracts from V. sphaerocephala leaves and flowers were determined. The results showed that all the investigated extracts have high phenolic and flavonoid contents. The flavonoid rutin was identified in all the extracts from V. sphaerocephala by high-performance thin-layer chromatography (HPTLC). The V. sphaerocephala extracts showed scavenging activity against DPPH• and ABTS•+ radicals (IC50 and 5.83 ± 0.50 and 0.93 ± 0.01 mg/mL, respectively) as well as relevant antioxidant capacity (51.05 ± 0.36 mg of ascorbic acid/g of dry tissue). The experimental results show that V. sphaerocephala extracts possessed a strong antimicrobial activity against Escherichia coli and Staphylococcus aureus bacteria. This research indicates that V. sphaerocephala could be considered as a potential source of natural compounds from the point of ethnopharmacological usage.

Highlights

The total phenolic contents of the V. sphaerocephala extracts ranged from 6.55 ± 0.71 to 10.50 ± 0.76 mg gallic acid equivalents (GAE)/g DT
The highest phenolic content was observed in leaves from Population 2 extracted with 100% methanol (P2-L-100M), and the lowest was observed in leaves from Population 1 extracted with 100% methanol (P1-L-100M)
To the best of our knowledge, this is the first report of the phenolic composition, separation and simultaneous quantification of rutin, and in vitro antioxidant and antibacterial activities of the different aerial parts of V. sphaerocephala extracts

Summary

Introduction

The most abundant secondary metabolites in plants, have received more and more attention in recent years because of their distinct bioactivities [1]. Flavonoids constitute the largest group of phenolic compounds [2]. According to their chemical structure, they are divided into several sub-classes: flavanones, flavanols, flavones, isoflavones, flavonols, and anthocyanins. The flavonoid rutin (quercetin-3-Orhamnoglucoside) is a natural flavonol with a low molecular weight that is widely distributed in plants [3]. Rutin has been reported to have high radical scavenging activity [4], antioxidant capacity [5], and antibacterial activity [6]

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