Phytochemical Characterization and In Vitro Antioxidant Properties of Four Brassica Wild Species from Italy.

Valentina Picchi,Aldo Tava,Ferdinando Branca,Stefania Toscano,Roberto Lo Scalzo,Filippo Doria,Simone Treccarichi,Sergio Argento

doi:10.3390/molecules25153495

Abstract

In the present study, we evaluated for the first time the variability of antioxidant traits of four Brassica wild species: B. incana, B. macrocarpa, B. villosa, and B. rupestris. The content of the main water-soluble antioxidants (phenolics, ascorbic acid, and total biothiols) and the in vitro antioxidant potential (1,1-diphenyl-2-picrylhydrazil (DPPH) and superoxide anion scavenging capacity) were investigated. A total of 28 polyphenolic compounds were identified by LC/MS and quantitated by HPLC/DAD analysis. Kaempferol and quercetin derivatives were the most abundant phenolics compared to hydroxycinnamoyl gentiobiosides. In the ten populations, phenolics ranged from 163.9 to 533.9 mg/100 g dry weight (d.w.), ascorbic acid from 7.6 to 375.8 mg/100 g d.w., and total biothiols from 0.59 to 5.13 mg/100 g d.w. The different classes of phytochemicals were separated using solid-phase extraction at increasing methanol concentrations, and the antioxidant power of fractionated extracts was evaluated. The superoxide anion scavenging activity was significantly correlated to phenolics, particularly to flavonol derivatives, while DPPH was mainly related to ascorbic acid content. The present findings improve the knowledge of the phytochemical composition of Italian Brassica wild species by showing the great diversity of phytochemicals among populations and highlighting their importance as a valuable genetic resource for developing new cultivars with improved bioactive content.

Highlights

Within the broad genetic differences in Brassica genus, crop wild relatives (CWRs) are worth considering for their potential economic importance [1]
The superoxide anion scavenging activity was significantly correlated to phenolics, to flavonol derivatives, while DPPH was mainly related to ascorbic acid content
The present findings show that Brassica wild species contained higher ascorbic acid (AsA) and thiol content compared to other Brassica crops, such as broccoli [19,34], representing an importance source of bioactive compounds with potential positive effects on human health

Summary

Introduction

Within the broad genetic differences in Brassica genus, crop wild relatives (CWRs) are worth considering for their potential economic importance [1]. Sánchez-Mata et al [4] provided evidence that several wild and underutilized vegetables of the Mediterranean area showed a high content of bioactive compounds. In this context, Brassicaceae wild Mediterranean species could be of great interest as sources of nutraceuticals, such as glucosinolates and phenolics, and could be used in developing new cultivars with enhanced accumulation of phytochemicals and proposed as new types of health-promoting foods. During the domestication process of several B. oleracea crops, the great variability of antioxidant traits was reduced For this reason, Brassica CWRs were the subject of recent research aiming to evaluate and exploit their plasticity in traits [5]

Methods

Results

Conclusion