Nutritional Composition and Phytochemical, Antioxidative, and Antifungal Activities of Pergularia tomentosa L

Abstract

Crude extracts from a medicinal Tunisian plant, Pergularia tomentosa L., were the investigated natural material. Butanolic extract of roots analyzed with IR spectra revealed the presence of hydroxyl, alcoholic, and carboxylic groups and sugars units. Analysis of some secondary metabolites, total phenolic, flavonoids, flavonols, and procyanidins, was performed using different solvents following the increased gradient of polarity. Fruits and leaves contained the highest amounts of all these compounds. Antioxidant properties were evaluated by the determination of free radical scavenging activity and the reducing power of methanolic extracts. Fruits and leaf extracts were the most powerful antioxidants for the two-assay in vitro system. Stems and fruits extracts exhibit an antifungal activity against Fusarium oxysporum f. sp. lycopersici which could become an alternative to synthetic fungicide to control Solanum species fungal diseases.

Figure 1

Diagram of fractional extraction of phenolic compounds from roots, stems, leaves, and fruits of Pergularia tomentosa L.

Figure 2

Infrared (IR) spectra of the aqueous phase of the n-butanolic extract of stems of Pergularia tomentosa.

Figure 3

Amounts of total phenolic (mg Eq GAE/g DW), flavonoids (mg Eq QE/g DW), flavonols (mg Eq QE/g DW), and condensed tannins (mg Eq CTE/100 g DW) of different extracts of Pergularia tomentosa. H: hexane; C: chloroform; A E: ethyl acetate; B: n-butanol; mg Eq GAE/g DW: mg of gallic acid equivalents per g of dry weight; mg Eq QE/g DW: mg of quercetin equivalent (QE) per g of dry weight; mg Eq CTE/100 g DW: mg catechin equivalents (CTE) per g dry weight. The values are the mean of three determinations ± standard error. The different lowercase letters represent significant differences between samples versus different solvents by Student's t-test (p < 0.05). Values for the same compound and the same solvent, not sharing a common letter (a, b, c, or d), differ significantly at p < 0.05.

Figure 4

Radical scavenging effect (%) on DPPH (2,2-diphenyl-1-picrylhydrazyl ) radicals of Pergularia tomentosa's organs. The values are the mean of three determinations ± standard error.

Figure 5

Reducing power of methanolic extracts of Pergularia tomentosa, as measured by changes in optical density at 700 nm. The values are the mean of three determinations ± standard error.