Phenolic and Volatile Composition and Antioxidant Properties of the Leaf Extract of Brassica fruticulosa subsp. fruticulosa (Brassicaceae) Growing Wild in Sicily (Italy)

Abstract

In continuation of research conducted on species of the spontaneous flora of Sicily (Italy) belonging to the Brassicaceae family, Brassica fruticulosa subsp. fruticulosa was selected. It is an edible species utilized in Sicilian traditional medicine. In this study, for the first time, the phenolic and the volatile compounds and the antioxidant properties of the hydroalcoholic extract obtained from the leaves of B. fruticulosa subsp. fruticulosa were characterized. Through HPLC-PDA/ESI-MS analysis, a total of 22 polyphenolic compounds (20 flavonoids and 2 phenolic acids) were identified, with 3-hydroxiferuloylsophoroside-7-O-glucoside (1.30 mg/g ± 0.01) and kaempferol-3-O-feruloylsophoroside-7-O-glucoside (1.28 mg/g ± 0.01) as the most abundant compounds. Through SPME-GC/MS several volatiles belonging to different chemical classes were characterized, with nitriles and aldehydes accounting for more than 54% of the whole volatile fraction. The extract of B. fruticulosa subsp. fruticulosa showed moderate activity in the DPPH assay (IC50 = 1.65 ± 0.08 mg/mL), weak reducing power (17.47 ± 0.65 ASE/mL), and good chelating properties (IC50 = 0.38 ± 0.02 mg/mL), reaching approximately 90% activity at the highest tested concentration. Lastly, the extract was non-toxic against Artemia salina, indicating its potential safety. According to the findings, it can be stated that B. fruticulosa subsp. fruticulosa represents a new valuable source of bioactive compounds.

Biological Investigation and Chemical Study of Brassica villosa subsp. drepanensis (Brassicaeae) Leaves

“…The total phenol content (TPC) of B. drepanensis whole extract was 29.87 ± 0.14 mg of gallic acid/g extract while the total flavonoid content (TFC) was 26.12 ± 0.09 mg of catechin/g extract ( Table 3 ). The total phenolic content determined by the Folin–Ciocalteau method is comparable to that of other hydroalcoholic extracts obtained from other previously analysed species [ 24 ].…”

“…Results obtained by these different tests showed that B. drepanensis extract possess good dose-dependent primary antioxidant properties, as demonstrated by ABTS assay (IC 50 3.32 ± 0.88 µg/mL) and SOD-like activity assay (IC 50 66.66 ± 1.1 µg/mL); in addition, the FRAP assay value (IC 50 10.46 ± 1.17 µMFe/g) highlighted the high reducing power of the extract compared to the reference compound BHT (IC 50 63.24 ± 2.34 µMFe/g) ( Table 1 ). Previous studies on B. incana and B. fruticulosa reported lower values for the same tests [ 24 , 31 ]. These differences are probably due to the compositions of the extract, which is influenced by plant phenology at the moment of harvesting and by differences in the applied extraction process [ 34 ].…”

“…In this study, the total phenolic content of the ethanolic extract was determined for this taxon for the first time. The results obtained by the Folin–Ciocalteau method revealed an amount of phenolic compounds (29.87 ± 0.14 mg GAE/g) that is higher than other 70% ethanol extracts reported for different cultivated varieties of B. oleracea L. (min 4.30, max 13.80 mg GAE/g); nevertheless it is lower than those reported for two other wild taxa belonging to the Brassica genus, namely B. incana (37.20 mg GAE/g extract) and B. fruticulosa (32.63 mg GAE/g extract) [ 24 , 31 ].…”

Comparative Study on Phenolic Profile and Biological Activities of the Aerial Parts of Sinapis pubescens L. subsp. pubescens (Brassicaceae) Wild from Sicily (Italy)

“…For the identification, information from retention times, absorption and mass spectra were used, further supported by literature data. [23][24][25][26][27][28][29][30][31][32] Table 2 shows the 67 detected compounds, together with the retention times, the characteristic maximum of absorption and the [MÀ H] À values. Moreover, when observed, the fragment ions deriving from the fragmentation of the precursor ion [MÀ H] À have also been reported; in all these cases the ions derived from the loss of the glycosidic portion, allowing the detection of the corresponding aglycones.…”

“…From the comparison of the polyphenols characterized in the extracts, a consistently different qualitative-quantitative profile was highlighted. Flavonoids, all belonging to the class of flavonols, are the main constituents; the leaf extract was found to contain the greatest number of flavonoid compounds (30) compared to those of flowers (26) and stems (11). Among the detected flavonoids, kaempferol derivatives represent the vast majority of compounds, all of them in the glycosylated form (18 in leaf, 9 in flower and 6 in stem extract).…”