Flavonoids, cytotoxic, antioxidant and antibacterial activities of Evax pygmaea.

CONTEXT: Phytochemical study and biological potential of Evax pygmaea (L.) Brot. (Asteraceae) are reported for the first time.

OBJECTIVE

To identify the secondary metabolites of Evax pygmaea and to determine its antioxidant, antibacterial and cytotoxic activities.

MATERIALS AND

METHODS

Dried aerial parts (1 kg) were macerated in 70% MeOH (5 L) during 72 h. The concentrated hydromethanolic extract was subjected to extractions with chloroform (3 × 300 mL), ethyl acetate (3 × 300 mL) and n-butanol (3 × 300 mL), successively. VLC of combined ethyl acetate (EAEP) and n-butanol (BEP) fractions was followed by column purifications. Antioxidant activity was investigated using DPPH, CUPRAC, and metal chelating, β-carotene/linoleic acid and ABTS assays. Agar method was used in the antibacterial study. Cytotoxic activity was determined by Brine shrimp lethality test in DMSO and ethanol, at varying concentrations (2, 1 and 0.2%) and (1, 0.2 and 0.1%) successively.

RESULTS

Quercetin (1), isorhamnetin 3-O-β-d-xyloside (2), isorhamnetin 3-O-β-d-glucoside (3), quercetin 3-O-β-d-glucoside (4), quercetin 7-O-β-D-glucoside (5), patuletin 3-O-β-d-glucoside (6) were isolated from for the first time from Evax genus. The EAEP was the most active in ABTS (IC50: <3.125 μg/mL) assay whereas the BEEP exhibited the highest activity in the β-carotene/linoleic acid assay (IC50: <3.125 μg/mL). The EAEP and BEP exhibited good antibacterial activity (MIC: 40-80 µg/mL). The plant did not show any toxicity (LD50>80 µg/mL).

DISCUSSION AND

CONCLUSIONS

Six flavonoids were isolated for the first time from Evax pygmaea which exhibited good antioxidant and antibacterial activities.