Characterisation of bioactive compounds from leaves of Smilax fluminensis Steud. by gc-MS and LC-DAD-MS, and analysis of its antioxidant and ecotoxicological activities.

Smilax fluminensis Steud. is distributed in Central and South America, commonly named as 'salsaparilha' or 'japicanga'. In the present work, the chemical composition was determined, antioxidant and cytotoxic effects were evaluated for the ethanol extract (EE) and fractions from leaves. Fatty acid esters and phytol were characterised in the hexane (HEX) fraction. O-glycosylated flavonols and flavones, caffeic acid derivatives, and steroidal saponins were annotated for EE, and dichloromethane (DCM), ethyl acetate (AC), and hydroethanol (HE) fractions. The samples contain flavonoids and phenolic compounds, and the AC fraction displayed the biggest concentration of these substances. Antioxidant potential was observed in all samples, being especially pronounced in the AC fraction by DPPH and FRAP assays, with IC50 values of 8.18 and 2.35 µg/mL, respectively. AC and HEX fractions showed 35% and 5% lethality at 1000 µg/mL, in the Artemia salina assay, and the other samples did not show a toxic effect.

Phytotoxic and antioxidant effects of dichloromethane fraction of Smilax Brasiliensis Sprengel.

Dichloromethane (DCM) fraction and sub-fractions obtained from Smilax brasiliensis leaves were examined in order to determine their phytotoxic and antioxidant effects. The dichloromethane fraction was submitted to a preparative layer chromatography leading to seven sub-fractions (DCM1-DCM7). Gas chromatography-mass spectrometry (GC-MS) was performed on the dichloromethane sub-fractions. The DCM sub-fractions presented phytotoxic potential; at a concentration of 125 µg per plate, DCM6 and DCM4 showed the strongest results on Lactuca sativa and Allium cepa, respectively. The DCM fraction and DCM4 sub-fraction were more effective than 2,6-di-tert-butyl-4-methylphenol (BHT) at scavenging the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. Analysis by GC-MS showed the presence of methyl palmitate (33.05%) in DCM4 and methyl palmitate (17.29%) and methyl oleate (50.96%) in DCM6, suggesting that the activities exhibited by the sub-fractions may be attributed, at least partially, to these major compounds. These results indicate that the DCM sub-fractions of S. brasiliensis could be used as natural herbicides and antioxidants.