POLYPHENOL AND TRITERPENOID CONSTITUENTS OF Eugenia florida DC. (MYRTACEAE) LEAVES AND THEIR ANTIOXIDANT AND CYTOTOXIC POTENTIAL

Abstract

Leaves of Eugenia florida DC. have been used in folk medicine as hypotensive, hypoglycemic, antipyretic and for gastrointestinal disorders, among others. In this study dried leaves were extracted with ethanol and the extract was partitioned with hexane, CHCl3, EtOAc, BuOH and water to afford triterpenoid- and polyphenol-rich fractions which were analyzed by GC-MS and UFLC-DAD-ESI-Ion Trap-MSn. All fractions were tested against the proliferation of leukemic K562 and human melanoma SK-Mel-28 cell lines and for their ability to scavenge DPPH radical. Twenty-nine compounds were fully identified (among triterpenic and phenolic acids, flavonol- and dihydroflavonol-monoglyclosides) based on mass fragmentation patterns and comparison to standards and/or literature data. The ability to scavenge DPPH radical resulted in the following order: BuOH ≈ EtOAc > crude extract ≈ Water >> CHCl3 >> hexane; with the two most active reaching half of the TBHQ control potency (EC50 6.59 ± 0.03 µg mL-1). On testing against the proliferation of K562 and SK-Mel-28 cell lines, the most significant inhibitions were achieved on the former by the crude extract (IC50 12 µg mL-1) and the hexane and EtOAc fractions at 15 µg mL-1.

Keywords

• Eugenia florida
• polyphenols
• triterpenoids
• antioxidant activity
• cytotoxic activity