4.

Phenolic Constituents of Eucalyptus camaldulensis Dehnh, with Potential Antioxidant and Cytotoxic Activities

Abdel-Nasser Singab, Nahla Ayoub, Eman Al-Sayed, Olli Martiskainen, Jari Sinkkonen, and Kalevi Pihlaja

Department of Pharmacognosy, Faculty of Pharmacy, Ain-Shams University, 11566 Cairo, Egypt.

Laboratory of Organic Chemistry and Chemical Biology, Department of Chemistry, University of Turku, FI-20014 Turku, Finland.

Abstract: A liquid chromatography-diode array detection-electrospray ionization mass spectrometric (HPLC–PDA– ESI/MS/MS) method was used for separation and characterization of the phytoconstituents of the aqueous acetone leaf extract of Eucalyptus camaldulensis Dehnh (Myrtaceae). The employed method was optimized for separation, identification and quantification of fifty six compounds including ellagitannins, flavonoids, phloroglucinol derivatives and galloyl esters. The antioxidant effect was determined in vitro using 1,1-diphenyl-2-picrylhydrazyl (DPPH ·), hydroxyl radical and super oxide anion radical scavenging assays. The cytotoxicity of the aqueous acetone extract was evaluated on MCF-7, Hep-2, HepG-2, HeLa, HCT-116 and Caco-2 cell lines. The results indicated that most of the fractions exhibited strong antioxidant activity. The aqueous acetone extract reduced the viability of all cell lines in a dose-dependent manner, and was more active on MCF-7 and HCT-116 cell lines.

Keywords: Myrtaceae; Eucalyptus camaldulensis; DPPH; 2-deoxy-2-ribose; HPLC–PDA–ESI/MS/MS; cytotoxicity .