abstract
High-performance liquid chromatography electrospray ionization mass spectrometry (HPLC-ESI-MS) and tandem mass spectrometry (MS") were used to investigate the phenolic constituents in methanol, water, and methanol/water extracts of Eucalyptus globulus Labill. bark. Twenty-nine phenolic compounds were identified, 16 of them referenced for the first time as constituents of E. globulus bark, namely, quinic, dihydroxyphenylacetic, and caffeic acids, bis(hexahydroxydiphenoyl (HHDP))-glucose, galloyl-bis(HHDP)-glucose, galloyl-HHDP-glucose, isorhamentin-hexoside, quercetin-hexoside, methylellagic acid (EA) pentose conjugate, myricetin-rhamnoside, isorhamnetin-rhamnoside, mearnsetin, phloridzin, mearnsetin-hexoside, luteolin, and a proanthocyanidin B-type dimer. Digalloylglucose was identified as the major compound in the methanol and methanol/water extracts, followed by isorhamnetin-rhamnoside in the methanol extract and by catechin in the methanol/water extract, whereas in the water extract catechin and galloyl- HHDP-glucose were identified as the predominant components. The methanol/water extract was shown be the most efficient to isolate phenolic compounds identified in E. globulus bark.
keywords
MOLECULAR-WEIGHT POLYPHENOLS; E-RUDIS; HYDROLYZABLE TANNINS; STEM BARK; ACID; CAMALDULENSIS; FLAVONOL; LEAVES; WOOD; AGLYCONES
subject category
Agriculture; Chemistry; Food Science & Technology
authors
Santos, SAO; Freire, CSR; Domingues, MRM; Silvestre, AJD; Neto, CP
our authors
Armando Jorge Domingues Silvestre
Full professor
Carlos Pascoal Neto
Raiz Director
Carmen Sofia da Rocha Freire Barros
Coordinating Researcher
Sónia Andreia Oliveira Santos
Assistant Researcheracknowledgements
We thank the 7th Framework Programme FP7/2007-2013 for funding project AFORE,