ABSTRACT
A new flavonoid glycoside, (-)-2S-8-methyl-5,7,4'-trihydroxyflavanone-7-O-ß-D-glucopyranoside (1), along with five known ones, quercetin-3-O-(2"-galloyl)-α-L-arabinoside (2), kaempferol-3-O-α-L-arabinoside (3), guaijaverin (4), trifolin (5) and hyperin (6), was isolated from the leaves of Eucalyptus robusta. Their structures with absolute configurations were elucidated by NMR, HR-ESI-MS, CD spectra data and physicochemical methods. In addition, 2-6 were isolated from E. robusta for the first time.
Subject(s)
Eucalyptus/chemistry , Flavonoids/isolation & purification , Glycosides/isolation & purification , Flavonoids/chemistry , Glycosides/chemistry , Plant Leaves/chemistryABSTRACT
Five new acylphloroglucinol glycosides, robustasides A-E (1-5), together with a known one (6), were isolated from the leaves of Eucalyptus robusta. The structures were elucidated on the basis of extensive spectroscopic and spectrometric analysis and chemical evidence. The absolute configuration of 1 was further determined by quantum chemical CD calculation.
Subject(s)
Eucalyptus/chemistry , Glycosides/isolation & purification , Circular Dichroism , Glycosides/chemistry , Magnetic Resonance Spectroscopy , Phloroglucinol/analogs & derivatives , Plant Leaves/chemistryABSTRACT
Two new euglobals, R1 (1) and R2 (2), together with eight known euglobals (3-10) were isolated from the leaves of Eucalyptus robusta. Their structures were established by means of spectroscopic analysis and single-crystal X-ray diffraction. Euglobal R1 (1) represents a new skeleton of formyl-isovaleryl phloroglucinol-coupled ß-phellandrene.
