Three new sesquiterpene glycosides,named codonopsesquilosides A C(1 3),were isolated from an aqueous extract of the dried roots of Codonopsis pilosula.Their structures including absolute configurations were determined...Three new sesquiterpene glycosides,named codonopsesquilosides A C(1 3),were isolated from an aqueous extract of the dried roots of Codonopsis pilosula.Their structures including absolute configurations were determined by spectroscopic and chemical methods.These glycosides are categorized as C_(15) carotenoid(1),gymnomitrane(2),and eudesmane(3)types of sesquiterpenoids,respectively.Compound 1 is the first diglycoside of C_(15) carotenoids to be reported.Compound 2 represents the second reported example of gymnomitrane-type sesquiterpenoids from higher plants.The absolute configurations were supported by comparison of the experimental circular dichroism(CD)spectra with the calculated electronic CD(ECD)spectra of 13,their aglycones,and model compounds based on quantummechanical time-dependent density functional theory.The influences of the glycosyls on the calculated ECD spectra of the glycosidic sesquiterpenoids,as well as some nomenclature and descriptive problems with gymnomitrane-type sesquiterpenoids are discussed.展开更多
基金Financial support from the National Natural Sciences Foundation of China(NNSFC,Grant Nos.30825044 and 20932007)the Program for Changjiang Scholars and Innovative Research Team in University(PCSIRT,Grant No.IRT1007)the National Science and Technology Project of China(Nos.2012ZX09301002-002 and 2011ZX09307-002-01)
文摘Three new sesquiterpene glycosides,named codonopsesquilosides A C(1 3),were isolated from an aqueous extract of the dried roots of Codonopsis pilosula.Their structures including absolute configurations were determined by spectroscopic and chemical methods.These glycosides are categorized as C_(15) carotenoid(1),gymnomitrane(2),and eudesmane(3)types of sesquiterpenoids,respectively.Compound 1 is the first diglycoside of C_(15) carotenoids to be reported.Compound 2 represents the second reported example of gymnomitrane-type sesquiterpenoids from higher plants.The absolute configurations were supported by comparison of the experimental circular dichroism(CD)spectra with the calculated electronic CD(ECD)spectra of 13,their aglycones,and model compounds based on quantummechanical time-dependent density functional theory.The influences of the glycosyls on the calculated ECD spectra of the glycosidic sesquiterpenoids,as well as some nomenclature and descriptive problems with gymnomitrane-type sesquiterpenoids are discussed.
