Nonvolatiles of Commercial Lime and Grapefruit Oils Separated by High-Speed Countercurrent Chromatography

Abstract

The nonvolatile fractions of cold-pressed peel oils of Key and Persian lime as well as grapefruit were separated by high-speed countercurrent chromatography (HS-CCC). In addition to the isolation of the main coumarins, psoralens and polymethoxyflavones, a number of minor constituents were enriched and successfully characterized by GC-MS and HPLC-UV. 5,7,8-Trimethoxycoumarin and the cyclical acetals of oxypeucedanin hydrate with citral were determined as new nonvolatile trace constituents of lime oils and confirmed by NMR spectroscopy. The citral oxypeucedaninyl acetals were found particularly in Key lime oil type A, which as a result of the juice-oil contact, is exposed to acidic conditions during industrial processing. Some of the confirmed minor constituents, such as pabulenol, isooxypeucedanin, and oxypeucedanin methanolate in lime as well as auraptenol in grapefruit, may have been generated by hydrolysis-sensitive precursors during CCC separation or their respective industrial processing techniques.

Minor Furanocoumarins and Coumarins in Grapefruit Peel Oil as Inhibitors of Human Cytochrome P450 3A4

“…This is in agreement with the broad 1 H NMR methylene proton resonance at 1.23 ppm with a large integration value and the absence of other terminal methyl group resonances other than those of C-10′′ of the alkane substituent and of the geranyl C-3′ and C-7′ methyl groups. The assignment of an acetal group to C-1′′ of 1 is consistent with the observation of a 1 H NMR resonance at To further verify this structure, 1 was synthesized from 2 and decanal using reaction conditions for the synthesis of acetals, similar to that reported by Feger et al 11 The MS and the 1 H and 13 C NMR data of the synthesized product and the originally isolated 1 were identical. Marmin (2) was previously shown to possess an Rconfiguration, 18 and thus, 1 was identified as (R)-6′,7′-marmin decanal acetal.…”

“…The assignment of an acetal group to C-1′′ of 1 is consistent with the observation of a 1 H NMR resonance at δ 4.77 (H-1′′, t, J ) 4.72 Hz) and the 13 C NMR resonance at δ 101.2. 11 The 1 H NMR spectrum revealed three signals associated with protons (H-1′ δ 4.67; H-6′ δ 3.44; H-1′′ δ 4.77) covalently bonded to three alkoxy carbons (C-1′, C-6′, and C-1′′), whereas the 13 C NMR data provided evidence of four alkoxy carbons (C-1′ δ 65.1, C-6′ δ 83.6, C-7′ δ 78.7, and C-1′′ δ 101.2). These data supported a structure lacking…”

“…[7][8][9][10][11][12][13] Assignments of NMR data for 3, 5, and 6 were based on published assignments for related compounds. 11,[13][14][15][16][17] The UV spectrum of 1 closely matched the spectrum of 7-geranyloxycoumarin (3), a major coumarin in grapefruit peel oil. 9 The ESIMS spectrum of 1 exhibited an [M + H] + ion at m/z 471, major fragment ions at m/z 315, 297, and 163, and neutral losses of 156, 174, and 308 amu.…”

Antifibrotic activity of coumarins from Cnidium monnieri fruits in HSC-T6 hepatic stellate cells

“…Further fractionation and separation of the CHCl 3 fraction by various chromatographic methods yielded ten coumarins, which were identified as osthol (1), meranzin (2), auraptenol (3), meranzin hydrate (4), 7-hydroxy-8-methoxy coumarin (5), imperatorin (6), xanthotoxol (7), xanthotoxin (8), bergapten (9) and isopimpinellin (10) (Fig. 1), by the direct comparison of their physicochemical and spectroscopic data with those previously reported [12][13][14][15][16]. Among the compounds isolated, compounds 2 and 5 are reported from this plant for the first time.…”

Variação dos teores de constituintes voláteis de Cymbopogon citratus (DC) Staf, Poaceae, coletados em diferentes regiões do Estado de São Paulo

“…Além destes, outros sinais foram detectados entre δ 164,0-122,4, relativos aos carbonos sp 2 C-2/C-3 e C-6/C-7 da mistura isomérica. Através da comparação dos dados obtidos com aqueles descritos na literatura (Feger et al, 2006;Pihlasalo et al, 2007), foi possível identificar os dois monoterpenos na mistura.…”