Captions to Figures
Fig. 1 General structure of (a ) tocopherols (T), (b ) tocotrienols (T3) and (c ) tocomonoenols (T1) (Kamal-Eldin, 1996; Saremi and Arora, 2010)
Fig. 2 GC/MS full scan chromatogram of the pumpkin seed oil (PSO) extract after saponification reaction and trimethylsilylation with: (a ) isoprenoidic compounds similar phytol and farnesol; (b ) squalene-like terpenoids and 5α-cholestane as internal standard (ISTD); (c ) tocochromanols including γ-T, γ-T1, α-T and α-T1; (d ) sterols
Fig. 3 CCC elution profile of all 18 detected tocochromanols in saponified pumpkin seed oil (PSO) after fractionation in head-to-tail mode using the BTF solvent system. Bubble sizes correlates with corrected GC/MS peak area of the corresponding CCC fractions. The doted area highlights the optimum range for the isolation of γ-T1
Fig. 4 (a ) GC/MS full scan chromatogram of the silylated CCC fraction with corrected elution volume (CEV) 72-74% and GC/MS spectra of silylated (b ) δ-T1 (2 ), (c ) γ-T2 isomer 1 (3), (d ) γ-T2 isomer 2 (4 ), (e ) uncommon T1 isomer 1 (5 ), (f ) uncommon T1 isomer 2 (6 )
Fig. 5 GC/MS full scan chromatogram of the silylated CCC fraction of saponified pumpkin seed oil (PSO) extract with corrected elution volume (CEV) 89-91% and GC/MS spectra of silylated (b ) γ -T1 (7 ), (c ) 11´-β-T1 (9 ), (d ) α-T2 isomer 1 (12 ) and (e ) α-T2 isomer 2 (13 )
Fig. 6 (a ) GC/MS fragmentation of silylated tocopherols and (b ) formation of the diagnostic 3-methylbut-2-en-1-ylium cation along with GC/MS spectra of the silylated CCC fraction with corrected elution volume (CEV) 89-91% of saponified pumpkin seed oil (PSO) extract of (c ) the uncommon tocopherol Tu, (d ) γ-tocopherol and (e ) β-tocopherol
Fig. 7 Representative elution scheme of fractions 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, and 4 collected by column chromatography with silica and elution with n -hexane/ethyl acetate (95:5, v/v ) in case of (a ) high and (b ) low shares of interfering substances. I1: impurity 1, I2: impurity 2, γ-T1: γ-tocomonoenol, I3: impurity 3
Fig. 8 GC/MS full scan chromatogram of silylated (a ) γ-T1 isolate after chromatography on a silica column with (b ) enlarged central part showing minor impurities in form of silylated γ-T and β-T1 and (c ) mass spectrum of silylated γ-T1
Fig. 9 Excerpts of 1H NMR spectra (500 MHz, 1024 scans) of 11´-γ-T1 with (a ) the singlet at ~6.30 ppm (proton at C-5 of the 6-chromanol ring), (b ) a triplet at ~5.03 ppm for the proton on C-11´ of the phytylic side chain, and (c ) the multiplet at ~2.60 ppm. (d ) shows the multiplet at ~2.70 ppm in the 1H spectrum of γ-T3 measured with the same conditions for comparison