GC - MS investigations. II. Lipid composition of Stevia rebaudiana

Full text of DOI:10.1007/s10600-008-9061-8

Chemistry of Natural Compounds, Vol. 44, No. 3, 2008
GC—MS INVESTIGATIONS. II. LIPID COMPOSITION OF Stevia rebaudiana
N. V. Korobko, Ya. A. Turko, V. V. Shokun, E. N. Chernyak, L. M. Pokrovskii,
UDC 547+582.949
O. N. Smetankina, B. F. Kerimzhanova, and U. A. Baltaev*
Herein we communicate results from a studyofthe components from leaves of
in particular, the composition of fatty acids and alcohols of neutral lipids.
Bertoni (Asteraceae),
Stevia rebaudiana
Air-dried and ground raw material was extracted three times with petroleum ether at room temperature. The yield of
total extracted substances was 4.7%. The combined extract was evaporated. The solid was separated by the standard
method [1].
The acidic part of the extract was methylated by diazomethane and passed over a microcolumn of Al O . The neutral
2
3
part of the extract was evaporated and passed over a column of silica gel with elution of alcohols by a small amount of CHCl .
3
The resulting samples were investigated using GC—MS in an Agilent 5973N GC with an Agilent 6890N quadrupole
MS as the detector. We used an HP-5 capillary quartz column (5% diphenyl—95% dimethylsiloxane copolymer) of length
30 m, inner diameter 0.25 mm, and stationary-phase film thickness 0.25 μm. The carrier gas was He; flow rate, 1 mL/min.
The column temperature gradient was 4 min at 70°C, from 70 to 280°C at 10°C/min, and 10 min at 280°C. The injector
temperature was 280°C; ion-source temperature, 175°C.
The percent composition of the components was calculated from the peak areas without using correction factors.
Components were identified by comparing retention times and full mass spectra with Wiley 275 and NIST 02 electronic
libraries.
TABLE 1. Component Composition of Lipid Fraction from
Stevia rebaudiana
Retention time, min
Area, %
Acidic lipid fraction
M+, m/z
Component
Fatty acids
14:0
16:0
18:2
18:3
18:0
20:0
22:0
24:0
17.19
19.27
20.98
21.05
21.25
23.05
24.90
26.92
0.87
2.11
9.32
24.95
2.03
0.84
0.94
0.78
242
270
294
292
298
326
354
382
Neutral lipid fraction
Alcohols
Phytol
Stigmasterol
β-Sitosterol
Lanosterol
β-Amyrin
Lupeol
21.16
35.25
36.83
37.36
37.81
39.29
12.95
1.22
2.57
4.53
19.44
296
412
414
426
426
426
44.65
Filial RGP "HTsBRK," MinistryofEducation and Science, Republic of Kazakhstan, Stepnogorsk, Kazakhstan, tel/fax
(71645) 5 24 50, e-mail: baltayev@yahoo.com. Translated from Khimiya Prirodnykh Soedinenii, No. 3, p. 286, May-June,
2008. Original article submitted October 19, 2007.
0009-3130/08/4403-0359 ©2008 Springer Science+Business Media, Inc.
359

Neutralandacidiclipid fractions contained 53 and 100 components, respectively. Ofthese, onlythosepresentat>0.5%
were identified. Table 1 gives the GC—MS data.
The acidic lipid fraction contained saturated fatty acids, among which hexadecanoic (16:0) acid dominated, and
unsaturated fattyacids, among which octadecadienoic (18:2) and octadecatrienoic (18:3) dominated. Octadecanoic, eicosanoic,
docosanoic, and tetracosanoic acids were found in smaller amounts.
The neutral lipid fraction contained lupeol as the main component and β-sitosterol, stigmasterol, and lanosterol from
the sterol part in addition to the unsaturated hydrocarbon squalene and terpenols β-amyrin and phytol.
REFERENCES
1.
M. T. Agedilova, A. Zh. Turmukhambetov, E. E. Shul′ts, M. M. Shakirov, and S. M. Adekenov, Khim. Prir. Soedin.,
186 (2006).
360