TITLE:
Extraction of the Main Ingredients from Chuanxiong by CO2 Supercritical Fluid Extraction
AUTHORS:
Ru Yan, Song-Lin Li, Ge Lin
KEYWORDS:
linge@cuhk.edu.hk
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.3 No.12A,
December
31,
2012
ABSTRACT:
As one of the most frequently used medicinal herbs in
China, Chuanxiong Rhizoma (Chuanxiong) is notable for its beneficial effects in
alleviation of cardio- and cerebro- vascular disorders. Results from previous
phytochemical, pharmacological and pharmacokinetic studies supported the
contributions of 10 main components, namely ferulic acid (3), senkyunolide I (4), senkyunolide H (5),
senkyunolide A (6), coniferylferulate (7), Z-ligustilide (8),
sedanolide (9), 3-butylidenephthalide (10), riligustilide (11)
and levistolide A (12), for therapeutic outcomes of the herb. To prepare
a Chuanxiong extract, which is selectively enriched with these main components, the supercritical fluid extraction (SCFE) technique using CO2 was chosen in the present study due to its
superiority in extraction of lipophilic components, especially thermo-labile
components from natural products. Eight Chuanxiong samples were extracted under
different SCFE conditions. Contents of 3 - 12 in SCFE extracts and
remained in herbal residues were determined using HPLC-UV and compared with
those in 95% ethanol extracts of the respective herbal samples. The results
showed that contents of 3 - 12 were generally enriched
by SCFE with higher recoveries achieved for lipophilic constituents, including
the three most abundant constituents 6, 7 and 8. Moreover, extraction yield of the less lipophilic 3, 4 and 5 was improved by adding ethanol as entrainer. Higher flow rate of
CO2 (10 - 13 L/h vs 9 - 12 L/h) enhanced the overall extraction, while lower temperature (32℃ vs
40℃) reduced degradation of thermo-labile compounds, in particular 7, 8 and 10. Our established SCFE condition yielded high extraction
recoveries for both total (75.6%) and three major chemical ingredients (6:
83.5%, 7: 77%, 8: 78.3%) from Chuanxiong with an adequate overall
reproducibility, demonstrating a successful application of SCFE in selective
enrichment of certain ingredients and efficient extraction of thermo-labile
components from medicinal herbs using specifically designed SCFE conditions.