The scientific name of Tianshan Snow Chrysanthemum is Coreopsis tinctoria Nutt., also known as “blood chrysanthemum”. The Uyghur language is “Gulichhar”. It is the only alpine wild plant in Xinjiang that has the same name as snow lotus and has unique effects. It has extremely high medicinal value.
In addition to polyphenols, flavonoids, and saponins, Tianshan Snow Chrysanthemum is also rich in volatile oil. It has various physiological activities such as lowering blood fat, lowering blood pressure, lowering blood sugar, protecting cells, and anti-oxidation and antibacterial.
Supercritical CO2 extraction technology has been widely used for the extraction of plant volatile components at the beginning of its development. It has the characteristics of completely retaining the natural flavor of plants, safe and free of solvent residues. It is a recognized high-tech green chemical industry.
Supercritical CO2 extraction
Accurately weigh 300.0 g of pulverized Tianshan Xueju raw material into the extraction kettle of the supercritical CO2 extraction device, and seal the device. Select the set extraction temperature and pressure, and pass CO2 into the extractor.
The components of Snow Chrysanthemum that can be dissolved in supercritical CO2 will dissolve in the CO2 fluid; when the CO2 fluid passes through the separator, the set At the separation temperature and pressure, the active ingredients of snow chrysanthemum dissolved in supercritical CO2 are resolved due to the reduced solubility under conditions such as reduced pressure and elevated temperature, and are separated from CO2 in the separator to extract the active ingredients of snow chrysanthemum.
It is left in the separator, and CO2 is separated from the separator in gaseous form. The separated CO2 gas is condensed by the condenser and recycled.
Controlled at a temperature of 45°C and an extraction pressure of 25 MPa for 2 hours, the equipment was stopped and the snow chrysanthemum extract was removed from the separator.
Analyzed by GC-MS,
A total of 50 components were identified in the supercritical CO2 extract of Snow Chrysanthemum, and the relative content accounted for 96.58% of the total. Among them, olefin compounds (including terpenes) have a total of 9 components, and their content accounts for only 7.74% of the total mass fraction, which is significantly lower than the proportion of their flowers analyzed by headspace solid phase micro extraction-GC-MS Higher than 85%); but limonene is still the highest component in its olefins. The total mass fraction of the 7 alcohol compounds is 27.12%, second only to the higher alkane compounds with the highest content ratio (28.59%).
Higher alkane compounds are generally present in the waxy component of plant cuticles, and the high content can reach more than 50% of the plant waxy component.
In this experiment, the extraction of snow chrysanthemum extract by supercritical extraction method extracts a large amount of waxy components in the extraction process, and in the process of headspace analysis, the waxy components are not volatile, so the detection of such advanced alkanes Less than.
It can be seen from the experimental data that the higher alkane compounds in Snow Chrysanthemum are alkane between C21 and C40, with C31 accounting for the highest proportion (10.99%). C35. In addition, the free fatty acids from C12 to C18 also occupy a considerable proportion (a total of 8 components content ratio of 18.98%), these components are also the main components of plant wax.
In addition, the extract also contains 8.81% aldehydes and ketones, 5.72% lipid compounds and 0.47% terpene oxides, these components are also metabolites during plant growth.
In addition to terpene compounds, the supercritical CO2 extract retains more of the plant’s waxy components (higher alkanes), especially the relatively high content of behenyl alcohol, which has a higher antibacterial resistance Viral activity. If it is used as an essential oil, further purification is required.