Echinacea extract is derived from E. purpurea and E. angustifolia species of this botanical. The whole Echinacea purpurea herb were were rinsed, crudely cut, and dried. and then the dried material was ground mechanically and then macerated in ethanol. After vacuum filtered and the filtered extract was concentrated using a rotatory evaporator and subjected to two stages of liquid-liquid partitioning. The filtrates were sprayed drying echinacea extract powder with a spray drying tower, the whole production process under aseptic conditions to ensure the moisture and ash content of the product. then transferred to a volumetric flask to determine the amount of chicoric acid using HPLC.
Polyphenols and chicory acid are the main active components derived from echinacea species. They are the most widely used medicinal active ingredient for upper respiratory viral infections, toothaches, snakebites and other injuries. It has been used in the United States for years as an alternative medicine to strengthen the immune system and clear the blood especially during the changing seasons and when colds and coughs are common. The chicory acid extracted from echinacea is a brownish-green powder with a slightly bitter taste. Chicory acid powder should be sealed at room temperature to avoid strong light exposure, a long time exposed outside will be oxidized and fail. Here we briefly introduce the extraction process of chicory acid derived from echinacea:
Ethanol, methanol, or their aqueous solutions are generally used to extract chicory acid from echinacea, but more ethanol is used. 20g echinacea roots were extracted by reflux extraction in different proportions of ethanol solution heated at 80℃ for 2 hours, and then the echinacea extract was obtained by evaporative drying. The content of chicory acid in echinacea extract was determined by HPLC and the yield of chicory acid was calculated. With the increase of the volume fraction of ethanol, the yield of chicory acid from echinacea extract increased gradually. When the volume fraction of ethanol solution was 40%, the yield of chicory acid reached the maximum. Subsequently, the yield of chicory acid from Echinacea decreased with the increase of ethanol volume fraction. This is because ethanol can inactivate polyphenol oxidase, which is contained in the echinacea root. Chicory acid is rapidly oxidized in a few minutes when extracted with water, and the yield is low. However, when the volume fraction of ethanol was too high, the solubility of chicory acid in echinacea tissue decreased, so that chicory acid could not be extracted from echinacea.
Concentrate echinacea extract to 1/10 of the original and recycle ethanol as the working fluid of the macroporous adsorption resin. The saturated adsorption capacity of AB-8 resin for chicory acid was 56.36mg/g. In desorption test, ab-8 resin was saturated after adsorption, and then eluted with water and ethanol solution in different proportions to collect the eluent of each part. HPLC analysis showed that no chicory acid was removed from water and 10% ethanol eluent, and there was chicory acid in 30% and 50% ethanol eluent, but there was no chicory acid in 70% and 90% ethanol solution. Therefore, after resin adsorption saturation, first eluting with water to colorless and then eluting with 50% ethanol to obtain chicory acid crude product.
Extraction and purification of ethyl acetate
The ab-8 resin treated powder was dissolved in 10 times the volume of water, and then adjusted to pH 3 with 6mol/LHCl. Aqueous solutions were extracted with ethyl acetate, n-butanol and iso-amyl alcohol, respectively. The recovery of n-butanol and isoamyl alcohol is difficult due to the high boiling point, so the extraction solution is first adjusted to pH 6.5 with 5% NaOH, and then extracted with water. The water layer is separated, and finally condensed into powder under pressure. Results The mass fractions of chicory acid were 69. 28%, 32. 52% and 46. It is known that ethyl acetate has the best extraction effect and the highest purity. Effect of PH value on extraction with ethylacetate solvent
|PH||Extraction rate, %||Chicory acid content, %|
The extraction effect of chicory acid in echinacea was better when the pH was 2 ~ 3, and the extraction rate and purity were the best. This is because when the pH is less than 3, chicory acid changes from the original chicory to free state, which changes the distribution rate of chicory acid in the aqueous phase and the organic phase, so it can be well extracted from the aqueous phase with ethyl acetate. When the pH of the solution was higher than 3, the extraction rates of chicneric acid from echinacea were 41.40%, 63.43%, 80. 51% and 96. 83%, respectively. That is, ethyl acetate extraction 4 times can be basically complete extraction.
Determination of chicory acid from Echinacea
After 40% ethanol extraction, AB-8 resin adsorption, 50% ethanol elution and ethyl acetate extraction, the final product was light yellow powder chicoric acid with a purity of more than 69%.