Optimization Of Extraction Process And Quality Analysis Of Flavonoids From Caesalpinia Minax Hance

The seeds of Caesalpinia minax Hance, which named'kushilian'in Chinese, are very rich in resources. As one species of Chinese herbal medicines recorded in"Chinese Materia Medica"which has the functions of clearing away heat and toxic material, dissipating dampness, eliminating stasis to subdue swelling and pain reliefing etc, have been mainly used as a folk remedy for the treatment of in?uenza, and hepatitis. Modern pharmacological studies have shown that Caesalpinia minax Hance possesses manifold physiological activities, such as anti-virus, bacteriostasis and liver-protecting. Despite the long history of Caesalpinia minax Hance has been used as Chinese folk medicine, investigation on the chemical constituents and pharmacological activities of the seeds of this plant is rare. In order to make more systematic chemical researches of Caesalpinia minax Hance as well as to further clarify the substance responsible for the pharmacological activities, these results may provide scientific basis for new drugs development. Based on a review on the advances in the research of chemical constituents and pharmacological activities of Caesalpinia minax Hance in this paper, then the technological conditions of extraction, purification, structural type identification of flavonoids, contents and dissolution rate of trace elements in the seeds of Caesalpinia minax Hance were studied. In addition, separation and purification of chemical compositions in n-butanol fraction isolated from ethanol extract of the seeds of Caesalpinia minax were carried out. The main experimental contents and results of this dissertation are as follows:1 Ultrasonic assisted extraction process and contents of total flavonoids in Caesalpinia minax HanceDetermination of the optimum ultrasonic assisted extraction process of flavonoids from the seed coat and cotyledon of Caesalpinia minax Hance was carried out according to single factor tests and orthogonal experiments using flavonoids and Rutin as index components. The best extraction conditions were listed as follows when Caesalpinia minax Hance or its seed coat is tested: 50% ethanol as extraction solvent with material to ethanol ratio of 1∶15, extraction 60 min at 80℃. While Caesalpinia minax Hance cotyledon is tested, 70% ethanol as extraction solvent with experimental material to ethanol ratio of 1∶15 and extracting 30 min at 70℃was proved to be the best extraction process. Treating with ultrasonic for three times repeatedly under the best extraction conditions, the extraction efficiency of the total flavonoids in Caesalpinia minax Hance and its seed coat and cotyledon was 2.75%, 8.09% and 0.246%, respectively. Thus, flavonoids mainly exist in the seed coat of Caesalpinia minax Hance. The results also showed that Caesalpinia minax Hance cotyledons have a significant inhibition on flavonoids leaching from the seed coat.2 Purification of flavonoids extracted from the seed coat of Caesalpinia minax Hance and preliminary identification of flavonoids typeFlavonoids extracted from the seed coat of Caesalpinia minax Hance was refined by solvent extraction and solvent precipitation method to remove proteins, polysaccharides, inorganic salts and fat-soluble impurities, and flavonoids purity of the product increased to 56.8%. The adsorption and desorption properties of the Caesalpinia minax Hance flavonoids on the polyamide resin were investigated. Results showed Caesalpinia minax Hance flavonoids dissolved in water have lager adsorption capacity and stronger absorption affinity on polyamide resin than in 95% ethanol, methanol and acetone, respectively. According to the solubility tests, chromogenic reaction method and the UV-vis spectra of the flavonoids dissolved in different detection reagents, the structure types of the flavonoids can be preliminary identified as a kind of flavanone with o-dihydroxy(6, 7 or 7, 8 ) in ring A or compounds of dihydro-flavonol glycosides. The methods were proved to be an easily operational, evident, low-cost and practicable.3 Study on separation and purification of chemical compositions in n-butanol fraction isolated from ethanol extract of Caesalpinia minax HanceCaesalpinia minax Hance was refluxed with 95% and 70% ethanol for three times, respectively. Extracts obtained were then suspended in distilled water following by successive extraction with hexane, chloroform, ethyl acetate and n-butanol. The n-butanol extract was subjected to silica gel column chromatography and gradient elution with chloroform-methanol as eluent. Similar fractions were collected together by TLC detection and were then condensed to obtain 5 components. According to the chromogenic reaction method and the UV-vis spectra of component C dissolved in different detection reagents, the existence of isoflavonoids in component C was suggested.4 Study on the content and dissolved rate of trace elements in Caesalpinia minax HanceThe content and dissolution rate of K, Ca, Mg, Mn, Fe, Zn and Cu were determined by Flame Atomic Absorption Spectrometry in Caesalpinia minax Hance treated with digestion and boiling approaches, respectively. Results indicated that Caesalpinia minax Hance contains rich nutrimental elements, and the potassium content in Caesalpinia minax Hance reaches 12054.67μg·g-1 which is much higher than other six metal elements. The content of above-mentioned nutrimental elements is decreased in sequence followed by K>Ca>Mg>Mn>Fe>Zn>Cu. The content of Ca, Fe and Mn is significantly higher in seed coat than that in cotyledon while the content of Mg, Zn, Cu are lower in seed coat comparing with cotyledon. The dissolved rates of the seven metal elements vary widely in the range of 4.43%～59.54%. The dissolved rate orderly reduces as follows: K > Zn > Cu > Fe > Ca > Mg > Mn. The dissolved rates of seven trace elements have no direct relationship with the content level of each nutrimental element but the existing chemical states in Caesalpinia minax Hance.