Studies On Extraction Of Botanical Valuable Compounds By Supercritical Carbon Dioxide

Characteristics of supercritical fluid and its extraction principle andprocess were introduced. Physicochemical properties of CO₂ and theadvantages of supercritical fluid extraction using CO₂ as a solvent werealso discussed. A review was given on the application of supercriticalCO₂ extraction especially on the extraction of natural products. Thegeneral rules of supercritical CO₂ extraction natural products were alsoexplored.Several valuable compounds extraction from the plenty materials ofperfume and medical plants originating from Guangxi by supercriticalCO₂ were studied. The specific subjects as bellow:The flowers of Osmanthus fragrans and Jasminum sambac wereextracted with supercritical CO₂ at different conditions of pressure,temperature and contact time to estimate the yield and quality of theconcretes. The optimum condition was also determined. Thespecifications such as appearance, colour, odour, melting point, estervalue, acid value and the content of absolute of Osmanthus and JasmineConcrete both extracted by supercritical CO₂ and by petroleum ether weredetermined. Most of constituents of the absolutes were analyzed by using GCand GC/MS. A comparative study of flower concretes extracted bysupercritical CO₂ and petroleum ether was made, and the results showedthat supercritical CO₂ extraction was more superior than the conventionalmethod bOth yield and quality of the concretes.The Whole herb of ArtemisiQ Annua L. was extracted withsupercritical CO2 at diffetal pressure, temPeratllre and contact hme tooptimize the yield of animalaria comPound of artemisinin. At the oPtimaltechnical parameters the yield was over 95% based on the content ofartemisinin in the raw material. The CO2 extract was purified combiningthe other separaion methods to obtain final product with purity over 99%.The authenticity ofartemisinin was verified by TLC. IR. MS. lH N''MRand l3C na.The air-dried bark of Cinnamomum Casia was extracted withsuPercritical CO2 at different pressure, temPetalre and colltact time tooPtimize the yield and quality of cassia oleoresin. At the oPtimal technicalparameters the yield of the oleoresin was up to 2.89%. The specificationof oleoresin such as aPpearance, colouf, odour and sense characteristicwas assessed and the conient of volatile oil was also determined withsimultaneous distillation and extraction method. The volatile oil of theoleoresins extracted by suPercritical CO2 and petroleum ether and theessential oil distilled from cassia bark were analyzed by GC, GC/MS,GC/IRFT and standard samPIes, and among Which 5 main comPounds(representing over 93% of the oil) were identified.