The Study On Eudesmane-type Sesquiterpene Of I.britanica Linn

Inula L. is a big medicinal genus of Compositae. The genus Inula (Compositae) plants consists of about 100 species distributed all over the word,widely distributed in Europe,Asia and Africa, mainly in Mediterranean region,among which over 20 species have been found in China.I. japonica Thunb.and I.britanica Linn have been recorded in Chinese Pharmacopoeia 2005 version,Flowers of them are used in traditional Chinese medicine for the treatment of diverse diseases such as cough due to wind-cold evil,vomiting,ructation and excessive sputum.I.britanica Linn widely distributed, mainly in China, Korea and Japan, is a traditional Chinese herbal medicine。It is reported that there are more than 40 chemical constituents in Inula Britannica L. and the main compounds are flavonoids, sesquiterpene lactones and terpenoids. Most of the pharmacological components of I.britanica Linn are sesquiterpene lactones. The extract has been reported to have many bioactivities, such as anti-inflammatory and anti-tumor. However, the medicinal herbs resource of I. britanica Linn is different, the species are in a mess. In order to change the confused state of liujinu specie, provide scientific basics for reasonablely using the medicine and search the bioactive constituents, a systematic study on chemical constituents of I. britanica Linn was carried out used by various chromatographers to set up the foundation for studying pharmacologic substance basis and establishing more scientific quality standard.The dried flowers of I. britanica Linn were extracted consecutively with water at 40℃thrice. The extracts evaporated under reduced pressure were applied to a macroporous resin column and eluted with water,30% ethanol,70% ethanol, ethanol. The 30% Ethanol elution position was suspended in water,and extracted with chloroform,ethyl acetate,n-butanol,respectively. The extract was applied to a silica gel column, a ODS column and HPLC.20 compounds have been isolated from the flowers of I. britanica Linn by various chromatographic methods.The structures of 8 compounds have been elucidated by spectroscopic methods,as Deacetyl-(?)-cyclopyrethrosin (Ⅰ), Sivasinolide (Ⅱ),5a-Hydroxyasperilin (Ⅲ), Britannilactone A (Ⅳ), Microcephalin (Ⅴ), Britannilactone B (Ⅵ) Britannilactone C, Britannilactone D (Ⅷ).Among them,there are 4 new compounds,including Britannilactone A (Ⅳ), Britannilactone B (Ⅵ), Britannilactone C (Ⅶ) and Britannilactone D (Ⅷ). The complete 13C NMR signal assignments of compound 5a-Hydroxyasperilin (Ⅲ) are listed for the first time. The complete1H and 13C NMR signal assignments of Microcephalin (Ⅴ) are listed for the first time.