| Du Zhong, the cortex of Eucommia ulmoides Oliv., has been used to strengthen the liver and kidneys, bones, tocolysis, lower blood pressure and anti-fatigue. So it is used for treating liver and kidney deficiency, weak waist, impotence, hypertension, hemorrhage of pregnancy and so on. Eucommia ulmoides belongs to a single species genus in the plant family Eucommiaceae. It is an economical plant native to China, while Korea and Japan start introducting in recent years. Eucommia ulmoides Oliv. is a deciduous tree, up to twenty meters. After break the bark and leaves have fine silver flexible plastic wire.Some traditional Chinese medicine which can strengthen the liver and kidneys, bones show phytoestrogenic activity and theirs phytoestrogenic constituents are lignans, flavonoids, stilbenes and so on. Eucommia ulmoides can strengthen the liver and kidneys, bones and its chemical composition is mainly lignans and flavonoids, so we choose it to do research.By solvent extraction, recrystallization, polyamide, silica gel and macroporous resin column chromatography, eighteen compounds were isolated from the ethanol extracts of Eucommia ulmoides. The structures of sixteen compounds were identified by NMR, MS and comparing with authentic samples including two lignans, four iridoids, three flavonoids, two triterpenoids, four anthraquinones and a sterol. They are sitosterol (EUC-1), betulinic acid (EUC-2), betulin (EUC-3), wogonin (EUC-4), aloe emodin (EUC-5), oroxylinA (EUC-6), genipin (EUC-7), baicalein (EUC-8), emodin (EUC-9), chrysophanol (EUC-11), physcion (EUC-12), geniposide (EUB30-1), geniposidic acid (EUB30-2), aucubin (EUB30-3), pinoresinol di-O-β-D-glucopyranoside (EUB30-4) and syringaresinol di-O-β-D-glucopyranoside (EUB30-5). Among these compounds, wogonin (EUC-4), aloe emodin (EUC-5), oroxylinA (EUC-6), baicalein (EUC-8), emodin (EUC-9), chrysophanol (EUC-11) and physcion (EUC-12) were the first found in Eucommia ulmoides.The ethanol extracts of Eucommia ulmoides partitioned by petroleum ether, chloroform, ethyl acetate and n-butanol, and obtain four parts. These four parts and twelve isolated compounds were screened phytoestrogenic activity, and we found that chloroform and n-butanol extracts show phytoestrogenic activity, in which n-butanol part of the best. Two lignans (pinoresinol di-O-β-D-glucopyranoside and syringaresinol di-O-β-D-glucopyranoside), three flavonoids (wogonin, oroxylinA, baicalein), an iridoid (genipin) and a triterpenoid (betulinic acid) show phytoestrogenic activity.In this thesis, phytoestrogenic constituents and the chemical studies on the lignans, iridoids, flavonoids isolated from Eucommia ulmoides and their bioactivities in the past few years were also summarized. |
