Isolation And Identification Of Chemical Constituents In The Organic Extracts From Daphne Odora Var. Marginata And Studies On Their Antioxidant Activities

Daphne odor a var. marginata, family of Thymelaeaceae, is a famous flower and medical plant in the regions along the Yangzi River. It has been used in Chinese traditional medicine for many diseases. The leaves have been mashed up to kurashiki the affected part for the ulcerate, injury, mastitis; The flowers soaked by white spirit have been used to cure rheumatoid arthritis, rheumatism, carbuncle, furuncle, miliaria, unknown toxin and traumatic injury. In the experiment research, the chemical constituents and antioxidant activity of the extracts from Daphne odora var. marginata were studied to find lead medicinal compounds with biological activity or novel structure. Hopes would offer the theoretical foundation for the depth development and utilization of Daphne odora var. marginata.In the first chapter, a review was presented, in which introduced the progress of chemical constituents, pharmacological activity in Daphne odora var. marginata.The distribute and bioactivity of coumarin and daphnodorin which were characteristic components in Thymelaeaceae were reviewed, too.In the second chapter, Fr2-B, one of the fractions eluted from Fr2 which was subjected to CC on silica gel, was analysed by HPLC-MS. Through the messages of retention time, relative molecular mass and ultraviolet spectrum, we guessed that daphnodorin A, B, C, dihydrodaphnodorin B, wikstrol A, B and isodaphneticin may have been existing in Daphne odora var. marginata. The hint:many daphnodorins have been existing in this plant.In the third chapter, the fractions were extracted by aether, Ethyl acetate from precipitation which was from Daphne odora var. marginata extracted by mixed organic solvent(95% ethanol and Ethyl acetatel:1,v/v), and then were subjected to column chromatography on silica gel, polyamide and ODS. Six compounds were separated and purified from this plant. They were established on the basis of spectral data including UV, IR, ESI-MS, EI-MS,1H NMR, 13C NMR, physical and chemical properties, as follow:daphnodorin B (JB-1), daphnodorin C (JB-2), daphnodorin I (JB-3), daphnoretin(JB-4), daphnodorin A(JB-5) and daphnodorin D2 (JB-6).In the fourth chapter, the pertinence relation between structural and the antioxidant activities of four daphnodorins and two coumarins was respectively studied by the total antioxidant activity, scavenging activity of DPPH radicals and reducing power. The results:the antioxidant activity mainly depends on the position and quantity of hydroxyl group; the antioxidant activity mainly depends on the position of hydroxyl group; the 2",3"-double bond and the 4"-carbonyl in the C ring contributes much to the antioxidant activity of daphnodorins; daphnodorin B with 3-OH is a little stronger than daphnodorin A; daphnodorin C is a little weaker than daphnodorin D2 with 7-OH; phenolic hydroxyl on the ortho-position is very helpful for the antioxidant activity of coumarin; compared with BHA, BHT, the antioxidant activities of daphnodorin A, daphnodorin B and daphnetin were very strong. Therefore, it is worth studying deeper to use them as safe, effective antioxidants or medicine for curing disease related to radicals.