Study On The Chemical Constituents And Biological Activities Of Two Wikstroemia Medicinal Plants

There are abundant plant resources in China, and ranks second in the world. It is an important pathway to search for novel bioactive natural products from traditional Chinese medicine and folklore medicinal plants as new drug leading compounds, and it will provide scientific material basis of traditional Chinese medicine and folklore medicine.The genus of Wikstroemia (Thymelaeaceae) is composed of about 70 species, and widely distributed in southeast Asia, Oceania and the Pacific Islands.40 of them are emidic to China, and mainly grown in the south of the Yangtze River. Most plants of Wikstroemia have better bast fiber which was usually used as raw materials in the manufacture of fine paper and rayon. Additionally, many of them are ornamental plant for garden cultivation. The plants of Wikstroemia have attracted much attention from many researchers for their significant physiological activities and toxicities.The Wikstroemia chamaedaphne Meissn. (Thymelaeaceae), a toxic shrub endemic to China, has been used to treat edema, cough, hepatitis, schizophrenia, and antifertility in folk medicine. W. chamaedaphne absorbed more focus on its traditional anti-fertility effect in modern scientific research but less focus on their chemical constituents. Some of diterpenoids, flavonoids, phenols and glucosides have been reported in the previous phytochemical investigation. "Xiao huang gou" is the whole plant of the Wikstroemia micrantha Hemsl (Thymelaeaceae), its bark and root have been used to treat cough, phlegm and asthma in folk medicine. However, its pharmacological effects and chemical composition are not reported yet.Repeated extensive column chromatographies on the acetone extract of the dry buds of W. chamaedaphne had resulted in 37 compounds. Based on the detailed MS, IR, and NMR spectroscopic analysis, these compounds were identified as (-)-(7R,7'R,7"R,8S,8'S,8"S)-4',4"-dihydroxy-3,3',3",5-tetramethoxy-7,9':7',9-diepoxy-4,8"-oxy-8,8'-sesquineolignan-7",9"-diol (1), (-)-(7R,7'R,7"S,8S,8'S,8"S)4',4"-dihy- droxy-3,3',3",5-tetramethoxy-7,9':7',9-diepoxy-4,8"-oxy-8,8'-sesquineolignan-7",9"-d iol (2), tsangane L (3), (+)-episesaminone (4), chamgnolone A (5), (-)-prestegane B (6), methylarctigenin (7), (+)-isolariciresinol (8), (-)-isolariciresinol (9), 1H,3H-Furo[3,4-c]furan-1-ol,tetrahydro-4-(4-hydroxy-3-methoxy-phenyl)-,(1R,3aS,4 R,6aS)-rel-(10), (+)-epipioresinol (11), (-)-lariciresinol (12), (+)-lariciresinol (13), (-)-dehydrodiconiferyl alcohol (14), (+)-pinoresinol (15),4-hydroxykobusin (16), prostratin (17), prostratin Q (18), wikstrotoxin D (19), pimelotides A (20) and C (21), pimelea factors S7(22), S6(23)., P2(24), and P3(25), wikstroelides R (26), S (27), T (28), U (29), and Q (30),1-propanone,3-hydroxy-l-(4-hydroxy-3-methoxyphenyl)-(31), phenethyl alcohol (32),trans-p-Hydroxycinnamic acid (33), (-)-matairesinol 4-O-glucoside (34), (+)-pinoresinol-β-D-glucoside (35), corchoionoside C (36) and 2-Cyclohexen-l-one,4-[(3S)-3-(β-D-glucopyranosyloxy)butyl]-4-hydroxy-3,5,5-trime thyl-, (4S)-(37), respectively. Among them, compounds 5,18,26,27,28,29,30 were new compounds, and compound 10 was new natrual one. Except for compound 19, all the known compounds were isolated for the first time from W. chamaedaphne. Using similar procedures, nine compounds were isolated from the acetone extracts of the whole plant W. micrantha, andwere identified asβ-sitosterol (38), ursolic acid (39), oleanolic acid (40), genkwanin (41), salipurpol (42), sikokianin A (43), sikokianin B (44), wikstrol B (45), and wikstrol A (46), repectively, and all of them were isolated from W.micrantha for the first time.Additionally, five tumor cells, leukemia HL-60, lung cancer A-549, of SMMC-7721, breast cancer MCF-7 and colon cancer SW480 and a normal lung epithelial cell BEAS-2B were selected to evaluate the diterpenoids cytotoxic activity in vitro. The bioassay results revealed that compounds 26 and 30 showed moderate antiproliferative activities against the HL-60, whereas, inactivities against the other four tumor cells. Compounds 18-25 and 27-29 are showed moderate cytotoxic activities against the five selected tumor cells. In a summary, the results of this thesis would contribute to the researeh on the chemical constituents of the two species of Wikstroemia (Thymelaeaceae) and supply seientific evidenees for searehing new natural medicines.