Studies On The Chemical Constituents Of Wedelia Trilobata

Wedelia trilobata is Wedelia plant of Compositae, which is native to South America. It completely displaces anything native where ever it is evidence, and now has widely distributed in the southern provinces of China. The major chemical constituents of Wedelia trilobata are sesquiterpenes, diterpenes, triterpenes, etc. The Miskito Indians of eastern Nicaragua use Wedelia trilobata for treatment of snakebite, stingray wounds, diarrhea, kidney stones and colds and as a purge. This plant has been reproted to possess antibacterial, antitumor, hepatoprotective and central nervous systerm depressant activity. In order to exploit and utilize the plant properly, it is very important and instructive to study the chemical constituents systematically. In this thesis, the chemical constituents and the inhibitory effect on the proliferation of tumor cells of the two new compounds are researched.In this thesis, the water extrat was re-extracted with chloroform, ethyl acetate, n-butanol. 11 compounds were isolated from the chloroform and ethyl acetate sections and separated by using gel chromatography, recrystallisation, Sephadex LH-20 and et al. On the basis of IR, MS, 1H-NMR, 13C-NMR, HMBC, NOESY data and physicochemical characters, They were elucidated as Grandiflorenic acid (1), 1α-Acetoxy-6α, 9β-dihydroxy- 4, 10α- dimethyl-5αH, 7αH, 8αH-endesm-3-en-8, 12-olide (2), 1β-Acetoxy-4α-hydroxyl -6β-isobutyryloxy-9α- isovaleryloxy prostatolide (3), 16α-Hydroxy-ent-kauran-19-oic acid (4), (3R, 4R, 6R)-3, 6-dihydroxy- 1-menthene (5), Trilobolide-6-O-isobutyrate (6), 1β- Acetoxy-4α, 9α-dihydroxy-6β- isobutyroxy prostatolide (7), 16β,17-Dihydroxy-ent-kauran- 19-oic acid (8), Daucosterol (9), Protocatechualdehyde (10), Caffeic acid (11). All the compounds are isolated from W.trilobata for the first time except 6 and 7, Compounds 2 and 3 are new sesquiterpene lactones, named as Trilobolide A and 1β-Acetoxy-4α-hydroxy -6β-isobutylryloxy- 9α-isovaleryloxyprostatolide.Compound 2 and 3 displayed anticancer activity on Lung squamous cell carcinoma...