Chemical Constituents Of Paederia Scandens And Their Bioactivities

Paederia scandens, belong to Paederia Linn of Rubiaceae, is a traditional Chinese herbal medicine. Its root and stem have been utilized as traditional Chinese medicine for the therapeutic purpose of analgesic, anticonvulsant, detoxification, anti-inflammatory as well as nameless swelling etc.. However, former researches on chemical composition of Paederia scandens were not sufficient, and the biological active components have not been identified and assigned clearly. Thus, in order to clarify the chemical compounds and enlarge the application of paederia scandens’ s medicinal value, we have further investigated the chemical constituents of Paederia scandens in the present study.To begin with, the air-dried whole plants of Paederia scandens(6 kg) were powdered and extracted with 95% ethanol at room temperature for three times. The ethanol extract was then concentrated in vacuum to give residue, which was suspended in water and successively extracted with ethyl acetate and n-butanol to afford the ethyl acetate extract and the n-butanol extract separately. Then, the natural compounds of Paederia scandens were isolated by silica gel column chromatography, Sephadex LH-20 column chromatography and purified via recrystallization. Additionally, compounds’ s purity were identified by both melting point and thin layer chromatography. As the result, twelve compounds were isolated from the whole plants of Paederia scandens. The structures of the isolated compounds were verified by comprehensive spectroscopic methods including 1D-NMR(1H-NMR, 13C-NMR, DEPT), 2D-NMR(HSQC, HMBC), HR-ESI-MS as well as chemical methods, of which can be elucidated as β-sitosterol(1), Stigmast-5-ene-3,7-diol(2), Ursolic Acid(3), 3-Oxours-12-en-28-oic acid(4), Oleanolic acid(5), Daucosterol(6), Taraxerol(7), Salicylic Acid(8), Succinic acid(9), Paederoside(10), Asperuloside(11), paederosidic acid(12). Among them, compounds 2, 4, 7and 8 were isolated from Paederia scandens for the first time. The antibacterial effects of the isolated compounds 10、11、12 were tested. The minimum inhibitory concentrations(MICs) were measured against 4 bacterias: Staphylococcus aureus, Streptococcus lacti, Pseudomonas aeruginosa and Esherichia coli. The results indicated that: both Paederoside and paederosidic acid have better antibacterial activities than Asperuloside, which may be related to their sulfur group.