Studies On The Chemical Constituents From The Stems Of Clausena Lansium

Clausena lansium(Lour.)Skeels,a small tree or shrub of the genus Clausena of Rutaceae,mainly distributed in mainly tropical and subtropical regions of China.Its fruits,leaves and roots all deserve medical uses.In modern researches,it has been found that the main chemical constituents in C.lansium are coumarin,alkaloids,terpenes,volatile oils,etc.And these chemicals may have neuroprotection,liver-protection,anti-cancer,or anti-platelet aggregation effects.Previously,our research group has been researching on the chemicals and bioactivities from the stems of C.lansim,and some carbazole alkaloids and amide alkaloids showed obvious neuroprotective effects.In order to discover more ingredients with bioactivities from C.lansium and develop in-depth pharmacological researches,we continued to research on the 95%ethanol extracts from the stems of C.lansium.By HPD-100 macroporous resin column chromatography,silica gel column chromatography,MPLC and pre-HPLC,the 95%ethanol extracts from the stems of C.lansium were isolated and purificated.The spectroscopy methods of NMR,HRESIMS,UV,IR,and CD were used to identify the structures of 52 compounds,including 10 new compounds.23 compounds were carbazole alkaloids(1*,2*,3a,3b*,4*,5*,6*,11-26).Others were 19 amide alkaloids(7-9*,27-37)and 10 coumarins(10*,38-46).Compounds 16 and 34 were new natural products;compound 43 was isolated from this genus for the first time;and compound 44 was isolated from this plant for the first time.And we reported the crystal structures of compounds 1*,7a,7b*8b,33 and 35b by single-crystal X-ray diffraction analysis.Many pharmacological activity screening tests in vitro were performed on some monomer compounds from the stems of C.lansium.The results showed that compounds 2*,6*,16,22 and 23 had protective effects on PC 12 cells induced by serum removal at 10μM.Compounds 3b*,16,17,19 and 32 had weak protective effects on primary neurons against oxygen glucose deprivation injury.As for hepatoprotection,compound 3a and 24 had protective effects on HepG2 cells against APAP injury.Compound 5*had significant cytotoxic effects on MCF-7,HCT-116,HepG2,and Capan2.