Studies On The Structures And Bioactivities Of Secondary Metabolites From Three Southern Plants

Three southern plants were researched systematically, including Ligularia veitchiana, Aphanamixis grandifolia and Hunteria zeylanica. L. veitchiana, belonging to the family Compositae, has effects on the treatment of influenza, coughs, ulcers and tuberculosis; A. grandifolia, belonging to the family Meliaceae, is an medicinal plant employed as an astringent for spleen, liver, tumors, abdominal diseases, and applied in treatment of rheumatism in southeast Asia; H. zeylanica, belonging to the family Apocynaceae, is used commonly for smearing on the sores caused by yaws.Therefore, there are important applicable perspectives for chemical research on these species.80 compounds were isolated from three plants by means of silica gel column chromatography (CC), preparative thin layer chromatography (PTLC), and recrystallization etc. Then various spectroscopic methods including IR, UV, CD, EIMS, FABMS, HRESIMS,1H NMR,13C NMR, DEPT, NOED,'H-'H COSY, HSQC, HMBC, and single-crystal X-ray crystallography were used to elucidate the structures of 69 compounds, among which there were 8 new compounds. The absolute configurations of two carbon stereocenters of compound Ap6 were determined to be 4R,9S by means of CD and auxiliary chiral MTPA derivatives, respectively.Furthermore the bioactivities of some compounds were also studied. Firstly, micro-broth dilution method was used to evaluate the antimicrobial activity of 8 compounds (Lvl,Lv2,Lv3,Lv7,Lv9,Lv11,Lv12,Lv15) against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli). Amongst them, compound Lv2 showed modest antibacterial activity against S. aureus. SRB method was used to evaluate the cytotoxicity against selected cancer cell lines of 13 compounds (Lv1,Lv7,Lv9,Lv11,Lv12,Lv15, Apl-Ap7) with mitomycin taken as positive control. The results revealed that compound Ap3 exhibited significant cytotoxicities against HL-60, Hep G2 and HeLa (against HL-60 at 5.97μg/mL). Compounds Lvll, Lv12, and Lv15 exhibited modest cytotoxicities against HL-60, SMMC-7721 and HeLa with IC50≈40μg/mL, and compounds Apl, Ap2, Ap5, Ap6 and Ap7 exhibited modest cytotoxicities against HL-60, Hep G2 and HeLa with IC50≈40μg/mL. By comparing the chemical constituents of plants collected from different places, the differents of structure isolated from southern and northwestern plants, may be due to different habitats.The paper would be a supplement for the research on bioactivity of chemical constituents as well as structure-activity relationship in traditional Chinese medicine, a helpful reference for pharmacology, chemotaxonomy and screening new medicines, and may benefit utilizing and developing the natural resources of our country.Finally, there is a summary of phytochemical studies on subtribe Guareinae Harms in chemical opinion, including the genues Aglaia, Amoora and Aphanamixis. The review was hoped to be useful for chemotaxonomy of subtribe Guareinae Harms.