Chemical Constituents Of Hypericum Przewalskii Maxim And Selective Cytotoxicity Against Six Human Tumor Cells

Objective:Today,cancer has become the primary enemy of the world's serious threat to human life and health.The incidence is still rising year by year.Traditional Chinese medicine has the characteristics of low toxicity and high cure rate,which attracting more and more people to invest anti-cancer Chinese herbal medicine.Most Chinese herbal medicine of Hypericum plants have been reported about their phytochemistry and pharmacological activities,however,there is only one paper about the report of dajinjing grass[1].In this study chemical constituents of Hprzewalskii and selective cytotoxicity against six human tumor cells.This research not only laid the foundation for the research and application of this Chinese herbal medicine,but also increased understanding of the chemical constituents and pharmacological activities of the Hprzewalskii.Methods:The ethanol extract was separated by 101 macroporous resin,silica gel,MCI,Sephadex LH-20,then purified by semi-prepared HPLC.Finally,the structure was identified by 1-D and 2-D NMR,UV chromatography,IR chromatography and high resolution mass spectrometry.A new compound hyperprzeones A(1)together with 20 known compounds(2-21)were isolated from the ethanol extract of H.przewalskii.Their structures were determined by comparison of spectral data with literatures.MTT assay was used to study the effects of compounds 1-21 and extracts on the cytotoxicity of six human cancer cell lines:A375(human melanoma cell),MDA-MB-231(human breast cancer cell),SMMC-7721(human liver cancer cell),NCI-H460(human pulmonary cancer cell),SH-SY5Y(human neural cancer cell)and SiHa(human cervical cancer cell).The apoptosis-inducing activities and cell cycle arrest of two phloroglucinol compound 1 in SH-SY5Y tumor cell were determined by flow cytometry.Results:A new compound(1)with 20 known compounds(2-21)were isolated from the ethanol extract ofH.przewalskii mainly including six phloroglucinols(1,2,4-7),seven xanthones(8-14),five flavonoids(15-19),one styrene acrylic(20),one sitosterol(21),one diphenyl ketone(3).Respectively hyperprzeones A(1),kakispyrone(2),2,2',5,6'-tetrahydroxy-benzophenone(3),Hypersampsone P(4),phloretin(5),phloridzin(6),(E)-1-(2,4-Dihy droxy-6-methoxyphenyl)-3-pheny lprop-2-en-1-one(7),1,7-dihydroxyxanthone(8),1-hydroxy-7-methoxyxanthone(9),2-hydroxyxanthone(10),2-methoxyxanthone(11),1,3,6,7-tetrahy droxy xanthone(12),1,3-dihydroxy-5-methoxyxanthone-4-sulfonate(13),1,3,5,7-tetrahydroxy-8-isoprenylxanthone(14),2S-5,7,3',4'-tetrahydroxyflavanone(15),Kaempferol(16),quercetin(17),Hyperoside(18),?3,?8-biapigenin(19),ethyl caffeate(20),?-sitosterol(21).Compound 1,7,12,18,20 and 21 had a good ability to inhibit the proliferation of tumor cells.The study revealed that most of the compounds showed inhibitory effects on proliferation of six tumor cells,especially compound 1 were the best.The study revealed that most of the compounds showed inhibitory effects on proliferation of six tumor cells,especially compound 1 were the best.It showed that the increase of drug concentration could block cell division at the S-phase,thus preventing the mitosis of cells and suppressing cell proliferation.Conclusion:This study further enriched the research on the chemical constituents of H.przewalskii,...