Studies On Chemical Constituents And Bioactivites Of Narcissus Tazetta Var. Chinensis

Plant Narcissua tazetta var. chinensis Roem, belonging to Narcissus genus (Amaryl-lidaceae), was first recorded in <Herbal Hui Bian>. N. tazetta var. chinensis mainly dis-tributes in moist, fertile sandy loam in Jiangsu, Zhejiang, Fujian, Guandong, Sichuan andGuizhou provinces. Since ancient times, amaryllidaceae plants have been used to treat ab-scessed, aching joints and sores in worldwide. Its properties of anticancer in early stage canbe traced back to the4thcentury BC. Pharmacology studies have shown that antitumor, an-tibacterial and antivival activities. Previous investigations have led to the isolation of anumber of chemical constituents from amarllidaceae plants.However, to this day, rarestudies were reported about the chemical constituents of N. tazetta var. chinensis. There-fore, we carried out the study of the chemical constituents of N. tazetta var. chinensis, aswell as bioactivity screening in virto, aimed at discovering new bioactive constituents fromN. tazetta var. chinensis.The phytochemical study on this plant led to the isolation and identification of fiftycompounds, including four flavan-derived constituents, ten flavans, four flavanones, fourlignans, eleven alkaloids, two nucleosides, eight substituted benzenes and seven others,among which there are eight new compounds.1.(1S,5S,8S)-5-hydroxy-8-(4-hydroxyphenyl)-1-methylbicyclo[3.3.1]non-3-ene-2,9-dione2.(1S,5S,8S)-5-hydroxy-8-(3-hydroxy-4-methoxyphenyl)-1-methylbicyclo[3.3.1]non-3-ene-2,9-dione3.(1R,5S,8R,9S)-5,9-dihydroxy-8-(4-hydroxyphenyl)bicyclo[3.3.1]non-3-ene-2-one4.(1R,5S,8S,9S)-5,9-dihydroxy-8-(4-hydroxyphenyl)-1-methylbicyclo[3.3.1]non-3-ene-2-one5.(2S)-7-hydroxy-3,4-dimethoxyflavan6.7,3,4-trihydroxy-8-methylflavan7.(2S)-7,4-dihydroxyflavan8.(2S)-4-hydroxy-7-methoxyflavan9.(2S)-7,4-dihydroxy-8-methylflavan 10.(2S)-7,3,4-trihydroxylflavan11.(2S)-3,4-dihydroxy-7-methoxyflavan12.(2S)-4-hydroxy-7,3-dimethoxyflavan13.(2S)-7,3,4-trimethoxyflavan14.(2S)-3,7-dihydroxy-4-methoxyl-8-methylflavan15.(2S)-4-hydroxy-7-dimethoxyflavanone16.8-methylnarignin17. farrerol18. cyrtominetin19.(+)-lariciresinol20.(+)-pinoresinol21.(+)-(7S,8R,7E)-4-hydroxy-3,5-dimethoxy-4,7-epoxy-8,3-neolign-7-ene-9,9-diol-9-ethyl ether22. ficusal23. tazettine24. littoraline25.6-deoxy-8-oxo-tazettine26.(+)-narciclasine27.7-deoxynarciclasine28.4-deoxylycoridine29. lycorine30. pseudolycorine chloride31.5,6-dihydrobicolorine32. ismine33. N-methylhemeanthidine chloride34.5-O-methyl-uridine 35. thymidine36. hydroxytyrosol37.3,5-dimethoxy-4-methylphenol38.2,4-dihydroxy-6-methoxyacetophenone39.2,6-dihydroxy-4-methoxy-3-methylacetophenone40.2-hydroxy-4,6-dimethoxy-3-methylacetophenone41.2,2-dihydroxy-4,6-dimethoxy-3-methyl-acetophenone42.1-(2,4-dihydroxy-6-methoxy-3-methylphenyl)-2-hydroxyethanone43.1-(2-dihydroxy-4,6-dimethoxy-3-methylphenyl)-2-methoxyethanone44.2-hydroxy-4,6-dimethoxy-7-methyl-1-benzofunan-3(2H)-one45.4-(1-ethoxy-2,3-dihydroxypropyl)-benzene-1,2-diol46. monomethylsulochrin47.2,4,4-trihydroxy-3-methylchalcone48.8-hydroxy-3-(2-hydroxypropyl)-6-methoxycoumarin49.12-hydroxy-2-tridecanone50.2,11-tridecanedioneAmong them,1-6,45,46are identified to be new compounds.7-22，24,25,27,28，31-36,46-48were isolated from this plant for the first time. Compounds1and2belong toa small group of natural products with a rare bicyclo[3.3.1]non-3-ene-2,9-dione core. Tothis day, only one similar natural product was reported from the Brazilian medicinal plantBrosimum acutifolium. And compounds3and4belongs to a group of natural productswith a rare9-hydroxy-bicyclo[3.3.1]non-3-ene-2-one core. To this day, no similar naturalproducts were reportedPart of compounds were evaluated for cytotoxicity activities against five human can-cer cell lines, A549, HCT116, SK-BR-3, MDA-MD-231and HepG2by MTT assay. Alka-loids26,27,30,31,33showed the strong inhibition against four cell lines A549, HCT116,MDA-MB-231, HepG2(IC50<10μg/mL). Compound29showed potent cytotoxicityagainst three cell lines HCT116, MDA-MB-231, HepG2(IC50<3μg/mL). The other alka- loids showed no cytotoxicity. Flavans8,9, and12showed weak cytotoxicities against fourcell lines A549, HCT116, SK-BR-3, and HepG2. Other flavans did not show cytotoxicity.The result showed that alkaloids are main cytotoxic constituents of N. tazetta var. chinen-sis.Part of compounds were screened for protect effect against hydrogen peroxide(H2O2)-induced oxidative damage in SH-SY5Y cells by CCK-8assay. These results sug-gested that compounds7，8，11，12，14，15，19have protective effects against oxidativestress-induced cell apoptosis of SH-SY5Y cell.