简介:Twonewaristolanesesquiterpenes,namely,aristolan-10-ol-9-oneandaristolan-8-en-1-one,wereisolatedfromtheredalgaLaurenciasimilis.TheirstructureswereestablishedonthebasisofvariousNMRspectroscopicanalyses,including2DNMRtechniques(1H-1HCOSY,HMQC,HMBC,andNOESY)andHR-FAB-MS.
简介:Twonewsaponins3-O-β-D-glucopyranosyl(1→2)-β-D-mannopyranosylsarsasapogenin,namedtimosaponinAIV(1)and(5β,25S)-26-O-β-D-glucopyranosyl-furost-20(22)-en-3,26-diol-3-O-β-D-glucopyranosyl(1→4)glucopyranosyl(1→2)-β-D-galacopyranoside,namedtimosaponinBIV(2),wereisolatedbysilicagelcolumnchromatographyandpreparativeHPLCfromAnemarrhenaasphodeloidesBge.Theirstructureswereelucidatedbychemicalcharactersandspectroscopicanalysis.
简介:Thefollowingdocumentationisanevaluationofthetwo-dimensionalMadelungconstantfortheNaClstructure.TheinfiniteseriesforthestructureisformultedasThefirsttermintheformulaconvergesto41n2.TheseriesafterK=2inthesecondtermisputtogetherwiththethirdtermandaconstant-4/2isleft.ThecombinationofthethirdtermandtheseriesafterK=2inthesecondtermisassumedtobe8Sn.TheconvergingseriesSncanbesolvedonacomputer.Thesevensignificantfiguresofthetwo-dimensionalMadelungconstantfortheNaClstructureisthendeterminedas1.615558.
简介:Afacilesyntheticroutetotwoseco-eudesmane,4,5-dioxo-10-epi-4,5-seco-γeudesmane(1)and4,5-dioxo-10-epi-4,5-seco-γ-eudesmol(2)from(+)-dihydrocarvonehasbeendescribed.Avoidingexpensivereagents,thishighlyeconomicmethodespeciallysuitsforthesynthesisof4,5-seco-eudesman-typeandophianon-typesesquiterpeneswithadoublebondatposition11and12.
简介:ChemicalinvestigationontheethanolextractfromtherootsofSpiraeajaponicavar.acutaresultedintheisolationoftwonewditerpenealkaloidsnamedspiratinesAandB(1-2),respectively.
简介:Twonovelcoordinationpolymers[Cd(NiL)(aipt)](1)and[Mn(nipt)(NiL)2]?H2O(2)(NiL,H2L=2,3-dioxo-5,6,14,15-dibenzo-1,4,8,12-tetraazacyclo-pentadeca-7,13-dien,H2aipt=5-aminoisophthalicacid,H2nipt=5-nitroisoph-thalicacid)werehydrothermallysynthesizedandcharacterizedbysingle-crystalX-raydiffraction.Compounds1and2consistofdifferent1Dchainsincludingbothoxamideand5-aminoisophthalateor5-nitroisophthalicbridge.Andallthesechainswerefurtherinterlinkedviahydrogenbonds,resultingina2Darchitectureincompounds1and2.