专业英语天然药化翻译材料

Compound1was isolatedas anamorphous solid.It wasshown byHRESIMSto havea molecularformula ofC20H18O5according tothequasimolecular ionpeak atm/z

361.1045[M+Na]+calcd for

361.1052C20H18O5Na.The1H and JMOD spectraof1revealed thepresence oftwomethoxy groups6H

4.05s,

3.41s,8C

56.1,

56.9and onemethylenedioxygroup6H

6.01s,6C

101.3Table

1.Additionally,theNMR spectraexhibited signalsattributed toa17carbon-containingskeleton involvingeight quaternarycarbons,eight methines,and onemethylenegroups.A thoroughevaluation ofits ID-and2DNMR spectrarevealedthat thiscompound hasa2-arylbenzofuran-type norneolignanstructure.One trisubstitutedaromatic ringring B was demonstratedbythe signalsof anABX spinsystem[5H

7.32d J=

0.7Hz H-2,

6.87d J=

8.1HzH-5,and

7.40brd J=

8.1Hz H-G7].The otheraromaticring ringA wasconcluded tobe tetrasubstitutedaccording tothearomatic protons at6H

7.14brs H-4and

6.87brs H-

6.The1H-1HCOSY spectrumshowed thepresence ofan unsaturatedC3unit withcorrelatedprotonsat5H

6.67dJ=

15.8Hz H・l〃,

6.26dt J=

15.8and

6.1Hz H-2Z,,and

4.12d

6.0Hz H-

3.The quaternarycarbon at5C

156.3was assignedas C-2,and theisolated methineat6H

6.82s and6C

100.5as C-3taking intoconsideration the longrange C-H correlationsobservedin the HMBC spectrumbetween C-2and H-3and H-2,andbetween theH-3and C-9and C-

8.The correlationof the methoxy signalat6H

4.05with thecarbon signal6C

145.2C-7indicated thepresenceof themethoxy groupat C-

7.Similarly,theHMBCcross-peak ofthemethoxy signalat6H

3.41with thecarbon signalsat6C

73.2C-3demonstrated theconnection ofthemethoxygroup tothe C3unit.The locationof this3-methoxypropenyl sidechain atC-5was provedbythelong-range correlationsbetween C-l”and H-4and H-

6.Themethylenedioxy groupon ringBwasevidenced bythe three-bondHMBC correlationsbetween theproton signalat5H

6.01and C-3andC-

4.The substitutionpattern wascorroborated bythe NOESYcross-peaks betweenH-3/H-2,OCH3-7/H・6,H-6/H-1”,H・l〃/H-4,H-4/H-3,and OCH3-3”/H-3Z,.The Egeometry ofthe C-lz,/C-2olefinwas deducedfrom thecoupling constantof

15.8Hz.All ofthe aboveevidencewas usedto confirmthe structureof thiscompound as1-dehydroegonol3-methyl ether

1.Extraction andIsolation.The freshroots ofH.helianthoides var.scabrawere extractedwith MeOH90L atroom temperature.Afterevaporation,the MeOHextract afterdilution withH2O wassubjectedto solventpartitioning toobtain CHCI3-and H2O-soluble fractions.Thelignan-containing CHCI3phase wasconcentrated undera vacuum,yielding80g ofmaterial,which wassubjected intwo partsto silicagelVLC2x250g,using agradient systemof n-hexane-EtOAc10:09:1,,8:2,7:3,1:1,and0:

10.In total,78fractions werecollected andcombinedinto12main fractionsl-XII withregard tothe resultsof TLCmonitoring.Lignan-containing fractionsVIII-IX,9g wereselected forfurtherpurification,which wascarried outby acombination ofRP-VLC,using MeOH-H2O8:2,85:15,9:1,10:0and thenMeOH-EtOAc9:1,6:4,10:0gradients.From atotal of75fractions,fractions35-

401.15g,41-46668mg,and17-22470mg wereselected forfurtherseparation.。