野桂花化学成分研究_英文_

1、天然产物研究与开发N at Prod R es D ev 2009,21:5932599文章编号:100126880(20090420593207Received March 25,2008;Accep ted May 15,20083Corres ponding author Tel:86228285225401;E 2mail:zhangglcib .ac .cn野桂花化学成分研究马晓莉1,2,林文彬1,2,张国林131中国科学院成都生物研究所,成都610041;2中国科学院研究生院,北京100039摘要:从野桂花(O s m anthus yunnanensis 地上部分95%乙醇提取物

2、中首次分离得到18个化合物,应用波谱方法及与已知品对照的手段鉴定它们为:E 2阿魏酸二十烷基酯(1、2谷甾醇(2、羽扇豆醇(3、齐墩果酸(4、72oxo 22sit oster ol (5、乙酰齐墩果酸(6、(62O 2pal m it oyl 2sit oster ol 232O 22D 2glucoside (7、r otundi oic acid (8、地榆糖甙(9、32hydr oxy 2272p 2(E 2cou mar oyl oxy olean 2122en 2282oic acid (10、32hydr oxy 2272p 2(Z 2cou mar oyl oxy 2olean

3、 2122en 2282oic acid (11、hycandinic acid ester (12、绿原酸丁酯(13、4,52二咖啡酰奎尼酸丁酯(14、282O 22D 2glucopyranosyl r otundi oic acid (16以及三个半萜类化合物:4,52dihydr oxyp renyl caffeate (15、42(62O 2caffeoyl 22D 2glucopyranosyl oxy 252hydr oxyp renyl caffeate (17、422D 2glucopyranosyl oxy 52hydr oxyp renyl caffeate (18。关键

4、词:野桂花;甾体;三萜;咖啡酰奎尼酸丁酯;半萜中图分类号:R284.1;Q946.91文献标识码:AChem i ca l Con stituen ts of O sm an thus yunnanensisMA Xiao 2li 1,2,L I N W en 2bing 1,2,Z HANG Guo 2lin131Chengdu Institute of B iology,Chinese A cade m y of Sciences,Chengdu 610041,China;2Graduate School of Chinese A cade m y of Sciences,B eijing

5、 100039,ChinaAbstract:Eighteen compounds were is olated fr om the 95%ethanol extract of the aerial parts of O s m anthus yunnanensis f or the first ti m e .On the basis of s pectral data or comparis on with authentic sa mp les,they were identified as E 2ferulicacid eicosyl ester (1,2sit oster ol (2,

6、lupenol (3,oleanolic acid (4,72oxo 22sit oster ol (5,acetyl oleanolic acid (6,(62O 2pal m it oyl 2sit oster ol 232O 22D 2glucoside (7,r otundi oic acid (8,ziyu glycoside (9,32hydr oxy 2272p 2(E 2cou mar oyl oxyolean 2122en 2282oic acid (10,32hydr oxy 2272p 2(Z 2cou mar oyl oxyolean 2122en 2282oic ac

7、id (11,hycandin 2ic acid ester (12,chl or ogenic acid butyl ester (13,4,52di 2O 2caffeoylquinic acid butyl ester (14,282O 22D 2glucopyr 2anosyl r otundi oic acid (16and three he m iter pene derivatives:4,52dihydr oxyp renyl caffeate (15,42(62O 2caffeoyl 22D 2glucopyranosyl oxy 252hydr oxyp renyl caf

8、feate (aohada 2glycoside C,17,422D 2glucopyranosyl oxy 252hydr oxyp renyl caf 2feate (aohada 2glycoside A,18.Key words:O s m anthus yunnanensis ;ster oid;triter pene;caffeoylquinic acid butyl ester;he m iter peneI n troducti onPrevi ous phyt oche m ical studies on O s m anthus genus re 2vealed the p

9、 resence of secoiridoid glycosides,lignans,phenyl p r opanoid glycosides and p 2coumar oyl glyco 2sides1,2,18.China is the center of geographical distri 2buti on of O s m anthus s pecies in the world .Research ofO s m anthus s pecies mainly focuses on the O s m an thus fragrans ,a traditi onal Chine

10、se medicinal p lant and fa 2mous orna mental p lant .Studies about ger mp las m re 2s ources,cultivar classificati on,cultivating and p r opaga 2ti on were reported 3.O.yunnanensis (Fr .P .S .Green is mainly distributed in Yunnan,Sichuan and Tibet p r ovinces of China 4.Its fl owers are used in f ol

11、k medi 2cine as expect orant and anti 2cough agent;Its r oots are used f or the treat m ent of gastralgia,odontalgia,expel 2ling wind and f or re moving da mpness17.Until now,noche m ical investigati ons were carried out on this p lant .I n this study eighteen compounds were is olated fr om the 95%e

12、thanol extract of aerial parts of this p lant .On the basis of s pectral evidence or comparis on of the m with authentic sa mp les,they were identified as f oll ows:E 2ferulic acid eicosyl ester (1,2sit oster ol (2,lupe 2 nol (3,oleanolic acid (4,72oxo 22sit oster ol (5,acetyl oleanolic acid (6,(62O

13、 2pal m it oyl 2sit oster ol 232O 22D 2glucoside (7,r otundi oic acid (8,ziyu glyco 2side (9,32hydr oxy 2272p 2(E 2cou mar oyl oxyolean 2122en 2282oic acid (10,32hydr oxy 2272p 2(Z 2cou 2mar oyl oxyolean 2122en 2282oic acid (11,hycandinic acid ester (12,chl or ogenic acid butyl ester (13, 4,52di 2O

14、2caffeoylquinic acid butyl ester (14,282O 22D 2glucopyranosyl r otundi oic acid (16,4,52dihydr oxyp re 2nyl caffeate (15,42(62O 2caffeoyl 22D 2glucopyranosy 2l oxy 252hydr oxyp renyl caffeate (aohada 2glycoside C,17and 422D 2glucopyranosyl oxy 252hydr oxyp renyl caf 2feate (aohada 2glycoside A ,18.图

15、1Co m pounds fro m O sm an thus yunnanensisResults and D iscussi onCompounds 12214were identified as butyl esters .Com 2pound 14was first is olated fr om Et O Ac s oluble fracti on of the methanol extract fr om the ste m bark of Isertia pit 2tieri14.It was reported that 12and 13were first ob 2tained

16、 fr om n 2butanol s oluble extract of Hydrastis cana 2densis and S pondias m o m bin ,res pectively12,13.I n thisstudy n 2butanol was extensively used f or extracti on .It is not clear that the original for m of these compounds in this p lant is butyl ester or acid .Thus,the fracti on F of Et O Ac f

17、racti on,obtained before the use of n 2butanol,was subjected t o ESI 2MS analysis,and the quasi molec 2ular i on peaks at m /z 463M +K +,433M +Na +,595M +Na +,corres ponding t o those of com 2pounds 12,13and 14were f ound .Theref ore,it could be concluded that compounds 12214may not be arti 2facts a

18、nd could p resent in butyl ester for m in the p lant .Exper i m en t a lM a ter i a ls and m ethodsMelting points were measured on an X 26melting point apparatus and are uncorrected .Op tical r otati ons were measured on a Perkin 2El m er 341aut omatic polari m e 2ter .UV and I R s pectra were recor

19、ded res pectively on a La mbda 35s pectr o meter and a Perkin El m er s pectru m one FT 2I R s pectr o meter (K B r disc .Mass s pectra were carried out on a Finnigan 2LCQDECAmass s pectr ometer(ESI 2MS ,and NMR s pectra (1H:600MHz;13C:150MHz on a B ruker Avance 600s pectr ometer with T MS as intern

20、al standard .Silica gel H (2002300mesh;Q ing 2dao Haiyang Che m ical Gr oup Co .of China ,MC I gel (752150m ,M itsubishi and Sephadex LH 220(Phar 2macia B i otech,S weden were used f or colu mn chr oma 2t ography (CC .The p lates f or thin layer chr omat ogra 2phy (T LC were p recoated with Silica g

21、el GF 254(0240m and activated at 110f or 2h .Spots on T LC p lates were visualized by s p raying 10%Et O H s oluti on of phos phomolybdic acid f oll owed by heating .Pl an t ma ter i a lThe aerial parts of O.yunnanensis were collected in A 2p ril 2004fr om Yanbian County,Sichuan Pr ovince of China,a

22、nd identified by Pr of .F U Fading at Chengdu I nstitute of B i ol ogy,Chinese Acade my of Sciences (CAS .A voucher s peci m en (No .A170was deposited in the Depart m ent for Natural Pr oducts Research at Chengdu I nstitute of B i ol ogy,CAS .Extracti on and isol a ti onThe air 2dried and powdered a

23、erial parts of O.yun 2nanensis (3.5kg were percolated with 95%ethanol(30L 3,each 10days at r oom te mperature .After evaporating the s olvents under reduced p ressure at 50,a residue (280g was obtained .The residue was sus pended in H 2O and fracti onated successively with petr oleu m ether (1.5L 2,

24、Et O Ac (1.5L 5and n 2Bu OH (1.5L 3t o aff ord petr oleum ether fracti on495N at P rod Res D ev Vol 121(4g,Et O Ac fracti on(92gand n2Bu OH fracti on(98 g.32 CH3COCH3(30151t o yield D4(1gand D6(2.1 g.Compound7(30mgwas p reci p itated fr om D4in Me OH.D6was further separated over silica gel colu mn(3

25、L14c m,using CHCl32Me OH (151as s ol2vents t o give8(17mgand9(13mg.Fracti on E was divided int o f our fracti ons E12E4by silica gel colu mn (5L20c m.E4(1.1gwas separated over Sephadex LH220colu mn(3L53c meluted with Me OH and the E422(100mgwas subjected t o silica gel colu mn(1.8L50cmwith CHCl32Me

26、OH(501 as s olvents t o yield10(10mgand11(15mg.The n2BuOH fracti on was subjected t o macr opor ous resin D101colu mn(3.9L50c m,eluted with H2O and then with Me OH.The Me OH fracti on Bu(28 gwas divided int o9fracti ons Bu12Bu9,over silica gel colu mn(9.2L30c meluted gradiently with CHCl32Me OH(8121

27、.Bu1(800mgwas subjec2 ted t o Sephadex LH220column(3L55c mand the Bu121(45mgwas purified by HP LC t o yield12(6 mg.Bu2(1.1gwas separated over Sephadex LH220 colu mn(3L55c mwith Me OH as s olvents andthe Bu225(27mgwas purified by T LC t o give13(10 mg.14(20mgand15(30mgwere obtained fr om the separati

28、 on of Bu3(1.7gover Sephadex LH220col2 u mn(3L55c mwith Me OH.Bu4(1.2gwas separated repeatedly over Sephadex LH220column(3L55c mwith Me OH t o p r ovide16(80mg.Bu5(3.2gwas first subjected t o silica gel colu mn(3.4L23c m,using CHCl32Me OH2H2O(710.1as s olvents and the Bu521(300mgwas purified by Seph

29、a2 dex LH220column(3L55c mwith Me OH t o give17(110mg.U sing Me OH as s olvent,Bu6was separated over Sephadex LH220colu mn(3L55 c mt o yield18(70mg.I den ti f i ca ti onCompounds2,3,4and6were identified successively as2sit oster ol,lupenol,oleanolic acid and acetyl olean2 olic acid by comparing the

30、m with authentic sa mp les on T LC and co2mp.E2Feruli c ac i d e i cosyl ester(1W hite powder;ESI2 MS(positive modem/z:497M+Na+,475M +H+,513M+K+;1H NMR(600MHz, CDCl3:7160(1H,d,J=1519Hz,H2,7107(1H, dd,J=812,116Hz,H26,7103(1H,d,J=116Hz, H22,6192(1H,d,J=812Hz,H25,6128(1H,d,J =1519Hz,H2,5183(1H,s,2OH,41

31、18(2H,t,J =618Hz,H21,3192(3H,s,2OCH3,1169(2H,m, H22,0187(3H,t,J=619Hz,H2201The ESI2MS and NMR data were in accordance with those repor2 ted5172O xo22sitosterol(5W hite powder,mp11202123;UVM eOHmax(l ogn m:237(3199;I RK B rmaxc m21: 3450,1674;ESI2MS(positive modem/z:451M+ Na+,429M+H+;1H NMR(600MHz,CD

32、Cl3:5168(1H,br s,H26,3167(1H,tt,J=1110,510 Hz,H23,2150(1H,ddd,J=1310,510,118Hz,H2 4,2140(1H,ddt,J=1310,1110,118Hz,H24, 2123(1H,t,J=1118Hz,H28,2103(1H,dt,J= 1217,410Hz,H212,1119(3H,s,H219,0193 (3H,d,J=615Hz,H221,0185(3H,d,J=618Hz, H227,0181(3H,t,J=618Hz,H229,0166(3H,s, H218;13C NMR(150MHz,CDCl3:20213

33、(C27, 16510(C25,12611(C26,7010(C23,5417(C217, 4919(C29,14,4518(C224,4514(C28,4311(C2595Vol121MA Xiao2li,et al:Che m ical Constituents of O s m anthus yunnanensis 13,4118(C24,3817(C212,3813(C210,3614(C2 1,3611(C220,3319(C222,3112(C22,2911(C2 25,2815(C216,2613(C215,2611(C223,2310 (C228,2112(C211,1918(

34、C227,1910(C226, 1819(C221,1713(C219,1119(C218,291The mp1,UV,I R,ESI2MS and NMR data were identical t o those reported61(62O2Pa l m itoyl2sitosterol232O22D2glucosi de(7Col ourless wax,mp11632165;20D24714(c0121,CHCl3;ESI2MS(positive modem/z:837M +Na+;1H NMR(600MHz,CDCl3:5135(1H,br s,H26,4137(1H,m,H26,

35、4136(1H,d,J=717 Hz,H21,4131(1H,d,J=1115Hz,H26,3155 (1H,m,H23,3153(1H,m,H23,3145(1H,m,H2 5,3138(1H,t,J=915Hz,H24,3135(1H,t,J= 717Hz,H22,2132(2H,t,J=715Hz,H22,1101(3H,s,2CH3,0192(3H,d,J=615Hz,2CH3,0189(3H,t,J=710Hz,H229,0185(3H,t,J=715Hz, H216,0184(3H,d,J=710Hz,2CH3,0181(3H, d,J=615Hz,2CH3,0168(3H,s,2

36、CH3;13C NMR(150MHz,CDCl3:17413(C21,14013(C25, 12211(C26,10112(C21,7916(C23,7611(C2 3,7319(C25,7314(C22,7013(C24,6314(C2 6,5617(C214,5611(C217,5011(C29,4518(C2 24,4213(C213,3917(C212,3819(C24,3712(C2 1,3617(C210,3611(C220,3412(C22,3319(C2 22,3119(C27,3118(C28,2917(C22,291722912(11CH2,2913(C225,2812(C

37、216,2611(C2 23,2419(CH2,2413(C215,2310(C228,2217(CH2,2110(C211,1918(C226,1913(C219, 1910(C221,1817(C227,1411(C216,1119(C2 29,1118(C2181The mp1,D,ESI2MS and NMR data were identical t o those reported71Rotund i o i c ac i d(8W hite a mor phous powder,mp12952298;UVM eOHmax(l ognm:210(3165;I RK B r max

38、cm21:360023200,1690,1635;ESI2MS(negative modem/z:501M2H2;1H NMR(600MHz,pyri2 dine2d5:5157(1H,br s,4196(1H,s,2OH,4164 (1H,dd,J=1011,610Hz,3104(1H,m,3101 (1H,s,1108(3H,d,J=615Hz,0195,1107,1141, 1160,1165(each3H,s;13C NMR(150MHz,pyri2 dine2d5:18014(C223,28,13917(C213,12716 (C212,7513(C23,7214(C219,5414

39、(C218,5412(C24,5117(C25,4810(C29,4718(C217,4211(C214,4118(C28,20,4015(C21,3819(C210, 3812(C222,3615(C27,3311(C215,2910(C22, 29,2715(C216,2618(C221,2616(C227,2611 (C211,2115(C26,1618(C230,1615(C226,1517 (C225,1119(C2241The mp1,UV,I R,ESI2MS and NMR data were equal t o those reported81Z i yu glycosi d

40、e(9Crystalline powder,mp12432 245;20D+3810(c212,DMS O;I RK B r max c m21: 3430,1689,1620,1459,1385;ESI2MS(negative modem/z:603M2H+;1H NMR(600MHz,pyri2 dine2d5:5159(1H,br s,H212,4175(1H,d,J= 710Hz,A ra2H21,4141(1H,dd,J=818,710Hz, A ra2H22,4131(1H,m,A ra2H24,4129(1H,m,A ra2 H25,4114(1H,dd,J=818,218Hz,

41、A ra2H23, 3182(1H,d,J=1110Hz,A ra2H25,3133(1H,dd,J =1211,413Hz,H23,3105(1H,br s,H218,1175 (3H,s,H229,1111(1H,d,J=616Hz,H230, 1143,1132,1108,0194,0187(each3H,s;13C NMR (150MHz,pyridine2d5:18115(C228,14018(C2 13,12819(C212,10813(C21,8917(C23,7515 (C23,7318(C22,7316(C219,7014(C24,6716 (C25,5618(C25,551

42、5(C218,4912(C217,4816 (C29,4312(C220,4310(C214,4112(C28,4015 (C24,3917(C21,3914(C222,3719(C210,3414 (C27,3012(C215,2911(C223,2810(C229,2718 (C221,2715(C22,2713(C216,2516(C227,2419 (C211,1915(C26,1811(C224,1718(C226,1716(C230,1614(C2251The mp1,D,I R,ESI2MS and NMR data were in accordance with those o

43、f ziyu glycoside9.32Hydroxy2272p2(E2cou maroyloxyolean2122en2 282o i c ac i d(10W hite a mor phous powder;20D22156(c015,i Pr OH;UViPr OHmax(l ognm:206(4117,229(4105,315(4137;I RK B rmaxc m213447, 1685,1640,1509,1168;ESI2MS(positive modem/z: 641M+Na+,657M+K+,455M2 C9H6O3+;1H NMR(600MHz,pyridine2d5:81

44、01 (1H,d,J=1519Hz,H23,7162(2H,d,J=619Hz, H25,9,7116(2H,d,J=619Hz,H26,8,6169 (1H,d,J=1519Hz,H22,5186(1H,br s,H212, 4173(1H,d,J=1216Hz,H227,4158(1H,d,J= 1216Hz,H227,3142(1H,br s,H23,1121,1107,695N at P rod Res D evVol121 1102,1100,0193,0192(each,3H,s;13C NMR(150 MHz,pyridine2d5:18114(C228,16815(C21, 1

45、6217(C27,14614(C23,14011(C213,13119(C2 5,9,12813(C212,12713(C24,11811(C26, 8,11618(C22,7912(C23,6714(C227,5710(C25,5014(C29,4717(C217,4713(C214,4617 (C219,4311(C218,4117(C28,4016(C21,4013 (C24,3818(C210,3513(C221,3419(C27,3414 (C222,29,3211(C220,2919(C223,2912(C22, 2516(C211,2513(C215,2510(C230,2419

46、(C2 16,2011(C26,1918(C226,1718(C225,1710(C2 241TheD,UV,I R,ESI2MS and NMR data were identical t o those reported10132Hydroxy2272p2(Z2cou maroyloxyolean2122en2 282o i c ac i d(11W hite a mor phous powder,mp12402 242;ESI2MS(positive modem/z:641M+Na +;1H NMR(600MHz,pyridine2d5:8105(2H,d,J =619Hz,H25,9,

47、7115(2H,d,J=619Hz,H26, 8,7100(1H,d,J=1219Hz,H23,6102(1H,d,J =1219Hz,H22,5178(1H,br s,H212,4163(1H, d,J=1217Hz,H227,4151(1H,d,J=1217Hz,H2 27,3142(1H,dd,J=1110,418Hz H23,1120, 1102,1100,0199,0190,0189(each,3H,s;13C NMR (150MHz,pyridine2d5:17919(C228,16614(C2 1,16014(C27,14319(C23,13814(C213, 13314(C25

48、,9,12619(C212,12612(C24,11611 (C22,11517(C26,8,7717(C23,6519(C227, 5515(C25,4818(C29,4612(C217,4516(C214, 4512(C219,4115(C218,4012(C28,3911(C21, 3815(C24,3713(C210,3318(C221,3313(C222, 3419(C27,3219(C229,3016(C220,2814(C223, 2718(C22,2411(C211,2410(C215,2316(C230, 2314(C216,1816(C26,1813(C226,1612(C

49、225, 1515(C2241The mp1,ESI2MS and NMR data were in accordance with those reported10,111Hycand i n i c ac i d ester(12Col orless oil;24D 23816(c01145,CHCl3;UVEt OH max223(4196,298(5100,340(5102;I RK B rmaxc m21:3420,2980,2920, 2860,1710,1620,1590,1510,1450,1420,1270, 1160,1120,1080,1050,1030,980,910,

50、850,810, 730;ESI2MS(positive modem/z:447M+Na+, 463M+K+;1H NMR(600MHz,CDCl3:7164 (1H,d,J=1519Hz,H23,7106(1H,d,J=719Hz,H29,7102(1H,s,H25,6191(1H,d,J=719Hz,H28,6131(1H,d,J=1519Hz,H22,5139(1H, ddd,J=1110,918,312Hz,H25,4121(1H,m,H2 3,4120(2H,t,J=612Hz,H28,3191(3H,s,62 OCH3,3168(1H,d,J=918Hz,H24,2131(1H,b

51、r d,J=1218Hz,H26,2121(1H,d,J=1415Hz,H2 2,2108(1H,d,J=1415Hz,H22,1193(1H,dd, J=1218,1110Hz,H26,1164(2H,m,H29,1138 (2H,sext,J=713Hz,H210,0194(3H,t,J=713 Hz,H211;13C NMR(150MHz,CDCl3:17411(C2 7,16714(C21,14811(C27,14618(C26,14517 (C23,12618(C24,12312(C29,11510(C22, 11417(C28,10914(C25,7516(C21,7410(C2

52、4,7017(C25,7016(C23,6614(C28,5519 (OCH3,3817(C26,3710(C22,3015(C29,1819(C210,1316(C211.TheD,UV,I R,ESI2MS and NMR data were in accordance with those reported121 Chlorogen i c ac i d butyl ester(13A pale yell ow needles(Me OH,mp11512152;ESI2MS m/z:433 M+Na+,449M+K+;1H NMR(600MHz, CDCl3:7152(1H,d,J=15

53、19Hz,H23,7103(1H, d,J=719Hz,H29,6194(1H,s,H25,6177(1H, d,J=719Hz,H28,6120(1H,d,J=1519Hz,H2 2,5127(1H,ddd,J=1018,910,315Hz,H25, 4115(1H,m,H23,4114(2H,t,J=710Hz,H28, 3172(1H,dd,J=1018,219Hz,H24,2122(1H,d,J =1318Hz,H26,2115(1H,d,J=1415Hz,H22, 2113(1H,d,J=1415Hz,H22,1193(1H,d,J= 1318Hz,H26,1161(2H,m,H29

54、,1134(2H,sext,J =715Hz,H210,0189(3H,t,J=715Hz,H211. The mp1,ESI2MS and NMR data were in consistent with those reported1314,52d i2O2Caffeoylqu i n i c ac i d butyl ester(14Yel2l owish gu m;UVM eOHmax(l ognm:242(4129,300 (4139,331(4152;ESI2MS(positive modem/z:595 M+Na+,611M+K+;1H NMR(600MHz, CD3OD:716

55、0(1H,d,J=1518Hz,H23,7150 (1H,d,J=1518Hz,H23,7102(1H,d,J=118Hz, H25,7100(1H,d,J=118Hz,H25,6191(1H,dd, J=814,118Hz,H29,6190(1H,dd,J=814,118 Hz,H29,6176(each1H,d,J=814Hz,H28,8, 6128(1H,d,J=1518Hz,H22,6116(1H,d,J= 1518Hz,H22,5154(1H,ddd,J=911,818,310Hz,795Vol121MA Xiao2li,et al:Che m ical Constituents o

56、f O s m anthus yunnanensis 598 H 2 , 5111 ( 1H , dd, J = 818, 310 Hz, H 2 , 4135 5 4 ( 1H , m , H 2 , 4109 ( 1H , m , H 2 , 2132 ( 1H , dd, J = 3 8 Colorless needles ( Et H , mp. 214 2 O 215 ; D + 24 ( 2H , sext, J = 715 Hz, H 2 , 0190 ( 3H , t, J = 715 10 ; 13 C NMR ( 150 MHz, CD3 OD : 17314 ( C 2

57、Hz, H 2 11 7 , 16711 ( C 2 , 16615 ( C 2 , 14813 ( C 2 , 14812 1 1 7 ( 26. 9 c 3. 2, M eOH ; ESI2 S ( positive mode m / z: M ( C 2 , 14613 ( C 2 , 14612 ( C 2 , 14514 ( C 2 , 7 3 3 6 15 Caf2 1 Caf2 2 Caf2 3 Caf2 4 Caf2 5 Caf2 6 Caf2 7 Caf2 8 Caf2 9 Glu2 1 Glu2 2 Glu2 3 Glu2 4 Glu2 5 Glu2 6 No1 1 2 3 4 5 1318, 310 Hz, H 2 , 2126 ( 1H , br d, J = 1111 Hz, H 2 6 2 , 2121 ( 1H , br d, J = 1111 Hz, H 2 , 2106 ( 1H , 2 ( J = Hz H C 6. 24, d, 1