王曉陽

(遼寧中醫(yī)藥大學(xué)附屬醫(yī)院,遼寧 沈陽 110032)

半邊蓮為桔?？浦参锇脒吷廘obelia chinensis Lour.的干燥全草,其味辛、平,歸心、小腸、肺經(jīng),具有清熱解毒、利尿消腫之功效,用于癰腫疔瘡、蛇蟲咬傷、臌脹水腫、濕熱黃疽、濕疹濕瘡等癥[1],主要化學(xué)成分有黃酮、生物堿、香豆素類等[2-4],具有顯著的抗腫瘤、抗氧化、鎮(zhèn)痛抗炎、抑制α-葡萄糖苷酶等藥理作用[5-7],在臨床上常用來治療支氣管炎、支氣管肺炎、呼吸道感染和嬰兒腹瀉等[5]。本課題組對半邊蓮化學(xué)成分進行研究,從中分離得到8 個化合物,其中,化合物2～6 為首次從該植物中分離得到。

1 材料

數(shù)顯SGW XT-4 顯微熔點儀(溫度計未經(jīng)校正,北京世紀科信科學(xué)儀器有限公司)；AM-400、AV-500 型核磁共振儀(德國Bruker 公司)；LCQDECA 型質(zhì)譜儀(美國Finnigan 公司)；薄層層析用硅膠H 與柱層析硅膠(100～200、200～300 目,青島海洋化工廠)。試劑均為分析純。

半邊蓮由遼寧中醫(yī)藥大學(xué)康廷國教授鑒定為桔梗科半邊蓮屬植物半邊蓮Lobelia chinensis Lour.的干燥全草。

2 提取與分離

取藥材干燥全草5.0 kg,用95%乙醇室溫萃取3 次,5 d/次,減壓濃縮成浸膏。乙醇浸膏經(jīng)熱水分散,依次用石油醚、乙酸乙酯、正丁醇萃取,得乙酸乙酯部位約100 g。將乙酸乙酯部位浸膏以硅膠拌樣,用硅膠進行柱層析,以石油醚-丙酮(100∶1～0∶1) 梯度洗脫,合并相同流分,得6個組分Fr.1～Fr.6。Fr.1 用硅膠柱,石油醚-丙酮(20∶1～5∶1) 梯度洗脫,再經(jīng)Sephadex LH-20 純化,得化合物6 (10 mg)；Fr.2 經(jīng)硅膠,以石油醚-丙酮梯度洗脫,分離純化得化合物5 (8 mg)；Fr.3經(jīng)硅膠柱層析,以石油醚-乙酸乙酯梯度洗脫,重結(jié)晶得化合物7 (25 mg)、8 (21 mg)；Fr.4 經(jīng)反復(fù)硅膠柱,以氯仿-甲醇(100∶1～10∶1) 梯度洗脫,得3 個亞流分Fr.4-1～Fr.4-3,Fr.4-3 經(jīng)硅膠柱,以氯仿-甲醇(20∶1～2∶1) 洗脫,得化合物4 (15 mg)；Fr.5 經(jīng)過硅膠柱層析,以氯仿-甲醇(15∶1～2∶1) 梯度洗脫,并經(jīng)過Sephadex LH-20 純化得化合物1 (12 mg)、3 (6 mg)；Fr.6 用Sephadex LH-20 柱色譜,并經(jīng)反復(fù)硅膠柱,氯仿-甲醇(12∶1～1∶1) 梯度洗脫,得化合物2 (10 mg)。

3 結(jié)構(gòu)鑒定

化合物1:黃色粉末,ESI-MS m/z:463.1[M-H]-。1H-NMR (DMSO-d6,400 MHz) δ:12.61(1H,s,5-OH),7.59 (2H,m,J=2.2,8.5 Hz,H-2′,H-6′),6.85 (1H,d,J=8.5 Hz,H-5′),6.41(1H,d,J=2.0 Hz,H-8),6.20 (1H,d,J=2.0 Hz,H-6),5.45 (1H,d,J=7.1 Hz,H-1″),3.62(1H,m,H-6″a),3.52 (1H,m,H-6″b),3.41(1H,d,J=9.0 Hz,H-2″),3.29 (1H,d,J=9.0 Hz,H-3″),3.18 (1H,d,J=9.0 Hz,H-4″),3.02(1H,m,H-5″)；13C-NMR (DMSO-d6,150 MHz) δ:156.1 (C-2),133.3 (C-3),177.4 (C-4),161.0(C-5),98.5 (C-6),164.2 (C-7),93.4 (C-8),156.3 (C-9),103.9 (C-10),121.1 (C-1′),115.2(C-2′),145.1 (C-3′),148.4 (C-4′),115.6 (C-5′),121.2 (C-6′),101.0 (C-1″),74.1 (C-2″),76.5 (C-3″),69.8 (C-4″),77.5 (C-5″),61.0 (C-6″)。以上數(shù)據(jù)與文獻[8]對照基本一致,故鑒定為槲皮素-3-O-β-D-葡萄糖苷。

化合物2:黃色粉末。ESI-MS m/z:463.1[M-H]-。1H-NMR (DMSO-d6,400 MHz) δ:12.65(1H,s,5-OH),7.61 (1H,d,J=2.0 Hz,H-2′),7.55 (1H,dd,J=2.2,8.5 Hz,H-6′),6.87 (1H,d,J=8.5 Hz,H-5′),6.75 (1H,d,J=2.0 Hz,H-8),6.41 (1H,d,J=2.0 Hz,H-6),5.31 (1H,d,J=7.1 Hz,H-1″),3.62 (2H,m,H-6″),3.58(1H,m,H-3″),3.51 (1H,t,J=9.0 Hz,H-2″),3.35 (1H,d,J=9.0 Hz,H-4″),3.02 (1H,t,J=6.0 Hz,H-5″)；13C-NMR (DMSO-d6,150 MHz) δ:151.1 (C-2),137.2 (C-3),177.3 (C-4),160.8(C-5),99.8 (C-6),163.1 (C-7),94.2 (C-8),156.5 (C-9),105.9 (C-10),121.2 (C-1′),115.2(C-2′),148.0 (C-3′),147.7 (C-4′),116.3 (C-5′),121.0 (C-6′),101.3 (C-1″),74.3 (C-2″),76.5 (C-3″),70.7 (C-4″),77.9 (C-5″),61.1 (C-6″)。以上數(shù)據(jù)與文獻[9]對照基本一致,故鑒定為槲皮素-7-O-β-D-葡萄糖苷。

化合物3:黃色粉末。ESI-MS m/z:491.3[M-H]-。1H-NMR (DMSO-d6,400 MHz) δ:12.97(1H,s,5-OH),9.42 (1H,s,4′-OH),6.47 (1H,d,J=1.9 Hz,H-6),6.95 (1H,d,J=1.9 Hz,H-8),5.28 (1H,d,J=7.2 Hz,H-1″),3.59 (1H,m,H-6″a),3.44 (1H,m,H-6″b),3.35 (1H,m,H-2″),3.19 (1H,m,H-3″),3.15 (1H,m,H-4″),3.05 (1H,m,H-5″)；13C-NMR (DMSO-d6,150 MHz) δ:164.5 (C-2),104.3 (C-3),182.5(C-4),161.5 (C-5),99.9 (C-6),163.3 (C-7),95.6 (C-8),157.1 (C-9),105.8 (C-10),120.7(C-1′),104.9 (C-2′,6′),148.7 (C-3′,5′),140.4 (C-4′),100.5 (C-1″),73.6 (C-2″),76.9(C-3″),69.9 (C-4″),77.8 (C-5″),60.9 (C-6″)。以上數(shù)據(jù)與文獻[10]對照基本一致,故鑒定為苜蓿素-7-O-β-D-葡萄糖苷。

化合物 4:丙酮中為無色針晶。1H-NMR(CD3OD,500 MHz) δ:7.01 (2H,s,H-2 和H-6)；13C-NMR (CD3OD,125 MHz) δ:169.9 (-C=O),124.4 (C-1),145.6 (C-3,5),137.3 (C-4),108.9 (C-2,6)。與沒食子酸對照品進行薄層色譜比對,Rf 值一致,且理化常數(shù)和光譜數(shù)據(jù)與文獻[11]對照基本一致,故鑒定為沒食子酸。

化合物5:鱗片狀晶體。ESI-MS m/z:409.2[M-H]-。1H-NMR (CDCl3,400 MHz) δ:3.65(2H,m,J=6.9 Hz,H-1),1.25 [m,-(CH2)26-],0.89 (3H,m,J=6.9 Hz,H-28)；13C-NMR (CDCl3,125 MHz) δ:63.3 (C-1),32.1(C-2),25.9 (C-3),29.6～29.2 (多個),22.8(C-27),14.3 (C-28)。EI-MS m/z:392 (MH2O),364,336～56,為以相 差 14 遞減的[CnH2n+]和[CnH2n-1+]系列烴基碎片離子。以上數(shù)據(jù)及文獻[12]對照基本一致,故鑒定為二十八烷醇。

化合物6:白色粉末。ESI-MS m/z:67.1[M-H]-。1H-NMR (DMSO-d6,500 MHz) δ:5.15(1H,t,J=3.4 Hz,H-12),4.23 (1H,dd,J=7.6 Hz,H-3),2.01 (3H,s,3-OCOOH),1.12 (3H,s,H-27),0.98 (3H,s,H-26),0.95 (3H,s,H-25),0.87 (3H,s,H-23),0.86 (3H,s,H-24),0.84 (3H,s,H-28),0.86 (3H,s,H-29),0.88(3H,s,H-30)；13C-NMR (DMSO-d6,150 MHz) δ:170.1 (HOOCO-CO),38.5 (C-1),23.7 (C-2),80.8 (C-3),37.3 (C-4),55.5 (C-5),18.5 (C-6),32.7 (C-7),39.9 (C-8),47.7 (C-9),36.8(C-10),23.5 (C-11),121.6 (C-12),145.4 (C-13),41.9 (C-14),28.0 (C-15),26.5 (C-16),32.6 (C-17),47.5 (C-18),46.9 (C-19),31.2 (C-20),35.0 (C-21),37.2 (C-22),28.5 (C-23),15.6(C-24),15.5 (C-25),16.9 (C-26),26.0 (C-27),27.3 (C-28),33.5 (C-29),23.6 (C-30),21.5 (-OCOOH-CH3)。以上數(shù)據(jù)與文獻[13]對照基本一致,故鑒定為β-香樹脂醇乙酸酯。

化合物7:無色針晶。ESI-MS m/z:413.1[M-H]-。1H-NMR (DMSO-d6,400 MHz) δ:5.37(1H,d,J=2.2 Hz,H-6),3.52 (1H,m,H-3),1.06 (3H,s,H-19),0.94 (3H,d,J=6.8 Hz,H-21),0.86 (3H,d,J=6.8 Hz,H-29),0.85 (3H,d,J=6.2 Hz,H-27),0.84 (3H,d,J=6.8 Hz,H-26),0.68 (3H,s,H-18)；13C-NMR (DMSO-d6,150 MHz) δ:36.7 (C-1),29.9 (C-2),72.1 (C-3),46.2 (C-4),140.9 (C-5),121.9 (C-6),31.9(C-7),32.0 (C-8),50.3 (C-9),36.3 (C-10),28.5 (C-11),39.9 (C-12),42.6 (C-13),56.9(C-14),26.2 (C-15),29.3 (C-16),56.3 (C-17),12.0 (C-18),20.1 (C-19),32.1 (C-20),19.6 (C-21),34.2 (C-22),24.6 (C-23),37.5(C-24),19.2 (C-25),12.2 (C-26),23.3 (C-27),21.2 (C-28),18.9 (C-29)。以上數(shù)據(jù)與文獻[14]對照基本一致,故鑒定為β-谷甾醇。

化合物8:黃色粉末。ESI-MS m/z:301.1[M-H]-。1H-NMR (DMSO-d6,400 MHz) δ:12.45(1H,s,5-OH),10.72 (1H,br,7-OH),9.53(1H,br,4′-OH),9.26 (2H,br,3,3′-OH),7.68(1H,d,J=2.1 Hz,H-2′),7.52 (1H,dd,J=8.5,2.1 Hz,H-6′),6.88 (1H,d,J=8.5 Hz,H-5′),6.41 (1H,d,J=2.0 Hz,H-8),6.17 (1H,d,J=2.0 Hz,H-6)；13C-NMR (DMSO-d6,400 MHz) δ:146.7 (C-2),135.6 (C-3),175.3 (C-4),156.0(C-5),98.2 (C-6),163.8 (C-7),93.2 (C-8),160.5 (C-9),102.9 (C-10),122.1 (C-1′),115.3(C-2′),145.1 (C-3′),147.6 (C-4′),115.2 (C-5′),119.9 (C-6′)。以上數(shù)據(jù)與文獻[15]對照基本一致,故鑒定為槲皮素。

4 討論

半邊蓮主要活性成分為生物堿類和黃酮類,前者大多具有中樞興奮、呼吸興奮、抗動脈粥樣硬化等作用,同時可明顯誘導(dǎo)腫瘤細胞凋亡[16-17],而后者具有一定的抑菌活性[18]。本研究從半邊蓮中分離得到8 個化合物,包括4 個黃酮類、1 個甾醇類、3 個其他類,可為其藥效物質(zhì)基礎(chǔ)與臨床應(yīng)用考察提供參考。