關(guān)煥玉,蘭燕宇,廖尚高,劉俊宏,韓 瑜,鄭 林,李勇軍*
1貴陽(yáng)醫(yī)學(xué)院藥學(xué)院,民族藥與中藥開發(fā)應(yīng)用教育部工程研究中心;2貴州省藥物制劑重點(diǎn)實(shí)驗(yàn)室,貴陽(yáng) 550004
羊耳菊Inula cappa 為菊科旋覆花屬植物,在我國(guó)四川、貴州、廣西、廣東、江西、浙江等地均有分布。以全草或根入藥,主要用于除痰定喘、活血調(diào)經(jīng)及跌打損傷等[1]。目前已有研究報(bào)道[2-5]羊耳菊中主要含有三萜、甾醇、蒽醌、黃酮、芳香化合物、酰胺類、有機(jī)酸、倍半萜內(nèi)酯等化學(xué)成分。而咖啡?;鼘幩犷惢衔锸且活愑煽鼘幩岷鸵粋€(gè)或多個(gè)咖啡酸通過(guò)酯化反應(yīng)縮合而成的酚酸類天然化合物,廣泛存在于植物之中,具有多種藥理活性,如抗氧化、抗炎、抗微生物、酶抑制及肝細(xì)胞保護(hù)等作用[6]。就以上研究現(xiàn)狀,本實(shí)驗(yàn)對(duì)羊耳菊植物中咖啡?;鼘幩犷惢衔镞M(jìn)行了系統(tǒng)研究,分離得到8個(gè)咖啡?;鼘幩犷惢衔?,分別為:1,5-O-二咖啡酰基奎寧酸(1)、1,3,5-O-三咖啡?;鼘幩?2)、3,5-O-二咖啡?;鼘幩峒柞?3)、3,4-O-二咖啡?;鼘幩峒柞?4)、3,4-O-二咖啡?;鼘幩嵋阴?5)、4,5-O-二咖啡?;鼘幩嵋阴?6)、3,5-O-二咖啡?;鼘幩?7)、3,4-O-二咖啡?;鼘幩?8),其中化合物1~8 的結(jié)構(gòu)式見圖1。為進(jìn)一步探索羊耳菊中咖啡?;鼘幩犷惢衔锏乃幚砘钚缘於ɑA(chǔ)。
圖1 化合物1~8 結(jié)構(gòu)式Fig.1 Chemical structure of compounds 1-8
X-4 數(shù)字顯微熔點(diǎn)儀(溫度未校正);美國(guó)Varian INOVA-500 型核磁共振波譜儀(TMS 內(nèi)標(biāo));美國(guó)HP 公司HP5973-MSD 型質(zhì)譜儀;Agilent 1100 高效液相色譜儀(美國(guó)安捷倫科技公司);BS-100A 自動(dòng)部分收集器(上海滬西分析儀器廠);BUCHI B-490旋轉(zhuǎn)蒸發(fā)儀為瑞士生產(chǎn);硅膠(200~300 目),硅膠H(10~40 μm),硅膠G(10~40 μm)均為青島海洋化工廠產(chǎn)品;葡聚糖凝膠Sephadex LH-20(40~70 μm)為Amersham Pharmacia Biotech AB 公司產(chǎn)品;反相Rp-18 薄層色譜板及柱色譜用硅膠(40~60 μm)均為德國(guó)MERCK 公司生產(chǎn);所用儀器均為分析純或色譜純。
實(shí)驗(yàn)用藥材采自貴州省赤水市,由貴陽(yáng)中醫(yī)學(xué)院陳德媛教授鑒定為菊科植物羊耳菊Inula cappa(Buch.-Ham.ex D.Don)DC.的干燥全草。
羊耳菊干燥藥材粗粉5 kg,80%乙醇回流提取2 次,每次1.5 h,過(guò)濾,合并濾液,減壓濃縮,加水使之分散,用正丁醇萃取并減壓濃縮,得正丁醇層浸膏182g。正丁醇萃取物經(jīng)硅膠(200~300 目)色譜柱,用石油醚-乙酸乙酯梯度洗脫,薄層色譜檢測(cè),合并組成相似的洗脫液,濃縮后得到4個(gè)部分(Fr.1~Fr.4)。其中Fr.3(35.2 g)再次經(jīng)硅膠(200~300目)色譜柱,氯仿-甲醇-冰醋酸(9∶1∶0.1~7∶3∶0.1)梯度洗脫,得到5個(gè)次流份(Fr.3.1~Fr.3.5)。Fr.3.1(300 mg)先后經(jīng)硅膠柱(10~40 μm)層析,分別用氯仿-甲醇(100∶2)和石油醚-乙酸乙酯(7∶3)洗脫,Sephadex LH-20(甲醇),制備HPLC(甲醇∶0.1%H3PO4=62 ∶38),得到化合物5(13 mg)。Fr.3.2(450 mg)先后經(jīng)硅膠柱(10~40 μm)分離,石油醚-乙酸乙酯(3 ∶7)洗脫,制備HPLC(甲醇∶0.1%H3PO4=40∶60),得到化合物7(20 mg)、2(17 mg)、1(19 mg)和8(87 mg)。Fr.3.5(210 mg)先后經(jīng)硅膠柱(10~40 μm)層析,分別用石油醚-乙酸乙酯(7∶3),氯仿-甲醇-乙酸乙酯(9∶0.5∶2)洗脫,Sephadex LH-20(甲醇)和硅膠柱(10~40 μm)層析(石油醚-乙酸乙酯=7∶3),得到化合物3(21 mg)。Fr.4(49.7 g)經(jīng)硅膠柱(200~300 目)層析,氯仿-甲醇梯度洗脫,得到7個(gè)次流份(Fr.4.1~Fr.4.7)。Fr.4.5(240 mg)先后經(jīng)Sephadex LH-20(甲醇),反相硅膠柱層析(甲醇-水梯度洗脫),經(jīng)制備HPLC(甲醇∶0.1% H3PO4水=30∶70),得到化合物6(35 mg)。Fr.4.6(195 mg)先后經(jīng)正相硅膠柱(10~40 μm)層析,氯仿-甲醇-乙酸乙酯(8∶2∶2)洗脫,Sephadex LH-20(甲醇),反相硅膠柱層析(甲醇-水梯度洗脫),Sephadex LH-20(丙酮∶水50∶50),制備HPLC(甲醇∶0.1% H3PO4水=48∶52),得到化合物4(20 mg)。
化合物1 淡黃色粉末;ESI-MS m/z:515.0[MH]–;1H NMR(500 MHz,CD3OD)δ:7.62(2H,d,J=16.0 Hz,H-7',7''),7.09(2H,d,J=2.0 Hz,H-2',2''),6.99(2H,dd,J=8.1,2.0 Hz,H-6',6''),6.80(2H,d,J=8.1 Hz,H-5',5''),6.35,6.32(各1H,d,J=16.0 Hz,H-8',8''),5.43(1H,m,H-5),4.31(1H,m,H-3),3.82(1H,dd,J=8.5,2.9 Hz,H-4),2.62(1H,dd,J=12.1,3.0 Hz,H-6a),2.54(1H,dd,J=13.8,4.0 Hz,H-2a),2.43(1H,dd,J=13.8,2.9 Hz,H-2b),2.07(1H,m H-6b);13C NMR(125 MHz,CD3OD)δ:178.0(C-7),168.6,168.0(C-9',C-9''),149.6 (C-4',C-4''),147.3,147.2 (C-7',C-7''),146.8 (C-3',C-3''),127.9,127.3 (C-1',C-1''),123.0,123.1 (C-6',C-6''),116.4 (C-5',C-5''),115.7,115.3(C-8',C-8''),115.4,(C-2',C-2''),81.7(C-1),73.4(C-4),71.8(C-5),69.8(C-3),37.4(C-6),36.0(C-2)。上述數(shù)據(jù)與文獻(xiàn)報(bào)道[7]的1,5-O-二咖啡?;鼘幩嵋恢隆?/p>
化合物2 淡黃色粉末;ESI-MS m/z:677.0[MH]–;1H NMR(500 MHz,CD3OD)δ:7.64,7.56,7.51(各1H,d,J=16.0 Hz,H-7',7'',7'''),7.07,6.96,6.84(各1H,d,J=2.0 Hz,H-2',2'',2'''),6.97,6.83,6.64(各1H,dd,J=8.0,2.0 Hz,H-6',6'',6'''),6.75,6.65,6.54(各1H,d,J=8.0 Hz,H-5',5'',5'''),6.34,6.30,6.25(各1H,d,J=16.0 Hz,H-8',8'',8'''),5.44(1H,m,H-5),5.37(1H,d,J=3.5,H-3),3.99(1H,dd,J=8.4,3.9 Hz,H-4),2.88(1H,d,J=16.8 Hz,H-2a),2.45(1H,dd,J=16.8,3.5 Hz,H-2b),2.55(1H,dd,J=13.9,3.4 Hz,H-6a),2.10(1H,dd,J=13.9,10.2 Hz,H-6b);13C NMR(125 MHz,CD3OD)δ:173.5(C-7),167.3,167.2,166.5,(C-9',9'',9'''),148.3(C-7',7'',7'''),146.2,146.0 (C-4',4'',4'''),145.6,145.4(C-3',3'',3'''),126.4,126.3 (C-1',1'',1'''),121.8,121.7(C-6',6'',6'''),115.2,115.1(C-5',5'',5'''),113.7,113.6 (C-2',2'',2'''),114.3,114.2(C-8',8'',8'''),79.5(C-1),70.2(C-5),71.0(C-3),70.7(C-4),35.5(C-6),34.3(C-2)。上述數(shù)據(jù)與文獻(xiàn)報(bào)道[8]的1,3,5-O-三咖啡?;鼘幩嵋恢?。
化合物3 淡黃色粉末;ESI-MS m/z:529.2[MH]–,553.2[M+Na]+;1H NMR(500 MHz,CD3OD)δ:7.62,7.55(各1H,d,J=16.1 Hz,H-7',7''),7.07,7.02(各1H,d,J=2.3 Hz,H-2',2''),6.98(2H,dd,J=8.4,2.3 Hz,H-6',6''),6.78(2H,d,J=8.4 Hz,H-5',5''),6.35,6.22(各1H,d,J=16.1 Hz,H-8',8''),5.40(1H,m,H-3),5.31(1H,m,H-5),3.98(1H,dd,J=8.0,3.5 Hz,H-4),3.69(3H,s,-OCH3),2.30(2H,m,H-6),2.19(2H,m,H-2);13C NMR(125 MHz,CD3OD)δ:175.6(C-7),168.7,167.9(C-9',9''),149.8,149.5(C-4',4''),147.4,147.1(C-7',7''),146.8(C-3',3''),127.8,127.6(C-1',1''),123.1,123.0(C-6',6''),116.5,116.4(C-5',5''),115.3,115.1(C-8',8''),115.1,114.9(C-2',2''),74.7(C-1),72.3(C-3),72.0(C-4),69.5(C-5),52.8(-OCH3),36.8(C-6),35.8(C-2)。
上述數(shù)據(jù)與文獻(xiàn)報(bào)道[9]的3,5-O-二咖啡酰基奎寧酸甲酯一致。
化合物4 黃色粉末;ESI-MS m/z:529.2[MH]–,553.0[M +Na]+;1H NMR(500 MHz,DMSOd6)δ:9.39 (2H,brs,2OH),9.28(2H,brs,2OH),7.51,7.42(各1H,d,J=16.0 Hz,H-7',7''),7.04,7.02(各1H,d,J=2.0 Hz,H-2',2''),6.99,6.97(各1H,dd,J=8.0,2.0 Hz,H-6',6''),6.76,6.75(各1H,d,J=8.0 Hz,H-5',5''),6.25,6.13(各1H,d,J=16.0 Hz,H-8',8''),5.26(1H,m,H-3),4.98(1H,dd,J=7.0,3.0 Hz,H-4),4.15(1H,m,H-5),3.59(3H,s,-OCH3),2.26-1.86 (4H,m,H-2,6);13C NMR(125 MHz,DMSO-d6)δ:173.4(C-7),165.9,165.2(C-9',9''),148.6,148.5(C-4',4''),145.7(C-7',7''),145.8,145.7(C-3',3''),125.6,125.5(C-1',1''),121.5,121.4(C-6',6''),115.8,115.0(C-5',5''),114.9,114.8(C-2',2''),113.9,113.5(C-8',8''),73.4(C-1),72.4(C-4),67.8(C-3),65.4(C-5),52.0(-OCH3),37.7(C-2),36.3(C-6)。上述數(shù)據(jù)與文獻(xiàn)報(bào)道[10]的3,4-O-二咖啡酰基奎寧酸甲酯一致。
化合物5 淡黃色塊晶;ESI-MS m/z:543[MH]–;1H NMR(500 MHz,CD3OD)δ:7.58,7.50(各1H,d,J=16.0 Hz,H-7',7''),7.02,7.01(各1H,d,J=2.0 Hz,H-2',2''),6.89,6.86(各1H,dd,J=8.0,2.0 Hz,H-6',6''),6.74,6.71(各1H,d,J=8.0 Hz,H-5',5''),6.25,6.20(各1H,d,J=16.0 Hz,H-8',8''),5.58(1H,m,H-3),5.09(1H,dd,J=9.0,3.0 Hz,H-4),4.36(1H,m,H-5),4.15(3H,q,J=7.0 Hz,-OCH2-),2.28-2.01(4H,m,H-2,6),1.24(1H,t,J=7.0 Hz,-CH3);13C NMR(125 MHz,CD3OD)δ:174.9(C-7),168.5,168.0(C-9',9''),149.0(C-4',4''),147.4,147.3(C-7',7''),146.5,146.4(C-3',3''),127.4(C-1',1''),123.0(C-6',6''),116.5,116.3(C-5',5''),115.6,115.5(C-2',2''),114.8,(C-8',8''),75.8(C-1),74.9(C-4),68.9(C-3),68.7(C-5),62.0(-OCH2-),38.0(C-6),38.9(C-2),14.3(-CH3)。上述數(shù)據(jù)與文獻(xiàn)報(bào)道[11]的化合物5 基本一致,并將上述數(shù)據(jù)與文獻(xiàn)[10,12]報(bào)道的3,4-O-二咖啡?;鼘幩峒柞ミM(jìn)行對(duì)比,發(fā)現(xiàn)除了成酯部分有差異之外,其他數(shù)據(jù)基本一致,證實(shí)該化合物為3,4-O-二咖啡酰基奎寧酸乙酯。
化合物6 黃色粉末;ESI-MS m/z:543[MH]–;1H NMR(500 MHz,CD3OD)δ:7.58,7.51(各1H,d,J=16.0 Hz,H-7',7''),7.03,7.00(各1H,d,J=2.0 Hz,H-2',2''),6.91,6.89(各1H,dd,J=8.0,2.0 Hz,H-6',6''),6.76,6.74(2H,d,J=8.0 Hz,H-5',5''),6.30,6.20(各1H,d,J=16.0 Hz,H-8',8''),5.62(1H,m,H-5),5.13(1H,m,H-4),4.37(1H,m,H-3),4.13(2H,q,J=7.0 Hz,-OCH2-),2.29-2.10(4H,m,H-2,6),1.24(3H,t,J=7.0 Hz,-CH3);13C NMR(125 MHz,CD3OD)δ:177.5(C-7),169.0,168.5(C-9',9''),148.9,148.7(C-4',4''),149.6(C-7',7''),147.9,147.7(C-3',3''),116.6(C-5',5''),124.1,124.0(C-1',1''),123.6(C-6',6''),115.9(C-2',2''),115.5,115.4(C-8',8''),76.2(C-1),74.8(C-4),69.8(C-5),69.2(C-3),62.8(C-8),39.9(C-6),39.6(-OCH2-),38.5(C-2),14.2(-CH3)。上述數(shù)據(jù)與文獻(xiàn)報(bào)道[13]的化合物4基本一致,并將上述數(shù)據(jù)與文獻(xiàn)[14]報(bào)道的4,5-O-二咖啡?;鼘幩峒柞ミM(jìn)行對(duì)比,發(fā)現(xiàn)除了成酯部分有差異之外,其他數(shù)據(jù)基本一致,證實(shí)該化合物為4,5-O-二咖啡?;鼘幩嵋阴?。
化合物7 淡黃色粉末;ESI-MS m/z:515.0[MH]–;1H NMR(500 MHz,CD3OD)δ:7.56,7.43(各1H,d,J=16.3 Hz,H-7',7''),7.05,7.01(各1H,d,J=2.0 Hz,H-2',2''),6.95,6.94(各1H,dd,J=8.1,2.0 Hz,H-6',6''),6.78(2H,d,J=8.1 Hz,H-5',5''),6.29,6.18(各1H,d,J=16.3 Hz,H-8',8''),5.44(1H,m,H-3),5.41(1H,m,H-5),3.96(1H,dd,J=7.5,3.5 Hz,H-4),2.24(2H,m,H-6),2.17(2H,m,H-2);13C NMR(125 MHz,CD3OD)δ:176.0(C-7),168.1(C-9',C-9''),147.9,147.7(C-4',C-4''),147.1,147.0(C-7',C-7''),146.8,146.7(C-3',C-3''),127.9,127.8(C-1',C-1''),123.1,123.0(C-6',C-6''),116.4,116.2 (C-5',C-5''),115.7,115.6(C-2',C-2''),115.2,115.1(C-8',C-8''),73.0(C-1),72.9(C-5),72.1(C-3),71.6(C-4),35.7(C-2),36.9(C-6)。上述數(shù)據(jù)與文獻(xiàn)報(bào)道[15]的3,5-O-二咖啡酰基奎寧酸一致。
化合物8 淡黃色粉末;ESI-MS m/z:515.0[MH]–;1H NMR(500 MHz,CD3OD)δ:7.60,7.53(各1H,d,J=16.0 Hz,H-7',7''),7.03,7.00(各1H,d,J=2.0 Hz,H-2',2''),6.93,6.90(各1H,dd,J=8.1,2.0 Hz,H-6',6''),6.75,6.73(各1H,d,J=8.1 Hz,H-5',5''),6.29,6.18(各1H,d,J=16.0 Hz,H-8',8''),5.62(1H,m,H-3),5.11(1H,dd,J=9.1,3.5 Hz,H-4),4.37(1H,m,H-5),2.32(1H,m,H-6a),2.26(2H,m,H-2),2.17(1H,m,H-6b);13C NMR(125 MHz,CD3OD)δ:176.8 (C-7),168.5,168.2(C-9',C-9''),149.7 (C-4',C-4''),147.7,147.6(C-7',C-7''),146.8(C-3',C-3''),127.7(C-1',C-1''),123.1,123.0(C-6',C-6''),116.5,116.4(C-5',C-5''),115.3,115.2(C-2',C-2''),114.8,114.7(C-8',C-8''),76.1(C-1),75.8(C-4),69.4(C-5),69.0(C-3),39.4(C-2),38.4(C-6)。上述數(shù)據(jù)與文獻(xiàn)報(bào)道[10]的3,4-O-二咖啡?;鼘幩嵋恢隆?/p>
本實(shí)驗(yàn)分離得到的一系列咖啡?;鼘幩犷惢衔铮蠖酁槲恢卯悩?gòu)體,結(jié)構(gòu)鑒定可通過(guò)奎寧酸母體中各取代位置上氫的化學(xué)位移、偶合常數(shù)和偶合類型確定。通常,對(duì)奎寧酸母核而言,如果OH-1 未酯化,H-2 和H-6 四個(gè)氫質(zhì)子會(huì)在δH2.1~2.3 處以一個(gè)多重峰的形式出現(xiàn)[16];當(dāng)OH-1 酯化后,H-2 和H-6 中的四個(gè)氫的共振頻率會(huì)出現(xiàn)明顯差異,以四個(gè)化學(xué)位移不同的雙二重峰質(zhì)子形式(δH2.0~3.5)出現(xiàn)在氫譜中[16]。化合物1 中,從所觀察到的質(zhì)子信號(hào)[2.62(1H,dd,J=12.1,3.0 Hz,H-6a),2.54(1H,dd,J=13.8,4.0 Hz,H-2a),2.43(1H,dd,J=13.8,2.9 Hz,H-2b),2.07(1H,m H-6b)]來(lái)看,化合物1 為1-O-咖啡?;〈亩Х弱;鼘幩犷惢衔?。H-4 由于緊鄰H-3 和H-5,通常以雙二重峰的形式出現(xiàn)。對(duì)沒有酯化的OH-4 來(lái)說(shuō),其H-4通常出現(xiàn)在δH3.7~4.1 之間;當(dāng)OH-4 酯化后,H-4會(huì)向低場(chǎng)位移δH1.0~1.6[16]?;衔? 中,由于H-4 出現(xiàn)在δH5.11,化合物8 可確定為4-O-咖啡?;〈亩Х弱;鼘幩犷惢衔?。H-3(或H-5)由于同時(shí)與H-2(或H-6)和H-4 偶合,一般以多重峰的形式出現(xiàn)。對(duì)沒有酯化的OH-3(或OH-5)來(lái)說(shuō),其H-3(或H-5)通常出現(xiàn)在δH4.0~4.6 之間;當(dāng)OH-3(或OH-5)酯化后,H-3(或H-5)會(huì)向低場(chǎng)位移δH1.0~1.6[16]。由于相對(duì)于二咖啡?;鼘幩?,位置異構(gòu)體7 的H-5 由δ 4.37 低場(chǎng)位移到了δH5.41,而H-4 由δH5.11 高場(chǎng)位移到了δ 3.96,表明化合物7 和8 分別應(yīng)該是3,5-和3,4(或4,5)-二咖啡酰基奎寧酸。
對(duì)3,4-二咖啡?;鼘幩岙悩?gòu)體來(lái)說(shuō),C-3 位上的咖啡?;幵谥绷㈡I上,H-4 和H-5 保持鄰位ax-ax 的偶合狀態(tài),從而H-4 出現(xiàn)雙二重峰;對(duì)于4,5-二咖啡?;鼘幩岙悩?gòu)體,由于鄰二咖啡?;目臻g效應(yīng),影響H-4 和H-5 的鄰位ax-ax 偶合,使偶合常數(shù)變小,而H-4 出現(xiàn)類似多重峰的窄峰[12,15,17],通過(guò)觀察到的信號(hào),可判斷化合物8 為3,4-二咖啡酰基奎寧酸,從而也可判斷化合物5 和6 的取代位置。
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