朱敏匯,楊貴香,鄭 林,汪 洋,馬 雪,林昌虎*,李勇軍*
[1.貴州醫(yī)科大學(xué)民族藥與中藥開發(fā)應(yīng)用教育部工程研究中心/省部共建藥用植物功效與利用國家重點(diǎn)實(shí)驗室,貴州 貴陽 550004;2.貴州醫(yī)科大學(xué)貴州省藥物制劑重點(diǎn)實(shí)驗室,貴州 貴陽 550004;3.貴州醫(yī)科大學(xué)藥學(xué)院,貴州 貴陽 550004]
鉤毛茜草RubiaoncotrichaHand.-Mazz.為茜草科茜草屬植物,其以干燥根及根莖入藥,具有涼血止血、止咳祛痰、通經(jīng)之功效,用于治療經(jīng)閉、黃疸、跌撲損傷等癥[1]?,F(xiàn)代化學(xué)成分和藥理學(xué)研究表明,茜草屬植物中含有蒽醌類、萘醌類、環(huán)肽類、萜類等成分,具有抗菌、抗腫瘤、升高白細(xì)胞、抗心肌缺血等生物活性[2]。我國茜草屬植物資源十分豐富,應(yīng)充分開發(fā)利用茜草屬植物的資源,挖掘其潛在的醫(yī)藥價值。鉤毛茜草為我國特有植物,產(chǎn)于貴州、云南、四川等地,是貴州省少數(shù)民族用藥。
經(jīng)文獻(xiàn)調(diào)研發(fā)現(xiàn),鉤毛茜草化學(xué)成分研究集中在較小極性部位[3-4],大極性部位的研究鮮有報道,鉤毛茜草在民間通過水煎煮或酒泡等方式用藥,水煎液及酒中可能含有大量有效成分;其次,同屬植物茜草RubiacordifoliaL.的正丁醇部位化合物種類較多且具有較好的藥理活性[5],根據(jù)親緣關(guān)系相近,化學(xué)成分及藥理作用相似的規(guī)律,提示鉤毛茜草正丁醇部位的化學(xué)成分種類可能也較豐富且具有較好的藥理活性。因此,為了深入研究鉤毛茜草的物質(zhì)基礎(chǔ),本研究對正丁醇部位的較大極性成分進(jìn)行研究,結(jié)果從中分離得到15個化合物,其中1~14為首次從該種植物中分離得到,化合物1~9為首次從茜草屬植物中分離得到。
JNM-ECS-400 MHz核磁共振波譜儀 (日本JEOL公司);超高液相色譜-三重四級桿串聯(lián)質(zhì)譜儀(ACQUITY-UPLC-TQD,美國Waters公司);LC-20AP 制備型高效液相色譜 (日本Shimadzu公司);Waters BEH-C18色譜柱(50 mm×2.1 mm,1.7 μm,美國Waters 公司);ACE-C18-PFP半制備色譜柱(250 mm×10 mm,5 μm);BUCHI R-200旋轉(zhuǎn)蒸發(fā)儀(瑞士BUCHI公司);KQ5200B型超聲波清洗器(昆山市超聲儀器有限公司);柱色譜硅膠(100~200目、200~300目、300~400目,青島海洋化工有限公司)。
鉤毛茜草藥材于2018年7月購于貴州貴陽萬東橋中藥材市場,經(jīng)貴州醫(yī)科大學(xué)龍慶德副教授鑒定為鉤毛茜草RubiaoncotrichaHand.-Mazz.的干燥根及根莖,保存于貴州醫(yī)科大學(xué)藥物制劑重點(diǎn)實(shí)驗室。
取干燥的鉤毛茜草根及根莖5 kg,切成1~2 cm小段,用70%乙醇回流提取3次,合并濾液,減壓濃縮,得總浸膏592 g。將浸膏與水混懸,經(jīng)萃取得到石油醚部位55 g、乙酸乙酯部位65 g、正丁醇部位215 g。
取正丁醇部位(215 g)經(jīng)正相硅膠柱,以二氯甲烷-甲醇(50∶1~1∶1)梯度洗脫,得Fr.1~Fr.7。將Fr.2過正相硅膠柱,用乙酸乙酯-甲醇(15∶1~1∶1)梯度洗脫,得Fr.2.1~ Fr.2.9。Fr.2.4反復(fù)經(jīng)正相硅膠柱色譜純化、Toyopearl HW-40F柱色譜分離,最后通過制備HPLC 甲醇-水(60∶40)分離得化合物1(4.5 mg)、8(5.3 mg)。Fr.2.5經(jīng)正相硅膠柱乙酸乙酯-甲醇(5∶1)、Sephadex LH-20、MCI柱甲醇-水(1∶1)得Fr.2.5.1~Fr.2.5.5。Fr.2.5.1先經(jīng)Toyopearl HW-40F柱色譜分離(甲醇),再經(jīng)正相硅膠柱乙酸乙酯-甲醇(6∶1~4∶1)得化合物10(4.6 mg)。Fr.2.5.2經(jīng)Toyopearl HW-40F柱、正相硅膠柱二氯甲烷-甲醇(8∶1~5∶1)得化合物5(4.3 mg)。Fr.2.5.3分別經(jīng)Sephadex LH-20、Toyopearl HW-40F柱、正相硅膠柱乙酸乙酯-甲醇(7∶1~1∶1)得化合物6(7.7 mg);Fr.3經(jīng)正相硅膠柱乙酸乙酯-甲醇(8∶1~1∶1),得Fr.3.1~ Fr.3.7。其中Fr.3.3經(jīng)Sephadex LH-20柱 三氯甲烷-甲醇(1∶1)、Toyopearl HW-40F柱得化合物9(4.7 mg)。Fr.3.4分別經(jīng)Sephadex LH-20三氯甲烷-甲醇(1∶1)、正相硅膠柱二氯甲烷-甲醇(10∶1~1∶1)得化合物7(6.0 mg)。Fr.3.5經(jīng)Sephadex LH-20、正相硅膠柱乙酸乙酯-甲醇(15∶1~1∶1)、Toyopearl HW-40F柱得化合物12(11.8 mg)。Fr.4經(jīng)Sephadex LH-20分離得Fr.4.1~ Fr.4.6。其中Fr.4.2經(jīng)MCI柱(甲醇-水)、正相硅膠柱乙酸乙酯-甲醇(20∶1~1∶1)及Toyopearl HW-40F柱得化合物2(3.5 mg)、3(2.8 mg)、4(7.0 mg)、11(4.0 mg)。Fr.6經(jīng)正相硅膠柱乙酸乙酯-甲醇(15∶1~1∶1)、Sephadex LH-20柱,再放置,過濾得化合物13(370.0 mg)。Fr.7經(jīng)Sephadex LH-20柱分離,得Fr.7.1~ Fr.7.5。其中Fr.7.2經(jīng)Sephadex LH-20柱三氯甲烷-甲醇(1∶1)得化合物14(7.0 mg)。Fr.7.4反復(fù)經(jīng)正相硅膠柱純化得化合物15(2.0 mg)。
化合物1:無色晶體,分子式C26H34O11。ESI-MSm/z:521.2[M-H]-。1H-NMR (400 MHz,CD3OD)δ:7.08 (1H,d,J=8 Hz,H-5′),6.94 (2H,s,H-6,6′),6.83 (1H,d,J=8 Hz,H-5),6.65 (1H,d,J=7.6 Hz,H-2),6.58(1H,d,J=7.6 Hz,H-2′),4.78 (1H,d,J=5.6 Hz,Glc-1),4.77 (1H,d,J=5.6 Hz,H-7′),3.96~4.00 (1H,m,H-9′a),3.85~3.88 (1H,m,H-9a),3.84 (6H,s,3,3′-OCH3),3.71~3.73 (1H,m,H-9′b),3.65~3.70 (1H,m,H-9b),2.85 (1H,d,J=13.6 Hz,H-7b),2.66~2.70 (1H,m,H-8′),2.44~2.48 (1H,m,H-7a),2.30 (1H,t,J=7.0 Hz,H-8);13C-NMR (100 MHz,CD3OD)δ:150.8 (C-3),149.1 (C-3′),147.2 (C-4′),146.2 (C-4),139.4 (C-1′),133.1 (C-1),122.1 (C-6),119.5 (C-6′),117.7 (C-5),116.3 (C-5′),113.3 (C-2),111.2 (C-2′),102.8 (C-1″),83.8 (C-7′),78.2 (C-3″),77.8 (C-5″),74.9 (C-2″),73.6 (C-9),71.3 (C-4″),62.5 (C-6″),60.4 (C-9′)56.7 (3′-OCH3),56.3 (3-OCH3),54.1 (C-8′),43.8 (C-8),33.6 (C-7)。以上數(shù)據(jù)與文獻(xiàn)[6]基本一致,故鑒定為落葉松脂醇-4′-O-β-D-葡萄糖苷。
化合物2:白色粉末,分子式C20H28O12。ESI-MSm/z:505.2[M+HCOO]-。1H-NMR (400 MHz,CD3OD)δ:7.65 (1H,d,J=1.6 Hz,H-3),6.02 (1H,s,H-7),5.05 (1H,d,J=9.2 Hz,H-1),4.93 (1H,d,J=15.2 Hz,H-10a),4.72 (1H,d,J=8.4 Hz,H-1′),4.20 (2H,q,J=7.2 Hz,H-12),3.86~3.82 (H-2′,3′,4′,5′,6′)3.03 (1H,t,J=6 Hz,H-5),2.63 (1H,t,J=8.4 Hz,H-9),2.08 (3H,s,-OAc);13C-NMR (100 MHz,CD3OD)δ:172.5 (C-11),168.9 (-OAc),155.2 (C-3),146.0 (C-8),131.8 (C-7),108.4 (C-4),101.3 (C-1),100.6 (C-1′),78.6 (C-5′),77.9 (C-3′),75.4 (C-2′),74.9 (C-6),71.6 (C-4′),63.8 (C-12),63.0 (C-6′),61.3 (C-10),46.2 (C-9),42.4 (C-5),20.7 (-OAc),14.6 (C-13)。以上數(shù)據(jù)與文獻(xiàn)[7]基本一致,故鑒定為11-demethoxy-11-ethoxydaphylloside。
化合物3:白色粉末,分子式C19H26O12S。ESI-MSm/z:523.1[M+HCOO]-。1H-NMR (400 MHz,CD3OD)δ:7.65 (1H,d,J=2.6 Hz,H-3),6.02 (1H,d,J=2 Hz,H-7),5.09 (1H,dd,J=14.4,1.2 Hz,H-10),5.05 (1H,d,J=9.2 Hz,H-1),4.94 (1H,d,J=14.8 Hz,H-10),4.80 (1H,m,H-6),4.71 (1H,d,J=7.6 Hz,H-1′),3.87~3.23 (H-2′,3′,4′,5′,6′),3.74 (3H,s,11-OCH3),3.03 (1H,m,H-5),2.62 (1H,t,J=16.4,8 Hz,H-9),2.34 (3H,s,13-CH3);13C-NMR (100 MHz,CD3OD)δ:172.9 (C-11),169.3 (C-12),155.4 (C-3),145.5 (C-8),132.4 (C-7),108.1 (C-4),101.2 (C-1),100.6 (C-1′),78.6 (C-5′),77.9 (C-3′),75.3 (C-6),74.9 (C-2′),71.5 (C-4′),66.2 (C-10),63.0 (C-6′),51.9 (11-OCH3),46.2 (C-9),42.4 (C-5),13.5 (C-13)。以上數(shù)據(jù)與文獻(xiàn)[8]基本一致,故鑒定為雞屎藤酸甲酯。
化合物4:無色油狀,分子式C12H16O6。ESI-MSm/z:279.1[M+Na]+。1H-NMR (400 MHz,CD3OD)δ:5.87 (1H,m,H-7),5.39 (1H,d,J=8 Hz,H-6),4.72 (1H,d,J=1.2 Hz,H-10a),4.72 (1H,d,J=1.2 Hz,H-10b),3.90 (1H,dd,J=4.8,11.2 Hz,H-3a),3.82 (1H,dd,J=3.6,11.2 Hz,H-3b),3.75 (1H,d,J=0.8 Hz,H-1a),3.74 (1H,d,J=2.4 Hz,H-1b),3.09 (1H,m,H-9),2.95 (1H,m,H-4),2.08 (3H,s,13-CH3);13C-NMR (100 MHz,CD3OD)δ:180.8 (C-11),172.3 (C-12),148.3 (C-8),126.9 (C-7),88.1 (C-6),62.8 (C-10),62.6 (C-3),60.5 (C-1),50.1 (C-9),45.9 (C-4),43.8 (C-5),20.6 (C-13)。以上數(shù)據(jù)與文獻(xiàn)[9]基本一致,故鑒定為10-acetylborreriagenin。
化合物5:無色粉末,分子式C18H26O11。ESI-MSm/z:463.1[M+HCOO]-。1H-NMR (400 MHz,CD3OD)δ:7.65 (1H,d,J=1.2 Hz,H-3),6.01 (1H,d,J=2 Hz,H-7),5.05 (1H,d,J=9.2 Hz,H-1),4.79 (1H,m,H-6),4.72 (1H,d,J=8.4 Hz,H-1′),4.45 (1H,d,J=16 Hz,H-10),4.20 (1H,dd,J=1.6,16 Hz,H-10),4.19 (2H,dd,J=1.2,7.2 Hz,-CH2CH3),3.84 (1H,dd,J=12,12 Hz,H-6′),3.61 (1H,dd,J=6,12 Hz,H-6′),3.01 (1H,m,H-5),2.56 (1H,t,J=8.4 Hz,H-9),1.29 (3H,t,J=6.8 Hz,-CH2CH3);13C-NMR (100 MHz,CD3OD)δ:169.0 (C-11),155.3 (C-3),151.5 (C-8),129.8 (C-7),108.5 (C-4),101.5 (C-1),100.4 (C-1′),78.5 (C-5′),77.8 (C-3′),75.4 (C-6),74.9 (C-2′),71.6 (C-4′),62.8 (-CH2CH3),61.7 (C-6′),61.3 (C-10),45.8 (C-9),42.7 (C-5),14.6 (-CH2CH3)。以上數(shù)據(jù)與文獻(xiàn)[10-11]基本一致,故鑒定為去乙酰車葉草苷酸乙酯。
化合物6:無色粉末,分子式C32H44O15。[α]20D-10.3°(c=0.39,CH3OH),ESI-MSm/z:667.3[M-H]-。1H-NMR (400 MHz,CD3OD)δ:6.98 (1H,d,J=2 Hz,H-2),6.84 (1H,dd,J=1.6,7.6 Hz,H-6),6.79 (1H,s,H-6′),6.75 (1H,J=8 Hz,,H-5),6.72 (1H,s,H-2′),5.59 (1H,d,J=6.4 Hz,H-7),4.73 (1H,d,J=1.2 Hz,H-1?),4.33 (1H,d,J=7.2 Hz,H-1″),4.03 (1H,dd,J=8,1.6 Hz,H-9),3.97 (1H,dd,J=1.6,11.2 Hz,H-6″),3.85 (3H,s,3′-OCH3),3.82 (3H,s,5-OCH3),3.85~3.19 (H-9,H-8,H-2″-6″,H-2?-5?),3.56 (2H,t,J=6.4 Hz,H-9′),2.62 (2H,t,J=7.6 Hz,H-7″),1.81 (2H,m,H-8′),1.22 (3H,d,J=6.6 Hz,6?-CH3);13C-NMR (100 MHz,CD3OD)δ:149.0 (C-3),147.4 (C-4),147.4 (C-4′),145.2 (C-3′),137.0 (C-1′),134.6 (C-1),129.5 (C-5′),119.7 (C-6),118.2 (C-6′),116.1 (C-5),114.0 (C-2′),110.7 (C-2),104.3 (C-1″),102.3 (C-1?),89.2 (C-7),78.1 (C-3″),76.9 (C-5″),75.1 (C-2″),74.0 (C-4?),72.5 (C-9),72.3 (C-3?),72.2 (C-2?),71.7 (C-4″),69.8 (C-5?),68.2 (C-6″),62.2 (C-9′),56.7 (3′-OCH3),56.4 (5-OCH3),53.0 (C-8),35.8 (C-8′),32.9 (C-7′),18.1 (5?-CH3)。以上數(shù)據(jù)與文獻(xiàn)[12]基本一致,故鑒定為(-)-(7S,8R)-4,9,9′-trihydroxy-3′,5,-dimethoxy-4′,7-epoxy-8,3′-neoligan-9-O-[α-L-rhamnopyranosyl(1→6)]-β-D-glucopyranoside。
化合物7:白黃色粉末,分子式C26H32O11。[α]20D-26.7°(c=0.27,CH3OH),ESI-MSm/z:519.0[M-H]-。1H-NMR (400 MHz,CD3OD)δ:6.99 (1H,s,H-6′),6.97 (1H,s,H-2′),6.94 (1H,d,J=2,H-2),6.82 (1H,dd,J=8.4,2.0 Hz,H-6),6.77 (1H,d,J=8 Hz,H-5),6.62 (1H,d,J=16 Hz,H-7′),6.24 (1H,dt,J=16,6.3 Hz,H-8′),5.53 (1H,d,J=6.3 Hz,H-7),4.50 (1H,m,H-9′),4.36 (1H,d,J=7.6 Hz,H-1″);4.33 (1H,m,H-9′),3.88 (3H,s,3′-OCH3),3.82 (3H,s,3-OCH3),3.49 (1H,m,H-8),3.90~3.76 (2H,m,H-9),3.69~3.21(5H,m,Glu);13C-NMR (100 MHz,CD3OD)δ:149.6 (C-4′),149.3 (C-3),147.7 (C-4),145.7 (C-3′),134.7 (C-1),134.4 (C-7′),132.5 (C-1′),130.4 (C-5′),124.3 (C-8′),119.9 (C-6),116.8 (C-6′),116.3 (C-5),112.1 (C-2′),110.6 (C-2),103.2 (C-1″),89.5 (C-7),78.3 (C-5″),78.1 (C-3″),75.3 (C-2″),71.8 (C-4″),71.1 (C-9′),65.0 (C-9),62.9 (C-6″),56.8 (C-8),56.5 (3′-OCH3),55.3 (3-OCH3)。以上數(shù)據(jù)與文獻(xiàn)[13]基本一致,故鑒定為(7S,8R)-脫氫雙松柏醇-9′-β-葡萄糖苷。
化合物8:無色晶體,分子式C26H34O11。ESI-MSm/z:521.2[M-H]-。1H-NMR (400 MHz,CD3OD)δ:7.08 (1H,d,J=8 Hz,H-5),6.89 (2H,s,H-2,2′),6.75 (3H,overlapped,H-5′,6,6′),4.85 (1H,d,J=7.6 Hz,H-1″),4.74 (1H,d,J=7.2 Hz,H-7′),3.97 (1H,dd,J=6.4,8.8 Hz,H-9a),3.84-3.39 (H-2″,H-3″,H-4″,H-5″,H-6″,H-9′,H-9b),2.97 (1H,dd,J=4.8,13.6 Hz,H-7a),2.74 (H,m,H-8),2.55 (1H,d,J=13.6 Hz,H-7b),2.38 (1H,m,H-8′);13C-NMR (100 MHz,CD3OD)δ:150.8 (C-3),149.2 (C-3′),147.5 (C-4′),146.3 (C-4),137.1 (C-1),135.3 (C-1′),122.3 (C-6),119.8 (C-6′),118.1 (C-5),116.1 (C-5′),114.2 (C-2),110.5 (C-2′),102.9 (C-1″),84.0 (C-7′),78.2 (C-3″),77.8 (C-5″),74.9 (C-2″),73.4 (C-9),71.3 (C-4″),62.5 (C-6″),60.4 (C-9′)56.7 (3′-OCH3),56.3 (3-OCH3),54.1 (C-8′),43.8 (C-8),33.7 (C-7)。以上數(shù)據(jù)與文獻(xiàn)[6]基本一致,故鑒定為落葉松脂醇-4-O-β-D-葡萄糖苷。
化合物9:白黃色粉末,分子式C9H10O5。ESI-MSm/z:197.1[M-H]-。1H-NMR (400 MHz,CD3OD)δ:7.05 (2H,s,H-2,6),4.27(2H,q,J=7.1 Hz,-OCH2),1.34 (3H,t,J=7.1,-CH3);13C-NMR (100 MHz,CD3OD)δ:168.7 (C-7),146.6 (C-3,5),139.9 (C-4),121.9 (C-1),110.1 (C-2,6),61.8 (OCH2),14.8 (CH3)。以上數(shù)據(jù)與文獻(xiàn)[14]基本一致,故鑒定為沒食子酸乙酯。
化合物10:白色粉末,分子式 C18H24O12。ESI-MSm/z:431.1[M-H]-。1H-NMR (400 MHz,CD3OD)δ:7.65 (1H,s,H-3),6.02 (1H,s,H-7),5.07 (1H,d,J=8.8 Hz,H-1),4.98~4.78 (2H,H-10,6),4.72 (1H,d,J=7.6 Hz,H-1′),3.89~3.21 (H-2′,3′,4′,5′,6′),3.02 (1H,m,H-5),2.63 (H,t,J=8 Hz,H-9),2.09 (3H,s,H-13);13C-NMR (100 MHz,CD3OD)δ:172.5 (C-12),172.5 (C-11),155.4 (C-3),145.9 (C-8),131.9 (C-7),101.2 (C-1′),100.5 (C-1),78.6 (C-5′),77.9 (C-3′),75.4 (C-6),74.9 (C-2′),71.6 (C-4′),63.8 (C-10),62.9 (C-6′),46.2 (C-9),42.5 (C-5),20.7 (C-13)。以上數(shù)據(jù)與文獻(xiàn)[15]基本一致,故鑒定為車葉草酸。
化合物11:白色粉末,分子式C18H22O11。ESI-MSm/z:459.1[M+HCOO]-。1H-NMR (400 MHz,CD3OD)δ:7.29 (1H,d,J=1.6 Hz,H-3),5.96 (1H,d,J=1.6 Hz,H-1),5.72 (1H,s,H-7),5.56 (1H,d,J=6.4 Hz,H-6),4.76 (1H,dd,J=14.4,1.6 Hz,H-10a),4.65 (1H,dd,J=14,0.8 Hz,H-10b),4.67 (H,d,J=8 Hz,H-1′),3.93~3.12 (H-2′,3′,4′,5′,6′,9,5),2.07 (3H,s,H-13);13C-NMR (100 MHz,CD3OD)δ:172.6 (C-12),172.2 (C-11),150.3 (C-3),144.3 (C-8),128.9 (C-7),106.2 (C-4),100.0 (C-1′),93.3 (C-1),86.3 (C-6),78.4 (C-3′),77.9 (C-5′),74.6 (C-2′),71.6 (C-4′),62.8 (C-6′),61.9 (C-10),45.3 (C-9),37.5 (C-5),20.6 (C-13)。以上數(shù)據(jù)與文獻(xiàn)[16]基本一致,故鑒定為車葉草苷。
化合物12:白色粉末,分子式C10H13N5O4。ESI-MSm/z:268[M+H]+。1H-NMR (400 MHz,DMSO-d6)δ:8.35 (1H,s,H-2),8.13 (1H,s,H-8),7.38 (2H,s,-NH2),5.87 (1H,d,J=6 Hz,H-1′),5.47 (2H,d,J=6.4 Hz,2′-OH,5′-OH),5.22 (1H,d,J=4.8 Hz,3′-OH),4.61 (1H,dd,J=11.2,6.0 Hz,H-2′),4.13 (1H,dd,J=8.0,4.4 Hz,H-3′),3.96 (1H,dd,J=6.8,3.2 Hz,H-4′),3.66 (1H,d,J=12.0 Hz,H-5′a),3.54 (1H,m,H-5′b);13C-NMR (100 MHz,DMSO-d6)δ:156.2 (C-6),152.4 (C-2),149.1 (C-4),140.0 (C-8),119.4 (C-5),87.9 (C-1′),85.9 (C-4′),73.4 (C-2′),70.7 (C-3′),61.7 (C-5′)。以上數(shù)據(jù)與文獻(xiàn)[17]基本一致,故鑒定為腺苷。
化合物13:白色粉末,分子式 C35H62O6。1H-NMR (400 MHz,DMSO-d6)δ:5.32 (1H,s,H-6),4.21 (1H,d,J=7.6 Hz,H-1′),3.63,3.40(1H,m,H-6′),3.06 (3H,m,H-3′,4′,5′),2.89 (1H,m,H-2′),1.0 (3H,s,H-18),0.91 (4H,d,J=6.4 Hz,H-24,26),0.82 (9H,m,H-2′),0.65 (3H,s,H-18);13C-NMR (100 MHz,DMSO-d6)δ:140.5 (C-5),121.3 (C-6),100.8 (C-1′),76.9 (C-5′),76.8 (C-3),73.5 (C-2′),70.1 (C-4′),61.6 (C-6′),56.2 (C-14),55.4 (C-17),49.6 (C-9),45.1 (C-24),41.9 (C-13),38.3 (C-4),36.9 (C-1),36.2 (C-10),35.5 (C-20),33.3 (C-22),31.4 (C-7,8),29.3 (C-2),28.7 (C-25),27.8 (C-16),25.4 (C-23),23.9 (C-15),22.6 (C-28),20.6 (C-11),19.7 (C-27),19.1 (C-26),19.0 (C-19),18.6 (C-21),11.8 (C-29),11.7(C-18)。以上數(shù)據(jù)與文獻(xiàn)[18]基本一致,故鑒定為β-胡蘿卜苷。
化合物14:黃白色粉末,分子式C7H6O5。ESI-MSm/z:169.1[M-H]-。1H-NMR (400 MHz,DMSO-d6)δ:6.91 (2H,s,H-2,6);13C-NMR (100 MHz,DMSO-d6)δ:167.5 (C-7),145.4 (C-3,5),137.9 (C-4),120.4 (C-1),108.7 (C-2,6)。以上數(shù)據(jù)與文獻(xiàn)[19]基本一致,故鑒定為沒食子酸。
化合物15:白色粉末,分子式C30H48O3。1H-NMR (400 MHz,CD3OD),ESI-MSm/z:455.4[M-H]-。δ:5.25 (1H,t,H-12),3.15 (1H,dd,J=4.8,11.2 Hz,H-3),2.85 (1H,dd,J=4.4,14.0 Hz,H-18),1.16,0.97,0.95,0.94,0.91,0.82,0.78 (3H×7,s,H-30,29,27,26,25,24,23);13C-NMR (100 MHz,CD3OD)δ:181.9 (C-28),145.4 (C-13),123.8 (C-12),79.8 (C-3),56.9 (C-5),47.8 (C-17),47.4 (C-19),43.0 (C-14),42.9 (C-18),40.7 (C-8),40.0 (C-4),40.0 (C-1),38.3 (C-10),35.0 (C-21),34.1 (C-7),34.0 (C-22),33.7 (C-29),31.8 (C-20),29.0 (C-15),28.9 (C-23),28.0 (C-2),26.5 (C-27),24.7 (C-16),24.2 (C-11),24.1 (C-30),19.6 (C-6),17.9 (C-26),16.5 (C-24),16.0 (C-25)。以上數(shù)據(jù)與文獻(xiàn)[20]基本一致,故鑒定為齊墩果酸。
本研究從正丁醇萃取部位分離得到15個化合物,主要為萜類(2~5、10、11、15)、木脂素類(1、6~8),除此之外還有酚酸類(9、14)、甾類(13)。據(jù)報道,茜草屬植物化學(xué)成分種類豐富,近年來從該屬植物中分離得到較多的萜類化合物[21]。本研究通過對鉤毛茜草進(jìn)行化學(xué)成分研究,分離得到7個萜類化合物,包括6個環(huán)烯醚萜和1個五環(huán)三萜,與茜草屬植物富含萜類化合物的文獻(xiàn)報道一致。此外,本實(shí)驗分離出的4個木脂素類化合物均為首次從茜草屬植物中分離得到,此類成分具有良好的生物活性,化合物6可降低乙酰氨基酚誘導(dǎo)的肝癌細(xì)胞系HepG2的細(xì)胞損傷[12],且含量相對較多,具有潛在的應(yīng)用前景,以期豐富茜草屬植物的抗癌活性成分,為后續(xù)抗癌藥物研究提供參考;化合物8對H1N1流感病毒有強(qiáng)烈的抑制作用,通過下調(diào)H1N1流感病毒感染誘導(dǎo)的 TNF-a、IL-6 和 IP-10 等分子發(fā)揮作用[22]。本研究結(jié)果豐富了鉤毛茜草的物質(zhì)基礎(chǔ),以期為鉤毛茜草的進(jìn)一步開發(fā)應(yīng)用提供理論依據(jù)。