楊光忠,何思文
(中南民族大學 藥學院,武漢 430074)
藤黃為藤黃科藤黃(GarciniahanburyiHook.f.)所分泌出的干燥樹脂.中醫(yī)記載藤黃具有消腫、化毒、止血、殺蟲等功效.近年來其抗腫瘤活性的研究受到關注,陸續(xù)從藤黃樹脂提取物中分離得到一系列結(jié)構新穎的籠狀多異戊烯基口山 酮類化合物[1]和三萜類化合物[2].研究表明,籠狀多異戊烯基口山 酮類化合物對腫瘤細胞具有明顯的毒性作用,如代表性的化合物藤黃酸既能抑制人肺癌細胞SMMC-7721中端粒酶逆轉(zhuǎn)錄酶基因的表達,也能調(diào)節(jié)人胃癌細胞MGC-803中Bax和Bcl-2蛋白的表達[3].
為進一步了解藤黃樹脂的有效成分,本文利用正相和反相硅膠柱色譜法、半制備高效液相色譜法對其分離和純化,從藤黃樹脂提取物中分離得到5種化合物,結(jié)合譜學技術鑒定其化學結(jié)構,其結(jié)構分別鑒定為2α-羥基-3-乙酰氧基白樺酯酸(I),2-O-乙?;?山楂酸(II),鄰苯二甲酸二丁酯(III),鄰苯二甲酸二異丁酯(IV),鄰苯二甲酸-二-2-乙基己酯(V),化合物2~5為首次從該植物中分離而得.
核磁共振儀(Bruker DRX-500型,TMS內(nèi)標),半制備型高效液相色譜儀(美國Dionex公司Ultimate 3000型),薄層層析硅膠H、柱層析硅膠(200~300目)、GF254薄層板(青島海洋化工廠),色譜純?nèi)軇?美國TEDIA公司),其余試劑均為分析純(國藥集團化學試劑有限公司).試驗材料藤黃樹脂購于安徽亳州.
藥用藤黃粉末5 kg用95%的工業(yè)乙醇浸泡提取3次,每次72 h,合并3次提取液,減壓濃縮至無醇味,得藤黃樹脂浸膏3942 g.取500 g浸膏,經(jīng)硅膠色譜(V(環(huán)己烷):V(丙酮)= 100︰0 ~ 0︰100)分離,TLC檢測合并成6個部分(Fr01~Fr06).Fr01(22g)加入吡啶溶解,再加入溫蒸餾水放置數(shù)天,出現(xiàn)黃色沉淀,抽濾,沉淀用MeOH重結(jié)晶數(shù)次得白色結(jié)晶,得化合物I (202mg);F02 (16g)經(jīng)硅膠色譜(V(環(huán)己烷)︰V(丙酮)= 95︰5 ~ 0︰100)分離得到5個部分(Fr02.1 ~ Fr02.5).Fr02.2(3.6g,取其中100 mg)經(jīng)HPLC(V(甲醇)︰V(水)= 90︰10)得到化合物II (3mg,tR=18.5min);F03 (35g)經(jīng)硅膠色譜(V(環(huán)己烷):V(氯仿)=90︰10 ~ 0︰100)分離得到8個部分(Fr03.1 ~ Fr03.8).Fr03.1(761mg)依次經(jīng)過硅膠柱色譜(V(環(huán)己烷)︰V(丙酮)=100︰0 ~99︰1)和HPLC(V(甲醇)︰V(水)= 78︰22)分離得到化合物III (3mg,tR:18.5min);Fr03.2(1.2g)依次經(jīng)過硅膠柱色譜(V(環(huán)己烷)︰V(丙酮)=100︰0 ~ 1︰1)、HPLC(V(甲醇)︰V(水)= 78︰22)分離得到化合物IV(2mg,tR=9.3 min),V(7mg,tR=19.8min).
化合物I:白色針狀結(jié)晶,分子式C32H50O5.1H-NMR (C5D5N,500 MHz)δ:0.84 (3H,s,H3-23),0.90 (3H,s,H3-24),0.93 (3H,s,H3-25),0.99 (3H,s,H3-26),1.01 (3H,s,H3-27),1.75 (3H,s,H3-30),2.06 (3H,s,COOCH3),3.51 (1H,td,J=10.4,5.3Hz,H-19),4.15 (1H,td,J= 10.7,4.5Hz,H-2),4.74 (1H,br s,H2-29a),4.91(1H,d,J= 1.37,H2-29b),5.04 (1H,d,J= 9.9 Hz,H-3);13C-NMR (C5D5N,125 MHz)δ:49.1 (C-1),66.1 (C-2),85.4 (C-3),39.9 (C-4),55.8(C-5),18.9 (C-6),34.9 (C-7),41.4 (C-8),51.1 (C-9),38.8 (C-10),21.5 (C-11),26.3 (C-12),29.0 (C-13,23),43.2 (C-14),30.5(C-15),33.1 (C-16),56.9 (C-17),50.0 (C-18),48.1 (C-19),151.5 (C-20),31.5 (C-21),37.9 (C-22),30.5 (C-23),18.2 (C-24),17.8 (C-25),16.7 (C-26),15.1 (C-27),179.0 (C-28),110.3 (C-29),19.7 (C-30),172.0 (COOCH3),21.6 (COOCH3),以上數(shù)據(jù)與文獻[2]報道一致,鑒定該化合物為2α-羥基-3β-乙酰氧基白樺酯酸.
化合物II:白色粉末,分子式C32H50O5.1H-NMR (CDCl3,500 MHz)δ:0.74 (3H,s,H3-26),0.85 (3H,s,H3-24),0.90 (3H,s,H3-29),0.92 (3H,s,H3-30),1.02 (3H,s,H3-25),1.05 (3H,s,H3-23),1.12 (3H,s,H3-27),2.07 (3H,s,COOCH3),3.19 (1H,d,J= 10.1 Hz,H-3),4.94 (3H,td,J= 10.5,4.3 Hz,H3-2),5.26 (1H,br s,H-12);13C-NMR (CDCl3,125 MHz)δ:43.7 (C-1),73.3 (C-2),81.0 (C-3),39.8 (C-4),55.2 (C-5),18.3 (C-6),32.5 (C-7),39.4 (C-8),47.6(C-9),38.4 (C-10),22.9 (C-11),122.4 (C-12),143.7 (C-13),41.7 (C-14),27.6 (C-15),23.5 (C-16),46.5 (C-17),41.1 (C-18),45.9 (C-19),32.4 (C-20),33.8 (C-21),30.7 (C-22),28.5 (C-23),16.6 (C-24),16.3 (C-25),17.1 (C-26),25.9 (C-27),182.3 (C-28),33.0 (C-29),23.6 (C-30),21.3 (OCOCH3),171.7 (OCOCH3),以上數(shù)據(jù)與文獻[4]報道一致,鑒定該化合物為2-O-乙?;?山楂酸.
化合物III:棕色粉末,分子式C16H22O4.1H-NMR (CDCl3,500 MHz)δ:0.96 (6H,br s,H3-12,12′),1.44 (4H,br s,H2-11,11′),1.72 (4H,br s,H2-10,10′),4.31 (4H,br s,H2-9 ,9′),7.53 (2H,br s,H2-4 ,5),7.72 (2H,br s,H2-3,6);13C-NMR(CDCl3,125 MHz)δ:132.3 (C-1,2),128.8 (C-3,6),130.9 (C-4,5),167.8 (C-7,7′),65.6 (C-9,9′),30.5 (C-10,10′),19.2 (C-11,11′),13.7 (C-12,12′),以上數(shù)據(jù)與文獻[5]報道一致,鑒定該化合物為鄰苯二甲酸二丁酯.
化合物IV:橙色油狀物,分子式C16H22O4.1H-NMR(CDCl3,500 MHz)δ:0.99 (12H,d,J= 6.7Hz,H3-11,11′ ,12,12′ ),1.96~2.30 (2H,m,H-10,10′),4.09 (4H,d,J= 6.8Hz,H2-9,9′ ),7.54 (2H,dd,J= 5.5,3.4Hz,H-4,5),7.74 (2H,dd,J= 5.4,3.4Hz ,H-3,6);13C-NMR (CDCl3,125 MHz)δ:132.3 (C-1,2),130.9 (C-3,6),128.8 (C-4,5),167.8 (C-7,7′ ),71.8 (C-9,9′),27.7 (C-10,10′),19.1 (C-11,11′,12,12′),以上數(shù)據(jù)與文獻[6]報道一致,鑒定該化合物為鄰苯二甲酸二異丁酯.
化合物V:橙色油狀物,分子式C24H38O4.1H-NMR (CDCl3,500MHz)δ:0.80~1.00 (12H,m,H3-14,14′,H-2′,2′′),1.21~1.48 (16H,m,H2-11,11′ ,12,12′ ,13,13′ ,1′ ,1′′),1.61~1.74 (2H,m,H-10,10′),4.13~4.27 (4H,m,H2-9,9′),7.53 (2H,dd,J= 5.4,3.2 Hz,H-3,4),7.71(2H,dd,J= 5.4,3.4Hz,H-2,5);13C-NMR (CDCl3,125MHz)δ:128.8 (C-4,5),130.9 (C-3 ,6),132.4 (C-1,2),167.8 (C-7,7′),68.1 (C-9,9′),38.7 (C-10,10′),30.3 (C-11,11′),28.9 (C-12,12′),23.0 (C-13,13′),14.0 (C-14 ,14′),23.7 (C-1′ ,1′′),10.9 (C-2′ ,2′′),以上數(shù)據(jù)與文獻[7]報道一致,鑒定該化合物為鄰苯二甲酸-二-2-乙基己酯.
圖1 化合物I~V的結(jié)構式
通過對藤黃樹脂化學成分的系統(tǒng)分離,得到了5個化合物,化合物I是羽扇豆烷型三萜,化合物II是齊墩果烷型三萜,化合物III~V為鄰苯二甲酯類化合物.說明藤黃樹脂除富含籠狀多異戊烯基口山酮類化合物外還有萜類化合物,羽扇豆烯型和齊墩果烷型三萜也表現(xiàn)出良好的抗腫瘤活性,豐富了藤黃抗腫瘤活性成分的結(jié)構類型.鄰苯二甲酯類化合物盡管可能是分離過程中所形成的人工產(chǎn)物,但也有文獻報道從金釵石斛莖、海藻基根硬毛藻和廣西血竭等植物中分離得到該類化合物[5-7],支持自然界也可能存在該類化合物,商品化鄰苯二甲酯類化合物為昆蟲的驅(qū)避劑,提供該類化合物在自然界存在可能發(fā)揮的生理功能.
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