白志強(qiáng),林秀萍,楊 斌,周雪峰,王俊峰,劉永宏*
1中國科學(xué)院南海海洋研究所 中國科學(xué)院海洋生物資源可持續(xù)利用重點(diǎn)實(shí)驗(yàn)室,廣州 510301;2 中國科學(xué)院大學(xué),北京 100049
近年來,從海洋真菌代謝產(chǎn)物得到了許多結(jié)構(gòu)新穎、活性顯著的藥物[1]。內(nèi)生真菌(endophytic fungi)指生活于生物組織內(nèi)部、不會對生物組織致病的一類真菌。內(nèi)生真菌全部或部分生活周期都在寄主體內(nèi),與之形成互惠共生的關(guān)系:一方面,寄主為其提供必需的光合產(chǎn)物、礦物質(zhì)等,以及相對穩(wěn)定的生活環(huán)境;另一方面,內(nèi)生真菌產(chǎn)生的活性代謝產(chǎn)物,或能刺激該生物生長發(fā)育,或能提高宿主對外界環(huán)境的抵抗能力[2]。目前,內(nèi)生真菌已經(jīng)成為發(fā)現(xiàn)結(jié)構(gòu)新穎、活性明顯的次級代謝產(chǎn)物的重要來源[3,4]。其中從內(nèi)生擬盤多毛孢菌的代謝產(chǎn)物中發(fā)現(xiàn)了許多結(jié)構(gòu)新穎的化合物,引起了人們的廣泛重視[5],如抗HIV 的pestalatazines[6],具有細(xì)胞毒活性的pestaloficiols[7],具有抗真菌活性的pestafolide A[8]。我們在對Pestalotiopsis versicolor 菌株液體發(fā)酵培養(yǎng)后,從該菌株的代謝產(chǎn)物中分離得到了8 個(gè)化合物,它們均為首次從該菌株中分離得到。
該擬盤多毛孢菌菌株采集自我國南海海域的紅樹林植物桐花樹的樹枝,為內(nèi)生真菌,經(jīng)鑒定為Pestalotiopsis versicolor。該菌種目前保藏于中國科學(xué)院南海海洋研究所海洋生物資源可持續(xù)利用重點(diǎn)實(shí)驗(yàn)室。
薄層硅膠板(煙臺江友硅膠開發(fā)有限公司);硅膠H(青島海洋化學(xué)儀器廠);Sephadex LH-20 柱色譜凝膠(Pharmacia 公司)。顯色劑:5%硫酸乙醇溶液;碘。所用試劑均為化學(xué)純,購自廣州化學(xué)試劑廠。
BS110S 型電子天平(德國塞多利斯股份公司);EYELAN-1001 型旋轉(zhuǎn)蒸發(fā)儀(上海愛郎儀器有限公司);SHZ-CB 型循環(huán)水真空泵(鞏義市予華儀器有限公司);KQ-250DB 型超聲儀(鞏義市予華儀器有限公司);AVANCE 500 核磁共振儀(美國BRUKER 公司);MAT 95XP 快原子轟擊質(zhì)譜儀(美國熱電公司);HYG-C 三層多功能搖床(北京博宇寶威實(shí)驗(yàn)設(shè)備有限公司);立式自動(dòng)電熱壓力蒸汽滅菌鍋(合肥華泰醫(yī)療器械有限公司)。
從采自我國南海海域的紅樹林桐花樹的樹枝分離得到一株內(nèi)生擬盤多毛孢真菌,對其固體發(fā)酵產(chǎn)物全面系統(tǒng)地研究之后,發(fā)現(xiàn)它能產(chǎn)生一些具有細(xì)胞毒活性和抗病毒活性的新化合物和新天然產(chǎn)物[9]。因此,我們對該真菌菌株進(jìn)行大規(guī)模液體發(fā)酵研究。發(fā)酵方法如圖1,培養(yǎng)過程中所用培養(yǎng)基均為馬鈴薯PDA 培養(yǎng)基[10]。種子培養(yǎng)液在搖床中培養(yǎng)時(shí)轉(zhuǎn)速設(shè)定為180 rpm,整個(gè)培養(yǎng)過程中的溫度均為25 ℃。
圖1 發(fā)酵培養(yǎng)過程Fig.1 The fermentation process
發(fā)酵結(jié)束后,對發(fā)酵產(chǎn)物用丙酮按照1∶1 比例進(jìn)行滅活萃取、提取三次后將菌絲體與液體培養(yǎng)基分離,分別進(jìn)行萃取,經(jīng)HPLC 分析后合并萃取物,得到油狀浸膏約60 g。對該粗浸膏用90%甲醇溶解后用正己烷萃取,得甲醇水部位約45 g 樣品,經(jīng)中壓硅膠色譜柱分離后,得到11 個(gè)餾分。所得各餾分經(jīng)過凝膠Sephadex LH-20,常壓硅膠色譜柱后,經(jīng)薄層制備(HPTLC)以及重結(jié)晶等方法分離得到8個(gè)化合物。化合物1,約50 .0mg;化合物2,約7.3 mg;化合物3,約4.2 mg;化合物4,約5.8 mg;化合物5,約10.0 mg;化合物6,約8.0 mg;化合物7,約8.0mg;化合物8,約10.0 mg。
化合物1 白色粉末(氯仿),1H NMR(CDCl3,500 MHz)δ:5.58(1H,d,J=3.0 Hz,H-6),5.39(1H,m,H-7),5.22(1H,dd,J=15.0,7.0 Hz,H-22),5.16(1H,d,J=15.0,7.0 Hz,H-23),3.68(1H,m,H-3),2.49(1H,d,J=7.5 Hz,H-14),2.31(1H,t,J=13.5 Hz,H-25),1.97(1H,t,J=1.5 Hz,H-9),1.04(3H,d,J=6.5 Hz,H-27),1.02(3H,J=6.5 Hz,H-26),0.99(3H,s,H-21),0.92(3H,d,J=7.0 Hz,H-19),0.83(3H,s,H-28),0.64(3H,s,H-18);13C NMR(CDCl3,125 MHz)δ:141.4(C-8),139.8(C-5),135.6(C-22),132.1(C-23),119.6(C-6),116.4(C-7),70.5(C-3),55.9(C-17),54.6(C-14),46.4(C-9),43.6(C-13),42.9(C-24),40.9(C-4),40.4(C-20),39.2(C-12),38.4(C-10),33.1(C-25),32.1(C-2),28.3(C-16),23.0(C-15),21.2(C-11),19.9(C-21),19.7(C-27),19.7(C-28),17.6(C-26),16.3(C-19),12.1(C-18);LR-EI-MS m/z[M-H]-395。以上數(shù)據(jù)與文獻(xiàn)報(bào)道[11]一致,確定該化合物為麥角甾醇(Ergosterol)。
化合物2 白色無定型粉末(氯仿),1H NMR(CDCl3,500 MHz),δ:5.60(1H,s,H-7),5.31(2H,m,H-22,H-23),3.98(1H,m,H-3),0.69(3H,s,H-19),1.01(3H,s,H-19),1.07(3H,d,J=6.5 Hz,H-21),0.88(6H,d,J=7.0 Hz,H-26,H-27),0.97(3H,d,J=6.5 Hz,H-28);13C NMR(CDCl3,125 MHz)δ:197.8(C-6),164.5(C-8),135.1(C-22),132.5(C-23),119.8(C-7),116.4(C-7),79.7(C-5),74.7(C-9),67.3(C-3),56.0(C-17),51.8(C-14),45.3(C-13),41.8(C-10),40.3(C-20),37.1(C-4),34.9(C-12),33.1(C-25),30.1(C-2),28.8(C-11),25.5(C-1),22.8(C-16),22.3(C-15),21.1(C-21),20.4(C-19),19.9(C-27),19.6(C-26),17.6(C-28),12.2(C-18);LR-EI-MS m/z [M +Na]+467。以上數(shù)據(jù)與文獻(xiàn)報(bào)道[12]一致,確定該化合物為3β,5α,9α-三羥基-7-22 麥角甾二烯-6-酮。
化合物3 白色粉末(氯仿),1H NMR(CDCL3,500 MHz),δ:5.24(2H,m,H-22,H-23),3.97(2H,m,H-3,H-6),3.31(1H,d,J=2.5 Hz,H-7),0.61(3H,s,H-18),0.84(3H,d,J=14.5 Hz,H-28),0.86(3H,d,J=10.0 Hz,H-27),0.93(3H,d,J=7.5 Hz,H-25),1.02(3H,d,J=6.5 Hz,H=21);13C NMR(CDCl3,125 MHz)δ:135.6(C-22),134.5(C-9),132.1(C-33),127.0(C-8),68.6(C-3),67.2(C-6),65.7(C-5),62.6(C-7),53.8(C-17),49.7(C-14),42.9(C-24),42.2(C-13),40.4(C-20),393(C-4),38.1(C-10),35.8(C-12),33.2(C-26),30.9(C-2),30.3(C-1),29.0(C-15),23.9(C-11),23.5(C-16),22.8(C-19),20.9(C-21),19.9(C-27),19.7(C-28),17.7(C-25),11.4(C-18);LR-EI-MS m/z[M+H]+447。以上數(shù)據(jù)與文獻(xiàn)報(bào)道[13]基本一致,確定該化合物為ergosta-8(9),22-diene-3,5,6,7-tetraol(3β,5α,7α,22E)。
化合物4 白色粉末(甲醇),1H NMR(MeOD,500 MHz),δ:4.25(1H,dd,J=5.0 Hz,H-5),4.19(2H,t,J=6.5 Hz,H-7),2.52(1H,m,H-4a),2.27(1H,m,H-4b),2.44(2H,m,H-3),1.67(2H,m,H-8),1.41(2H,m,H-9),0.96(3H,t,J=7.5 Hz,H-10);13C NMR(MeOD,125 MHz)δ:177.4(C-6),171.9(C-2),65.6(C-7),55.4(C-5),30.6(C-8),29.1(C-3),24.9(C-4),19.1(C-9),13.6(C-10);LR-EI-MS m/z[M +H]+186。以上數(shù)據(jù)與文獻(xiàn)報(bào)道[14]一致,確定該化合物為butyl 2-pyrrolidone-5-carboxylate。
化合物5 白色粉末(甲醇),1H NMR(CDCl3,500 MHz)δ:1H NMR(MeOD,500 MHz),δ:7.25(1H,s,H-6),1.86(3H,s,H-5);13C NMR(CDCl3,125 MHz),δ:163.7(C-4),151.0(C-2),140.2(C-6),107.1(C-5),18.1(C-5)。以上數(shù)據(jù)與文獻(xiàn)報(bào)道[15]一致,由此鑒定該化合物為胸腺嘧啶。
化合物6 白色粉末(甲醇),1H NMR(CDCl3,500 MHz)δ:7.41(1H,d,J=7.5 Hz,H-6),5.72(1H,d,J=7.5,H-5);13C NMR(CDCl3,125 MHz),δ:166.4(C-4),153.5(C-2),141.3(C-6),101.6(C-5);LR-EI-MS m/z[M+H]+113。以上數(shù)據(jù)與文獻(xiàn)報(bào)道[15]一致,故確定為尿嘧啶。
化合物7 白色粉末(甲醇),1H NMR(CDCl3,500 MHz)δ:7.71(2H,m,H-2,H-5),7.53(2H,m,H-3,H-4),4.31(4H,t,J=6.5 Hz,H-1'),1.74(4H,m,H-2'),1.47(4H,m,H-3'),0.97(3H,t,J=7.5 Hz,H-Me-4');13C NMR(MeOD,125 MHz)δ:167.7(C-7),166.4(C-4),132.3(C-1,C-6),130.9(C-3,C-4),128.8(C-2,C-5),65.6(C-1'),30.6(C-2'),19.2(C-3'),13.7(C-4');LR-EI-MS m/z[M +H]+279。以上數(shù)據(jù)與文獻(xiàn)[16]報(bào)道一致,確定該化合物為鄰苯二甲酸正丁酯。
化合物8 白色粉末(氯仿),1H NMR(MeOD,500 MHz),δ:9.79(1H,s,H-7),7.81(2H,d,J=8.5 Hz,H-2,H-6),6.94(2H,d,J=8.5 Hz,H-3,H-7);13C NMR(MeOD,125 MHz)δ:191.0(C-1),166.4(C-4),133.1(C-2,H-6),129.6(C-1),117.4(C-3);LR-EI-MS m/z[M+H]+122。以上數(shù)據(jù)與文獻(xiàn)[17]報(bào)道一致,確定該化合物為對羥基苯甲醛。
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