吳植獻(xiàn),王亞軍,陳 瑋,薛 鋒,萬(wàn)南微,鄭裕國(guó)
(浙江工業(yè)大學(xué)生物工程研究所,浙江杭州 310014)
布雷菲德菌素A(3,Chart 1)是一種具有多重生物活性,由真菌發(fā)酵產(chǎn)生的13元環(huán)的大環(huán)內(nèi)酯類抗生素[1]。3通過(guò)與高爾基體關(guān)聯(lián)的蛋白轉(zhuǎn)運(yùn)因子結(jié)合,阻礙蛋白質(zhì)向高爾基體轉(zhuǎn)運(yùn),從而表現(xiàn)出抗真菌、抗病毒、抗有絲分裂活性[2],而隨著蛋白在內(nèi)質(zhì)網(wǎng)上的積累會(huì)造成內(nèi)質(zhì)網(wǎng)滲透壓的升高,最終導(dǎo)致細(xì)胞的程序性死亡,使其具有了對(duì)多種癌細(xì)胞具有抑制活性[3-4]。
Scheme 1
Chart 1
美國(guó)腫瘤研究院將3作為抗腫瘤藥物重點(diǎn)研究,視為新型抗癌候選藥物[5]。但由于3自身的藥代動(dòng)力學(xué)性質(zhì)(水溶性差、血漿半衰期短、細(xì)胞選擇性差等)不理想,阻礙了其作為抗腫瘤治療藥物的臨床研究[6]。研究發(fā)現(xiàn),3的4-羥基是其活性的關(guān)鍵位點(diǎn)[7-9]。
本課題組曾對(duì)3的發(fā)酵和分離純化進(jìn)行過(guò)研究[10-11]。本文將芳胺(1a ~1m)或環(huán)己胺(1n)與三光氣反應(yīng)制得芳基異氰酸酯(2a~2n);2a~2n分別對(duì)3的7-羥基進(jìn)行結(jié)構(gòu)修飾,合成了14個(gè)新型布雷菲德菌素A氨基甲酸酯類衍生物——7-O-(芳基氨基甲酸酯)-布雷菲德菌素A(4a~4n),其結(jié)構(gòu)經(jīng)1H NMR,13C NMR和 ESIHR-MS表征。并對(duì)其抗腫瘤活性進(jìn)行了研究。
AvanceⅢ500 MHz型和Avance 126 MHz型核磁共振儀(CDCl3為溶劑,TMS為內(nèi)標(biāo));Esquire 6000型電感耦合等離子體質(zhì)譜儀。
3 按文獻(xiàn)方法[10-11]制備(含量 99.5%);其余所用試劑均為分析純,其中甲苯經(jīng)干燥重蒸后使用。
(1)2a~2n的合成(以2a為例)
在反應(yīng)瓶中加入三光氣60 mg(0.2 mmol)和無(wú)水甲苯20 mL,攪拌使其溶解;冰浴冷卻,于1 h內(nèi)滴加混合液[苯胺(1a)46 mg(0.5 mmol)+催化劑三乙胺40 μL+無(wú)水甲苯50 mL],滴畢,于室溫反應(yīng)30 min;回流(80℃)反應(yīng)3 h至反應(yīng)液澄清[12]。減壓蒸除溶劑得黃色固體2a 58 mg(直接進(jìn)行下步反應(yīng))。
用類似的方法合成2b~2n。
(2)4a~4n的合成(以4a為例)
在反應(yīng)瓶中依次加入3 110 mg(0.4 mmol),無(wú)水甲苯30 mL和吡啶200 μL,升溫至回流(90℃)使其溶解;將溶液直接倒入上述2a的濃縮圓底瓶中,回流反應(yīng)6 h[TLC跟蹤:展開劑:A=V(乙酸乙酯)∶V(石油醚)=1∶5]。減壓旋干甲苯,殘余物用二氯甲烷50 mL溶解,用飽和氯化鈉溶液(3×10 mL)洗滌,無(wú)水硫酸鈉干燥,減壓旋干溶劑后用少量甲醇溶解,經(jīng)自制硅膠板(展開劑:A=1∶2)分離,取目標(biāo)產(chǎn)物條帶,將硅膠條帶刮下,粉碎,經(jīng)硅膠柱層析(洗脫劑:A=1∶2)純化得淡黃色粉末4a。
用類似的方法合成淡黃色粉末4b~4n。
7-O-(苯基氨基甲酸酯)-布雷菲德菌素 A(4a):產(chǎn)率 31.7%;1H NMR δ:7.41 ~7.19(m,6H),5.92(d,J=15.6 Hz,1H),5.82 ~ 5.57(m,1H),5.12(dd,J=8.7 Hz,4.5 Hz,1H),4.85(dd,J=10.4 Hz,5.7 Hz,1H),4.11(d,J=8.7 Hz,1H),2.49 ~2.05(m,4H),2.03(d,J=27.9 Hz,1H),1.93 ~1.78(m,3H),1.77 ~1.69(m,1H),1.67 ~ 1.57(m,1H),1.69 ~1.58(m,1H),1.57 ~ 1.45(m,1H),1.26(t,J=6.2 Hz,3H),0.92(dd,J=19.6 Hz,12.7 Hz,1H);13C NMR δ:166.28,154.88,151.61,136.04,131.50,130.90,129.46,129.05,121.68,121.62,117.69,75.81,75.69,71.82,52.22,43.98,43.94,40.23,38.74,34.98,31.83,26.67,20.84;ESI-HR-MS m/z:Calcd for C23H29NO5Na{[M+Na]+}422.2,found 422.1。
7-O-(芐基氨基甲酸酯)-布雷菲德菌素 A(4b):產(chǎn)率 26.4%;1H NMR δ:7.41 ~7.19(m,6H),5.92(d,J=15.6 Hz,1H),5.82 ~ 5.57(m,1H),5.12(dd,J=8.7 Hz,4.5 Hz,1H),4.85(dd,J=10.4 Hz,5.7 Hz,1H),4.48 ~4.19(m,2H),4.11(d,J=8.7 Hz,1H),2.49 ~2.05(m,4H),2.03(d,J=27.9 Hz,1H),1.93 ~1.78(m,3H),1.77 ~1.69(m,1H),1.67 ~1.57(m,1H),1.69 ~1.58(m,1H),1.57 ~1.45(m,1H),1.26(t,J=6.2 Hz,3H),0.92(dd,J=19.6 Hz,12.7 Hz,1H);13C NMR δ:166.28,156.23,151.68,138.50,136.14,130.70,130.56,128.66,128.63,127.53,127.47,117.60,75.80,75.73,71.72,52.14,45.01,43.91,40.26,38.71,34.15,31.80,26.65,20.83;ESI-HR-MS m/z:Calcd for C24H31NO5Na{[M+Na]+}436.2,found 436.1。
7-O-(鄰甲基苯氨基甲酸酯)-布雷菲德菌素A(4c):產(chǎn)率32.0%;1H NMR δ:7.54 ~7.01(m,5H),5.91(s,1H),5.23(d,J=64.1 Hz,2H),4.85(s,1H),4.41(s,1H),4.09(s,1H),2.31(t,J=33.2 Hz,6H),1.86(s,3H),1.75 ~1.62(m,3H),1.45(d,J=80.0 Hz,2H),1.28 ~1.08(m,3H),0.93(s,1H);13C NMR δ:166.33,156.67,151.84,136.00,135.34,131.54,131.01,130.74,130.37,127.05,126.75,117.53,76.18,75.59,71.72,52.01,43.86,40.17,38.60,34.04,31.77,26.62,20.80,17.67;ESI-HR-MS m/z:Calcd for C24H31NO5Na{[M+Na]+}436.2,found 436.1。
7-O-(對(duì)甲苯基氨基甲酸酯)-布雷菲德菌素A(4d):產(chǎn)率 31.8%;1H NMR δ:8.02 ~6.50(m,5H),5.80(m,1H),5.62 ~4.98(m,2H),4.87(s,1H),4.87(s,1H),4.40(s,1H),4.40(s,1H),3.04 ~2.11(m,6H),2.01(s,1H),1.78(dd,J=78.0 Hz,16.3 Hz,4H),1.50(d,J=39.1 Hz,2H),1.25(t,J=20.2 Hz,3H),0.93(s,1H);13C NMR δ:166.30,155.05,151.72,136.08,135.11,130.80,129.99,129.56,129.52,123.38,122.00,117.62,75.76,75.64,71.79,52.20,43.93,40.21,38.74,34.09,31.82,26.68,20.85,20.74;ESI-HR-MS m/z:Calcd for C24H31NO5Na{[M+Na]+}436.2,found 436.1。
7-O-(對(duì)氯苯基氨基甲酸酯)-布雷菲德菌素A(4e):產(chǎn)率 30.5%;1H NMR δ:7.51 ~ 7.44(m,3H),7.34(t,J=14.0 Hz,3H),5.72(s,2H),5.33 ~5.21(m,2H),5.03(s,1H),4.72(s,1H),4.03(s,1H),2.27 ~2.07(m,4H),1.77 ~1.61(m,4H),1.50(d,J=8.3 Hz,3H),1.20(t,J=10.2 Hz,3H),0.76(s,1H);13C NMR(DMSO)δ:196.96,165.63,154.11,153.12,138.26,136.43,130.59,130.03,129.11,128.59,123.44,119.60,116.94,75.49,73.96,70.88,51.90,42.69,40.02,38.29,33.45,31.42,26.53,20.70;ESI-HR-MS m/z:Calcd for C23H28NO5ClNa{[M+Na]+}456.2,found 456.1。
7-O-(鄰氯苯基氨基甲酸酯)-布雷菲德菌素A(4f):產(chǎn)率 28.2%;1H NMR δ:7.33(t,J=26.3 Hz,4H),7.11(s,1H),7.00(s,1H),5.94(s,J=15.7 Hz,1.8 Hz,1H),5.74(s,J=15.0 Hz,10.2 Hz,4.6 Hz,1H),5.33 ~ 5.22(m,1H),5.22 ~5.12(m,1H),4.92 ~4.79(m,1H),4.14(d,J=9.0 Hz,1H),2.37 ~2.27(m,3H),1.86(d,J=6.9 Hz,3H),1.72(d,J=6.6 Hz,2H),1.52(d,J=16.4 Hz,2H),1.27(t,3H),0.96(s,1H);13C NMR δ:166.17,152.79,151.45,135.89,134.67,131.01,129.06,127.72,125.80,125.37,123.73,117.75,76.54,75.76,71.73,52.04,43.93,41.97,40.18,38.62,34.11,31.79,27.00,26.63,20.83;ESI-HR-MS m/z:Calcd for C23H28NO5ClNa{[M+Na]+}456.2,found 456.1。
7-O-(2,4-二氯苯胺氨基甲酸酯)-布雷菲德菌素 A(4g):產(chǎn)率 28.9%;1H NMR δ:7.33(t,J=26.3 Hz,4H),7.11(s,1H),7.00(s,1H),5.94(d,J=15.7 Hz,1.8 Hz,1H),5.74(d,J=15.0 Hz,10.2 Hz,4.6 Hz,1H),5.33 ~5.22(m,1H),5.22 ~5.12(m,1H),4.92 ~4.79(m,1H),4.14(d,J=9.0 Hz,1H),2.37 ~2.27(m,3H),1.86(d,J=6.9 Hz,3H),1.72(d,J=6.6 Hz,2H),1.52(d,J=16.4 Hz,2H),1.27(t,J=5.3 Hz,3H),0.96(s,1H);13C NMR δ:166.17,165.67,152.66,151.38,147.11,136.22,135.82,133.52,131.13,128.76,127.90,117.83,75.77,71.77,52.04,43.95,40.19,38.65,34.15,31.80,26.62,20.83;ESI-HR-MS m/z:Calcd for C23H27NO5Cl2Na{[M+Na]+}490.1,found 490.4。
7-O-(對(duì)氟苯基氨基甲酸酯)-布雷菲德菌素A(4h):產(chǎn)率 30.5%;1H NMR(DMSO-d6)δ:7.53(s,1H),7.47(s,2H),7.36(d,J=15.6 Hz,1H),7.27(s,1H),7.12(d,J=8.8 Hz,2H),5.74(d,J=15.4 Hz,2H),5.25(d,J=11.0 Hz,3H),5.02(s,1H),4.72(s,2H),4.09(d,J=43.8 Hz,2H),2.49(d,J=15.7 Hz,3H),2.23(s,1H),2.07(s,1H),1.94(s,1H),1.80(d,J=12.4 Hz,4H),1.64(s,1H),1.50(d,J=11.2 Hz,2H),1.21(t,J=10.7 Hz,3H),0.75(s,1H);13C NMR δ:166.10,157.06,154.58,153.75,136.92,131.00,130.48,125.38,125.31,116.93,115.80,115.62,75.81,74.45,71.36,52.38,43.16,41.47,38.77,33.92,31.89,26.87,21.16;ESI-HR-MS m/z:Calcd for C23H28NO5FNa{[M+Na]+}440.2,found 440.1。
7-O-(2,4-二氟苯基氨基甲酸酯)-布雷菲德菌素 A(4i):產(chǎn)率 30.3%;1H NMR δ:7.32(d,J=15.6 Hz,3H),7.27(s,1H),7.12(d,J=8.8 Hz,2H),5.74(d,J=15.4 Hz,2H),5.25(d,J=11.0 Hz,3H),5.02(s,1H),4.72(s,2H),4.09(d,J=43.8 Hz,2H),2.49(d,J=15.7 Hz,3H),2.23(s,1H),2.07(s,1H),1.94(s,1H),1.80(d,J=12.4 Hz,4H),1.64(s,1H),1.50(d,J=11.2 Hz,2H),1.21(t,J=10.7 Hz,3H),0.75(s,1H);13C NMR δ:166.26,158.47,154.29,151.54,136.06,130.90,130.88,120.59,117.72,114.59,114.29,100.53,75.83,71.80,55.53,52.24,43.95,40.23,38.75,34.14,31.84,26.65,20.85;ESI-HR-MS m/z:Calcd for C23H28NO5F2Na{[M+Na]+}458.2,found 458.1。
7-O-(對(duì)二氟氧甲基苯基氨基甲酸酯)-布雷菲德菌素 A(4j):產(chǎn)率 26.3%;1H NMR δ:7.41(m,2H),7.28(t,3H),7.18(t,1H),7.02(d,J=4.6 Hz,2H),5.92 ~ 5.98(d,J=15.7 Hz,1H),5.72(s,2H),5.33 ~5.21(m,2H),5.03(s,1H),4.72(s,1H),4.03(s,1H),2.27 ~2.07(m,4H),1.77 ~1.61(m,4H),1.50(d,J=8.3 Hz,3H),1.20(t,J=10.2 Hz,3H),0.76(s,1H);13C NMR δ:169.43,166.55,153.30,151.97,136.04,130.87,124.45,123.11,120.85,120.57,117.56,116.05,113.96,75.82,72.05,52.28,43.94,40.20,38.83,34.06,31.86,26.69,20.82;ESI-HR-MS m/z:Calcd for C23H29NO6F2Na{[M+Na]+}488.2,found 488.1。
7-O-(鄰三氟甲基苯氨基甲酸酯)-布雷菲德菌素 A(4k):產(chǎn)率 28.7%;1H NMR δ:7.55(s,2H),7.38(s,1H),7.28(s,1H),7.19(s,1H),6.88(s,1H),5.92 ~ 5.98(d,J=15.7 Hz,1H),5.72(s,2H),5.33 ~5.21(m,5H),5.03(s,1H),4.72(s,1H),4.03(s,1H),2.27 ~2.07(m,4H),1.77 ~ 1.61(m,4H),1.50(d,J=8.3 Hz,3H),1.20(t,J=10.2 Hz,3H),0.76(s,1H);13C NMR δ:166.26,166.19,153.06,151.43,135.81,135.61,132.93,131.07,129.17,126.10,126.05,123.61,117.80,75.79,71.77,52.02,43.95,40.19,38.54,34.14,31.81,26.61,20.83;ESI-HR-MS m/z:Calcd for C23H28NO5F3Na{[M+Na]+}490.2,found 490.5。
7-O-(對(duì)氧甲基苯氨基甲酸酯)-布雷菲德菌素 A(4l):產(chǎn)率29.7%;1H NMR δ:7.37(d,J=15.7 Hz,1H),7.28(s,1H),6.87(d,J=5.2 Hz,1H),5.92 ~ 5.98(d,J=15.7 Hz,1H),5.72(s,2H),5.33 ~ 5.21(m,2H),5.03(s,1H),4.72(s,1H),4.03(s,1H),2.27 ~2.07(m,4H),1.77 ~1.61(m,4H),1.50(d,J=8.3 Hz,3H),1.20(t,J=10.2 Hz,3H),0.76(s,1H);13C NMR δ:166.19,152.99,151.41,135.89,135.18,131.44,131.10,131.07,130.76,117.80,111.33,111.16,75.75,71.79,52.16,44.16,43.94,40.18,38.70,34.15,31.83,26.64,20.84;ESI-HR-MS m/z:Calcd for C24H31NO5Na{[M+Na]+}451.2,found 451.1。
7-O-(萘基氨基甲酸酯)-布雷菲德菌素 A(4m):產(chǎn)率 35.6%;1H NMR δ:7.87(d,J=7.1 Hz,2H),7.68(d,J=8.2 Hz,1H),7.62 ~7.43(m,3H),7.28(s,1H),7.08(d,J=4.3 Hz,1H),5.92(d,J=15.6 Hz,1H),5.82 ~5.57(m,1H),5.12(dd,J=8.7 Hz,4.5 Hz,1H),4.85(dd,J=10.4 Hz,5.7 Hz,1H),4.11(d,J=8.7 Hz,1H),2.49 ~ 2.05(m,4H),2.03(d,J=27.9 Hz,1H),1.93 ~ 1.78(m,3H),1.77 ~ 1.69(m,1H),1.67 ~ 1.60(m,1H),1.57 ~1.45(m,1H),1.26(t,J=6.2 Hz,3H),0.92(s,1H);13C NMR δ:166.28,151.67,149.73,136.30,136.01,134.08,132.54,130.74,129.39,128.68,126.26,126.03,125.75,120.65,118.16,117.62,76.49,75.68,71.87,52.12,43.85,41.97,38.71,34.09,31.79,26.83,20.72;ESI-HR-MS m/z:Calcd for C27H31NO5FNa{[M+Na]+}472.2,found 472.1。
7-O-(環(huán)己烷氨基甲酸酯)-布雷菲德菌素A(4n):產(chǎn)率 18.1%;1H NMR δ:7.41 ~7.19(m,1H),5.92(d,J=15.6 Hz,1H),5.82 ~ 5.57(m,1H),5.12(d,J=8.7 Hz,4.5 Hz,1H),4.85(d,J=10.4 Hz,5.7 Hz,1H),4.11(d,J=8.7 Hz,1H),3.50(m,1H),2.49 ~ 2.05(m,4H),2.03(d,J=27.9 Hz,1H),1.93 ~1.78(m,3H),1.77 ~ 1.69(m,1H),1.67 ~1.57(m,1H),1.69 ~ 1.58(m,3H),1.57 ~1.45(m,4H),1.26(t,J=6.2 Hz,3H),0.92(d,J=19.6 Hz,12.7 Hz,1H);13C NMR δ:166.34,156.75,151.63,130.73,130.61,117.65,75.83,75.19,71.73,49.18,43.96,38.74,34.13,33.96,33.46,31.82,26.68,25.63,25.50,25.47,24.95,24.80,20.86;ESI-HR-MS m/z:Calcd for C23H35NO5FNa{[M+Na]+}433.2,found 433.1。
將人食管癌細(xì)胞TE-1按5.0×103細(xì)胞/孔均勻種植于細(xì)胞培養(yǎng)96孔板中,置于5%二氧化碳培養(yǎng)箱,于37℃培養(yǎng)24 h。以DMSO為溶劑,配制不同c(4)溶液;向各孔中添加c(4)(每個(gè)重復(fù)處理3次,取平均值),于37℃培養(yǎng)48 h。每孔中加入10 μL WST-1細(xì)胞增殖及細(xì)胞毒性檢測(cè)試劑盒,于37℃孵育2 h,利用酶標(biāo)儀測(cè)定每孔450 nm處的吸光度(A),以空白細(xì)胞培養(yǎng)液作為對(duì)照組,計(jì)算c(4)處理后人食管癌細(xì)胞TE-1存活率[存活率/%=(A藥液-A培養(yǎng)液)/(A對(duì)照-A培養(yǎng)液)×100%]。
本文首次采用異氰酸酯對(duì)3的7-羥基進(jìn)行結(jié)構(gòu)修飾,合成了14個(gè)新型的布雷菲德菌素A氨基甲酸酯類衍生物。該方法具有催化劑便宜易得,反應(yīng)條件較溫和等優(yōu)點(diǎn)。
4g,4i~4l對(duì)食管癌TE-1細(xì)胞株的腫瘤抑制活性見表1。由表1可見,在各個(gè)用藥量時(shí),他們中的大部份化合物均失去了對(duì)食管癌TE-1細(xì)胞株的抗腫瘤活性。
表1 4g,4i~4l對(duì)TE-1的抑制活性Table 1 Inhibitions activities of 4g,4i~4l against TE-1 cell
為了從靶位蛋白與小分子作用關(guān)系來(lái)解釋抗腫瘤活性實(shí)驗(yàn)結(jié)果,我們選取4i,4j和4l與蛋白進(jìn)行分子對(duì)接研究。利用DS2.5軟件中的LiDOCK模塊進(jìn)行了分子對(duì)接,結(jié)果見圖1。圖1結(jié)果表明,3被帶苯環(huán)的大基團(tuán)修飾以后,分子空間體積變大。分子4只能結(jié)合在活性區(qū)域的外表面,而不能進(jìn)入3所結(jié)合的活性區(qū)域,與特定的ASP67和TRP78兩個(gè)氨基酸作用,導(dǎo)致4與靶位蛋白的相互作用力減弱,腫瘤抑制活性降低。這就是4喪失抑制食管癌細(xì)胞株TE-1活性的原因。
圖1 4與靶點(diǎn)ARF1-GDP-GEF復(fù)合體的模擬對(duì)接圖Figure 1 Docking for 4 in the ARF1-GDP-GEF interface
首次采用異氰酸酯對(duì)布雷菲德菌素A的7-羥基進(jìn)行結(jié)構(gòu)修飾,合成了14個(gè)新型的布雷菲德菌素A氨基甲酸酯類衍生物。布雷菲德菌素A氨基甲酸酯類衍生物的合成及其生物活性評(píng)價(jià),為布雷菲德菌素A衍生化研究提供借鑒。
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