趙祥升 楊美華 弓寶
[摘要] 目的 建立同時(shí)測(cè)定酸棗仁中6種成分含量的高效液相色譜-蒸發(fā)光檢測(cè)器(HPLC-ELSD)法。 方法 經(jīng)70%乙醇超聲提取80 min,采用Kromasil C18(250 mm×4.6 mm,5.0 μm)色譜柱進(jìn)行分離,以乙腈-0.1%乙酸為流動(dòng)相,梯度洗脫,流速為1.0 mL/min,柱溫35℃;ELSD檢測(cè),載氣流速為2.9 mL/min,漂移管溫度為100℃,測(cè)定酸棗仁中斯皮諾素、酸棗仁皂苷A、酸棗仁皂苷D、酸棗仁皂苷B、酸棗仁皂苷B1和白樺脂酸6種成分的含量?;厥章视?jì)算采用外標(biāo)法,按峰面積計(jì)算。 結(jié)果 斯皮諾素、酸棗仁皂苷A、酸棗仁皂苷D、酸棗仁皂苷B、酸棗仁皂苷B1和白樺脂酸在各自質(zhì)量濃度范圍內(nèi)與峰面積呈良好的線性關(guān)系(R2>0.9991);平均加樣回收率為94.91%~99.35%,RSD為0.78%~1.23%。不同產(chǎn)地酸棗仁中6種成分的含量差異較大,斯皮諾素和白樺脂酸的含量最高,3批樣品中檢測(cè)到酸棗仁皂苷B1。 結(jié)論 該方法簡(jiǎn)便、準(zhǔn)確、重現(xiàn)性好,適用于酸棗仁中多成分的同時(shí)快速檢測(cè)。
[關(guān)鍵詞] 酸棗仁;多成分測(cè)定;高效液相色譜-蒸發(fā)光檢測(cè)器
[中圖分類號(hào)] R917 [文獻(xiàn)標(biāo)識(shí)碼] A [文章編號(hào)] 1673-7210(2016)12(c)-0149-05
[Abstract] Objective To establish a HPLC-ELSD method for simultaneous determination of six compounds in ZiziphiSpinosae Semen. Methods The sample was extracted by ultrasonication for 80 min using 70% ethanol and the target compounds were separated on a Kromasil C18 chromatographic column (250 mm×4.6 mm, 5.0 μm). A mixture of acetonitrile-water containing 0.1% acetic acid was utilized as the mobile phase at the flow rate of 1.0 mL/min, and the column temperature was set 35℃. The drift tube temperature of ELSD was 100℃ with carrier gas flow rate of 2.9 mL/min. The contents of spinosin, jujuboside A, juboside D, jujuboside B, jujuboside B1 and betulinic acid were determined on the above conditions. External standard method was used to measure recovery based on the peak areas. Results The six target analytes (spinosin, jujuboside A, jujuboside D, jujuboside B, jujuboside B1, betulinic acid) all exhibited good linear relationships (R2 > 0.9991) in their relatively wide concentration ranges. The average recoveries varied between 94.91% and 99.35% with RSD of 0.78%-1.23%. The contents of the six components in ZiziphiSpinosae Semen collected from different locations in China exhibited great variations. Spinosin and betulinic acid had the highest contents in all samples, and jujuboside B1 was only detected in three samples. Conclusion This established HPLC-ELSD method is simple, quick and accurate, which can be used for quality control of Semen ZiziphiSpinosae.
[Key words] Semen ZiziphiSpinosae; Multi-compound analysis; HPLC-ELSD
酸棗仁為鼠李科植物酸棗[Ziziphus jujube Mill. Var. spinosa (Bunge) Hu ex H.F. Chou]的干燥成熟種子,具有養(yǎng)心補(bǔ)肝、寧心安神、斂汗、生津的功效,為鎮(zhèn)靜安神的傳統(tǒng)藥物之一[1],主要成分為皂苷類、黃酮類和三萜類[2-7]。黃酮和皂苷類是酸棗仁鎮(zhèn)靜安眠的有效成分[8-10],三萜類具有抗腫瘤、抗HIV等作用[11-12]。2015年版《中國藥典》僅將斯皮諾素和酸棗仁皂苷A作為其質(zhì)量控制的指標(biāo)性成分,由于中藥多組分、多靶點(diǎn)的特性,個(gè)別指標(biāo)不足以全面反映其品質(zhì),因此建立多指標(biāo)的質(zhì)量評(píng)價(jià)方法更具有科學(xué)意義。目前酸棗仁活性成分含量測(cè)定方法主要是HPLC測(cè)定其中一類或兩類的含量[2-4,13-19],同時(shí)測(cè)定黃酮、皂苷和三萜類的研究還未見報(bào)道。本研究采用高效液相色譜-蒸發(fā)光檢測(cè)器(HPLC-ELSD)法同時(shí)測(cè)定酸棗仁中斯皮諾素,酸棗仁皂苷A、B、B1、D和白樺脂酸的含量,為其質(zhì)量控制提供參考。
1 儀器與試藥
1.1 儀器
Waters 1525型高效液相色譜儀;2000ES型蒸發(fā)光散射檢測(cè)器(美國Alltech公司);KQ-500DE型超聲波清洗器(昆山市超聲儀器有限公司)。XS105DU電子分析天平(上海托利多有限公司);Milli-Q超純水系統(tǒng)(Millipore USA)。
1.2 試藥
酸棗仁收集于河北、北京、山西、陜西、河南、山東、遼寧等地。斯皮諾素(11869-201203)、酸棗仁皂苷A(110734-200510)、酸棗仁皂苷B(110814-200607)和白樺脂酸(111802-201001)對(duì)照品由中國藥品生物制品檢定所提供;酸棗仁皂苷B1(20120527)和酸棗仁皂苷D(20120605)購自大連美倫生物科技有限公司,對(duì)照品純度均大于98.0%。乙腈、甲醇為色譜純(Fisher),其他試劑為分析純。
2 方法與結(jié)果
2.1 對(duì)照品儲(chǔ)備液的制備
精密稱取6種對(duì)照品適量,加甲醇制成含斯皮諾素1.26 mg/mL,酸棗仁皂苷A 1.02 mg/mL,酸棗仁皂苷D 0.876 mg/mL,酸棗仁皂苷B 0.732 mg/mL,酸棗仁皂苷B1 0.918 mg/mL和白樺脂酸1.314 mg/mL的混合對(duì)照品儲(chǔ)備液。
2.2 供試品溶液的制備
精密稱取1.0 g過40目篩的酸棗仁樣品,置于15 mL離心管中,加入5.0 mL 70%乙醇,稱重,室溫超聲80 min,放冷,用溶劑補(bǔ)足減失的量,搖勻,濾過,續(xù)濾液經(jīng)0.22 μm微孔濾膜濾過,即得。
2.3 色譜條件
色譜柱:Kromasil C18(250 mm×4.6 mm,5.0 μm);流動(dòng)相:乙腈(A)-0.1%(V/V)乙酸(B),梯度洗脫:0~10 min,19%~23% A;10~15 min,23%~45% A;15~20 min,45%~50% A;20~25 min,50%~70% A;25~30 min;70%~100% A;30~35 min,100%~19% A;運(yùn)行時(shí)間50 min;流速:1.0 mL/min,進(jìn)樣量20 μL,柱溫:35℃;蒸發(fā)光檢測(cè)器漂移管溫度為100℃,霧化氣:N2,載氣流速為2.9 mL/min。
2.4提取方法的優(yōu)化
實(shí)驗(yàn)中考察了影響超聲提取效率的因素:溶劑(50%、70%、80%乙醇),時(shí)間(30、45、60、80 min)和料液比(1∶5、1∶10、1∶15)。結(jié)果顯示,當(dāng)乙醇濃度大于70%和時(shí)間大于80 min時(shí),待測(cè)物的含量無顯著增加,料液比對(duì)提取率沒有明顯差異。最終提取方法為1.0 g樣品經(jīng)5 mL 70%乙醇超聲提取80 min。見圖1。
2.5方法學(xué)驗(yàn)證
2.5.1 線性關(guān)系考察 取混合對(duì)照品溶液,用流動(dòng)相稀釋成一系列不同質(zhì)量濃度的工作溶液,進(jìn)樣分析,以進(jìn)樣濃度的對(duì)數(shù)和對(duì)應(yīng)平均峰面積(n=3)的對(duì)數(shù)計(jì)算回歸方程(表1)。目標(biāo)化合物在各自的質(zhì)量濃度范圍內(nèi)呈良好的線性關(guān)系(R2>0.9991)。以信噪比為3時(shí)的質(zhì)量濃度為檢測(cè)限(LOD),以信噪比為10時(shí)的質(zhì)量濃度為定量限(LOQ)(表1)。
2.5.2 精密度實(shí)驗(yàn) 精密吸取混合對(duì)照品溶液,連續(xù)進(jìn)樣6次,結(jié)果6種成分的峰面積RSD<2.0%,表明儀器精密度較好。
2.5.3 穩(wěn)定性實(shí)驗(yàn) 取同一供試品溶液,分別于0、2、4、8、16、24 h進(jìn)樣,計(jì)算峰面積RSD。結(jié)果6種成分峰面積的RSD < 3.0%,表明供試溶液在24 h內(nèi)穩(wěn)定。
2.5.4 重復(fù)性試驗(yàn) 按“2.2”項(xiàng)下方法制備6份供試品溶液,按“2.3”項(xiàng)下色譜條件進(jìn)樣,結(jié)果6種成分峰面積的RSD值在1.8%~3.0%之間,表明該方法的重復(fù)性良好。
2.5.5 加樣回收試驗(yàn) 精密稱取已知含量的酸棗仁0.5 g(n=6),分別加入相當(dāng)于含量100%的對(duì)照品溶液,按照“2.2”項(xiàng)制備供試品溶液,進(jìn)樣,計(jì)算加樣回收率,結(jié)果見表2。
2.6 樣品檢測(cè)
分別制備不同產(chǎn)地酸棗仁樣品的供試品溶液,進(jìn)樣測(cè)定,對(duì)照品和樣品色譜圖見圖2,樣品中6種成分的含量見表3。
3 討論
文獻(xiàn)中常用的流動(dòng)相為甲醇/乙腈和酸(甲酸、乙酸)的水溶液[2-4,12,20],乙腈較甲醇有較強(qiáng)的洗脫能力。在水溶液中添加甲酸可以防止峰拖尾,提高分離度和峰形,結(jié)合預(yù)實(shí)驗(yàn)效果,本研究采用乙腈-0.1%乙酸為流動(dòng)相。蒸發(fā)光檢測(cè)器漂移管的溫度目標(biāo)物的響應(yīng)值沒有規(guī)律性,當(dāng)溫度為100℃時(shí)響應(yīng)較好。目標(biāo)物響應(yīng)值隨著載氣流速的降低而增加,但載氣流速太小可能會(huì)使流動(dòng)相不能完全揮發(fā),最終確定載氣流速為2.9 mL/min。
本研究建立了同時(shí)測(cè)定酸棗仁中6種成分的HPLC-ELSD方法,操作簡(jiǎn)便,結(jié)果可靠,對(duì)其質(zhì)控具有科學(xué)意義。通過對(duì)不同產(chǎn)地酸棗仁樣品的檢測(cè),結(jié)果表明不同產(chǎn)地中目標(biāo)成分含量差異較大。所有樣品中斯皮諾素和酸棗仁皂苷A的含量均高于《中國藥典》規(guī)定的標(biāo)準(zhǔn),而酸棗仁皂苷B1僅在3批樣品(山西、陜西和遼寧)中檢測(cè)到,反映了不同產(chǎn)地和來源的酸棗仁樣品存在質(zhì)量差異。
[參考文獻(xiàn)]
[1] 國家藥典委員會(huì).中國藥典[M].一部.北京:中國醫(yī)藥科技出版社,2015:366-367.
[2] Bao KD,Li P,Li HJ,et al. Simultaneous determination of flavonoids and saponins in Semen Ziziphispinosae (Suanzaoren) by high performance liquid chromatography with evaporative light scattering detection [J]. Chin J Nat Med,2009,7(1):47-52.
[3] Zhao J,Li SP,Yang FQ,et al. Simultaneous determination of saponins and fatty acids in Semen Ziziphusjujuba (Suanzaoren) by high performance liquid chromatography-evaporative light scattering detection and pressurized liquid extraction [J]. J Chromatogr A,2006,1108(2):188-194.
[4] Zhang MC,Zhang YQ,Xie J. Simultaneous determination of jujuboside A,B and betulinic acid in Semen Ziziphispinosae by high performance liquid chromatography-evaporativelight scattering detection [J]. J Pharmaceut Biomed,2008, 48(5):1467-1470.
[5] 王衛(wèi)記,羅建光,孔令義.HPLC-ESI-MSn分析酸棗仁有效部位的化學(xué)成分[J].中國中藥雜志,2009,34(21):2768-2773.
[6] Zhang FX,Li M,Qiao LR,et al. Rapid characterization of ZiziphiSpinosae Semen by UPLC/Qtof MS with novel informatics platform and its application in evaluation of two seeds from Ziziphus species [J]. J Pharm Biomed Anal,2016,122:59-80.
[7] 王建忠,楊勁松.酸棗仁中三萜皂苷的分離和結(jié)構(gòu)研究[J].有機(jī)化學(xué),2008,28(1):69-72.
[8] Jiang JG,Huang XJ,Chen J,et al. Comparison of the sedative and hypnotic effects of flavonoids,saponins,and polysaccharides extracted from Semen Ziziphus Jujube [J]. Nat Prod Res,2007,21(4):310-320.
[9] Wang LE,Cui XY,Cui SY,et al. Potentiating effect of spinosin,a C-glycoside flavonoid of Semen ZiziphiSpinosae,on pentobarbital-induced sleep may be related to postsynaptic 5-HT 1A receptors [J]. Phytomedicine,2010,6(17):404-409.
[10] Sun S,Liu HL,Xu SJ,et al. Quality analysis of commercial samples of Ziziphispinosae semen (suanzaoren) by means of chromatographic fingerprinting assisted by principal component analysis [J]. J Pharm Anal,2014,4(3):217-222.
[11] Mullauer FB,Kessler JH,Medema JP. Betulinic acid,a natural compound with potent anticancer effects [J]. Anticancer Drugs,2010,21(3):215-227.
[12] Feng Y,Li M,Liu J,et al. A novel one-step microbial transformation of betulin to betulinic acid catalysed by Cunninghamella blakesleeana [J]. Food Chem,2013,136(1):73-79.
[13] Liao LJ,Won TH,Kang SS,et al. Simultaneous analysis of bioactive metabolites from Ziziphusjujuba by HPLC-DAD-ELSD-MS/MS [J]. J Pharm Inves,2012,42(1):21-31.
[14] 祝洪艷,張力娜,唐姍,等.HPLC法測(cè)定3個(gè)產(chǎn)地酸棗仁中斯皮諾素和酸棗仁皂苷A、B的含量[J].藥物分析雜志,2015,35(12):2099-2104.
[15] Guo S,Duan JA,Tang YP,et al. Characterization of Triterpenic Acids in Fruits of Ziziphus Species by HPLC-ELSD-MS [J]. J Agric Food Chem,2010,58(10):6285-6289.
[16] 孫延芳,梁宗鎖,劉文婷,等.HPLC-ELSD法分析酸棗果中的白樺脂酸和熊果酸[J].中成藥,2012,34(5):895-898.
[17] 曹相蘭,周雯,謝憲斌,等.HPLC-DAD法同時(shí)測(cè)定酸棗仁皂苷中酸棗仁皂苷A、B和白樺脂酸、白樺脂醇[J].中成藥,2015,37(5):1013-1016.
[18] 張巧月,楊浩天,史賀,等.HPLC-MS法同時(shí)測(cè)定酸棗仁中9種成分[J].中草藥,2015,46(1):123-127.
[19] Guo S,Duan JA,Tang YP,et al. Simultaneous qualitative and quantitative analysis of triterpenic acids,saponins and flavonoids in the leaves of two Ziziphus species by HPLC-PDA-MS/ELSD [J]. J Pharm Biomed Anal,2011, 56(2):264-270.
[20] Zhao XS,Xie LW,Wu HF,et al. Analysis of six bioactive components in Semen ZiziphiSpinosae by UPLC-ELSD and UPLC-QTOF-MS [J]. Anal. Methods,2014,15(6):5856-5864.
(收稿日期:2016-09-20 本文編輯:王紅雙)