中藥提取過(guò)程的動(dòng)力學(xué)

藥學(xué)學(xué)報 Acta pharmaceutica sinica20023x7)559-562559中藥提取過(guò)程的動(dòng)力學(xué)儲茂泉,劉國杰華東理工大學(xué)化學(xué)與制藥學(xué)院,上海200237)摘要:目的為中藥提取工藝設計提供理論依據。方法基于Fick擴散第二定律,建立中藥提取過(guò)程的動(dòng)力學(xué)方程并以實(shí)驗對其進(jìn)行檢驗。結果中藥提取過(guò)程的動(dòng)力學(xué)服從一級動(dòng)力學(xué)方程甘草、五味子、麥冬中有效成分以及丹參中丹參酮的提取等實(shí)驗結果與動(dòng)力學(xué)方程能較好地吻合乙醇提取丹參酮的過(guò)程為內擴散控制的其提取表觀(guān)活化能為20.26 kJ mol-l。結論建立的中藥提取過(guò)程的動(dòng)力學(xué)方程是可靠的。關(guān)鍵詞∶中藥;提取;動(dòng)力學(xué)方程;Fick擴散第二定律;丹參酮中圖分類(lèi)號:TQ461;R969.1;R921文獻標識碼:A文章編號:0513-48702002)7-0559-04在中藥生產(chǎn)工藝中從藥材中提取有效成分是一r處的溶質(zhì)質(zhì)量濃度為c,固相外溶液體積為V液相個(gè)重要的組成部分。怎樣提高有效成分的提取得率直主體溶質(zhì)質(zhì)量濃度為C內擴散系數為Ds,則根據接關(guān)系到中藥生產(chǎn)的成本和經(jīng)濟效益。因此提供可Fick擴散第二定律有靠的中藥提取過(guò)程動(dòng)力學(xué)方程是十分必要的。然而D(1)由于中藥提取過(guò)程的復雜性目前這方面的研究不多已提出的模型1-5還不足以全面反映中藥提取過(guò)程令u=cr'則的動(dòng)力學(xué)規律。at(2)本工作試圖以Fick擴散第二定律為基礎,導得個(gè)形式簡(jiǎn)單的新動(dòng)力學(xué)方程旨在為中藥提取工藝的邊界條件為0(3)最優(yōu)化提供有價(jià)值的理論依據。(?C)V=-Ds()=r(4)模型與動(dòng)力學(xué)方程的建立式中,S為藥材顆粒與溶劑的接觸面積。若t=0時(shí)藥材顆粒內溶質(zhì)平均質(zhì)量濃度為coκ測則初始條件為5中藥提取實(shí)質(zhì)上是使有效成分即溶質(zhì)從固相向對于藥材其與溶液主體之間有無(wú)數毛細孔相連平衡液相轉移的傳質(zhì)過(guò)程。其過(guò)程的物理化學(xué)模式一般可時(shí)固體內外溶質(zhì)質(zhì)量濃度可認為相等即設想分3步完成溶劑向藥材內部的滲透和藥材的t= oo(6)潤濕②藥材內部溶質(zhì)的溶解③溶質(zhì)從藥材內部向式中c和C分別為提取平衡時(shí)固相內、外溶質(zhì)質(zhì)量藥材表面以及由藥材表面向溶液主體的擴散。其中內濃度。擴散常被認為是整個(gè)提取過(guò)程的速率控制步驟6如果溶液中溶質(zhì)的初始質(zhì)量濃度為Cσ用分離變假定藥材顆粒為球形半徑為r滲入藥材內的溶量法可解得液體積為v′在提取過(guò)程中,t時(shí)刻顆粒內距球心為Dexp((7)[1+1+。)ki其中,TYH中國煤化工CNMHG收稿日期:2001-08-24通訊作者Te:(021423092662932831-16Fax:(0212933466l: machu@mail.stu.edu,cmn的根式中a=V/V'。藥學(xué)學(xué)報 Acta pharmaceutica sinica20023x7)559-562因提取是內擴散控制,可認為溶質(zhì)一經(jīng)擴散到顆取首項即i=1就足夠了。這樣式14)簡(jiǎn)化為粒表面就立即進(jìn)入溶液主體。于是在r′=r處,CCx-C 2c又C2=c因此由式7)可得[1+d(19[1+以1+?ex(-122)(15)2Dst(9)根據質(zhì)量守恒得(10)上式兩邊同除以V′得o+aC0=c∞+aCa(11)由式11不難得到co-Co=Ca+1 Co-Co)(12)將式(12代入式9)得da+1)Figure 1 Schematic digram of equation ytgm; and y=1/(1+am, 2exp([1+d因t=0時(shí),C=C0于是由式15河得藥材內部結構是極其復雜的如果溶質(zhì)從藥材顆2a+1)1(16)粒中心向顆粒表面擴散則要經(jīng)過(guò)曲折的孔隙所經(jīng)過(guò)的路徑要比顆粒半徑大。因此,可假定溶質(zhì)是通過(guò)半從而式15地也可表示為徑為Kr的理想球體直線(xiàn)向外擴散的其中K被稱(chēng)為CD、孔隙的形狀因子。于是式13)可修正為(17)C∞-C對式17籌號兩邊取對數則得d(18))(14)+d1+-。)]其中k為表觀(guān)速率常數其值為D式14還可進(jìn)一步加以簡(jiǎn)化。若令y=tgm;則(19)式8地可聯(lián)立表示為式18)進(jìn)一步整理為CIn()(20)=1/(1+這便是本工作建立的動(dòng)力學(xué)方程前已述及,m是這組聯(lián)立方程的根,它可由圖1所的兩條曲線(xiàn)的交點(diǎn)示意地表示新動(dòng)力學(xué)方程在中草藥提取中的應用不難看出隨著(zhù)m;的增大兩曲線(xiàn)的交點(diǎn)y值逐漸減小。因溶劑提取時(shí)藥材固相所含的溶液體積遠1甘草中國煤化工分提取小于固相外溶液的體積a是一個(gè)很大的值因此交點(diǎn)CNMH甘阜、丑咻丁和愛(ài)零中背雙成分是以水為溶劑提的y值將隨m;的增大而快速地逼近于0。由此可見(jiàn),取的89。文獻89衛分別發(fā)表了提取動(dòng)力學(xué)數式14沖中的11+1+“0)地將隨著(zhù)m,的增大據圖2是它們的C2(C=-C)對t作圖而衰減卉快的速度逼近于0以致其多項式只由圖可見(jiàn)它們均呈線(xiàn)性關(guān)系。由于這些提取實(shí)藥學(xué)學(xué)報 Acta pharmaceutica sinica20023x7)559-562561驗都沒(méi)有經(jīng)過(guò)預浸泡故Co=0直線(xiàn)通過(guò)坐標原點(diǎn)Figure 4 Relationship between In[ CoA Co-C)]and t at different temperature(r=90. 5 umT=313KT=323K;▲-▲T=333Kt/min0→0T=348K從圖3A可見(jiàn)除了初始階段實(shí)驗尚未穩定外,它們的C。(C-C)]~t均成較好的線(xiàn)性關(guān)系。Figure2 Relationship bet ween In[C=XC=-C)]由于預漫泡,Co≠0故直線(xiàn)不再通過(guò)原點(diǎn)nd t for extracting actiGlycyrrhiza uralensis Fisch(■■), Schisandra由此可見(jiàn)本工作建立的動(dòng)力學(xué)方程能夠廣泛地chinesis(··) and Ophiopogon japonicus( Thunb.)適用于藥材的提取過(guò)程。不僅如此由圖34中的直Ker-Gawl(c-o )with water respectively線(xiàn)斜率還能得到它們的速率常數與藥材顆粒大小和2乙醇提取丹參酮溫度的關(guān)系如表1所示為了更廣泛地檢驗所建立的動(dòng)力學(xué)方程,作者還進(jìn)行了以乙醇為溶劑提取中藥丹參中的有效成分丹參 Table 1 values of k(×105s-1) at different particle酮的動(dòng)力學(xué)實(shí)驗。先將干燥丹參顆粒用少量乙醇進(jìn)行 size and temperature了預浸泡然后再加入乙醇在三口燒瓶中加熱回流提T/K取攪拌器轉速為100rmin-常壓?？疾炝怂幉念w68.75137.50181.25255.50313323333348粒大小以顆粒半徑r表示提取溫度以T表示對176.007.508.3313.17浸出丹參酮質(zhì)量濃度的影響。實(shí)驗詳細過(guò)程可參考文根據式(19),/Kr與r應呈比例關(guān)系。由表1列獻10圖34分別為不同顆粒大小和溫度下測得的動(dòng)力出的數據還能獲得乙醇提取丹參酮的活化能。因為在學(xué)實(shí)驗數據的HCAC-C)對t作圖。般情況下速率常數與溫度的關(guān)系服從 Arrhenius方程即lnk對1/T作圖應是一條直線(xiàn),它可表示成如下方程lnk=-2436.3/T-1.9594(21)據此可得乙醇提取丹參酮過(guò)程的活化能為20.26綜上所述利用Fick擴散第二定律建立了一個(gè)中藥提取過(guò)程的動(dòng)力學(xué)方程這個(gè)方程具有較普遍的適用性它中國煤化工方程其速率常數不00400500僅與溫HCNMH半徑的平方成反比Figure3 Relationship between Inl[CaKC-C)與內擴散系數成正比。只要實(shí)驗提供完整的動(dòng)力學(xué)數and t at different particle size( T=343K)據便能獲得提取過(guò)程的速率常數和活化能等動(dòng)力學(xué)參數r=137.背數據r=6875m藥學(xué)學(xué)報 Acta pharmaceutica sinica20023x7)559-562REFERENCES[6]Spiro M, Page CM. The kinetics and mechanism of caffeineI 1] SpiI wood RM. The kinetics and equilibria of teainfusion from coffee: hydrodynamic aspects[ J]. J Sci Foodinfusion. Part 3. Rotating-disc experiagric,198435925-930steady-state mode[J]. J Chem Soc Faraday Trans,1982[7] Piret EL, Ebel RA, Kiang CT, et al. Di78:95-305extraction of porous solids. I. Single phase extractions[ JI2 I Spiro M, Selwood RM. The kinetics and mechanism ofChem Eng Progr, 1951 Ax 8)405-414affeine infusion from coffee: the effect of particle size[ J][8] Hou SX, Li ZW, He Q, et al. Studies on the influentialJ Sci Food Agric, 1984 35 915-924factors affecting the efficiency of Chinese material medical[3]Li YR, Cheng S. Simulation and optimization of herbtraction[J. Chin Tradit Herb Drugs(中草藥),1996,extraction process[ J]. Chin Tradit Herb Drugs(中草藥)273):43-14199728(7)399-401[9 J Cheng ZY, Liu L, Liu DS, et al. Variational disciplinarianand approximate calculating method of theconcentrationof4] Hou KF, Zheng Q, Li YR, et al. Modeling andoptimization of herb leaching processes[ J ] Comput Chemactive components in solution during the Chinese traditionalEng,2000242-7):1343-1348herbs leaching processes with water[ J ]. Chin Tradit Pat[5] Yin YX. Study on microwave-assisted extraction of activeMed(中成藥),1994,166)component tanshinone from Salvia miltiorrhiza Bge[ A10 J Chu MQ. Studies on the kinetics of Chinese traditionalMaster' s Thesis east China Uniy Sci Technol(華東理工medicine extraction process and new dosage forms of大學(xué)碩士論文川[D] Shanghai: East China University oftanshinone[ A ] Doctors Thesis East China Univ SciTechnot(華東理工大學(xué)博士論文)[D] Shanghai:Eastcience and Technology 1997 20-50China University of Science and Technology 2001 20-22KINETIC MODEL FOR EXTRACTION PROCESS OFCHINESE TRADITIONAL MEDICINECHU Mao-quan, LIU Guo-jieChemical and Pharmaceutical College, East China University of Science and Technology Shanghai 200237, ChinaABSTRACT: AIM To present a theory bases for Chinese traditional medicine extraction process. METHODSA kinetic equation for Chinese traditional medicine extraction process was presented based on Fick s second law ofdiffusion. Experiments for extracting tanshinone from Salvia miltiorrhiza bge with ethanol under different particlesizes and temperatures were studied. In addition the data of extraction process of three kinds of herbs includinGlycyrrhiza uralensis Fisch, Schisandra chinesis and Ophiopogon japonicus( Thunb. ) Ker-Gawl were introducedto evaluate the kinetic equation. RESULTS The kinetic of Chinese traditional medicine extraction process agreedwith the first-order rate equation. Experiment data of active components extracted from the herbs above couldperfectly match with the kinetic equation. The rate-determining step for extracting tanshinone from Salviamiltiorrhiza Bge was the diffusion of tanshinone through the herb particles. The apparent activation energy fortanshinone diffusion process was 20.26 kJ mol". CONCLUSION The relation between the concentration of activecomponent and extraction time size of herb particles and temperature could be got from this kinetic equation. Theextraction process of other herbs besides the above could be described by this equationKEY WORDS Chinese traditional medicine extraction kir中國煤化工d law of diffusiontansTHCNMHG