目的: 制备几种不同摩尔取代度的羟乙基直链淀粉（HEA）,并测定其相对分子质量和摩尔取代度。方法: 本文采用玉米淀粉作为原料,通过丁醇凝沉法提纯出直链淀粉,采用蓝值法对其纯度进行了鉴定, 分别采用乌氏粘度计和凝胶渗透色谱（GPC）测定了其粘均相对分子质量和重均相对分子质量。通过在碱性条件下加入不同比例的环氧乙烷对直链淀粉进行醚化,制备HEA,采用气相色谱法检测HEA 的摩尔取代度,采用GPC 测定HEA 的相对分子质量。结果: 纯化后的直链淀粉蓝值为0.92,粘均相对分子质量为2.64×106,重均相对分子质量为3.021×106,环氧乙烷/ 直链淀粉葡萄糖单元摩尔投料比分别为4∶1、8∶1、16∶1 和32∶1 时,制备出的HEA 摩尔取代度分别为0.18、0.50、1.00 和1.37,重均相对分子质量分别为3.318×106、3.338×106、3.432×106 和3.457×106。结论: 丁醇凝沉法可从玉米淀粉中提取出高纯度,窄分布的直链淀粉,通过不同浓度的环氧乙烷醚化直链淀粉可得到不同摩尔取代度的HEA。
Objective： To prepare hydroxyethyl amylose（HEA） with different molar masses and determine their relative molecular mass and molar substitution ratio. Methods： Amylose was purified from corn starch by a butanol coagulation method. Blue value was measured by visible spectrophotometer to identify the purity of amylose. Viscosity average relative molecular mass and weight average relative molecular mass of amylose was determined by Ubbelohde viscometer and gel permeation chromatography（GPC） respectively. Amylose was etherified by adding different concentrations of ethylene oxide under basic conditions. HEA was purified by dialysis and their molar substitution ratio was measured by gas chromatography. The weight average relative molecular mass of HEA was determined by GPC. Results： Blue value of the purified amylose was 0.92,viscosity average relative molecular mass was 2.64×106 and weight average relative molecular mass was 3.021×106. When the feed molar ratio of ethylene oxide to amylose glucose units was 4∶1,8∶1,16∶1 and 32∶1,the molar substitutions of HEA were 0.18,0.50, 1.00 and 1.37,respectively. The weight average relative molecular mass of HEA was 3.318×106,3.338×106, 3.432×106 and 3.457×106,respectively. Conclusion： Amylose with high purity and good polydispersity can be purified from corn starch by butanol coagulation method,and HEA with different molar substitution degrees can be obtained by etherifying amylose using ethylene oxide of different concentrations.
[1] SUK JS,XU Q,KIM N,et al.PEGylation as a strategy for improving nanoparticle-based drug and gene delivery[J]. Adv Drug Deliv Rev,2016,99(Pt A):28
[2] PASUT G,VERONESE FM.State of the art in PEGylation:The great versatility achieved after forty years of research[J]. J Control Release,2012,161(2):461
[3] MAEDA H,WU J,SAWA T,et al.Tumor vascular permeability and the EPR effect in macromolecular therapeutics:a review[J]. J Control Release,2000,65(1):271
[4] FANG J,NAKAMURA H,MAEDA H.The EPR effect:unique features of tumor blood vessels for drug delivery,factors involved, and limitations and augmentation of the effect[J]. Adv Drug Deliv Rev,2011,63(3):136
[5] FANG Y,XUE J,GAO S,et al.Cleavable PEGylation:a strategy for overcoming the "PEG dilemma" in efficient drug delivery[J]. Drug Deliv,2017,24(2):22
[6] THAKUR VK,THAKUR M.Eco-friendly Polymer Nanocomposites: Chemistry and Applications[M]. New Delhi:Springer, 2015
[7] Plasma-volume replacement with hydroxyethyl starch[J]. Lancet, 1971,2(7716):147
[8] LIEBNER R,MATHAES R,MEYER M,et a l. Protein HESylation for half-life extension:synthesis,characterization and pharmacokinetics of HESylated anakinra[J]. Eur J Pharm Biopharm,2014,87(2):378
[9] LI Y,HU H,ZHOU Q,et al.α-amylase- and redox-responsive nanoparticles for tumor-targeted drug delivery[J]. ACS Appl Mater Interfaces,2017,9(22):19215
[10] XU W,DING J,XIAO C,et al.Versatile preparation of intracellular-acidity-sensitive oxime-linked polysaccharide-doxorubicin conjugate for malignancy therapeutic[J]. Biomaterials, 2015,54:72
[11] LUO Q,WANG P,MIAO Y,et al.A novel 5-fluorouracil prodrug using hydroxyethyl starch as a macromolecular carrier for sustained release[J]. Carbohydr Polym,2012,87(4):2642
[12] LI G,LI Y,TANG Y,et al.Hydroxyethyl starch conjugates for improving the stability,pharmacokinetic behavior and antitumor activity of 10-hydroxy camptothecin[J]. Int J Pharm,2014,471(1):234
[13] LIU Q,YANG X,XU H,et al.Novel nanomicelles originating from hydroxyethyl starch-g-polylactide and their release behavior of docetaxel modulated by the PLA chain length[J]. Eur Polym J, 2013,49(11):3522
[14] HU H,XIAO C,WU H,et al.Nanocolloidosomes with selective drug release for active tumor-targeted imaging-guided photothermal/ chemo combination therapy[J]. ACS Appl Mater Interfaces,2017, 9(48):42225
[15] 洪雁,顾正彪,刘晓欣. 直链淀粉和支链淀粉纯品的提取及其鉴定[J]. 食品工业科技,2004(4):86
HONG Y,GU ZB,LIU XX.Extraction and identification of pure amylose and amylopectin[J]. Scie Technol Food Ind,2004(4):86
[16] GIBERT GT,SPRAGG SP.Iodimetric Determination of Amylose Iodine Sorption:“Blue Value"[M]. New York and London: Academic Press,1964:168
[17] ZOBEL HF.Methods in Carbohydrate Chemistry. Vol. 4. X-ray Analysis of Starch Granules.[M]. New York and London:Academic Press,1964:67
[18] SHYLUK WP,TIMELL TE.A new method for preparing hydroxyethyl ethers of glucose[J]. Can J Chem,1956,34(5):571
[19] 杜中海,任传杰,于鹏,等. GC 法测定羟乙基淀粉摩尔取代度的研究[J]. 齐鲁药事,2012,31(2):92
DU ZH,REN CJ,YU P,et al.Study on the determination of molar substitution ratio of hydroxyethyl starch by GC[J]. Qilu Pharm Aff, 2012,31(2):92
