优化I型胶原蛋白的纯化工艺

本文使用0.5mol/L乙酸和胃蛋白酶提取I型胶原蛋白后，结合等电点沉淀法和超滤纯化技术对I型胶原蛋白进行纯化。通过鞣酸沉淀法和聚丙烯酰胺凝胶电泳（SDS-PAGE）证实等电点沉淀可有效除去胃蛋白酶；经超滤纯化后的胶原蛋白紫外光谱检测在235nm处有最大吸收峰；在SDS-PAGE谱图上出现3条I型胶原蛋白特征谱带；采用凯氏定氮法也证实其纯度符合YY/T 1511-2017医药行业标准；通过傅里叶变换红外光谱、圆二色谱法(Circular Dichroism, CD)测定证实胶原蛋白三螺旋结构被完整保留下来。采用等电点沉淀法结合超滤纯化技术，可保证I型胶原蛋白的高纯度及三螺旋结构的完整性。     

Extraction of native collagen from limed bovine split wastes through improved pretreatment methods

BACKGROUND: The large amount of limed bovine split wastes discharged by the leather industry has raised concerns regarding their environmental effect. The objective of this work was to perform pilot plant trials to extract high‐value native collagen from these wastes through improved pretreatment methods. RESULTS: EDTA‐ and HCl‐pretreatment gave similar removal percentages of inorganic substances. Owing to the open structure of fibers, the collagen yield of HCl‐pretreated splits (HPS) (41.31%) was higher than that of EDTA‐pretreated splits (EPS) (10.42%). Furthermore, HCl‐pretreated split collagen (HPC) had a more acidic isoelectric point, lower content of primary amino groups, larger Z‐average particle size and higher relative viscosity than EDTA‐pretreated split collagen (EPC). Electrophoretic analysis and circular dichroism spectra revealed the maintenance of polypeptide and triple helix conformation, respectively. In addition, the transition temperatures of EPC (34.7 °C) and HPC (34.6 °C) detected by differential scanning calorimetry (DSC) were close to that of commercial collagen from calfskin (CCC) (35.7 °C). CONCLUSION: A process of native collagen extraction from limed bovine split wastes was proposed. While both EPC and HPC represented similar physicochemical properties to those of CCC, the collagen yield of HPS was much higher than that of EPS. Copyright © 2008 Society of Chemical Industry     

月桂醛和琥珀酸酐接枝改性天然胶原所得产物的表面活性

以月桂醛与琥珀酸酐接枝改性具有三股螺旋结构的天然胶原,得到了一种保留了天然胶原结构的生物表面活性剂(胶原基生物表面活性剂,简称BCB)。研究了BCB的基本表面活性,结果表明,BCB具有较好的泡沫膨胀和泡沫稳定性,其乳化活性(284.08 m2/g)与天然胶原(32.23 m2/g)相比有显著的提高,乳化稳定性和吸油能力也有所提升。BCB的润湿能力随着其浓度的增加而提高,表面张力随存放时间的延长而降低,在质量浓度为5.0×10-3g/L时,表面张力在3 000 s时达到平衡,为52.58 m N/m。研究表明,BCB和天然胶原的乳液类型均为O/W型。     

H-732阳离子交换树脂催化酯化反应

以H-732阳离子交换树脂为催化剂进行了酯化反应研究,合成了丁二酸单乙酯和乙酰水杨酸,通过单因素实验和正交实验优化了反应工艺。单因素实验结果表明：催化剂用量为丁二酸酐质量的20%、乙醇与丁二酸酐的摩尔比1.8∶1、反应时间2 h、反应温度90 ℃时,丁二酸单乙酯产率最高为68.76%;在丁二酸单乙酯的合成体系中加入分离出的副产物丁二酸二乙酯可以抑制副反应的发生,大大提高单酯的产率（90.79%）。正交实验结果表明：乙酸酐与水杨酸的摩尔比为3∶1,催化剂用量为水杨酸质量的14.50%,反应时间2 h、反应温度60 ℃时,乙酰水杨酸产率最高为77.57%;催化剂连续使用5次时,催化能力才有明显下降,对连续使用过5次的催化剂重新活化后催化能力无明显降低。     

Production of alkenyl succinic anhydrides from low‐erucic and low‐linolenic rapeseed oil methyl esters

Fatty acid methyl esters from low‐erucic and low‐linolenic rapeseed oil were used to produce alkenyl succinic anhydrides. A second‐order Doehlert uniform network design was used to investigate the influence of the reaction temperature and the molar ratio between the maleic anhydride and the main unsaturated rapeseed oil methyl esters on the yield of alkenyl succinic anhydride from methyl oleate. Further subjects of investigation were the conversion of methyl oleate, the formation of side reaction products, the Gardner color of the product and its viscosity, and finally the content of maleic anhydride remaining in the medium after the reaction. Alkenyl succinic anhydride from methyl oleate was isolated by column chromatography and analyzed by IR, ¹H‐ and ¹³C‐NMR and MS. The optimal reaction conditions for obtaining the maximum yield of alkenyl succinic anhydride from methyl oleate in the experimental domain (80%) were 210‐220 °C and a maleic anhydride/rapeseed oil methyl ester molar ratio of 1.5. However, the products synthesized in these conditions showed a high degree of viscosity (0.45 kg m^?1 s^?1), a very dark color (18 Gardner color) and a high content of undesirable side products (6%), which could hinder their industrial use. A molar ratio of less than 1.5 led to a clearer and less viscous product, although with a lower alkenyl succinic anhydride content.     

丁二酸酐性能及各种生产工艺介绍

丁二酸酐是一种重要的精细化工原料,用途广泛,尤其它的衍生物更是附加值高的精细化工产品,全球丁二酸酐的生产工艺主要有丁二酸脱水法、顺丁烯二酸酐催化加氢法。本文章主要介绍了丁二酸酐的性能、用途和生产工艺技术,并对生产工艺技术进行了比较,顺丁烯二酸酐熔融催化加氢法由于生产成本和综合能耗较低,是最具竞争力,发展前景看好的一种方法。     

Succinic Acid Production in Fed‐Batch Fermentation of Anaerobiospirillum succiniciproducens Using Glycerol as Carbon Source

Considering glycerol as an inexpensive alternative carbon source, the optimal glycerol concentration for succinic acid production with Anaerobiospirillum succiniciproducens was identified in shake‐flask trials. The addition of a defined amount of glucose improved the growth and succinic acid productivity significantly. In fed‐batch processes with glycerol as sole substrate, a maximum succinic acid concentration and product substrate yield were obtained. The addition of glucose led to a 2.5‐fold increased succinic acid concentration whereas the product substrate yield remained nearly constant.     

单过氧丁二酸氧化环己酮合成ε-己内酯(英文)

In the absence of catalyst, 70% hydrogen peroxide was used to oxidize succinic anhydride to solid monoperoxysuccinic acid（PSA）. Then PSA was applied to synthesis of ε-caprolactone（ε-CL） by oxidation of cyclohexanone in the heterogeneous system. In order to achieve material recycle, solid precipitated in the process of synthesizing ε-CL was dehydrated via reactive distillation followed by recrystallization to prepare succinic anhydride, which was characterized by IR（infrared spectra） and1HNMR（1H nuclear magnetic resonance）. Effects of molar ratio of PSA to cyclohexanone, acetic acid dosage, reaction temperature, reaction time on conversion of cyclohexanone, yield and selectivity of ε-CL were investigated respectively. The results indicated that conversion of cyclohexanone, yield and selectivity of ε-CL were upto 98.1%, 97.5% and 99.4% respectively under the optimal conditions. In addition, in the process of synthesizing succinic anhydride, the optimal yield of succinic anhydride reached 67.4%.     

维生素E琥珀酸酯的酶促合成及优化

在有机溶剂中以维生素E和琥珀酸酐为底物在脂肪酶的催化下合成了维生素E琥珀酸酯。首先对酶促反应的脂肪酶、反应介质和反应温度进行了考察,在所选的几种脂肪酶中,假丝酵母脂肪酶(Candidasp.)的催化活性最好;叔丁醇和DMSO组成的混合溶剂(体积比为2∶3)为最合适的反应介质;30℃为适宜的反应温度。并采用Box-Behnken实验设计和响应面因子分析法对底物摩尔比等其他反应条件进行了优化。维生素E琥珀酸酯最优反应条件为:维生素E浓度0.26mmol.ml-1,维生素E和琥珀酸酐摩尔比1∶5,在5ml叔丁醇和DMSO混合溶剂(体积比为2∶3)中,30℃下在0.02gCandidasp.脂肪酶的催化下反应71h,维生素E琥珀酸酯产率达到98.71%。     

胃蛋白酶提取牛皮胶原蛋白的工艺研究

以新鲜牛皮为原料,分析了牛皮的基本组成;采用胃蛋白酶提取牛皮胶原蛋白,研究了提取过程中加酶量、提取温度、提取时间和料液比对胶原蛋白提取率的影响,得到酸酶结合法提取牛皮中胶原蛋白的最佳工艺条件为:以0.5 mol/L乙酸作提取剂,每1 g牛皮加入30 mL浸提液(即料液比1∶30),胃蛋白酶加入量3 000 U/g牛皮,提取温度30℃,提取时间为8 h,在该条件下胶原蛋白的提取率为61.7%。提取的胶原蛋白经过初步纯化后进行紫外扫描,测得其最大紫外吸收波长为232 nm,与Sigma标准Ⅰ型胶原蛋白一致。     

Vapour phase hydrogenolysis of biomass‐derived diethyl succinate to tetrahydrofuran over CuO?ZnO/solid acid bifunctional catalysts

BACKGROUND: Catalytic upgrading of fermentation‐derived succinic acid or its derivates (succinic acid esters and succinic anhydride) to value added chemicals has received great attention recently. The aim of this work is to provide a process for the production of tetrahydrofuran from succinic acid esters. RESULTS: The hydrogenolysis of biomass‐derived diethyl succinate was investigated over CuO? ZnO and CuO? ZnO/solid acid (HY, HZSM‐5, SAPO‐11 and Al₂O₃) catalysts in a fixed‐bed reactor. Over CuO? ZnO, gamma‐butyrolactone and 1,4‐butanediol can be selectively produced under appropriate reaction conditions, while the selectivity of tetrahydrofuran is relatively low due to the weak acidity of CuO? ZnO. Over CuO? ZnO/HZSM, both the formed 1,4‐butanediol and ethanol can be further converted to tetrahydrofuran and diethyl ether, while tetrahydrofuran is selectively produced over CuO? ZnO/HY. CuO? ZnO/Al₂O₃ and CuO? ZnO/SAPO exhibit slight improvements in terms of selectivity to tetrahydrofuran when compared with CuO? ZnO. CONCLUSION: CuO? ZnO/HY is an appropriate catalyst to produce tetrahydrofuran from biomass‐derived diethyl succinate with high activity, selectivity and stability. Furthermore, Brønsted acid sites with appropriate acid strength are responsible for the selective formation of tetrahydrofuran under the applied reaction conditions. Copyright © 2010 Society of Chemical Industry     

Hydrogenation of Succinic Acid to γ-Butyrolactone (GBL) Over Palladium-Alumina Composite Catalyst Prepared by a Single-Step Sol–Gel Method

Abstract  

Mesoporous palladium-alumina (Pd-A) composite catalysts prepared by a single-step sol–gel method were calcined at various temperatures to control palladium surface area and acidity. The Pd-A catalysts were characterized by XRD, BET, N₂ adsorption–desorption isotherm, H₂ chemisorption, ²⁷Al MAS NMR, NH₃-TPD, and HR-TEM analyses. Liquid-phase hydrogenation of succinic acid to γ-butyrolactone (GBL) was carried out over Pd-A catalyst in a batch reactor. The effect of calcination temperature of Pd-A catalyst on the palladium surface area and catalytic performance was investigated. In the hydrogenation of succinic acid, conversion of succinic acid increased with increasing palladium surface area of Pd-A catalyst. Selectivity for GBL depended on the formation of succinic anhydride (an intermediate product formed by acid catalysis) and by-products (formed by hydrogenolysis). Nevertheless, yield for GBL also increased with increasing palladium surface area of Pd-A catalyst. Thus, palladium surface area played an important role in enhancing the catalytic performance of Pd-A catalyst in the hydrogenation of succinic acid to GBL.     

猪皮胶原的降解

采用低温-胃蛋白酶法从新鲜猪皮中提取胶原。通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳（SDS—PAGE）结合紫外、红外光谱分析证明所提取的胶原为Ⅰ型活性胶原,即胶原分子量约为32万道尔顿,组成为α1）2α2,且具有完整的三股螺旋结构;利用天然胶原的特性降解酶细菌胶原酶进行低温降解,得到分子量在3万到20万道尔顿之间的降解产物,降解产物红外光谱证明大部分仍然保持三股螺旋结构,并与市售的胶原多肽（失活）的红外光谱图比较,充分体现了此降解方案的优越性。     

The effect of various anhydride modifications on mechanical properties and water absorption of oil palm empty fruit bunches reinforced polyester composites

The chemical modification of oil palm empty fruit bunches (EFB) using non‐catalysed reaction with acetic, propionic and succinic anhydrides were investigated. Proof of modification was indicated by the increase of weight and was confirmed by Fourier‐transform infrared analysis (FT‐IR). The mechanical and water‐absorption properties of all anhydride‐modified EFB composites were evaluated at different volume fractions (V_f). The properties were improved for these modified fibres, whereas unmodified EFB fibres exhibited poor mechanical properties and higher water absorption. Acetic anhydride modification showed the greatest benefit on composite properties, followed by propionic and succinic anhydride modification. © 2001 Society of Chemical Industry     

Solid‐state grafting of succinic anhydride onto poly(vinyl alcohol)

The graft reaction of succinic anhydride onto poly(vinyl alcohol) (PVA) was catalyzed by p‐toluenesulfonic acid monohydrate in solid state. The infrared spectra and ¹H‐NMR spectra confirmed that succinic anhydride was successfully grafted onto PVA backbone. The influences of reaction temperature, reaction time, the amount of succinic anhydride, and the amount of catalyst on the graft reaction were studied. Uncrosslinked PVA graft copolymer with grafting degree up to about 6.5% could be obtained under low reaction temperature, short reaction time, and low amount of catalyst, whereas crosslinked PVA with high gel content could be obtained under high reaction temperature, long reaction time, and high amount of catalyst. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 848–852, 2007     

Sea Buckthorn Oil Tocopherol Extraction's By‐Product Utilization in Green Synthesis of Polyurethane Coating

The focus of the present study is to utilize a by‐product obtained during extraction of tocopherols, a valuable vitamin E compound, from sea buckthorn (SBT) oil and in doing so find a reliable alternative to petrochemical based polyols. Bio‐based polyurethane (PU) is prepared by using SBT oil based fatty acid methyl ester polyesteramide polyols (SBTPEP) with toluene diisocyanate (TDI). The fatty acid methyl ester is converted to the corresponding fatty amide by reaction with diethanolamine. The formed fatty amide is then esterified with phthalic anhydride to synthesize polyesteramide polyol. Characterization techniques used to evaluate polyesteramide polyol are Fourier‐transform infrared spectroscopy (FTIR) and NMR. The cured PU coating is also put through various mechanical tests to analyze the physical properties. The cured PU coating shows good surface and mechanical properties. It shows a gloss value of 87.4 and passes impact, adhesion, and chemical resistance tests. It is hydrophobic which is evident from its contact angle of 100.2°. It has good thermal stability which is evident by its glass transition temperature of 53.9 °C. Use of phthalic anhydride contributes to the bio‐based characteristics of synthesized PU. Practical Application: The present study presents a synthesis route which has minimal dependence on hazardous feedstock by utilization of green feedstock. The results obtained from physical and mechanical evaluations favor the use of this PU formulation in the coating sector. The adhesion and impact strength test results show potential application in the industrial sector coatings where the applied coat must be able to withstand high levels of physical stress and strain. The presence of aromatic rings and oil‐based moiety, that is the fatty acid hydrocarbon chain, contributes to the hydrophobic nature of the PU coating. Hydrophobic coatings have tremendous application in various fields such as marine coatings, automotive, electronics, and decorative coatings. These are potential fields of application for the synthesized green PU coating obtained from tocopherol extraction by‐products.     

Electrochemical analysis of the adsorption and desorption behaviors of carboxylic acid and anhydride monomers onto zinc surfaces

The interfacial bondings formed between succinic acid and myristic acid, as well as succinic anhydride molecules with a set of differently treated zinc substrates have been investigated using infrared reflection absorption spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). The compounds were selected to model typically used carboxylic-based adhesives and coatings. Moreover, the adsorption kinetic has been evaluated by means of chronoamperometry (CA) and chronovoltammetry measurements. XPS results showed a relation between the amount of carboxylates formed by adsorption of succinic acid/myristic acid and the hydroxyl fraction presented on the surfaces as proved by a higher electron transfer in CA. On the other hand a set of oxidative/reductive interactions was detected during the adsorption of succinic anhydride, in turn proving a spontaneous ring opening and adsorption mechanism. A clear relationship between the amount of adsorbents and surface hydroxyls/carbonates was detected for the adsorption of succinic anhydride. The extent to which the formed carboxylates resisted negative potentials was also investigated by cyclic voltammetry (CV) in an aqueous solution. The coordinative bonding of a bifunctional carboxylic acid group to the oxide surface was found to be not stable in the presence of a negative potential, while a monofunctional carboxylic acid group could resist displacement by water for a prolonged period of time. On the other hand, a low double layer capacitance was obtained after the adsorption of succinic anhydride, which was related to a change in potential of zero charge (PZC) upon the adsorption.     

生物法制造丁二酸研究进展

丁二酸因其C₄分子结构在化工领域的潜在价值，被认为是一种具有广阔应用前景的生物基平台化合物。结合生物基丁二酸的产业现状，综合分析了丁二酸生产菌种及菌株改造、生物过程优化和丁二酸分离纯化这三个方面的研究现状。重点介绍以大肠杆菌、产琥珀酸放线杆菌、解脂耶氏酵母为代表的主要生产菌株及其改造策略；低值生物质利用及控制发酵过程中CO₂ 供给和pH 调节等生物过程优化策略；包括钙盐法、电渗析法、直接分离法等方法在内的丁二酸分离工艺。同时指出未来的研究重点将综合考虑经济性与能耗问题，将菌株与发酵和分离全过程整合，提高丁二酸产量，降低发酵及分离成本，进一步拓展生物基丁二酸市场应用领域。     

米格列奈钙的合成新工艺

(S)-2-苄基丁二酸脱水生成酸酐后与顺式全氢异吲哚反应生成米格列奈酸及其异构体副产物酸。将副产物酸分离出并异构化为米格列奈酸;米格列奈酸经成盐得产品米格列奈钙。考察了工艺条件对反应的影响,结果表明：以10mL甲苯为溶剂,5mL乙酸酐为脱水剂,0.03mol (S)-2-苄基丁二酸在110℃下脱水反应1h,酸酐收率可达90.49%;酸酐与顺式全氢异吲哚反应产物收率可达97.60%;用乙酸乙酯对产物米格列奈酸及其异构体副产物酸进行分离后,二者HPLC含量均高于98%;以甲苯为溶剂,回流反应3h,异构体副产物酸异构化为米格列奈酸,转化率达到57.65%;产品米格列奈钙总收率可达67.49%,HPLC含量高达99.25%。中间体和产物结构用¹H NMR进行表征确认。     

The hydrogenation of maleic anhydride to γ-butyrolactone using mixed metal oxide catalysts in a batch-type reactor

An improved catalytic hydrogenation process for converting maleic anhydride and/or succinic anhydride to γ-butyrolactone uses a novel selective catalyst in a liquid phase operating at high pressure batch-type reactor. The catalysts are composed of palladium, molybdenum and nickel on a silica support of high surface area. This multi-component mixed metal oxide catalyst system in a batch-type reactor is found to be suitable for the hydrogenation of maleic anhydride selectively to γ-butyrolactone. The effects of temperature, pressure and catalyst to reactant ratio are investigated in order to optimize the reaction conditions for better activity, yield and selectivity. A reaction temperature of 220 to 260 °C and pressure of 60 to 80 atm were afforded, the mixed metal oxide catalyst containing nickel, palladium and molybdenum oxide is shown almost 100% conversion of maleic anhydride within 120 min and 56–96% yield of γ-butyrolactone. The hydrogenation of maleic anhydride using this catalyst is not observed by-products and the selectivity of γ-butyrolactone is very high.