Aflatoxins B1, B2, G1, and G2: Separation and purification

Aflatoxins B₁, B₂, G₁, and G₂ have been separated on a series of chromatographic columns. Chromatography of crude products isolated from molded wheat and rice on silicic acid with washed chloroform:ethanol (99:1) gave relatively pure B₁. The rest of the column fractions containing predominantly G₁, along with B₁, B₂, and G₂, were pooled and fractionated on a Silica Gel G column. The mobile phase was washed chloroform:acetone:ethanol (97.3:2.0:0.75). Thin-layer chromatography was used to follow column development. Each of the aflatoxins was treated with either decolorizing carbon or copper carbonate to remove colored pigments, and rechromatographed on Silica Gel G. Crystalline aflatoxins were prepared from chloroform solutions by addition ofn-hexane, methanol, or ethanol. Presented at the AOCS Meeting, New Orleans, May 1967. No. Utiliz. Res. Dev. Div., ARS, USDA.     

Kinetic study of acid-catalyzed conversion of aflatoxins B1 and G1 to B2a and G2a

Adjusting dilute aqueous solutions of aflatoxins B₁ and G₁ to pH 1, 2 and 3, and heating over a range of 40–100 C resulted in the conversion of B₁ to B_2a and G₁ to G_2a as major products. Both B_2a and G_2a were identified by co-thin layer chromatography with authentic B_2a and G_2a and M₁ on silica gel plates developed in two different solvents. The rate of disappearance of B₁ or G₁ at given temperature and at constant pH was found to be first order with respect to each aflatoxin. At given temperature the conversion is strongly pH dependent, a 10-fold increase in H⁺ ion (1 pH unit) producing about a 9-fold increase in the reaction rate, indicating first order dependent of the rate on H⁺ ion concentration. S. Market. Nutr. Res. Div., ARS, USDA.     

杜檊氏菌B2的蓝色素成分的分离及化学结构解析

从杜檊氏B2菌体中提取蓝色色素,从中分离得到两中组分（Ⅰ、Ⅱ）,经过高效液相色谱分离纯化,质谱以及核磁共振等分析,确定组分Ⅰ脱氧紫色杆菌素、组分Ⅱ为紫色杆菌素。本研究首次证明杜檊氏菌属也能合成紫色杆菌素。     

食品中的黄曲霉毒素B1、B2、G1、G2的超高效液相色谱—串联质谱检测

建立用超高效液相色谱-串联质谱检测器测定食品中的黄曲霉毒素B1、B2、G1、G2的方法。样品中残留的黄曲霉毒素经过乙腈(乙腈∶水=84∶16)提取,取经过4000 r/min离心机离心过的上层清液,经装有反相离子交换吸附剂的多功能净化柱,去除脂肪、蛋白质、色素及碳水化合物等干扰物质,氮吹定容后上机至液相质谱联用仪,根据色谱图出峰时间及与之相应标物的特征离子对作对比,对黄曲霉毒素B1、B2、G1、G2定性,再根据标准系列得出的标准曲线,换算出各黄曲霉毒素的含量。     

α2-巨球蛋白的分离纯化及临床应用

α2-巨球蛋白(α2-macroglobulin,α2-M)是一种大分子糖蛋白,主要存在于人体的血浆中,是一种广谱蛋白酶抑制剂,可清除内源性及外源性蛋白酶。制备α2-M工艺的起始原料多为人血浆,实验室制备工艺大多结合使用免疫亲和层析、凝胶过滤、Cibacron蓝色琼脂糖亲和层析等,而规模化制备工艺一般先使用硫酸铵、利凡诺、聚乙二醇等方法进行粗分离,再使用锌离子亲和层析、凝胶过滤等方法进行精细分离。α2-M用于治疗放射性皮肤黏膜溃疡损伤、放射性肺炎、放射性膀胱炎、角膜炎及角膜溃疡具有良好效果。α2-M还可作为判断肝纤维化分期、胰腺炎病情轻重的一个生物标记物。本文主要就α2-M的制备工艺及临床应用作一综述。     

Extraction partition and column chromatographic separation of aflatoxins B1 and M1

Extraction, partition and chromatographic elution characteristics of aflatoxin were studied. The novel use of aqueous dimethylsulfoxide or aqueous dimethylformamide for extraction from agricultural products was tested and found effective. Partition studies suggest advantages in analytical work of using solvent pairs in which benzene rather than (the usually employed) chloroform is used to transfer aflatoxin B₁ from primary extracts (aqueous phases). Tests of elution characteristics of aflatoxins B₁ and M₁ on silica gel columns with different developing solvents provided a basis for a procedure in which aflatoxins B₁ and M₁ of a test sample are recovered in separate eluates in which substances which interfere with TLC separation are minimized. Presented at the AOCS Spring Meeting, San Francisco, April 1969. W. Utiliz. Res. Dev. Div., ARS, USDA.     

疏水性电荷诱导色谱分离抗HER2单克隆抗体

采用疏水性电荷诱导色谱（HCIC）新型生物分离方法,从CHO细胞培养液中高效分离抗HER2单克隆抗体（单抗）。选用典型HCIC介质MEP HyperCel,考察了细胞培养液中单抗稳定性,比较了不同pH下MEP HyperCel介质对抗HER2单抗的吸附性能,发现pH6～9范围内吸附容量均较高,酸性条件下吸附容量显著下降。进一步考察了抗HER2单抗的动态吸附载量,优化了上样和洗脱条件,确定了合适的分离条件,实现了细胞培养液中高效分离单抗,纯度达到94.6%,收率约0.1 mg·（ml料液）^-1。结果表明,HCIC从哺乳动物细胞培养液中分离单抗是切实可行的,为单抗分离提供了新思路。     

2-甲基萘从洗油中分离提纯的研究

介绍了一种从含2-甲基萘量较低的洗油中分离、提纯2-甲基萘的有效方法。所得2-甲基萘经气相色谱分析其纯度可达99．5％,回收率在79．8％以上,此方法具有工艺简单、产物纯度高、污染低、共沸剂可以重复利用和成本低等特点。     

胰岛素受体的分离纯化及活性检测

分离了大鼠肝细胞膜胰岛素受体,并用麦胚凝集素-琼脂糖亲和层析纯化,用免疫印迹法检测胰岛素刺激下大鼠肝细胞膜胰岛素受体的酪氨酸自磷酸化。结果表明,纯化的胰岛素受体发生了酪氨酸自磷酸化反应,说明所提取的胰岛素受体具有生物活性,可用于胰岛素信号传导的进一步研究。该方法简便、稳定、可靠,可用于胰岛素受体的分离和纯化。     

棕榈酸果糖单酯的提纯分离

为了得到果糖单酯纯品,需要将果糖单酯与未反应的糖及脂肪酸、催化剂、以及其他残留物进行提纯分离。利用混合溶剂萃取的方法,对固定化脂肪酶(Novozym435)促合成的棕榈酸果糖单酯进行了提纯分离研究。结果表明,混合溶剂环己烷乙醇水萃取棕榈酸果糖单酯的纯度可达93.8%,收率达到92.5%,同时确定了萃取的最佳条件是V(环己烷):V(乙醇):V(水)=2∶2∶1,棕榈酸果糖单酯的初始质量浓度在0.48~0.60 mg/mL,温度为60℃。     

去乙酰头孢菌素C的分离纯化

利用粒径分布为0.27~1.70 mm的煤质颗粒活性炭为吸附剂,采用固定床方式分离废弃液中的去乙酰头孢菌素C(DCPC)。以8%(体积)乙醇水溶液洗脱,得到DCPC纯度大于85%的洗脱液,收率为60%~65%。洗脱液经过纳滤膜浓缩后,通过阴离子交换树脂Amberlite IRA67吸附,以0.5 mol.L-1醋酸钠缓冲液(pH6.3)洗脱,得到DCPC纯度96%、含量大于30 g.L-1的去乙酰头孢菌素C的钠盐溶液,收率在90%~95%。加入丙酮,可得到去乙酰头孢菌素C钠盐结晶。以含有异丙醇的强碱溶液浸泡洗涤洗脱后的煤质颗粒活性炭,再用酸溶液中和冲洗,可恢复其吸附能力。     

2-(1,1,2,3,3-五甲基茚满)异丙醇的制备与纯化

以1,1,2,3,3-五甲基茚满与环氧丙烷为原料,二氯甲烷为溶剂,无水氯化铝催化合成2-(1,1,2,3,3-五甲基茚满)异丙醇(俗称茚满醇)。考察了原料摩尔比、无水氯化铝用量、反应温度对茚满醇选择性的影响。采用超声辅助溶解-结晶的方式对产品进行了纯化。结果表明,在-10～-15℃时,原料摩尔比n(五甲基茚满)∶n(环氧丙烷)∶n(无水氯化铝)=1∶1.2∶1.2的条件下反应2 h,五甲基茚满转化率55.8%,茚满醇选择性99%。经结晶纯化后茚满醇纯度达99%,避免了减压蒸馏产生的焦杂味。通过FTIR、GC-MS、HRESIMS、元素分析、1HNMR和13CNMR对茚满醇结构进行了表征。     

Photoluminescent Polymer Aerogels with R,G and B Emission

In this work, three new polymer aerogels based on 2-hydroxy ethyl methacrylate (HEMA) complexes with Eu(III), Tb(III) and La(III) are prepared and investigated. The polymer aerogels present strong photoluminescence with emissions located in the red, green and blue regions of the visible spectrum. Depending on the water content used during the preparation path, the consistency of the photoluminescent aerogels varies from rigid, regularly shaped monoliths to a flexible, fibrous material with very low density. The morpho-structural investigation was performed by FT-IR, XPS and SEM. Thermal behavior was also evaluated, while steady-state fluorescence spectroscopy, absolute PLQY and lifetime were used for the investigation of their luminescent properties. The impressive photoluminescent emission located in the red, green and blue areas of the visible spectrum is preserved irrespective of the selected porosity. Their photo-emissive properties, tunable porosity and the convenience of the preparation path could be some arguments for applications as photonic conversion mediums in special-purpose optoelectronic devices or sensors.     

重组人生长激素的分离纯化及其结构确证

目的对重组人生长激素(recombinant human growth hormone,rh GH)进行分离纯化,并进行结构确证。方法取rh GH工程菌菌体,进行初步纯化(低渗抽提法、盐析法)及层析纯化(Sephadex G-25分子排阻层析、DEAESephadex.F.F离子交换层析、Phenyl-Sepharose.F.F疏水层析、Phenyl S-100HR分子排阻层析),收集纯化产物,进行15%SDS-PAGE分析、相关蛋白含量检测、高分子蛋白含量检测,并进行分子量检测、氨基酸组成分析、N-末端氨基酸序列分析、C-末端氨基酸序列分析和等电聚焦电泳。结果纯化产物的相对分子质量22 125,纯度可达99.5%以上,rh GH蛋白总收率为13.36%,相关蛋白含量为1.55%,高分子蛋白含量低于0.1%;相对分子质量、氨基酸组成、N-末端氨基酸序列、C-末端氨基酸序列及等电点等均与rh GH国际标准品一致。结论纯化后获得了高纯度的rh GH蛋白,该纯化工艺简单、高效,为本产品的工业化生产奠定了基础。     

环丁砜萃取精馏提纯连三甲苯的实验和模拟

针对混合C₉芳烃原料中沸点接近、分离困难的连三甲苯-茚满物系,以环丁砜为萃取剂进行了萃取精馏分离提纯实验,并采用Aspen Plus化工流程模拟软件对萃取精馏工艺过程进行了模拟研究,萃取精馏实验数据与模拟结果吻合较好,相对偏差小于5%。结合萃取精馏实验和流程模拟考察了萃取精馏塔的理论塔板数、溶剂比（萃取剂与原料的质量比）、回流比以及原料和萃取剂的进料位置等因素对分离效果的影响规律。结果表明,环丁砜萃取精馏提纯连三甲苯较适宜的工艺条件是：萃取精馏塔的理论塔板数为60~65、溶剂比为5~7、回流比为3~4、原料的进料位置为第34~36块板、萃取剂的进料位置为第8~10块板,在此条件下,塔顶可获得高纯度的连三甲苯产品,其质量分数可达99%以上,回收率可达93%以上。     

汉麻叶中大麻二酚的分离纯化及其抗抑郁功能

采用柱层析技术对汉麻叶中大麻二酚(CBD)进行分离纯化,并探究其在抑郁症状方面的应用.汉麻叶经预处理后通过超临界CO2萃取得到汉麻浸膏,然后采用树脂两步色谱方法,得到高纯度CBD,并建立慢性不可预测的轻度应激模型小鼠,采用灌胃CBD方式来探究其抑郁行为及对炎症因子的影响.结果表明,通过该法分离纯化提取CBD的纯度高达9...     

含萘量较低煤焦油中萘的分离与提纯

报道了一种从含萘量较低的煤焦油中分离、提纯萘的有效方法。先用乙醇对煤焦油进行萃取,然后对萃出液减压蒸馏,得到含萘量较高的固液混合物,经过滤抽干得到粗萘。建立了水蒸汽蒸馏提纯粗萘的方法,所得的精萘经气相色谱检测其纯度可达99．48％,回收率在93％以上。随后与精馏法、溶剂结晶法等提纯方法进行了比较,体现了水蒸汽蒸馏提纯萘的优越性。