Isolation and purification of oridonin from the whole plant of Isodon rubescens by high-speed counter-current chromatography

Semi-preparative high-speed counter-current chromatography (HSCCC) was successfully used for isolation and purification of oridonin from Isodon rubescens by using a two-phase-solvent system composed of n-hexane-ethyl acetate-methanol-water (2.8:5:2.8:5, v/v/v/v). The targeted compound isolated, collected and purified by HSCCC was analyzed by high performance liquid chromatography (HPLC). A total of 40.6 mg of oridonin with the purity of 73.5% was obtained in less than 100 min from 100 mg of crude Isodon rubescens extract. The chemical structure of the compound was identified by IR, 1H-NMR and 13C-NMR.     

Flexible total synthesis of biphenomycin B

A total synthesis of the biaryl antibiotic biphenomycin B is reported which makes use of three independent building blocks (key steps were a clean Suzuki-Miyaura coupling of a free acid iodide, a novel 4-hydroxyornithine synthesis, and a high-yielding macrolactamization); a practical deprotection protocol allowed isolation of the target compound with excellent recovery and purity.     

Application of high-speed counter-current chromatography coupled with high-performance liquid chromatography-diode array detection for the preparative isolation and purification of hyperoside from Hypericum perforatum with online purity monitoring

Following preparative isolation and purification by high-speed counter-current chromatography (HSCCC), the collected fractions were generally analyzed by high-performance liquid chromatography (HPLC) to determine the relative purities of each fraction. Our paper reports for the first time a preparative isolation-purity detection hyphenated system: online coupling of HSCCC with high-performance liquid chromatography-diode array detection (HSCCC-HPLC-DAD). The introduction of online purity analysis in HSCCC has dramatically improved the efficiency of this technique by overcoming the drawbacks of post analysis in HSCCC isolation. The effluent from the outlet of HSCCC was splitted into two parts: one was collected, while the other was introduced directly into an HPLC-DAD system for purity analysis through a switch valve. Therefore, the purities of the obtained fractions from HSCCC were monitored, and fractions with high purities were collected. This strategy has been successfully demonstrated with the preparative isolation and purification of hyperoside from Hypericum perforatum (St. Jone's Wort); a model of TBE-300A HSCCC was used to isolate and separate hyperoside from H. perforatum with a two-phase solvent system composed of ethyl acetate-ethanol-water at the volume ratio of 5:1:5 (v/v) using online detection technique. The isolation was done in less than 3.5 h, and a total of 83.0-mg hyperoside at over 99.0% purity was yielded from 300 mg of the partially purified extract. This new strategy possesses general utility in the preparation of bioactive compounds from traditional Chinese medicine (TCM).     

Bioassay-Guided Isolation and Identification of Antimicrobial Compounds from Thyme Essential Oil by Means of Overpressured Layer Chromatography,Bioautography and GC–MS

A simple method is described for efficient isolation of compounds having an antibacterial effect. Two thyme (Thymus vulgaris) essential oils, obtained from the market, were chosen as prospective materials likely to feature several bioactive components when examined by thin layer chromatography coupled with direct bioautography as a screening method. The newly developed infusion overpressured layer chromatographic separation method coupled with direct bioautography assured that only the active components were isolated by means of overrun overpressured layer chromatography (OPLC) with on-line detection and fractionation. Each of the 5 collected fractions represented one of the five antimicrobial essential oil components designated at the screening. The purity and the activity of the fractions were confirmed with chromatography coupled with various detection methods (UV, vanillin–sulphuric acid reagent, direct bioautography). The antibacterial components were identified with GC–MS as thymol, carvacrol, (−)-linalool, diethyl-phthalate, and α-terpineol. The oil component diethyl-phthalate is an artificial compound, used as a plasticizer or detergent base in the industry. Our results support that exploiting its flexibility and the possible hyphenations, OPLC is especially attractive for isolation of antimicrobial components from various matrixes.

     

Isolation of the lignan secoisolariciresinol diglucoside from flaxseed (Linum usitatissimum L.) by high-speed counter-current chromatography

High-speed counter-current chromatography was successfully used for the isolation and purification of secoisolariciresinol diglucoside, a bioactive lignan from flaxseed (Linum usitatissimum L.). The solvent system consisted of tert.-butylmethyl ether-n-butanol-acetonitrile-water (1:3:1:5). The purity and identity of the isolated compound was checked by high-performance liquid chromatography analysis in combination with mass spectrometry and NMR measurements.     

From the dilute solution to the pure compound: Extraction strategy based on a multi-stage process of phase separation

It is very rare that a one-step process of extraction leads to the pure compound with a high degree of purity specified by an industrial application. The various stages of a synthesis process and possible secondary reactions may lead to the synthesis of more or less complex and highly diluted solutions. In this work, the rationale and strategy for extraction and purification of a high added value compound are discussed. All the thinking is based on the knowledge and the exploitation of phase diagrams and then developed for different unit operations of the process. The most significant research tools are the experimental data and the modelling of phase equilibrium to estimate the yield of each step of extraction. The significant example chosen involves all the basic methods of phase separation, starting with liquid-vapour equilibrium: stripping of high volatility components and then more or less complex distillation are classically employed. The theoretical plateau number can be deduced from the equilibrium equation curves. The second step is based on the study of the liquid-liquid equilibrium and is an intermediate step for enrichment of the solution when distillation is not possible. A final step based on solid-liquid equilibrium consists of the selective crystallization of the pure product at low temperature, in order to satisfy the requirements of purity and safety imposed by industrial use. The conclusion includes all isolation operations in the form of a general extraction and purification scheme.

     

Synthesis, structure, and 19F NMR spectra of 1,3,7,10,14,17,23,28,31,40-C60(CF3)10

A significant improvement in the selectivity of fullerene trifluoromethylation reactions was achieved. Reaction of trifluoroiodomethane with [60]fullerene at 460 degrees C and [70]fullerene at 470 degrees C in a flow reactor led to isolation of cold-zone-condensed mixtures of C60(CF3)n and C70(CF3)n compounds with narrow composition ranges: 6 < or = n < or = 12 for C(60)(CF3)n and 8 < or = n < or = 14 for C70(CF3)n. The predominant products in the C(60) reaction, an estimated 40+ mol % of the cold-zone condensate, were three isomers of C60(CF3)10. Two of these were purified by two-stage HPLC to 80+% isomeric purity. The third isomer was purified by three-stage HPLC to 95% isomeric purity. Thirteen milligrams of this orange-brown compound was isolated (5% overall yield based on C60, and its C1-symmetric structure was determined to be 1,3,7,10,14,17,23,28,31,40-C60(CF3)10 by X-ray crystallography. The CF3 groups are either meta or para to one another on a p-m-p-p-p-m-p-m-p ribbon of edge-sharing C6(CF3)2 hexagons (each pair of adjacent hexagons shares a common CF3 group). The selectivity of the C70 reaction was even higher. The predominant product was a single C70(CF3)10 isomer representing >40 mol % of the cold-zone condensate. Single-stage HPLC led to the isolation of 12 mg of this brown compound in 95% isomeric purity (27% overall yield based on converted C70. The new compounds were characterized by EI or S(8)-MALDI mass spectrometry and 2D-COSY 19F NMR spectroscopy. The NMR data demonstrate that through-space coupling via direct overlap of fluorine orbitals is the predominant contribution to J(FF) values in these and most other fullerene(CF3)n compounds.     

主客体包结法选择分离青花椒挥发油中的化学成分

以1,1,6,6-四苯基-2,4-己二炔-1,6-二醇为主体分子, 可简单、迅速地从青椒挥发油中选择分离出化学成分烯丙基茴香醚, 基于挥发油的用量, 收率为3.78%. IR, ¹H NMR, ¹³C NMR光谱和单晶衍射证实了包结化合物结构, 用气相色谱法评价了选择分离效果, 分离的烯丙基茴香醚气相色谱纯度为94.5%. 同时, 主体分子形成的隧道框架对茴香醛具有识别作用, 形成2∶1(主/客)物质的量比的特殊结构包结物晶体, 它是主客体分子物质的量比为1∶2包结物的超分子异构体.     

Semipreparative separation and determination of eleutheroside E in Acanthopanax giraldii Harms by high-performance liquid chromatography

A method for the isolation, purification, and determination of eleutheroside E in Acanthopanax giraldii Harms, collected in the Sichuan province (China), is established. The water extraction of A. giraldii Harms is pre-isolated using macroporous adsorption resin (D-101) and a C18 solid-phase extraction cartridge, and the enriched extract is purified to give eleutheroside E (syringaresinol-di-O-beta-D-glucoside; liriodendrin) by semipreparative reversed-phase high-performance liquid chromatography. Structure identification is performed by a comparison of IR, 1H-NMR, 13C-NMR, and electrospray ionization-mass spectrometric data with the literature. The final purity of the compound is 97%. Quantitative determination of eleutheroside E in A. giraldii Harms is performed on a Zorbax SB C18 (150- x 4.6-mm i.d., 5 microm) column. The linear range of eleutheroside E is 4.85-194 mg/L (r = 0.9998), and the average recovery is 99.6-101%. The developed method is simple, reproducible, and easy to operate. It is useful for the evaluation of Acanthopanax giraldii Harms.     

Preparative high-speed counter-current chromatography for purification of shikonin from the Chinese medicinal plant Lithospermum erythrorhizon

The bioactive compound shikonin was successfully isolated and purified from the crude extract of the traditional Chinese medicinal plant Lithospermum erythrorhizon Sieb. et Zucc. by preparative high-speed counter-current chromatography (HSCCC). The preparative HSCCC was performed using a two-phase solvent system composed of n-hexane-ethylacetate-ethanol-water (16:14:14:5 (v/v)). A total amount of 19.6 mg of shikonin at 98.9% purity was obtained from 52 mg of the crude extract (containing 38.9% shikonin) with 96.9% recovery. The preparative isolation and purification of shikonin by HSCCC was completed in 200 min in a one-step separation.     

The use of polyhedral oligomeric silsesquioxane (POSS) as a soluble support for organic synthesis: A case study with a POSS-bound isocyanate scavenger reagent

The use of polyhedral oligomeric silsesquioxane (POSS) as a soluble support in organic synthesis is reported. A POSS-bound isocyanate was readily synthesised in one step from commercially available starting materials and was isolated in high yield and purity by simple filtration. It was found to perform well as a scavenger for excess amine in the solution phase synthesis of amides and sulfonamides, allowing product isolation in high yield and purity.     

高速逆流色谱法分离紫锥菊花色苷及其抗氧化性研究

建立了高速逆流色谱(HSCCC)分离制备紫锥菊花色苷类化合物的方法,并对所获得的2个花色苷单体进行了体外抗氧化性实验。以新鲜紫锥菊花瓣为原料,含0.1%HCl的60%乙醇为溶剂避光冷浸提取,经乙酸乙酯萃取和D101大孔吸附树脂(100 mL,2 cm×30 cm)纯化后,得2.1 g紫锥菊花色苷提取物干粉样品。以水-正丁醇-甲基叔丁基甲醚-乙腈-三氟乙酸(6∶3∶2∶1∶0.001)为HSCCC分离溶剂系统,上相为固定相,下相为流动相,流速2.0 mL/min,进样量160 mg,通过一次分离得到2种花色苷单体化合物,经HPLC检测其纯度分别达95.1%(9.8 mg)、98.2%(14.3 mg),MS及NMR技术鉴定其结构分别为矢车菊素-3-O-β-D葡萄糖苷(化合物1)和矢车菊素-3-O-(6″-O-丙二酰-β-D葡萄糖苷)(化合物2)。以Vc为对照组,对所获得的2种花色苷单体化合物进行了1,1-二苯基-2苦肼基(DPPH.)体外抗氧化性能评价,结果显示2种花色苷对DPPH.的半清除率(EC50)均小于10 mg/L,小于对照样Vc,表明2种花色苷均具有较强的自由基清除作用,且化合物1的清除能力强于化合物2。     

Multidimensional preparative liquid chromatography to isolate flavonoids from bergamot juice and evaluation of their anti‐inflammatory potential

Important objectives of a high‐performance liquid chromatography preparative process are: purity of products isolated, yield, and throughput. The multidimensional preparative liquid chromatography method used in this work was developed mainly to increase the throughput; moreover purity and yield are increased thanks to the automated collection of the molecules based on the intensity of a signal generated from the mass spectrometer detector, in this way only a specific product can be targeted. This preparative system allowed, in few analyses both in the first and second dimensions, the isolation of eight pure compounds present at very different concentration in the original sample with high purity (>95%) and yield, which showed how the system is efficient and versatile. Pure molecules were used to validate the analytical method and to test the anti‐inflammatory and antiproliferative potential of flavonoids. The contemporary presence, in bergamot juice, of all the flavonoids together increases the anti‐inflammatory effect with respect to the single compound alone.     

Efficient Protocol for Large-Scale Purification of Naringin with High Recovery from Fructus aurantii by Macroporous Resin Column Chromatography and HSCCC

Several kinds of resins were investigated in the first step and D101 macroporous resin was selected for cleaning-up naringin (NAR), a major flavonoid glycoside from Fructus aurantii. In the subsequent column chromatography, 10% aqueous ethanol was first used to elute the column to remove the undesired constituents and 70% aqueous ethanol was used to elute the target. The content of NAR was 57.1% with 95.7% recovery in this process. In the second step, the obtained crude sample was directly isolated by high-speed counter-current chromatography (HSCCC) with a two-phase solvent system composed of ethyl acetate–n-butanol–water at a volume ratio of 2: 0.8: 3.2 (v/v/v), and 331 mg NAR with 98.3% purity was obtained from 600 mg crude extract in only one run. The recovery of the compound in this step was 95.0%. Thus, the total recovery of NAR was 90.9% after the two step purification. The established protocol for large-scale isolation and separation of NAR with high purity and recovery from F. aurantii was simple, efficient, and suitable for pharmace- utical and commercial use.     

Effects of peptide density and elution pH on affinity chromatographic purification of human immunoglobulins A and M

A family of linear hexamer peptide ligands HWRGWV, HYFKFD and HFRRHL, initially identified for their affinity to the Fc portion of human immunoglobulin G (hIgG), also have potential for use in the purification of human immunoglobulins A (hIgA) and M (hIgM). HWRGWV demonstrated the strongest binding affinity to hIgM, followed by hIgA and hIgG respectively. The effects of N-terminal acetylation of the peptide, as well as elution buffer pH, on the chromatographic elution of human IgG, IgA and IgM from HWRGWV resins at various peptide densities (0.04-0.55 meq/g) were investigated. Over 80% recovery and 90% purity were achieved for human IgG and IgA isolation from complete minimum essential medium (cMEM) using HWRGWV resin at optimum peptide densities. For human IgM, 75.7% recovery and 86.0% purity were achieved by using HWRGWV at a low peptide density of 0.04 meq/g. Although HYFKFD and HFRRHL exhibited their ability for isolation of human IgG, IgA and IgM from cMEM as well, HWRGWV is the best option among them for large-scale purification of human IgG, IgA and IgM based on conditions tested.     

反相柱色谱法分离纯化洛沙坦原料中的杂质

采用反相柱色谱法对洛沙坦原料中的洛沙坦同分异构体杂质(含量约4%)进行了分离制备。收集每份流出液并进行高效液相色谱(HPLC)检测,合并含有目标化合物的流出液。对杂质粗品进行重结晶,所得产物的纯度大于99%(经HPLC检测);质谱分析结果表明,该杂质的相对分子质量与洛沙坦的相同,质谱裂解规律与洛沙坦一致;并通过核磁共振对该化合物进行了结构确证。与常规制备色谱相比,该方法分离步骤简单,分离效率高,上样量大,收率高。     

Application of preparative high-speed counter-current chromatography for separation and purification of arctiin from Fructus Arctii

Following an initial clean-up step on the AB-8 resin (polystyrene resin, 0.3-1.25 mm: NanKai Chemical Factory, Tianjin, China), high-speed counter-current chromatography (HSCCC) was used to purify an arctiin from an extract of the fruits of the Arctium lappa L. Arctiin is a major lignan compound in the traditional Chinese medicinal herb A. lappa L. The two-phase solvent system used was composed of ethyl acetate-n-butanol-ethanol-water at an optimized volume ratio of 5:0.5:1:5 (v/v/v/v). The upper phase was used as the mobile phase in the head to tail elution mode. A total amount of 159 mg of arctiin at 98% purity was obtained from 350 mg of the crude extract (containing 49% arctiin) with 91% recovery. The preparative isolation and purification of arctiin by HSCCC was completed in 5 h in a separation. Identification of the target compound was performed by LC-electrospray ionization MS and 13C-NMR. The structure of the product was further confirmed by comparison with authentic sample (National Institute of the Control of Pharmaceutical and Biological Products, Beijing, China).     

Preparation, purification and quality control of 131I-m-iodobenzylguanidine (MIBG)*

Iodination of meta-iodobenzylguanidine was carried out at optimum conditions. The labeling yield at these conditions was more than 95%. Further purification of the prepared compound increased the radiochemical purity to more than of 99.5%, this high purity was revealed in the quality of the images resulting from the use of the prepared compounds.     

包结物晶析法选择分离辛夷挥发油中1,8-桉叶素

主客体化学的分子识别在同分异构体选择分离、外消旋异构体光学拆分中已有广泛研究[1～3].我们利用中草药挥发油中化学组分的分子形状、几何拓扑性质、官能团数量和键力性质的不同,选定主体分子对挥发油中某一组分进行分子识别,并以结晶的形式从挥发油体系中离析出来,达到选择分离单一挥发油化学组分的目的[4～7].本文利用主体分子1,1,6,6-四苯基-2,4-己二炔-1,6-二醇(A)作为主体分子[8],以辛夷挥发油为研究对象,其主要成分1,8-桉叶素(B)为分子识别的客体分子,与化合物A形成稳定的包结物晶体(A+B),并从辛夷挥发油中析出,得到纯度为100%的…     

Preparative isolation of terpene trilactones from Ginkgo biloba leaves

This study investigated and compared some techniques for the preparative isolation of terpene trilactones, including ginkgolides (GA and GB, etc.) and bilobalide (BB), from Ginkgo biloba leaves. The crude Ginkgo biloba L. extracts (GBE) were prepared using an extractor with solvent refluxing operated under an optimal extraction condition. The extraction yield was 20-23% and the purity of terpene trilactones was about 1.0-1.4 wt%. Before the isolation operations, the extracts were dissolved in de-ionized water. The isolation procedures included the method of liquid-liquid extraction and the method of column chromatography. For the method of liquid-liquid extraction using ethyl acetate as the organic solvent operated under the optimal extraction conditions, the purity, concentration ratio, and yield of terpene trilactones were 13.5-18.0%, 15-16, and >99%. For the method of column chromatography, XAD-7HP, XAD-4, and C-18 adsorbents with different polarities were used as the packing materials. Only for the XAD-7HP column, a part of more polar impurities was efficiently separated with the majority of terpene trilactones by a proper step-gradient elution, which resulted in an efficient isolation: the purity, concentration ratio, and yield of terpene trilactones were approximately 20, approximately 15, and approximately 80%. In comparison, the XAD-7HP column achieved the highest purity, but at the expense of the yield of terpene trilactones; on the contrary, the liquid-liquid extraction method, achieving the highest yield but with a slightly lower purity, was proved to be superior to the method of column chromatography in the current isolation stage.