Sep-Pak Cartridge Research Articles

PP-030 Setup of the Procedure for Synthesis of 18F-Fluoromethylcholine by GE Medical Systems TRACERlab FXFN

Background18F-Fluoromethyl-choline (18F- FMCH) has recently been used in the detection of tumours with slow glucose metabolism such as cancer of the prostate. However, to get good imaging in the radiopharmaceutical...

Synthesis and Biological Evaluation of 10‐11C‐Dihydrotetrabenazine as a Vesicular Monoamine Transporter 2 Radioligand

In this study, we synthesized a new carbon-11-labeled radiotracer, 10-(11) C-dihydrotetrabenazine (10-(11) C-DTBZ), and evaluated its potential as a vesicular monoamine transporter 2 (VMAT2) radioligand. The radiolabeled precursor 10-O-desmethyl-dihydrotetrabenazine (10-O-desmethyl-DTBZ) was prepared with a six-step reaction using 3-methoxy-4-benzyloxybenzaldehyde as starting material. 10-(11) C-DTBZ was synthesized by heating 1.0 mg of 10-hydroxy precursor and (11) C-methyl iodide in the presence of 0.3 mL of dimethyl sulfoxide and 4.0 µL of 3 N KOH at room temperature for 3 min. After purification by solid phase extraction using an alumina Sep-Pak cartridge, the final 10-(11) C-DTBZ product was obtained with a radiochemical purity of >99% and an uncorrected radiochemical yield of 18-26% (end of bombardment (EOB), n = 6). The overall synthesis time was approximately 20 min from the EOB to release of the product for quality control. Using small-animal positron emission tomography (microPET), the striatum of normal rats was found to exhibit symmetrical labeling (STR /STL = 0.98 ± 0.05, n = 3) and the highest uptake of radioactivity (striatum/cerebellum, ST/CB = 2.89 ± 0.31 at 30-60 min, n = 3). In contrast, rats with 6-hydroxydopamine unilateral lesions yielded asymmetrical striatal images with a higher 10-(11) C-DTBZ concentration on the unlesioned side (STunlesioned /CB = 2.53 ± 0.18, at 30-60 min, n = 3) compared with the lesioned side (STlesioned /CB = 1.26 ± 0.10, n = 3). These results suggest that 10-(11) C-DTBZ may represent a promising PET radiotracer for imaging VMAT2.

Estimation of angiotensin peptides in biological samples by LC–MS method

The low abundance of angiotensin peptides in biological tissues such as the kidney cortex, adipose tissue, urine and plasma makes their detection and quantification a challenge. A few available methods used to quantify these peptides involve lengthy processes of sample preparation and are hardly quantitative. Here, we report a mass spectrometry approach for quantifying angiotensin peptides [Ang II, Ang-(1-7)] in the kidney cortex, epididymal white adipose tissue (eWAT), urine and plasma of male mice. Tissue homogenates, urine and plasma samples were solid-phase extracted with C18 Sep-Pak cartridges and eluted off proteinaceous compounds. These extracted peptide samples were separated on C18 column with a linear acetonitrile gradient and detected by Q-ToF mass analyzer in ESI+-MS ion mode based on their retention time, accurate mass measurement of peptides, the isotope pattern of doubly charged molecular ion, and quantitation of peak area (or ion count) when referencing to the angiotensin peptide standards. The lower limit of quantitation for each angiotensin peptide was 10 pgmg-1 with the percent recovery at 100.6%. The intra-batch precision for Ang-(1-7) and Ang II were 24.0 and 12.7%, accuracy 84.0-123.0% and 100.2-116.0% respectively. Using this method, we determined the levels of Ang II and Ang-(1-7) in the kidney cortex, eWAT, urine and plasma. Quantification of angiotensin peptides could help target subtle therapeutics changes against pathophysiological conditions such as obesity, kidney disease and hypertension.

Host-centric Proteomics of Stool: A Novel Strategy Focused on intestinal Responses to the Gut Microbiota

The diverse community of microbes that inhabits the human bowel is vitally important to human health. Host-expressed proteins are essential for maintaining this mutualistic relationship and serve as reporters on the status of host-microbiota interaction. Therefore, unbiased and sensitive methods focused on host proteome characterization are needed. Herein we describe a novel method for applying shotgun proteomics to the analysis of feces, focusing on the secreted host proteome. We have conducted the most complete analysis of the extracellular mouse gut proteome to date by employing a gnotobiotic mouse model. Using mice colonized with defined microbial communities of increasing complexity or a complete human microbiota ('humanized'), we show that the complexity of the host stool proteome mirrors the complexity of microbiota composition. We further show that host responses exhibit signatures specific to the different colonization states. We demonstrate feasibility of this approach in human stool samples and provide evidence for a "core" stool proteome as well as personalized host response features. Our method provides a new avenue for noninvasive monitoring of host-microbiota interaction dynamics via host-produced proteins in stool.

Microwave-assisted extraction and determination of dicyandiamide residue in infant formula samples by liquid chromatography-tandem mass spectrometry

A simple, precise, accurate, and validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed for the determination of dicyandiamide residue in infant formula samples. Following microwave-assisted extraction with 5% formic acid and clean-up on a Sep-Pak AC-2 SPE cartridge, samples were separated on a ZIC-HILIC HPLC column (150×2.1mm i.d., 5-µm film thickness; Merck KGaA, Darmstadt, Germany) with 20mM ammonium acetate solution-acetonitrile as mobile phase at a flow rate of 0.25mL/min. A linear calibration curve was obtained in the concentration range from 1.0 to 50ng/mL. Infant formula samples were fortified with dicyandiamide at 3 levels, producing average recovery yields of 83.6 to 95.7%. The limits of detection and quantification of dicyandiamide were 3 and 10μg/kg, respectively. Due to its simplicity and accuracy, the straightforward method is particularly suitable for routine dicyandiamide detection.

Acute modulation of rat plasma glucose byan aqueous garlic extract

In this study, the putative antidiabetic effect of garlic was re-investigated. Aqueous crude garlic solution was prepared at high concentration (2 g/ml) and extracts were obtained by ethanol precipitation followed by chromatography on C18 Sep-Pak cartridge. Garlic or extracts were administered by single intraperitoneal injection to euglycaemic rats. Plasma glucose, insulin and nitric oxide (NO) were determined after 30 min, 1 and 2 h, respectively. Garlic induced hypoglycemia and hyperinsulinemia which is mimicked by an ethanol soluble and non polar extract. This active principle appeared different from S-allyl-cystein sulfoxide based on physico-chemical properties and mode of action. Data of thin layer chromatography experiments indicated the presence of at least four molecular species, indicating a more non polar nature, with Rf values higher than S-allyl-cystein sulfoxide. The mechanism of action seemed to involve nitric oxide as its glucose induced lowering activity is abolished by diphenyleneiodonium which is a selective constitutive nitric oxide synthase inhibitor. Key words: Garlic, Plasma Glucose, Insulinemia, Nitric Oxide, Thin Layer Chromatography.

Phytochemicals in Lowbush Wild Blueberry InactivateEscherichia coliO157:H7 by Damaging Its Cell Membrane

The antimicrobial activity and model of action of polyphenolic compounds extracted from lowbush wild blueberries (LWB) were studied against Escherichia coli O157:H7. Polyphenols in LWB were extracted using 80% vol/vol methanol and designated as total blueberry phenolics (TBP). The fraction was further separated by a C-18 Sep-Pak cartridge into monomeric phenolics acids (MPA) and anthocyanins plus proanthocyanidins (A&P). The A&P fraction was further separated into anthocyanins and proanthocyanidins using a LH-20 Sephadex column. Each fraction was diluted in 0.85% wt/vol NaCl, inoculated with E. coli O157:H7 to achieve 8 log colony-forming units (CFU)/mL, and incubated at 25 °C for 1 h. The survival populations of E. coli O157:H7 in the phenolic fractions were determined by a viable cell counts method. The permeability of the cell membrane of E. coli O157:H7 was determined using LIVE/DEAD viability assay, and the damage was visualized by using transmission electron microscopy (TEM). Significant (p<0.05) reductions of 5 log CFU/mL of E. coli O157:H7 were observed for MPA at 0.4 g/L gallic acid equivalents (GAE), A&P at 0.9 g/L GAE, and anthocyanins at 0.65 g/L GAE. Reductions of 6-7 CFU/mL were observed for MPA at 0.8 g/L GAE, A&P at 1.8 g/L GAE, and anthocyanins at 1.3 g/L GAE compared to the control. The cell membrane of E. coli O157:H7 exhibited a significantly increased permeability when treated with proanthocyanidins (0.15 g/L GAE), A&P (0.45 g/L GAE), anthocyanins (0.65 g/L GAE), and TBP (0.14 g/L GAE). TEM confirmed the inactivation and increased membrane permeability of E. coli O157:H7. This study demonstrated the antimicrobial effect of polyphenols from LWB against E. coli O157:H7 and the probable mode of action.

A fully-automated one-pot synthesis of [18F]fluoromethylcholine with reduced dimethylaminoethanol contamination via [18F]fluoromethyl tosylate

IntroductionA novel one-pot method for preparing [18F]fluoromethylcholine ([18F]FCH) via in situ generation of [18F]fluoromethyl tosylate ([18F]FCH2OTs), and subsequent [18F]fluoromethylation of dimethylaminoethanol (DMAE), has been developed. Methods[18F]FCH was prepared using a GE TRACERlab FXFN, although the method should be readily adaptable to any other fluorine-18 synthesis module. Initially ditosylmethane was fluorinated to generate [18F]FCH2OTs. DMAE was then added and the reaction was heated at 120°C for 10min to generate [18F]FCH. After this time, reaction solvent was evaporated, and the crude reaction mixture was purified by solid-phase extraction using C18-Plus and CM-Light Sep-Pak cartridges to provide [18F]FCH formulated in USP saline. The formulated product was passed through a 0.22µm filter into a sterile dose vial, and submitted for quality control testing. Total synthesis time was 1.25h from end-of-bombardment. ResultsTypical non-decay-corrected yields of [18F]FCH prepared using this method were 91mCi (7% non-decay corrected based upon ∼1.3Ci [18F]fluoride), and doses passed all other quality control (QC) tests. ConclusionA one-pot liquid-phase synthesis of [18F]FCH has been developed. Doses contain extremely low levels of residual DMAE (31.6µg/10mL dose or ∼3ppm) and passed all other requisite QC testing, confirming their suitability for use in clinical imaging studies.

Biodistribution of99mTc Labeled Integrin Antagonist

The selective targeting of an integrin αvβ3 receptor using radioligands may enable the assessment of angiogenesis and integrin αvβ3 receptor status in tumors. The aim of this research was to label a peptidomimetic integrin αvβ3 antagonist (PIA) with 99mTc(CO)3 and to test its receptor targeting properties in nude mice bearing receptor-positive tumors. PIA was reacted with tris-succinimidyl aminotriacetate (TSAT) (20 mM) as a PIA per TSAT. The product, PIA-aminodiacetic acid (ADA), was radiolabeled with [99mTc(CO)3(H2O)3]+1, and purified sequentially on a Sep-Pak C-18 cartridge followed by a Sep-Pak QMA anion exchange cartridge. Using gradient C-18 reverse-phase HPLC, the radiochemical purity of 99mTc(CO)3-ADA-PIA (retention time, 10.5 min) was confirmed to be > 95%. Biodistribution analysis was performed in nude mice (n = 5 per time point) bearing receptor-positive M21 human melanoma xenografts. The mice were administered 99mTc(CO)3-ADA-PIA intravenously. The animals were euthanized at 0.33, 1, and 2 hr after injection for the biodistribution study. A separate group of mice were also co-injected with 200 μg of PIA and euthanized at 1 hr to quantify tumor uptake. 99mTc(CO)3-ADA-PIA was stable in phosphate buffer for 21 hr, but at 3 and 6 hr, 7.9 and 11.5% of the radioactivity was lost as histidine, respectively. In tumor bearing mice, 99mTc(CO)3-ADA-PIA accumulated rapidly in a receptor-positive tumor with a peak uptake at 20 min, and rapid clearance from blood occurring primarily through the hepatobiliary system. At 20 min, the tumor-toblood ratio was 1.8. At 1 hr, the tumor uptake was 0.47% injected dose (ID)/g, but decreased to 0.12% ID/g when co-injected with an excess amount of PIA, indicating that accumulation was receptor mediated. These results demonstrate successful 99mTc labeling of a peptidomimetic integrin antagonist that accumulated in a tumor via receptor-specific binding. However, tumor uptake was very low because of low blood concentrations that likely resulted from rapid uptake of the agent into the hepatobiliary system. This study suggests that for 99mTc(CO)3-ADA-PIA to be useful as a tumor detection agent, it will be necessary to improve receptor binding affinity and increase the hydrophilicity of the product to minimize rapid hepatobiliary uptake.

The effect of American cranberry (Vaccinium macrocarpon) constituents on the growth inhibition, membrane integrity, and injury of Escherichia coli O157:H7 and Listeria monocytogenes in comparison to Lactobacillus rhamnosus

The antimicrobial properties of the American cranberry were studied against Escherichia coli O157:H7, Listeria monocytogenes, and Lactobacillus rhamnosus to determine the effects on growth inhibition, membrane permeability, and injury. Cranberry powder was separated using a C-18 Sep-Pak cartridge into sugars plus organic acids (F1), monomeric phenolics (F2), and anthocyanins plus proanthocyanidins (F3). Fraction 3 was further separated into anthocyanins (F4) and proanthocyanidins (F5) using an LH-20 Sephadex column. Each fraction was diluted in the brain heart infusion (BHI) broth to determine the minimum inhibitory/bactericidal concentrations (MIC/MBC). L. monocytogenes was the most susceptible to cranberry fraction treatment with the lowest MIC/MBC for each treatment, followed by E. coli O157:H7 and L. rhamnosus. Membrane permeability and potential was studied using LIVE/DEAD viability assay and using Bis (1, 3-dibutylbarbituric acid) trimethine oxonol (DiBAC4), respectively. L. rhamnosus demonstrated the highest permeability followed by E. coli O157:H7, and L. monocytogenes. L. rhamnosus demonstrated the highest recovery followed by E. coli O157:H7, and L. monocytogenes. Each cranberry fraction demonstrated membrane hyperpolarization at their native pH, while F2, F3, and F5 demonstrated membrane depolarization at neutral pH. With this knowledge cranberry compounds may be used to prevent maladies and potentially substitute for synthetic preservatives and antibiotics.

Development of a microwave-assisted-extraction-based method for the determination of aflatoxins B1, G1, B2, and G2 in grains and grain products

This article describes the use of microwave-assisted extraction (MAE) as a pretreatment technique for the determination of aflatoxins B(1), G(1), B(2), and G(2) in grains and grain products. The optimal operation parameters, including extraction solvent, temperature, and time, were identified to be acetonitrile as the extraction solvent at 80 °C with 15 min of MAE. The extracts were cleaned up using solid-phase extraction followed by derivatization with trifluoroacetic acid and were determined by liquid chromatography-fluorescence detection. A Sep-Pak cartridge was chosen over Oasis HLB and Bond Elut cartridges. By the use of aflatoxin M(1) as an internal standard, relative recoveries of the aflatoxins ranged from 90.7 to 105.7 % for corn and from 88.1 to 103.4 % for wheat, with relative standard deviations between 2.5 and 8.7 %. A total of 36 samples from local markets were analyzed, and aflatoxin B(1) was found to be the predominant toxin, with concentrations ranging from 0.42 to 3.41 μg/kg.

Comparison of analytical methods for anthocyanin quantification in berries: HPLC and pH differential methods

Interest in the beneficial effects of anthocyanins on human health has resulted in increased demand for their use as food ingredients and created a need for an inexpensive and effective method to quantify the total anthocyanin contents. The pH differential method has been demonstrated to be simple, quick, and reliable for measuring the total monomeric anthocyanin content of a sample compared to HPLC method. However; results obtained by these two methods are still inconsistent. Thus, this study aimed to evaluate these two analytical methods in measuring total anthocyanin contents in berries having different anthocyanin contents and compositions. Anthocyanin fractions, obtained from the phenolic extracts of five berries (blueberry, blackberry, black currant, raspberry, and cranberry) using C18 Sep‐Pak cartridge, were used to quantitate total anthocyanin contents using pH differential and HPLC methods. In pH differential method, blueberry showed the highest anthocyanin content as 1,034 mg cyanidin‐3‐glucoside equivalent/100g dry weight, followed by blackberry (819 mg), blackcurrent (801 mg), raspberry (381 mg), and cranberry (220 mg). Results by HPLC analysis also showed similar trends but lower than those by pH differential method. In conclusion, the pH differential method is reliable and in good accordance with the data obtained by HPLC method for measuring total anthocyanin contents in berries.

Qualitative identification of permitted and non-permitted colour additives in food products

Colour additives are dyes, pigments or other substances that can impart colour when added or applied to food, drugs, cosmetics, medical devices, or the human body. The substances must be pre-approved by the US Food and Drug Administration (USFDA) and listed in Title 21 of the US Code of Federal Regulations before they may be used in products marketed in the United States. Some also are required to be batch certified by the USFDA prior to their use. Both domestic and imported products sold in interstate commerce fall under USFDA jurisdiction, and the USFDA's district laboratories use a combination of analytical methods for identifying or confirming the presence of potentially violative colour additives. We have developed a qualitative method for identifying 17 certifiable, certification exempt, and non-permitted colour additives in various food products. The method involves extracting the colour additives from a product and isolating them from non-coloured components with a C18 Sep-Pak cartridge. The colour additives are then separated and identified by liquid chromatography (LC) with photodiode array detection, using an Xterra RP18 column and gradient elution with aqueous ammonium acetate and methanol. Limits of detection (LODs) ranged from 0.02 to 1.49 mg/l. This qualititative LC method supplements the visible spectrophotometric and thin-layer chromatography methods currently used by the USFDA's district laboratories and is less time-consuming and requires less solvent compared to the other methods. The extraction step in the new LC method is a simple and an efficient process that can be used for most food types.

Identification of Grass-specific Enzyme That Acylates Monolignols with p-Coumarate

Lignin is a major component of plant cell walls that is essential to their function. However, the strong bonds that bind the various subunits of lignin, and its cross-linking with other plant cell wall polymers, make it one of the most important factors in the recalcitrance of plant cell walls against polysaccharide utilization. Plants make lignin from a variety of monolignols including p-coumaryl, coniferyl, and sinapyl alcohols to produce the three primary lignin units: p-hydroxyphenyl, guaiacyl, and syringyl, respectively, when incorporated into the lignin polymer. In grasses, these monolignols can be enzymatically preacylated by p-coumarates prior to their incorporation into lignin, and these monolignol conjugates can also be "monomer" precursors of lignin. Although monolignol p-coumarate-derived units may comprise up to 40% of the lignin in some grass tissues, the p-coumarate moiety from such conjugates does not enter into the radical coupling (polymerization) reactions of lignification. With a greater understanding of monolignol p-coumarate conjugates, grass lignins could be engineered to contain fewer pendent p-coumarate groups and more monolignol conjugates that improve lignin cleavage. We have cloned and expressed an enzyme from rice that has p-coumarate monolignol transferase activity and determined its kinetic parameters.

The antimicrobial properties of the lowbush blueberry (Vaccinium angustifolium) fractional components against foodborne pathogens and the conservation of probiotic Lactobacillus rhamnosus

The antimicrobial properties of lowbush blueberry (Vaccinium angustifolium) were studied against Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium, and Lactobacillus rhamnosus to determine which fractional components have antimicrobial effects and which microorganisms are most susceptible to these antimicrobial properties. Lowbush blueberry extract (F1) was separated using a C-18 Sep-Pak cartridge into monomeric phenolics (F2) and anthocyanins plus proanthocyanidins (F3). Fraction 3 was further separated into anthocyanins (F4) and proanthocyanidins (F5) using a LH-20 Sephadex column. Each fraction was initially screened for antimicrobial properties using agar diffusion assay. Treatments that demonstrated inhibition were further analyzed for inhibition in liquid culture. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined using a two-fold dilution series and viable cell counts taken at 0 and 24 h to examine growth reduction. Fraction 3 demonstrated the lowest MICs/MBCs followed by F1, F2, F4, and F5. L. monocytogenes was the most susceptible to blueberry fraction treatment, followed by E. coli O157:H7, and S. Typhimurium. L. rhamnosus was the least susceptible to each fraction treatment. The results can be applied to the field of preventive medicine, food safety, and enrich the understanding of the health benefits of lowbush blueberries.

Interaction of Actin with Carcinoembryonic Antigen-related Cell Adhesion Molecule 1 (CEACAM1) Receptor in Liposomes Is Ca2+- and Phospholipid-dependent

The regulation of binding of G-actin to cytoplasmic domains of cell surface receptors is a common mechanism to control diverse biological processes. To model the regulation of G-actin binding to a cell surface receptor we used the cell-cell adhesion molecule carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1-S) in which G-actin binds to its short cytoplasmic domain (12 amino acids; Chen, C. J., Kirshner, J., Sherman, M. A., Hu, W., Nguyen, T., and Shively, J. E. (2007) J. Biol. Chem. 282, 5749-5760). A liposome model system demonstrates that G-actin binds to the cytosolic domain peptide of CEACAM1-S in the presence of negatively charged palmitoyl-oleoyl phosphatidylserine (POPS) liposomes and Ca(2+). In contrast, no binding of G-actin was observed in palmitoyl-oleoyl phosphatidylcholine (POPC) liposomes or when a key residue in the peptide, Phe-454, is replaced with Ala. Molecular Dynamics simulations on CEACAM1-S in an asymmetric phospholipid bilayer show migration of Ca(2+) ions to the lipid leaflet containing POPS and reveal two conformations for Phe-454 explaining the reversible availability of this residue for G-actin binding. NMR transverse relaxation optimized spectroscopic analysis of (13)C-labeled Phe-454 CEACAM1-S peptide in liposomes plus actin further confirmed the existence of two peptide conformers and the Ca(2+) dependence of actin binding. These findings explain how a receptor with a short cytoplasmic domain can recruit a cytosolic protein in a phospholipid and Ca(2+)-specific manner. In addition, this model system provides a powerful approach that can be applied to study other membrane protein interactions with their cytosolic targets.

Bacillus polyfermenticus CJ6가 생산하는 항세균 물질의 특성 및 병원성 식중독 미생물의 성장 억제 효과

In this study, Bacillus polyfermenticus CJ6 harboring antibacterial activity was isolated from meju. The antibacterial activity of Bacillus polyfermenticus CJ6 was stable in the pH range of 3.0~9.0, but it disappeared after culture at for 24 hr. Antibacterial activity was inactivated by proteinase K, protease, and -chymotrypsin, indicating its proteinaceous nature. The growth inhibitory effects of B. polyfermenticus CJ6 culture on food-borne pathogens such as Staphylococcus aureus, Salmonella Typhi, Listeria monocytogenes, and Escherichia coli O157:H7 were examined in this study. Approximately 6~6.2 log CFU/mL of each pathogen was co-cultured with B. polyfermenticus CJ6 in a 50 mL culture volume for 24 hr. Growth of S. aureus and L. monocytogenes was completely inhibited after 3 hr of incubation. Growth of S. Typhi and E. coli O157:H7 was also completely inhibited after 6 hr of incubation. The antibacterial compounds from B. polyfermenticus CJ6 were purified by solid phase extraction (C18 Sep-pak cartridge), recycling preparative HPLC, and analytical HPLC. Ultra-high performance liquid chromatography and electrospray ionization tandem mass spectrometry analysis were used to identify the purified antibacterial compounds, which were confirmed to be five peptides (757.4153 Da, 750.3444 Da, 1024.5282 Da, 1123.6083 Da, and 1617.8170 Da).

Efficient preparation of [11C]CH3Br for the labeling of [11C]CH3-containing tracers in positron emission tomography clinical practice

[C]methyl iodide ([C]CH3I) is the most extensively used methylation agent for the preparation of a majority of C-labeled positron emission tomography (PET) radiotracers, which is commonly produced by the wet method and the gas-phase method. On account of the complexity of the gas-phase method, a simple automated synthesis of [C]methyl bromide ([C]CH3Br) as an analog of [C]CH3I is derived by the wet method in this study. Radiosynthesis of L-[S-methyl-C]methionine (MET), L-[S-methyl-C]cysteine (MCYS), [N-methyl-C]choline (CH), [C]methyl triflate ([C]CH3OSO2CF3), and [C]-2-β-carbomethoxy-3-β-(4-fluorophenyl)-tropane (CFT) by methylation reaction with [C]CH3Br, and PET imaging of patients are also described. The preparation of [C]CH3Br by a one-pot wet method involved the following steps: reduction of [C]carbon dioxide with lithium aluminium hydride (LiAlH4) solution, treatment with hydrobromic acid, and distillation of [C]CH3Br under continuous nitrogen flow. [C]methylation of L-homocysteine thiolactone hydrochloride, L-cysteine, 2-dimethylaminoethanol, silver triflate, and nor-β-CFT as precursors with [C]CH3Br and purification with Sep-Pak cartridges gave MET, MCYS, CH, [C]CH3OSO2CF3, and CFT, respectively. In addition, PET imaging of brain cancer and Parkinson's disease was carried out. The uncorrected radiochemical yield of [C]CH3Br was (37.8±2.5%) based on [C]carbon dioxide within a total synthesis time of 10 min and the radiochemical purity of [C]CH3Br was greater than 95%. The uncorrected yields of MET, MCYS, CH, [C]CH3OSO2CF3, and CFT were 70.1±0.5%, 70.2±2.3%, 60.3±1.8%, 95.1±2.2%, and 60.1±1.5% (from [C]CH3OSO2CF3) within a total synthesis time of 2, 2, 5, 1, and 8 min, respectively. The radiochemical purity of MET, MCYS, CH, [C]CH3OSO2CF3, and CFT was more than 95%. Good PET images in the patients are obtained. Automated synthesis of [C]CH3Br can be done by the wet method on the commercial [C]CH3I synthesizer. [C]CH3Br can be used for a [C]methylation reaction to produce C-labeled tracers for clinical PET imaging.

Evaluation of alternative methods for radiochemical purity testing of indium-111 capromab pendetide

ObjectiveTo evaluate alternative methods for radiochemical purity testing of indium (In)-111 capromab pendetide after the discontinuation of instant thin-layer chromatography silica gel (ITLC-SG) strips. DesignDescriptive experimental study. SettingUnited States in 2009. ParticipantsNot applicable. InterventionPaper chromatography using Whatman 3MM strips, paper chromatography using Whatman 31ET strips, and mini-column chromatography using silica Sep-Pak cartridges were evaluated in the radiochemical purity testing of 13 consecutive vials of In-111 capromab pendetide prepared for clinical patient imaging procedures. These methods also were evaluated by testing seven aliquots of In-111 capromab pendetide that had been spiked with 5% to 15% In-111 pentetate (diethylene triamine pentaacetic acid). Main outcome measuresCorrelation coefficients, radiochemical purity values for each method compared with ITLC-SG, and procedure times. ResultsCorrelation coefficients of 0.988, 0.996, and 0.979 were found for ITLC-SG compared with Whatman 3MM, Whatman 31ET, and silica Sep-Pak, respectively. Compared with ITLC-SG, mean (±SD) radiochemical purity values differed by −0.8± (range −2.5 to 0.4) for Whatman 3MM, −0.8± (–2.3 to 0) for Whatman 31ET, and −0.5± (–3.6 to 0.7) for silica Sep-Pak. The approximate time required to develop the chromatography strip or elute the mini-column was 3, 14, 5, and 6 minutes for ITLC-SG, Whatman 3MM, Whatman 31ET, and silica Sep-Pak, respectively. ConclusionAll three methods evaluated were acceptable alternatives to ITLC-SG for radiochemical purity testing of In-111 capromab pendetide. Based on its slightly higher correlation to ITLC-SG, slightly tighter SD and range, and slightly shorter development time, Whatman 31ET is preferred in our facility.

Composition analysis and structural identification of anthocyanins in fruit of waxberry

Anthocyanin pigments in the fruit of waxberry (Myrica rubra Sieb. et Zucc.), were extracted with 0.1% HCl in ethanol, and the crude anthocyanin extract was purified by C18 Sep-Pak cartridge open-column chromatography. High-performance liquid chromatography (HPLC) with photodiode array detection (PAD) and matrix-assisted laser desorption/ionisation-time of flight-mass spectrometry (MALDI-TOF-MS) was applied for the separation and identification of anthocyanins in the fruit of waxberry and their aglycones resulting from acid hydrolysis. Three anthocyanins were found in the fruit of waxberry and identified as Cyanidin 3-O-&amp;beta;-galacopyranoside (14.8%), Cyanidin 3-O-&amp;beta;-gluco-&lt;br /&gt;pyranoside (60.5%), and petunidin 3-O-&amp;beta;-glucopyranoside (24.7%), respectively, using spectroscopic methods (UV-Vis&lt;br /&gt;and MS). The three anthocyanins were isolated and purified by preparative HPLC, and their chemical structures were further characterised by H&lt;sup&gt;1&lt;/sup&gt; NMR. On the basis of chromatographic data, the total anthocyanin content was 286 mg/g in fresh fruit of waxberry. &amp;nbsp;