A Micropreparative HPLC Purification Procedure for (G-3H)-Benzo(a)-Pyrene and 3-(6-14C)-Methylcholanthrene

1987 ◽  
Vol 10 (10) ◽  
pp. 2105-2114
Author(s):  
Jan A. Rosier
Keyword(s):  
Purification Procedure ◽  
Hplc Purification ◽  
Micropreparative Hplc

One-Step HPLC Purification Procedure for Porcine Brain 90-kDa Heat Shock Protein

1997 ◽  
Vol 10 (2) ◽  
pp. 180-184 ◽  
Author(s):  
Lawrence Fu-nien Chu ◽  
Wen-Chuan Lee ◽  
Ping-Cheng Yang ◽  
Redman Chu ◽  
Teh-Yang Huang ◽  
...  
Keyword(s):  
Heat Shock ◽  
Heat Shock Protein ◽  
Purification Procedure ◽  
Hplc Purification ◽  
Porcine Brain ◽  
One Step

Synthesis and Reactivity of Precolibactin 886

2019 ◽  
Author(s):  
Seth Herzon ◽  
Alan R. Healy ◽  
kevin wernke ◽  
Chung Sub Kim ◽  
Nicholas Lees ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Gene Cluster ◽  
Amino Alcohol ◽  
Biomimetic Synthesis ◽  
Cross Linking ◽  
E Coli ◽  
Hplc Purification ◽  
Structural Assignment ◽  
Biosynthetic Precursor ◽  
Double Oxidation

<div>The clb gene cluster encodes the biosynthesis of metabolites known as precolibactins and colibactins. The clb pathway is found in gut commensal E. coli, and clb metabolites are thought to initiate colorectal cancer via DNA cross-linking. Precolibactin 886 (1) is one of the most complex isolated clb metabolites; it contains a 15-atom macrocycle and an unusual 5-hydroxy-3-oxazoline ring. Here we report confirmation of the structural assignment via a biomimetic synthesis of precolibactin 886 (1) proceeding through the amino alcohol 9. Double oxidation of 9 afforded the unstable α-ketoimine 2 which underwent macrocyclization to precolibactin 886 (1) upon HPLC purification (3% from 9). Studies of the putative precolibactin 886 (1) biosynthetic precursor 2, the model α-ketoimine 25, and the α-dicarbonyl 26 revealed that these compounds are susceptible to nucleophilic rupture of the C36–C37 bond. Moreover, cleavage of 2 produces other known clb metabolites or biosynthetic intermediates. This unexpected reactivity explains the difficulties in isolating full clb metabolites and accounts for the structure of a recently identified colibactin–adenine adduct. The colibactin peptidase ClbP deacylates synthetic precolibactin 886 (1) to form a non-genotoxic pyridone, suggesting precolibactin 886 (1) lies off-path of the major biosynthetic route.</div>

Confirmation of Long Term Excreted Metabolites of Stanozolol by Gas Chromatography Coupled with High Resolution Mass Spectrometry (GC/HRMS)

2008 ◽  
Vol 59 (7) ◽  
Author(s):  
Ileana Vajiala ◽  
Ruxandra Subasu ◽  
Mirela Zorio ◽  
Rodica Picu
Keyword(s):  
High Resolution Mass Spectrometry ◽  
Parent Compound ◽  
Urine Specimen ◽  
Decision Making Process ◽  
Purification Procedure ◽  
Specific Identification ◽  
Immunoaffinity Purification ◽  
In Doping ◽  
Resolution Mass

Upon screening identification of Stanozolol, GC/HRMS confirmation of the suspicious sample is done by reanalysis of the urine specimen, where a specific immunoaffinity purification procedure is used to selectively isolate the long term excreted metabolites of Stanozolol. By meeting the specific identification criteria for more than one metabolite of the same parent compound, additional evidence could be obtained in the decision making process in doping control.

Examination of Conditions for the Determination of Carbamate Pesticides in Soils

1992 ◽  
Vol 57 (8) ◽  
pp. 1632-1638 ◽  
Author(s):  
Věra Tatarkovičová ◽  
Zdeněk Stránský
Keyword(s):  
Activated Carbon ◽  
Solvent Extraction ◽  
Soil Type ◽  
Extraction Procedure ◽  
Purification Procedure ◽  
Factors Affecting ◽  
Carbamate Pesticides ◽  
Rp Hplc ◽  
Extracting Solvent

The procedure for the determination of carbamate pesticides in soil was optimized. The following factors affecting the final results were investigated: extracting solvent, extraction procedure, extract purification procedure, and soil type. Triple extraction with acetone and purification of the extract on a two-stage purification column containing an activated carbon-silica gel 1+1 mixture were found optimal. The extracts after treatment were analyzed by RP-HPLC with UV detection. The method developed allows carbamate pesticides in soil to be determined at concentrations in excess of 30 μg kg-1.

scholarly journals Protease nexin. Properties and a modified purification procedure.

1985 ◽  
Vol 260 (11) ◽  
pp. 7029-7034 ◽  
Author(s):  
R W Scott ◽  
B L Bergman ◽  
A Bajpai ◽  
R T Hersh ◽  
H Rodriguez ◽  
...  
Keyword(s):  
Purification Procedure ◽  
Protease Nexin

scholarly journals Validation of Recombinant Chicken Liver Bile Acid Binding Protein as a Tool for Cholic Acid Hosting

Biomolecules ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 645
Author(s):  
Giusy Tassone ◽  
Maurizio Orlandini ◽  
Massimo Olivucci ◽  
Cecilia Pozzi
Keyword(s):  
Bile Acid ◽  
High Resolution ◽  
Affinity Chromatography ◽  
Bile Acids ◽  
Drug Carriers ◽  
Chicken Liver ◽  
Purification Procedure ◽  
Acid Binding Protein ◽  
Bile Acid Binding ◽  
Exogenous Substances

Bile acids (BAs) are hydroxylated steroids derived from cholesterol that act at the intestinal level to facilitate the absorption of several nutrients and also play a role as signaling molecules. In the liver of various vertebrates, the trafficking of BAs is mediated by bile acid-binding proteins (L-BABPs). The ability to host hydrophobic or amphipathic molecules makes BABPs suitable for the distribution of a variety of physiological and exogenous substances. Thus, BABPs have been proposed as drug carriers, and more recently, they have also been employed to develop innovative nanotechnology and biotechnology systems. Here, we report an efficient protocol for the production, purification, and crystallization of chicken liver BABP (cL-BABP). By means of target expression as His6-tag cL-BABP, we obtained a large amount of pure and homogeneous proteins through a simple purification procedure relying on affinity chromatography. The recombinant cL-BABP showed a raised propensity to crystallize, allowing us to obtain its structure at high resolution and, in turn, assess the structural conservation of the recombinant cL-BABP with respect to the liver-extracted protein. The results support the use of recombinant cL-BABP for the development of drug carriers, nanotechnologies, and innovative synthetic photoswitch systems.

Purification of Chalcone Synthase from Tulip Anthers and Comparison with the Synthase from Cosmos Petals

1981 ◽  
Vol 36 (1-2) ◽  
pp. 30-34 ◽  
Author(s):  
Rainer Sütfeld ◽  
Rolf Wiermann
Keyword(s):  
Chalcone Synthase ◽  
In Vitro Assay ◽  
Flavonoid Biosynthesis ◽  
Chalcone Isomerase ◽  
Gel Chromatography ◽  
Purification Procedure ◽  
Reaction Products ◽  
Complete Elimination ◽  
Vitro Assay

Abstract Chalcone synthase was isolated from both anthers of Tulipa cv. “Apeldoorn” and petals of Cosmos sulphureus Cav. After certain prepurification steps, the enzymes were further purified using gel chromatography on Sephadex G-200 followed by repeated hydroxylapatite absorption chromatography. Both the enzymes showed the same chromatographic properties. After gel chromatography as well as after the first hydroxylapatite fractionation, the reaction products appeared as flavanones. However, after the second hydroxylapatite step, production of chalcones was observed. Like the enzyme from tulip anthers, the synthase from Cosmos petals produced the correspondingly substituted chalcones when p-coumaroyl-CoA, caffeoyl-CoA and feruloyl-CoA, respectively, were used as substractes. In both the cases, the ratios of the different chalcones produced were found to be about the same. The appearance of chalcone synthesis in this in vitro assay is caused by the complete elimination of chalcone isomerase in the purification procedure. The importance of the isomerase for flavonoid biosynthesis, particularly in plant systems which are accumulating chalcones, is discussed.

scholarly journals Increasing molar activity by HPLC purification improves 68Ga-DOTA-NAPamide tumor accumulation in a B16/F1 melanoma xenograft model

PLoS ONE ◽  
2019 ◽  
Vol 14 (6) ◽  
pp. e0217883
Author(s):  
Jan Lennart von Hacht ◽  
Sarah Erdmann ◽  
Lars Niederstadt ◽  
Sonal Prasad ◽  
Asja Wagener ◽  
...  
Keyword(s):  
Xenograft Model ◽  
Hplc Purification ◽  
Molar Activity ◽  
Melanoma Xenograft ◽  
Tumor Accumulation
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