Identification of domoic acid, a neuroexcitatory amino acid, in toxic mussels from eastern Prince Edward Island

1989 ◽  
Vol 67 (3) ◽  
pp. 481-490 ◽  
Author(s):  
J. L. C. Wright ◽  
R. K. Boyd ◽  
A. S. W. de Freitas ◽  
M. Falk ◽  
R. A. Foxall ◽  
...  
Keyword(s):  
Amino Acid ◽  
Prince Edward Island ◽  
High Performance ◽  
Domoic Acid ◽  
Analytical Data ◽  
Paper Electrophoresis ◽  
Exchange Chromatography ◽  
Spectroscopic Techniques ◽  
Isolation And Purification ◽  
Shellfish Toxin

The causative agent of toxicity in cultured mussels from a localized area of eastern Prince Edward Island has been identified as domoic acid, a neuroexcitatory amino acid. The toxin was isolated by a number of different bioassay-directed separation techniques including high-performance liquid chromatography, high-voltage paper electrophoresis, and ion-exchange chromatography, and characterized by a number of spectroscopic techniques including ultraviolet, infrared, mass spectrometry, and nuclear magnetic resonance. The isolation and purification methods are described in detail and some new analytical data for domoic acid are reported. Keywords: shellfish toxin, domoic acid, neurotoxin, bioassay-directed analysis.

scholarly journals Identification and Quantification of an Adulterant in a Dietary Supplement Marketed for Sexual Enhancement

2018 ◽  
Vol 1 (4) ◽  
pp. 25-33 ◽  
Author(s):  
Flavia Redko ◽  
Sabrina Flor ◽  
Silvia Lucangioli ◽  
Jerónimo Ulloa ◽  
Rafael Ricco ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Performance ◽  
Spectroscopic Techniques ◽  
Easy Method ◽  
Isolation And Purification ◽  
Chromatography Analysis ◽  
Pharmaceutical Ingredients ◽  
Emerging Risk ◽  
The Mean ◽  
Layer Chromatography

In recent years, the consumption of dietary supplements (DS) has increased worldwide. In Argentina, approximately 14 million DS units were sold between 2015 and 2017. The adulteration of DS with active pharmaceutical ingredients or their analogues has been reported. This represents an alarming emerging risk to public health. The aim of this work was to detect the possible adulteration of a DS marketed in Argentina for the treatment of erectile dysfunction. Initially, thin layer chromatography analysis of the DS capsules content suggested the presence of a major compound. For the isolation and purification of this compound, an easy method consisted of a liquid-liquid extraction (water/CH2Cl2) followed by re-crystallisation from ethanol, is reported. Spectroscopic techniques such as mono- and bidimensional nuclear magnetic resonance, Fourier transform infrared spectroscopy and mass spectrometry allowed its identification as tadalafil. A rapid and reliable method was developed for the quantification of tadalafil in this DS by high performance liquid chromatography-mass spectrometry (HPLC-MS/MS). The mean content of tadalafil per capsule was 21.2 mg which represents a slightly higher value than that found in approved products in Argentina (5 or 20 mg per tablet). In addition, an undeclared alga was identified in the DS by microscopic techniques.

A NEW PEPTIDE THROMBIN INHIBITOR FROM STREPTOMYCES GRISEUS

1987 ◽  
Author(s):  
Hua-zhen Liu ◽  
Wei Chen ◽  
Qi-ying Liu ◽  
Xia Zhang ◽  
Li-xiu Wang ◽  
...  
Keyword(s):  
Amino Acid ◽  
High Performance ◽  
Antithrombin Iii ◽  
Streptomyces Griseus ◽  
Exchange Chromatography ◽  
Performic Acid ◽  
Thrombin Inhibitor ◽  
Amino Acid Residues ◽  
Macroporous Resin ◽  
Terminal Residue

A new peptide thrombin inhibitor was found in the Streptomyces griseus strain 254 isolated from a soil sample from Tongan, Fujian province, China, the inhibitor being a secondary metabolic product. The production of the inhibitor reached a maximum after 3 days culture of bacteria at 28°C in a rotary shaker. The inhibitor excreted in the culture filtrate was purified by absorption on macroporous resin, followed by ion exchange chromatography on DEAE-52, CM-32 cellulose, affinity chromatography on the immobilized thrombin and high performance liquid chromatography. The amino acid composition of the inhibitor was determined to be Val(2), Met(l), Ile(l), Leu(2) and Arg (1), similar to that of the amino acid residues around the reactive site of human antithrombin III, the critical plasma inhibitor of thrombin. The NH2-terminal residue of the inhibitor seems to be blocked by the alkyl group due to the negative reaction to ninhydrin, whereas the COO-terminal residue is most likely to be arginal because of that Arg was not found in the amino acid analysis, unless the peptide was oxidized by performic acid before acid hydrolysis. The chromogen substrates Bz-Phe-Val-Arg-PNA and Bz-Gly-Pro-Lys-PNA were used to determine the thrombin and plasmin activities, respectively. Besides thrombin, the purified inhibitor also exhibits a weak inhibitory activities on trypsin and much weak on plasmin, but not on chymotrypsin and other protein-ases.

scholarly journals Improved Method for Isolation of Lycopsamine from Roots of Comfrey (Symphytum officinale)

2012 ◽  
Vol 7 (7) ◽  
pp. 1934578X1200700
Author(s):  
Damjan Janeš ◽  
Boštjan Kalamar ◽  
Samo Kreft
Keyword(s):  
High Performance ◽  
Pyrrolizidine Alkaloids ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Improved Method ◽  
Isolation And Purification ◽  
H Nmr ◽  
Symphytum Officinale ◽  
Layer Chromatography ◽  
Preparative Layer Chromatography

An improved method for the isolation and purification of pyrrolizidine alkaloids from comfrey ( Symphytum officinale L.) roots was developed, introducing very fast, selective and ion residue-free reduction of N-oxides followed by ion-exchange chromatography giving a non-aqueous solution of alkaloids, from which solvents can be easily removed. With this procedure the use of large volumes of organic solvents, very slow reduction of N-oxides and input of additional impurities was avoided. Lycopsamine, which proved to be the major alkaloid, was additionally purified by preparative layer chromatography (PLC) and high performance liquid chromatography (HPLC). The identity of the alkaloid was confirmed by 1H NMR spectroscopy and mass spectrometry.

Antifreeze glycoproteins in the plasma of Newfoundland Atlantic cod (Gadus morhua)

1981 ◽  
Vol 59 (11) ◽  
pp. 2186-2192 ◽  
Author(s):  
Choy L. Hew ◽  
Don Slaughter ◽  
Garth L. Fletcher ◽  
Shashikant B. Joshi
Keyword(s):  
Amino Acid ◽  
High Performance ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Antifreeze Proteins ◽  
Gel Filtration ◽  
Exchange Chromatography ◽  
Polar Cod ◽  
Antifreeze Glycoproteins ◽  
Molecular Weights

The plasma of the Atlantic cod, Gadus morhua, contained antifreeze glycoproteins which were present only during the winter months. The antifreeze proteins were isolated, using gel filtration and ion exchange chromatography, and characterized by high performance liquid chromatography. The antifreeze proteins appeared to consist of at least seven components with molecular weights ranging from 2 500 to 33 000. Chemical analysis of the larger components showed a predominance of alanine, threonine, and galactosamine in a ratio of 2:1:1. The smaller peptides contained proline, in addition to alanine and threonine. The amino acid sequence of the smallest glycopeptide (molecular weight 2500) was found to be Ala Ala Thr Pro Ala Thr Ala Ala Thr Pro Ala Thr Ala Ala.These glycoproteins are very similar, if not identical, in amino acid and carbohydrate composition to those isolated from Antaractic nototheniids and several northern gadoids. The sequence of the smallest glycopeptide from the Atlantic cod is identical to that reported for the polar cod, Boreogadus saida.

An endogenous peptide that stimulates lanthanum-resistant calcium uptake in vascular tissue

1987 ◽  
Vol 65 (9) ◽  
pp. 1991-1995 ◽  
Author(s):  
William D. McCumbee ◽  
Peter Johnson ◽  
Peter J. Kasvinsky ◽  
Gary L. Wright
Keyword(s):  
High Performance ◽  
Calcium Uptake ◽  
Vascular Tissue ◽  
Paper Electrophoresis ◽  
Exchange Chromatography ◽  
Calcium Dependent ◽  
Significant Stimulation ◽  
Cation Exchange Column ◽  
Residue Concentration

A recent report has described the preparation of an extract from hemolyzed erythrocytes that has a stimulatory effect on lanthanum-resistant calcium uptake by vascular tissue in vitro and a hypertensive effect when injected into normotensive rats. The compound having a stimulatory effect on calcium uptake was further fractionated by molecular sieve and ion exchange chromatography, precipitation with CaCl2, high voltage paper electrophoresis, and high performance liquid chromatography (HPLC). HPLC yielded only a single fraction containing biological activity. This fraction was ninhydrin positive and acid labile. The amino acid composition was as follows: Asp/Asn (1.41), Ser (1.02), Glu/Gln (1.00), and Gly (2.00). Based on the assumption that the compound contains a single glutamic acid or glutamine residue, concentration–response data indicated that only nanomolar amounts of material were necessary to achieve significant stimulation. There was a marked increase in stimulatory activity of the resolubilized compound following calcium precipitation. The compound became inactive or showed a reduction in activity after being applied to a cation exchange column to remove calcium. Subsequent reprecipitation with CaCl2 and resolubilization restored the lost activity. Thus, we conclude that the compound is a small, acidic, calcium-dependent peptide that is extremely potent in stimulating lanthanum-resistant calcium uptake in vascular tissue.

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