Effect of mobile-phase pH on the chromatographic behavior of biogenic amine neurotransmitters and their metabolites

2004 ◽  
Vol 17 (4) ◽  
pp. 297-299 ◽  
Author(s):  
Irena Baranowska ◽  
Mirosława Zydroń
Keyword(s):  
Biogenic Amine ◽  
Mobile Phase ◽  
Chromatographic Behavior ◽  
Amine Neurotransmitters

scholarly journals Application of Hydrophilic Interaction Liquid Chromatography for the Quantification of Flavonoids inGenista tinctoriaExtract

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Aleksandra Sentkowska ◽  
Magdalena Biesaga ◽  
Krystyna Pyrzynska
Keyword(s):  
Mobile Phase ◽  
Retention Mechanism ◽  
Chromatographic Behavior ◽  
Hydrophilic Interaction ◽  
Silica Column ◽  
Retention Factors ◽  
Component Content ◽  
Chromatographic Procedure ◽  
Unmodified Silica ◽  
Genista Tinctoria

Hydrophilic interaction chromatography (HILIC) was employed to investigate chromatographic behavior of selected flavonoids from their different subgroups differing in polarity. Chromatographic measurements were performed on two different HILIC columns: unmodified silica (Atlantis-HILIC) and zwitterionic sulfoalkylbetaine (SeQuant ZIC-HILIC). Separation parameters such as content and type of organic modifier were studied. On ZIC column retention factors were observed to be inversely proportional to the buffer content in the mobile phase, which is the typical partitioning mechanism. In the case of bare silica column more or less apparent dual retention mechanism was observed, depending on the water component content in the mobile phase. ZIC-HILIC showed better selectivity (in comparison to silica column) with the detection limit of 0.01 mg/L (only for rutin was 0.05 mg/L). Finally, this chromatographic procedure was validated and applied for the determination of some flavonoids inGenista tinctoriaL. extract.

Chromatographic Behavior of Deoxyribonucleosides with Respect to Organic Modifier Content in the Mobile Phase

1995 ◽  
Vol 18 (15) ◽  
pp. 3091-3104 ◽  
Author(s):  
Jae-Duck Kim ◽  
Kyung Ho Row ◽  
Myoung Seup So ◽  
I. A. Polunina ◽  
A. V. Larin
Keyword(s):  
Mobile Phase ◽  
Chromatographic Behavior ◽  
Organic Modifier ◽  
Modifier Content

Development and Validation of a Reversed-Phase HPLC Method for Determination of Alkaloids from Papaver somniferum L. (Papaveraceae)

2012 ◽  
Vol 95 (2) ◽  
pp. 399-405 ◽  
Author(s):  
Jelena Acevska ◽  
Aneta Dimitrovska ◽  
Gjoshe Stefkov ◽  
Katerina Brezovska ◽  
Marija Karapandzova ◽  
...  
Keyword(s):  
Mobile Phase ◽  
Ph Value ◽  
Reversed Phase ◽  
Hplc Method ◽  
Papaver Somniferum ◽  
Chromatographic Behavior ◽  
Organic Modifier ◽  
Column Temperature ◽  
Development And Validation

Abstract An HPLC method for the separation of six target alkaloids from Papaver somniferum L. (morphine, codeine, oripavine, thebaine, papaverine, and noscapine) was developed, optimized, and validated. The chromatographic behavior of these alkaloids was investigated using a reversed-phase chromatography at acidic and alkaline pH. The effects of ion-pairing agents, pH value of the mobile phase, concentration of the buffer components, mobile phase organic modifier, and column temperature were studied. Regardless of the large differences in their pKa values, all alkaloids were separated within a close retention window, and good peak shape was achieved for each of the six alkaloids. The proposed method has adequate selectivity, linearity, accuracy, precision, and reproducibility and is applicable for poppy straw.

scholarly journals Deorphanisation of novel biogenic amine-gated ion channels identifies a new serotonin receptor for learning

2020 ◽  
Author(s):  
Julia Morud ◽  
Iris Hardege ◽  
He Liu ◽  
Taihong Wu ◽  
Swaraj Basu ◽  
...  
Keyword(s):  
Ion Channels ◽  
Biogenic Amine ◽  
Pathogenic Bacteria ◽  
Serotonin Receptor ◽  
Neuronal Function ◽  
Olfactory Conditioning ◽  
C Elegans ◽  
Neuronal Processes ◽  
Amine Neurotransmitters ◽  
Gated Ion Channels

SummaryPentameric ligand-gated ion channels (LGCs) play conserved, critical roles in fast synaptic transmission, and changes in LGC expression and localisation are thought to underlie many forms of learning and memory. The C. elegans genome encodes a large number of LGCs without a known ligand or function. Here, we deorphanize five members of a family of Cys-loop LGCs by characterizing their diverse functional properties that are activated by biogenic amine neurotransmitters. To analyse the neuronal function of these LGCs, we show that a novel serotonin-gated cation channel, LGC-50, is essential for aversive olfactory learning. lgc-50 mutants show a specific defect in learned olfactory avoidance of pathogenic bacteria, a process known to depend on serotonergic neurotransmission. Remarkably, the expression of LGC-50 in neuronal processes is enhanced by olfactory conditioning; thus, the regulated expression of these receptors at synapses appears to represent a molecular cornerstone of the learning mechanism.

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