Alterations in Ecdysone Content during the Post-Embryonic Development of Chironomus thummi: Correlations with Chromosomal Puffing

1978 ◽  
Vol 33 (7-8) ◽  
pp. 557-560 ◽  
Author(s):  
M. Valentin ◽  
W. E. Bollenbacher ◽  
L. I. Gilbert ◽  
H. Kroeger
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Embryonic Development ◽  
Fresh Weight ◽  
Pupal Development ◽  
Radioimmune Assay ◽  
Chromosomal Site ◽  
Titer Curve ◽  
High Degree ◽  
Chironomus Thummi

Abstract The ecdysone titer of larvae and pupae of Chironomus thummi was determined by radioimmune assay (RIA) and revealed a concentration of about 150 ng/g fresh weigth in late third instar larvae and a peak of more than 450 ng/g fresh weight just preceding pupation. The ecdysone titer curve shows a high degree of correlation with previously observed puffing activity at the ecdysone sensitive chromosomal site IIIdl. Further, β-ecdysone is the only endogenous ecdysone detected by high pressure liquid chromatography during larval-pupal development. It was also observed that developmentally arrested Chironomus contain less ecdysone than “normal” larvae.

Cyclic adenosine 3′, 5′-monophosphate in Gastrothylax crumenifer and Explanatum explanatum

1997 ◽  
Vol 71 (2) ◽  
pp. 147-149
Author(s):  
H. Ehsan ◽  
K.A. Rashid ◽  
W. Van Dongen ◽  
H.A. Van Onckelen
Keyword(s):  
Mass Spectrometry ◽  
High Pressure ◽  
Liquid Chromatography ◽  
Reliable Method ◽  
Trematode Species ◽  
Tandem Mass ◽  
Electrospray Tandem Mass Spectrometry ◽  
Fresh Weight ◽  
Gastrothylax Crumenifer ◽  
Extraction And Purification

AbstractA rapid and reliable method based on immuno-affinity chromatography and preparative high pressure liquid chromatography was used for extraction and purification of cAMP from the two trematode species Gastrothylax crumenifer and Explanatum explanatum. The purified cAMP was quantified by electrospray tandem mass spectrometry in an amount of 44 and 83 picomole/g fresh weight of Gastrothylax crumenifer and Explanatum explanatum respectively.

Preparation and properties of three analogues of [5-leucine]enkephalin, substrates for enzyme conversion studies

1985 ◽  
Vol 50 (6) ◽  
pp. 1329-1334
Author(s):  
Jaroslav Vičar ◽  
Linda Servítová ◽  
Martin Flegel ◽  
Karel Hauzer ◽  
Tomislav Barth
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Guinea Pig ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Guinea Pig Ileum ◽  
Opioid Activity ◽  
C Terminus ◽  
N Terminus ◽  
Fragment Condensation

Analogues of [5-Leu]enkephalin, prolonged by methionine on the N-terminus or, by lysine or methionine on the C-terminus were prepared by fragment condensation, purified by ion exchange chromatography or high-pressure liquid chromatography. The substances were characterised by their opioid activity in a test on guinea-pig ileum in comparison with the activity of [5-Leu]enkephalin.

Production of Aflatoxin in Cocoa Beans

1979 ◽  
Vol 62 (5) ◽  
pp. 1076-1079 ◽  
Author(s):  
Lawrence M Lenovich ◽  
W Jeffrey Hurst
Keyword(s):  
High Pressure ◽  
Liquid Chromatography ◽  
Ivory Coast ◽  
Aspergillus Parasiticus ◽  
Aflatoxin Production ◽  
Growth Conditions ◽  
Aflatoxin Contamination ◽  
Cocoa Beans ◽  
Total Aflatoxin ◽  
Substrate Variation

Abstract Aflatoxin was produced in both non-autoclaved and autoclaved Ivory Coast cocoa beans inoculated with Aspergillus parasiticus NRRL 2999 under optimum laboratory growth conditions. Total aflatoxin levels ranged from 213 to 5597 ng/g substrate. Aflatoxin was quantitated by using high pressure liquid chromatography (HPLC). Raw, non-autoclaved cocoa beans, also inoculated with aspergilli, produced 6359 ng aflatoxin/g substrate. Variation in aflatoxin production between bean varieties was observed. Total aflatoxin levels of 10,446 and 23,076 ng/g substrate were obtained on Ivory Coast beans inoculated with A. parasiticus NRRL 2999 and NRRL 3240, respectively. Aflatoxin production on Trinidad and Malaysian beans was 28 and 65 ng aflatoxin/g substrate. These data support previously reported low level natural aflatoxin contamination in cocoa.

scholarly journals Ethoxylated Butoxyethanol-BADGE Adducts—New Potential Migrants from Epoxy Resin Can Coating Material

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3682
Author(s):  
Monika Beszterda ◽  
Małgorzata Kasperkowiak ◽  
Magdalena Frańska ◽  
Sandra Jęziołowska ◽  
Rafał Frański
Keyword(s):  
Mass Spectrometry ◽  
High Pressure ◽  
Liquid Chromatography ◽  
Epoxy Resin ◽  
Diglycidyl Ether ◽  
Ionization Mass ◽  
Coating Materials ◽  
Oxyethylene Unit ◽  
Bisphenol A Diglycidyl Ether ◽  
Product Ions

The acetonitrile extracts of can-coating materials have been analyzed by using high-pressure liquid chromatography/electrospray ionization-mass spectrometry (HPLC/ESI-MS). On the basis of detected ions [M + H]+, [M + NH4]+, [M + Na]+ and product ions, the ethoxylated butoxyethanol-bisphenol A diglycidyl ether adducts were identified in two of the analyzed extracts. Although the oxyethylene unit-containing compounds are widely used for the production of different kinds of materials, the ethoxylated species have not been earlier detected in epoxy resin can-coatings.

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