scholarly journals Studien über Wespengift, I Niedermolekulare Bestandteile des Giftblasenextraktes von Paravespula vulgaris / Studies on Wasp Venom, I Low Molecular Weight Constituents of Venom Sac Extracts from Paravespula vulgaris

1981 ◽  
Vol 36 (6) ◽  
pp. 757-762 ◽  
Author(s):  
Hartmut Klein ◽  
Wittko Francke ◽  
Wilfried A. König
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Fatty Acids ◽  
Molecular Weight ◽  
Gas Chromatography ◽  
Acetic Acid ◽  
Quantitative Analysis ◽  
Amino Acid ◽  
Low Molecular Weight ◽  
Wasp Venom

Abstract Low molecular weight constituents of 3400 venom sacs of Paravespula vulgaris were extracted with water, diluted acetic acid, and methanol. After conversion to volatile derivatives carbohydrates, amino acids, fatty acids, other constituents of phospho lipids, and biogenic amines were identified by gas chromatography and mass spectrometry. Quantitative analysis was achieved for amino acids by amino acid analysis and for glucose by an enzymatic assay. Results are discussed with regard to biosynthesis of wasp toxins and phylogenetic aspects of hymenopteran venoms.

Trans-tegumental absorption of L-alanine and L-leucine by a monogenean, Diclidophora merlangi

Parasitology ◽  
1978 ◽  
Vol 76 (1) ◽  
pp. 29-37 ◽  
Author(s):  
D. W. Halton
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Sea Water ◽  
Low Molecular Weight ◽  
Acid Uptake ◽  
Neutral Amino Acids ◽  
Freeze Dried ◽  
Significant Difference

SummaryAn in vitro investigation has been made of the relative roles of the gut and tegument in the absorption of the neutral amino acids L-alanine and L-leucine by a marine fish-gill parasite, Diclidophora merlangi. The use of ligatures to preclude oral ingestion of trace-labelled medium has proved inadequate, invariably damaging the tegument, as revealed by stereoscan electron microscopy, and resulting in artifactual levels of absorption. Three alternative procedures have given consistently reliable data on the route of entry of low molecular weight substrates. (1) Ultrastructural examination of worms previously incubated in electron-dense cationic tracers has shown that, in vitro, there is no oral intake of sea water. (2) The suspending of worms in trace-labelled medium with the mouth out of the medium and comparing amino acid uptake with that of worms totally immersed in medium has revealed no statistically significant difference in the absorption levels. (3) Application of section (freeze-dried) auto-radiography to detect diffusible isotope has demonstrated directly transtegumental absorption of a neutral amino acid. It is concluded from these experiments that Diclidophora has a tegumental transport system for absorbing certain neutral amino acids, and whilst, clearly, the worm is sanguinivorous and digests blood in a well-developed gut, it may also be capable of supplementing this diet with low molecular weight organic nutrient absorbed directly from sea water via the tegument.

scholarly journals Study in aroma of sweet natural non Muscat wines 2nd part : quantitative analysis of volatil compounds taking part in aroma of sweet natural wines during ageing

OENO One ◽  
1998 ◽  
Vol 32 (4) ◽  
pp. 211
Author(s):  
Isabelle Cutzach ◽  
Pascal Chatonnet ◽  
R. Henry ◽  
Monique Pons ◽  
Denis Dubourdieu
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Gas Chromatography ◽  
Quantitative Analysis ◽  
Volatile Compounds ◽  
Olfactory Perception ◽  
Maillard Reactions ◽  
Furanic Compounds ◽  
Port Wines

<p style="text-align: justify;">This study is dedicated to quantification, by gas chromatography combined with mass spectrometry, of some volatile compounds founded during ageing of sweet natural wines. Besides determination of the thresholds olfactory perception enable us knowing better the more active compound in sweet natural wines aroma.</p><p style="text-align: justify;">The results enable to know better volatile compounds which are able to produce ageing aromas characteristic of sweet natural wines. These products are always rich in sugar and grown up in a more or less oxidising environment. Logically, many of the compounds identified in this work (derived furanic compounds and many others) are Iinked with chemical like Maillard reactions between sugars and amino-acids. Others compounds as a sotolon need oxidising phenomena to increase in the environment.</p><p style="text-align: justify;">Comparatively, oldest Port wines have been analysed. The compounds measured in these Port wines also exist in French sweet natural wines of type Banyuls and Rivesaltes, keeped under oxidising environment. But the dillerences of concentrations in some compounds discriminate them from the Port wines.</p>

Massenspektrometrische Identifizierung der Phenylthiohydantoin-Derivate von Aminosäuren / Identification of Amino Acid Phenylthiohydantoins by Mass Spectrometry

1970 ◽  
Vol 25 (7) ◽  
pp. 681-689 ◽  
Author(s):  
H. Hagenmaier ◽  
W. Ebbighausen ◽  
G. Nicholson ◽  
W. Vötsch
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Gas Chromatography ◽  
Amino Acid ◽  
Mass Spectra ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry ◽  
Unequivocal Identification

The unequivocal identification of phenylthiohydantoins of the 20 amino acids usually occurring in proteins is possible by mass spectrometry and by combined gas chromatography-mass spectrometry. The method is sensitive enough to be applied to the identification of phenylthiohydantoins obtained from automated Edman degradations of polypeptides. Mass spectra of 21 amino acid phenylthiohydantoins are presented and interpreted.

Chemical analysis of flavour volatiles in heat-treated milks

1978 ◽  
Vol 45 (3) ◽  
pp. 391-403 ◽  
Author(s):  
Haytham A. Jaddou ◽  
John A. Pavey ◽  
Donald J. Manning
Keyword(s):  
Mass Spectrometry ◽  
Heat Treatment ◽  
Molecular Weight ◽  
Gas Chromatography ◽  
Chemical Composition ◽  
Volatile Compounds ◽  
Raw Milk ◽  
Low Molecular Weight ◽  
Total Volatile ◽  
Heat Treated

SummaryThe effect of heat treatment of milk on low molecular weight, volatile compounds was studied in order to relate changes in the flavour of milks to changes in chemical composition. Milks were heat treated in a UHT plant for 3 or 90 s at 140 °C and stored at ambient temperature for periods up to 112 d. Volatile compounds in raw milk and in heated milks were isolated by a low temperature spray distillation technique and identified using gas chromatography and mass spectrometry. Cabbagey defects in heated milks are correlated with total volatile sulphur and it is concluded that the compounds H2S, COS, CH3SH, CS2 and (CH3)2S could be responsible for this defect.

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