Curupira tefeensis II: Occurrence of Acetylenic Fatty Acids

Four acetylenic fatty acids [11-octadecen-9-ynoic acid (E) (ximenynic acid), 11-octadecen-9-ynoic acid (Z), 9,11-octadecadiynoic acid and 13-octadecen-9,11-diynoic acid (E) (exocarpic acid)] were found in the seed oil of Curupira tefeensis (Olacaceae) as minor compounds. The mass spectra of the methyl esters (EI and CI mode), picolinyl esters and 4,4-dimethyloxazoline derivatives of these acids are discussed in detail. Furthermore the NMR data of 9,11-octadecadiynoic acid and 13-octadecen-9,11-diynoic acid are presented.     

The Mass Spectra of the Picolinyl Ester Derivatives of Malvalic and Sterculic Acid

The mass spectra of the picolinyl derivatives of two natural occurring cyclopropenoid fatty acids (malvalic and sterculic acid) showed, besides the typical peaks for picolinyl derivatives, a characteristic gap of 66 amu between the two allylic positions of the ring system. This phenomenon could be used for the determination of the ring position of this type of fatty acids.     

Isolierung der durch ?thylenoxyd-1,214C derivatisierten Inhaltsstoffe aus Kakao und ihre massenspektrometrisch ermittelte Struktur

Zusammenfassung Bei der Auftrennung zahlreicher Fraktionen durch Extraktion und PDC aus dem Äthylenoxyd-1,2-¹⁴C begasten Kakaopulver (Entkeimung) konnten aus dem Wasserextrakt 2 Verbindungen isoliert werden, deren Struktur aufgrund der Massenspektren und IR-Spektren alsN,N-Bis-(Di-Äthoxy-O-hydroxyäthyl)-isoleucyl-alanyl-cystein (MG = 569) undN-(Äthoxy-O-hydroxyäthyl)-Tyrosin gefunden wurde. Die Konzentrationen liegen ungefü:hr bei 20 bzw. 50 mg/kg Kakaopulver.

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Isolation of the derivatives from coca-powder fumigated by ethylene oxide 1,2-¹⁴C and their Structure Suggested on the Basis of I. R. and Mass-Spectrometry

Summary In Coca-powder fumigated with Ethylene Oxide-1,2¹⁴C, several derivatives were isolated by extraction and preparative Thin Layer Chromatography. Of the two compounds isolated from the water-extract, the structures have been suggested asN,N-Bis-(Di-Ethoxy-O-Hydroxy-ethyl)-Isoleucyl-Alanyl-Cysteine (MW = 569) andN-(Ethoxy-O-Hydroxyethyl)-Tyrosine (MW = 269), based on I. R. and Mass Spectrometry. Their approximate concentrations were found to be 20 and 50 mg/kg respectively.

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Wir danken der Deutschen Forschungsgemeinschaft für ihre finanzielle Unterstützung dieser Arbeit.

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Untersuchungen über das Verhalten von Äthylenoxyd bei der Begasung von Lebensmitteln, IX. Mitteilung.

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Zum Teil aus der Dissertation von I. R. Siddiqui, Universität Bonn.     

Group separation of ethylene oxide 1,2-14c fumigated coca-powder derivatives and their distribution of radioactivity (author's transl)]

A procedure based on extraction, column chromatography and precipitation is described for the separation of ethylene oxide-1,2-14C fumigated coca-powder derivatives in 9 different groups. As it was found in wheat [1], the major portion of radioactivity lies in water extract; in coca-powder the major portion of radioactivity is also found in low molecular components.     

Nachweis der Behandlung von Hühnerbrust mit ionisierenden Strahlen und Abschätzung der Bestrahlungsdosis mit Hilfe der Headspace-Gaschromatographie und diskriminanzanalytischer Auswertung

Chicken breast was irradiated with doses of 3, 5, and 7 kGy. Headspace gas chromatographical analysis demonstrated the tendency that the amounts of volatile compounds (mainly pentanal, hexanal and heptanal) are higher in irradiated samples in comparison with non irradiated. Statistical evaluation of the gas chromatograms by discriminant analysis enabled the detection of irradiation. Unknown samples could be classified in the groups ?unirradiated“ or ?irradiated in most cases.     

Curupira tefeensis (Olacaceae) — A Rich Source of Very Long Chain Fatty Acids

The fatty acid composition of the seed oil of Curupira tefeensis was analysed by capillary GC of their methyl esters. The gaschromatographic assignments were ensured by corresponding mass spectra. The oil is composed to more than 62% of very long chain fatty acids (>C18). Erucic acid is found to be the main component (35%). The position of the double bonds of the monounsaturated fatty acids (MUFAME) was verified after derivatization with dimethyl disulfide and subsequent GC/MS analysis. All identified MUFAME belong to the (n-9-)type. The UV-spectroscopical data show that approx. 1.2% conjugated acetylenic fatty acids occur in the oil. Furthermore IR- and NMR-spectroscopical investigations and the basic analyses of the seed were carried out.     

Initial steps of the metal-catalysed degradation of L-dehydroascorbic acid in acidic aqueous solutions

The initial steps of the degradation of L-de- hydroascorbic acid (L-DHA) in acidic aqueous solutions and the catalytic effect of different transition metal ions on this reaction were studied. The main product was identified as 3,6-furanosido-2,3-hexodiulosonic acid-2-hydrate (compound I) by GLC-MS and ¹³C-NMR, formed by lactone hydrolysis and hydration of the carbonyl group in the C-2 position of L-dehydroascorbic acid. In addition, number of other compounds were detected; they are formed from compound I by simple enolisation, lactonisation, hydration and dehydration reactions as well as by cleavage and formation of cyclic half acetal bonds. The chemical structures of these compounds were tentatively deduced by the mass spectra of their TMS derivatives and a reaction scheme for their formation is proposed. The velocity and the direction of the reactions were found to be strongly influenced by the presence of catalytic amounts of different transition metal ions. It was concluded that in acidic medium, in contrast to the situation in neutral and alkaline solutions, the opening of the lactone ring of L-DHA is, to a certain degree, a reversible reaction.