Gas chromatographic studies of isotopically labelled ethylenes

Atkinson, J. G.; Russell, Anita; Stuart, R. S.

doi:10.1139/v67-312

Cited by 22 publications

(5 citation statements)

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“…I t can be readily observed that the heavy sterols are eluted faster than the analogous light sterols. This isotope effect has been reported in a large number of cases (4,(11)(12)(13) and has been discussed by Saha and Sweeley (14). It is of greater magnitude and more easily detected when the molecules under study contain a large number of hydrogen atoms.…”

supporting

confidence: 69%

Identification by Combined Gas–Liquid Chromatography – Mass Spectrometry of Sterols Isolated from Scenedesmus obliquus Grown in Light and Heavy Water

Bélanger¹,

Zintel²,

Heuvel³

et al. 1973

Can. J. Chem.

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The sterol fraction from Scet~edesmus obliquus, grown in heavy water, has been shown by combined g.1.c. -mass spectrometry to contain A7~Z2-ergostadiene-3P-ol, A7-ergostenol, chondrillasterol, and A7-chondrillastenol. The same algae, grown in light water, contain these four sterols and, i n addition, ergosterol and corbisterol.La fraction des sttrols obtenus de Scenedesnl~ts obliqurts, une Algue croissant dans I'eau lourde, a t t t analyste par la combinaison c.p.v. et spectromttrie de masse. I1 est montrte que les sttrols isolts sont le A7.22-ergostadiene-3p-ol, le A'-ergostenol, le chondrillasterol et le A7-chondrillastenol. La msme algue croissant dans I'eau ordinaire contient aussi I'ergosttrol et le corbisttrol en plus des quatres autres sttrols d t j i mentionnts.

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supporting

confidence: 69%

Identification by Combined Gas–Liquid Chromatography – Mass Spectrometry of Sterols Isolated from Scenedesmus obliquus Grown in Light and Heavy Water

Bélanger¹,

Zintel²,

Heuvel³

et al. 1973

Can. J. Chem.

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“…The radioactive ethylene was first separated on a 1.83 m X 6.25 mm stainless steel silver nitrate ethylene-glycol coated Gas-Chrom R (45-60 mesh firebrick, Applied Science Laboratories, Inc. State College, Pa.) column (3) at 0 C with a flow rate of 50 cc/min. This column effectively separated the saturated hydrocarbons from the unsaturated ones ( Fig.…”

mentioning

confidence: 99%

¹⁴C₂H₄: Its Purification for Biological Studies

Beyer¹

1975

Plant Physiol.

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A gas chromatographic technique is described for obtaining ultra high purity 14(GH for use in biological studies. l4CHL purchased from commercial sources contained readily detectable impurities including radioactive acetylene. Following purification on two different columns, no impurities were detected by high sensitivity gas chromatographic analysis. However, shortly thereafter impurities were detected as a result of radiation decomposition. Trapping and immediately regenerating ultra high purity 14C24 from dilute, filtered Hg(CI04)2 solutions did not cause the formation of impurities, whereas additional impurities were formed when unpurified 14C2HI was used. Impurities were also formed when ultra high purity "GC-L was stored in such solutions prior to its regeneration or when it was trapped and immediately regenerated from more concentrated Hg(CI04) solutions.Surprisingly little is known about the metabolic fate of ethylene. In fact, it is not yet clear whether or not ethylene is incorporated into plant tissues, despite the fact that several studies (8-12, 14, 15) using radioactive ethylene have reported that a small but significant amount of label was incorporated by fruit and vegetative tissues. The present uncertainty, even in light of these reports, exists because of three major criticisms which have been raised (1, 2, 5) and the fact that other studies (4,6,7, 13) have failed to obtain any ethylene incorporation or metabolism. The first criticism is that adequate precautions were not taken to ensure that the label incorporated was derived from radioactive ethylene. Therefore, the reported incorporation may have been an artifact due to impurities originally present in the labeled ethylene or impurities derived from radiation decomposition (16). Second, several studies (8,14,15) was undertaken using ultra high purity "4C-labeled ethylene and aseptic conditions. This paper describes the GC' technique used throughout this study for obtaining ultra high purity "4C-labeled ethylene.Purchased samples of uniformly 14C-labeled ethylene with a reported radiochemical purity of 98% (22, 31, and 53 mCi/ mmole, Amersham/Searle) were purified twice by GC. All separations were performed on a Perkin-Elmer 900 GC connected to a Hewlett-Packard Model 7128A recorder and equipped with a fiame ionization detector and subambient accessory. Ultra high purity helium (Matheson Gas Products) served as the carrier gas while ultra high purity hydrogen (Elhygen H, generator) and oxygen (Matheson Gas Products) provided the flame. Routine ethylene analyses were performed isothermally at 110 C on a 1.83 m X 3.13 mm stainless steel activated alumina column (80-100 mesh) at a flow rate of 70 cc/ min. The sensitivity and stability of this instrument was such that 6 nl/l of ethylene could routinely be detected in a 1-cc gas sample producing a peak twice the baseline noise level with a retention time of 0.9 min.The "4C-labeled ethylene samples were purchased in 250-,4Ci lots and were shipped in small evacuated glass vials with a bre...

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“…Ethylene was analyzed in a Perkin-Elmer 900 gas chromatograph using a flame ionization detector with helium as the carrier gas. Separations were made at -20 C on a 63-foot by one-eighth inch stainless steel column packed with Chromosorb R which had been coated with a saturated silver nitrate-ethylene glycol solution (1). cis-and trans-Dideuteroethylenes were analyzed in a Perkin-Elmer Model 21 infrared spectrophotometer using a 3.3-cm micro gas cell.…”

mentioning

confidence: 99%

“…On the basis of gas chromatography data, deuteration has been shown to increase the stability of the silver ion-ethylene complex (1,10). Therefore, if ethylene does bind to a metallic receptor site, deuterated ethylene might be expected to be slightly more effective than ordinary ethylene.…”

mentioning

confidence: 99%

Mechanism of Ethylene Action

Beyer

1972

Plant Physiol.

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Deuterated ethylene was used to study the mechanism of ethylene action in etiolated pea seedlings (Pisum sativum L. cv. Alaska). No apparent differences were observed in the biological activity of tetradeuteroethylene (CGD4) and ordinary ethylene (C2H4) using the pea stem straight growth assay. The absence of an isotopic effect is discussed in relation to the possibility that ethylene binds to a metal or that carbon to hydrogen bonds of ethylene are broken during its mechanism of action.Analyses by gas chromatography of gas samples obtained from chambers containing intact etiolated pea plants exposed to 2 microliters of C2D4 per liter of air for up to 5 days resulted in no detectable exchange between the deuterium atoms of C2D4 and the hydrogen atoms of the tissue. Similarly, infrared spectra of gas samples obtained from chambers containing strengthen the concept that ethylene binds to a metal. If C2D, were less active, this would also provide some clue as to the chemistry involved in receptor site(s) activation. For example, the formation of an activated complex which involves the cleavage of a carbon-to-hydrogen bond of ethylene would be expected to form more easily with C2H4 than C2D4 because of differences in zero-point energies of the C-H and C-D bonds (16).Molecular changes (e.g., hydrogen exchange, cis-trans-isomerization) may occur in the ethylene molecule itself during receptor site activation because of intermolecular stresses. The detection of such changes, if they occur, would not only aid in the understanding of the biological chemistry involved in ethylene action but would also provide an assay for the isolation of the ethylene-receptor molecule(s) and a technique to explore other questions such as the apparent weak competition between CO, and ethylene for the receptor site (5).MATERIALS AND METHODS Biological Activity of Deuterated Ethylene. Pea seeds (Pisum sativum L. cv. Alaska), soaked in distilled water for 3 hr, were planted in moist vermiculite in plastic trays and were germinated in the dark at 27 C and 70% relative humidity. Sections 7 mm long cut from directly below the plumular hook of 7-day-old etiolated seedlings were placed in Petri dishes with 10 ml of a medium containing 2% sucrose, 0.2 ,uM IAA and 20 mm potassium phosphate buffer, pH 6.8, in double distilled water. Two Petri dishes containing 10 sections each in 200-mm sealed glass desiccators were fumigated with the desired concentration of C2D4 or CM,4. The length of the sections was measured following a 20-hr fumigation period at 27 C in the dark.Isotopic Exchange and cis-trans Isomerization. Approximately 200 pea seeds were germinated in 160-mm glass desiccators as described for the pea straight-growth test. When the seedlings were approximately 3 cm long, the desiccators were sealed and C,D4, cis-C,D,H2, or trans-C2DM2 was added to four such desiccators to give a concentration of 2 to 10 ptl/l. The desiccators were connected in a series with Tygon tubing. Controls were four similar desiccators which contained no seedli...

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Gas chromatographic studies of isotopically labelled ethylenes

Cited by 22 publications

References 0 publications

Identification by Combined Gas–Liquid Chromatography – Mass Spectrometry of Sterols Isolated from Scenedesmus obliquus Grown in Light and Heavy Water

Identification by Combined Gas–Liquid Chromatography – Mass Spectrometry of Sterols Isolated from Scenedesmus obliquus Grown in Light and Heavy Water

¹⁴C₂H₄: Its Purification for Biological Studies

Mechanism of Ethylene Action

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Gas chromatographic studies of isotopically labelled ethylenes

Cited by 22 publications

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Identification by Combined Gas–Liquid Chromatography – Mass Spectrometry of Sterols Isolated from Scenedesmus obliquus Grown in Light and Heavy Water

Identification by Combined Gas–Liquid Chromatography – Mass Spectrometry of Sterols Isolated from Scenedesmus obliquus Grown in Light and Heavy Water

14C2H4: Its Purification for Biological Studies

Mechanism of Ethylene Action

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¹⁴C₂H₄: Its Purification for Biological Studies