Molecular characterization of a seed-fern ovule (Pennsylvanian, Sydney Coalfield, Canada) by FTIR, <sup>13</sup>C NMR, and Py-GC-MS
Despite the abundance of detached seed-fern ovules (Euramerican and Cathaysian floral provinces, Pennsylvanian - Permian) as compression / impression, their palaeobiochemistry remains unknown. The Late Pennsylvanian strata of the Sydney Coalfield, Canada, have yielded numerous ovulate trigonocarpale...
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Formato: | Objeto de conferencia Resumen |
Lenguaje: | Inglés |
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2010
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Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/16853 |
Aporte de: |
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I19-R120-10915-16853 |
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institution |
Universidad Nacional de La Plata |
institution_str |
I-19 |
repository_str |
R-120 |
collection |
SEDICI (UNLP) |
language |
Inglés |
topic |
Ciencias Naturales Paleontología Molecular characterization Seed-fern ovule |
spellingShingle |
Ciencias Naturales Paleontología Molecular characterization Seed-fern ovule D'Angelo, José A. Werner-Zwanziger, U. Helleur, R. Zodrow, E. L. Molecular characterization of a seed-fern ovule (Pennsylvanian, Sydney Coalfield, Canada) by FTIR, <sup>13</sup>C NMR, and Py-GC-MS |
topic_facet |
Ciencias Naturales Paleontología Molecular characterization Seed-fern ovule |
description |
Despite the abundance of detached seed-fern ovules (Euramerican and Cathaysian floral provinces, Pennsylvanian - Permian) as compression / impression, their palaeobiochemistry remains unknown. The Late Pennsylvanian strata of the Sydney Coalfield, Canada, have yielded numerous ovulate trigonocarpalean compressions, 6-8cm long, with preserved cuticles assigned to Trigonocarpus grandis (Lesquereux) Cleal et Zodrow. The macerated cuticles are analyzed by Fourier Transform Infrared spectroscopy (FTIR), Carbon-13 Nuclear Magnetic Resonance (<sup>13</sup>C NMR), and Pyrolysis Gas Chromatography-mass spectrometry (Py-GC-MS). FTIR and <sup>13</sup>C NMR data reveal a predominantly aliphatic structure including C-H groups (with or without hetero-substitution such as in alkyl and aryl alcohols, ethers, esters, and ketones). Larger CH<sub>2</sub>/CH<sub>3</sub> ratios (above 20) suggest the presence of long and straight aliphatic side chains linked to the main macromolecular structure. Other groups present include C-O (in phenols and phenoxy structures, and aryl and alkyl ethers and alcohols), C=O carbonyl groups (in carboxylic acids and conjugated and highly conjugated structures such as ketones), C=C (in aromatic carbon structures with and without bridging to other carbon groups), and O-H (in aliphatic or aromatic alcohols). In addition, <sup>13</sup>C NMR shows, compared to other cuticles in related seed ferns, a high amount of acetal groups as they occur in di- and polysaccharides. In agreement with FTIR and NMR results, Py-GC-MS data show the presence of highly aliphatic molecules (alkanes/alkenes) with carbons between C<sub>4</sub> and C<sub>8</sub> (including a complex mixture of mono and di unsaturated hydrocarbon isomers up to C<sub>8</sub>). Other compounds detected include benzene and toluene. However, the most striking chemical feature of the pyrolysates markers is the presence of 5 isomers of C<sub>5</sub>H<sub>8</sub> including isoprene (0.5 - 1.0 % abundance). The latter could be derived from some tocopherol precursor (vitamin E-like compound). If confirmed, this is the earliest chemical evidence for the presence of isoprenoids in vascular plants. |
format |
Objeto de conferencia Resumen |
author |
D'Angelo, José A. Werner-Zwanziger, U. Helleur, R. Zodrow, E. L. |
author_facet |
D'Angelo, José A. Werner-Zwanziger, U. Helleur, R. Zodrow, E. L. |
author_sort |
D'Angelo, José A. |
title |
Molecular characterization of a seed-fern ovule (Pennsylvanian, Sydney Coalfield, Canada) by FTIR, <sup>13</sup>C NMR, and Py-GC-MS |
title_short |
Molecular characterization of a seed-fern ovule (Pennsylvanian, Sydney Coalfield, Canada) by FTIR, <sup>13</sup>C NMR, and Py-GC-MS |
title_full |
Molecular characterization of a seed-fern ovule (Pennsylvanian, Sydney Coalfield, Canada) by FTIR, <sup>13</sup>C NMR, and Py-GC-MS |
title_fullStr |
Molecular characterization of a seed-fern ovule (Pennsylvanian, Sydney Coalfield, Canada) by FTIR, <sup>13</sup>C NMR, and Py-GC-MS |
title_full_unstemmed |
Molecular characterization of a seed-fern ovule (Pennsylvanian, Sydney Coalfield, Canada) by FTIR, <sup>13</sup>C NMR, and Py-GC-MS |
title_sort |
molecular characterization of a seed-fern ovule (pennsylvanian, sydney coalfield, canada) by ftir, <sup>13</sup>c nmr, and py-gc-ms |
publishDate |
2010 |
url |
http://sedici.unlp.edu.ar/handle/10915/16853 |
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bdutipo_str |
Repositorios |
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