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J Oró

Publications and source records attributed to J Oró.

66 records · Page 4Linked to original sources
PubMed1969

The unextractable organic fraction of the pueblito de allende meteorite: evidence for its indigenous nature.

The Pueblito de Allende meteorite contains only 0.1-0.5 ppm of solvent-extractable carbon, most or all of which is due to terrestrial contamination. Determinations of the total carbon content gives values from 0.23 to 0.35 per cent. The presumed indigenous insoluble carbon is thus present in a ratio of 2300:1 relative to contaminant carbon. A sample of the meteorite was extracted with a deuterated solvent containing benzene:methanol (4:1 w/w) to remove contaminants and then was subjected to pyrolysis-gas chromatography-mass spectrometry to investigate the nature of the remaining carbon. The pyrolysis products (about 20 ppm) consisted chiefly of aromatic and substituted aromatic hydrocarbons. The pyrolysis results were confirmed by oxidative thermal analysis which showed that the bulk of the carbon present was a macromolecular structure and not graphite. This suggests that an insoluble nongraphitic condensed aromatic polymer is indigenous to the meteorite. The origin and precise chemical structure of this material has not been determined, but it bears a superficial resemblance to coal-like structures.

Journal Article↗
PubMed1968

Olefins of high molecular weight in two microscopic algae.

The hydrocarbon composition of two algae, a golden-brown (Bot-ryococcus braunii) and a blue-green (Anacystis montana), has been investigated by gas chromatography-mass spectrometry. Both show distributions of aliphatic hydrocarbons of odd carbon numbers in the medium and high ranges of molecular weight, with maxima at n-C(17) and n-C(29) for B. braunii and n-C(17) and n-C(29) for A. montana. With the exception of the n-heptadecane of A. montana all the hydrocarbons are monoenes, dienes, or trienes. Since certain continental sediments and oils show similar distributions of alkanes with respect to carbon number, these organisms may be the precursors of the hydrocarbons in these formations.

Alkenes↗
PubMed1967

Aliphatic hydrocarbons and fatty acids of some marine and freshwater microorganisms.

Gas chromatography and combined gas chromatography-mass spectrometry have been used to study the fatty acids and hydrocarbons of a bacterium from the Pacific Ocean, Vibrio marinus, a freshwater blue-green alga, Anacystis nidulans, and algal mat communities from the Gulf of Mexico. Both types of microorganisms (bacteria and algae) showed relatively simple hydrocarbon and fatty acid patterns, the hydrocarbons predominating in the region of C-17 and the fatty acids in the range of C-14 to C-18. The patterns of V. marinus were more comparable to those of the algal populations than to patterns reported for other bacteria. An incomplete correlation between fatty acids and hydrocarbons in both types of organisms was observed, making it difficult to accept the concept that the biosynthesis of hydrocarbons follows a simple fatty acid decarboxylation process.

Chromatography, Gas↗
PubMed1967

Identification of fatty acids and aliphatic hydrocarbons in Sarcina lutea by gas chromatography and combined gas chromatography-mass spectrometry.

The composition and nature of the fatty acids and hydrocarbons of Sarcina lutea were elucidated by gas chromatography and by combined gas chromatography-mass spectrometry. The distribution of fatty acids found in S. lutea showed two families of pairs, or dyads, of saturated monocarboxylic acids (C12-C18) with and without methyl branching. These pairs of fatty acids showed a pattern of iso and anteiso structures for C13, C15, and C17, and iso and normal structures for C12, C14, and C16. Only the C18 showed unsaturation. The distribution of hydrocarbons in the range C22-C29 showed two families of tetrads of unsaturated aliphatic hydrocarbons all showing methyl branching. Each tetrad was composed of four isomers identified as two iso olefins and two anteiso olefins. The only difference between the tetrads pertaining to different families was found in the relative gas chromatographic retention times of the last two components of each group.

Chromatography, Gas↗
PubMed1967

Fatty acid and aliphatic hydrocarbon composition of Sarcina lutea grown in three different media.

Sarcina lutea was grown in Trypticase Soy Broth, Nutrient Broth, and a chemically defined medium. Gas chromatographic analysis of lipid components demonstrated that the composition of the medium had an effect on the relative per cent composition of the aliphatic hydrocarbons and fatty acids present in the cells. The branched olefinic hydrocarbons from the organisms grown in Trypticase Soy Broth showed no predominance or only a slight predominance of odd-numbered carbon chains, whereas the hydrocarbons from cells grown in the other two media showed an obvious predominance of odd-numbered carbon chains. The monocarboxylic fatty acid content and distribution showed only minor differences, with all normal saturated fatty acids present in relatively small quantities for cells grown in Nutrient Broth and in a chemically defined medium.

Chromatography, Gas↗
PubMed1967

14-C incorporation into the fatty acids and aliphatic hydrocarbons of Sarcina lutea.

An initial investigation into the mechanism of hydrocarbon biosynthesis in Sarcina lutea was performed by measuring the amounts of (14)C incorporated into the hydrocarbons and fatty acids by use of a combination gas chromatograph and high-temperature gas-flow ionization apparatus. Uniformly labeled l-isoleucine-(14)C was predominantly incorporated into the anteiso-branched chains. Palmitate-16-(14)C gave evidence that a direct correlation may exist between the nonpolar end of the palmitate and the biosynthesis of hydrocarbons and carotenoids. The label from palmitate-1-(14)C was incorporated into the various hydrocarbon groups as a compound, derived from the polar end of the palmitate, consisting of more than two carbon atoms. Palmitate-16-(14)C and -1-(14)C gave no detectable evidence that transformed products were incorporated into other fatty acids. Sodium acetate-2-(14)C and uniformly labeled l-leucine-(14)C gave evidence of a nonspecific incorporation into both the aliphatic hydrocarbons and fatty acids of Sarcina lutea.

Acetates↗
PubMed1966

Alkanes in fungal spores.

The chlamydospores of Ustilago maydis, U. nuda, and Sphacelotheca reiliana were analyzed by gas chromatography and mass spectrometry for their hydrocarbon contents. For the first time we observed that they contain paraffinic hydrocarbons; the average contents were 42, 58, and 146 parts per million, respectively. n-Alkanes having odd numbers of carbon atoms predom-inate, with carbon-chain lengths ranging from C(14) to C(37). The major alkanes are n-C(27) in U. maydis, n-C(27) and n-C(35) in U. nuda, and n-C(29) in S. reiliana. Each type of spore carried a distinctly characteristic population of hydrocarbons.

Alkanes↗
PubMedDate not supplied

Possible prebiotic significance of polyamines in the condensation, protection, encapsulation, and biological properties of DNA.

Some properties of DNA condensed with spermidine have been compared with the properties of DNA condensed with Co3+(NH3)6 to determine whether condensation of DNA with these trivalent cations protects DNA against the action of DNase I and increases transcription and encapsulation of DNA into liposomes. It was shown that DNA condensed with Co3+(NH3)6 was resistant to the action of the endonuclease DNase I such as DNA condensed with spermidine was. However, DNA condensed with Co3+(NH3)6 was significantly less active in transcription with the E. coli RNA polymerase than DNA-spermidine condensed forms. In addition, it was demonstrated that both compacted forms of DNA were more efficiently encapsulated into neutral liposomes; however, negatively, charged liposomes were scarcely formed in the presence of DNA condensed with Co3+(NH3)6. These experiments and the well documented properties of polyamines increasing the resistance to radiations and hydrolysis of nucleic acids, as well as their biological activities, such as replication, transcription, and translation, together with the low concentration of Co3+ in the environment, lead us to propose spermidine as a plausible prebiotic DNA condensing agent rather than Co3+ and the basic proteins proposed by other authors. Then, we consider the possible role and relevance of the polyamine-nucleic acids complexes in the evolution of life.

Animals↗