Nonracemic isovaline in the Murchison meteorite: chiral distribution and mineral association

Pizzarello, Sandra; Zolensky, M. E.; Turk, Kendra A.

doi:10.1016/s0016-7037(02)01283-8

Cited by 206 publications

(217 citation statements)

References 21 publications

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“…Abiotic theories, on the other hand, propose that some asymmetry preceded the onset of life, overcame racemization, and contributed to homochirality. The finding in meteorites of amino acids resistant to racemization and displaying enantiomeric excesses (ee) that, if less extensive, have the same sign (L-) as in terrestrial amino acids (3,4) supports, albeit does not prove, the latter hypothesis.…”

mentioning

confidence: 97%

The peptide-catalyzed stereospecific synthesis of tetroses: A possible model for prebiotic molecular evolution

Weber

Pizzarello

2006

Proc. Natl. Acad. Sci. U.S.A.

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115

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Using a water-based prebiotic model of sugar synthesis involving glycolaldehyde self-condensation, we demonstrate that homochiral L-dipeptide catalysts lead to the stereospecific syntheses of tetroses. The asymmetric effect is largest for erythrose, which may reach a D-enantiomeric excess of >80% with L-Val-L-Val catalyst. Based on results obtained with various peptides, we propose a possible catalytic-reaction intermediate, consisting of an imidazolidinone ring formed between the two nitrogen atoms of the peptide catalyst and the C1 of one glycolaldehyde molecule. The study was motivated by the premise that exogenous material, such as the nonracemic amino acids found in meteorites, could have participated in the terrestrial evolution of molecular asymmetry by stereospecific catalysis. Because peptides might have formed readily on the early Earth, it is possible that their catalytic contribution was relevant in the prebiotic processes that preceded the onset of life.prebiotic chemistry ͉ chirality ͉ catalysis A lthough the chemical environments that led to life's origin on the Earth are unknown, our knowledge of current and extinct life processes allows us to postulate some possible working assumptions. For example, we may describe life as an autocatalytic chemical process where simple molecules, such as amino acids and nucleotides, assemble into larger proteins and nucleic acids that, in turn, control their metabolism and synthesis (1). In these terms, we may also identify key requirements that make such processes possible. One such prerequisite is the exclusive one-handedness of the chiral constituents of proteins and nucleotides (L-amino acids and D-sugars) that is essential to extant biopolymers' structure and function and whose origin is unknown.Several general theories have been brought forward in regard to the origin of this terrestrial homochirality (2). Some propose that life first arose from a racemic environment and later evolved to chiral homogeneity; this ''biotic'' premise circumvents the ease with which prebiotic amino acids and sugars would have lost any incremental gain in asymmetry to racemization. Abiotic theories, on the other hand, propose that some asymmetry preceded the onset of life, overcame racemization, and contributed to homochirality. The finding in meteorites of amino acids resistant to racemization and displaying enantiomeric excesses (ee) that, if less extensive, have the same sign (L-) as in terrestrial amino acids (3, 4) supports, albeit does not prove, the latter hypothesis.Apart from either hypothesis, because abiotic syntheses of chiral molecules would produce only racemic mixtures if unaided by catalysts and meteorites' composition shows that any preexisting ee available for the formation of biomolecules would not have been large (4), it is reasonable to assume that the development of chiral homogeneity was an evolutionary process that involved catalysis. This inference, in turn, leads to the question of whether the unique nonracemic amino acids of meteorites might have play...

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mentioning

confidence: 97%

The peptide-catalyzed stereospecific synthesis of tetroses: A possible model for prebiotic molecular evolution

Weber

Pizzarello

2006

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

115

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“…This was further confirmed by the discovery of L-excess in non-protein chiral amino acids and in other meteorites [37,38]. Enantiomeric excesses are variable among meteorites [39], and also inside the same objects [40] but never exceed 18%. The hydrated meteorites exhibit higher excess, pointing to a possible amplification during aqueous alteration [39].…”

Section: -P4mentioning

confidence: 69%

Organic and volatile elements in the solar system

Rémusat

2011

EPJ Web of Conferences

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Abstract. Chondrites and comets have accreted primitive materials from the early solar system. Those materials include organics, water and other volatile components. The most primitive chondrites and comets have undergone few modifications on their respective parent bodies and can deliver to laboratories components that were present at the origin of the protosolar nebula. Here I present a review of the organic material and volatile components that have been studied in the most primitive chondrites, and the last data from the stardust mission about the cometary record. This paper focuses on materials that can be studied in laboratories, by mass spectrometry, ion probes or organic chemistry techniques.

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“…Enantiomeric excesses have been detected in chondrites, in amino acids [30,31]. Enantiomeric excesses are variable among meteorites [31], and also inside the same objects [32] but do not exceed 18%. The hydrated meteorites exhibit higher excess, pointing to a possible amplification during aqueous alteration [31].…”

Section: Diversity Of Organic Compounds In Meteoritesmentioning

confidence: 96%

Organic material in meteorites and the link to the origin of life

Rémusat

2014

BIO Web of Conferences

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Abstract. Life requires specific conditions that have been, so far, only proven to meet on Earth. Though the chemical elements required to form living organism (C, H, N, O, S, etc) are widespread in the universe, the molecules that are crucial for Life, like nucleobases or amino acids, may not be so ubiquitous. The question of the formation of small and complex molecules is highly relevant to understand the process of Life origin. Carbonaceous chondrites are a class of meteorites rich in organic compounds and host potential precursors for the emergence of Life (organic matter and water). They could have been the source of complex molecules on the early Earth. This contribution will describe the main properties of the organic matter recovered from carbonaceous chondrites. However, the isotopic and molecular record of organic compounds is faded by secondary processes that occurred on the parent body of these meteorites. This results in complex signatures that raise multiple questions about the origin of organic compounds in the Solar System.

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Nonracemic isovaline in the Murchison meteorite: chiral distribution and mineral association

Cited by 206 publications

References 21 publications

The peptide-catalyzed stereospecific synthesis of tetroses: A possible model for prebiotic molecular evolution

The peptide-catalyzed stereospecific synthesis of tetroses: A possible model for prebiotic molecular evolution

Organic and volatile elements in the solar system

Organic material in meteorites and the link to the origin of life

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