Abiotic formation of uroporphyrinogen and coproporphyrinogen from acyclic reactants

Lindsey, Jonathan S.; Chandrashaker, Vanampally; Taniguchi, Masahiko; Ptaszek, Marcin

doi:10.1039/c0nj00716a

Cited by 44 publications

(89 citation statements)

References 43 publications

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“…Two possible explanations for the HB/O 2 effect on stabilizing blood vessel tissues are based on earlier observations in different environments: (i) enhanced tissue fixation by free radicals, initiated by haeme-oxygen interactions [65]; or (ii) inhibition of microbial growth by free radicals [63,64]. Ironically, haeme, a molecule thought to have contributed to the formation of life [41,74], may contribute to preservation after death.…”

Section: Discussionmentioning

confidence: 99%

A role for iron and oxygen chemistry in preserving soft tissues, cells and molecules from deep time

Schweitzer¹,

et al. 2014

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The persistence of original soft tissues in Mesozoic fossil bone is not explained by current chemical degradation models. We identified iron particles (goethite-aFeO(OH)) associated with soft tissues recovered from two Mesozoic dinosaurs, using transmission electron microscopy, electron energy loss spectroscopy, micro-X-ray diffraction and Fe micro-X-ray absorption nearedge structure. Iron chelators increased fossil tissue immunoreactivity to multiple antibodies dramatically, suggesting a role for iron in both preserving and masking proteins in fossil tissues. Haemoglobin (HB) increased tissue stability more than 200-fold, from approximately 3 days to more than two years at room temperature (258C) in an ostrich blood vessel model developed to test post-mortem 'tissue fixation' by cross-linking or peroxidation. HB-induced solution hypoxia coupled with iron chelation enhances preservation as follows: HB þ O 2 . HB 2 O 2 . 2O 2 þO 2 . The well-known O 2 /haeme interactions in the chemistry of life, such as respiration and bioenergetics, are complemented by O 2 /haeme interactions in the preservation of fossil soft tissues.

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Section: Discussionmentioning

confidence: 99%

A role for iron and oxygen chemistry in preserving soft tissues, cells and molecules from deep time

Schweitzer¹,

et al. 2014

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“…Nucleation is one of the most important processes to understand self-assemblyp athways in biological anda rtificial supramolecular assemblies. [1][2][3][4][5] The nucleation-elongation mechanism hasr ecently been ak ey concept to realize sophisticated supramoleculars ystemsi nt he solution phase. [6][7][8][9] Meijer et al reportedasupramolecular assembly with ak inetically controlled chirality that eventually convertsi nto the thermodynamically stable opposite chirality during growth of the supramolecular assembly.…”

Section: Introductionmentioning

confidence: 99%

Investigation on the Surface‐Confined Self‐Assembly Stabilized by Hydrogen Bonds of Urea and Amide Groups: Quantitative Analysis of Concentration Dependence of Surface Coverage

Nishitani

Hirose

Matsuda

2015

Chemistry An Asian Journal

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Formation of a hydrogen-bond network via an amide group is a key driving force for the nucleation-elongation-type self-assembly that is often seen in biomolecules and artificial supramolecular assemblies. In this work, rod-coil-like aromatic compounds bearing an amide (1 a-3 a) or urea group (1 u-3 u) were synthesized, and their self-assemblies on a 2-D surface were investigated by scanning tunneling microscopy (STM). According to the quantitative analysis of the concentration dependence of the surface coverage, it was revealed that the strength of the hydrogen bond (i.e., amide or urea) and the number of non-hydrogen atoms in a molecular component (i.e., size of core and length of alkyl side chain) play a primary role in determining the stabilization energy during nucleation and elongation processes of molecular ordering on the HOPG surface.

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“…One of the classic examples of a structure-directed reaction of proposed prebiotic relevance is the conversion of hydrogen cyanide to heterocycles including adenine. [7][8][9][10][11][12][13][14] Tetrapyrrole macrocycles have been suggested as valuable photoactive constituents in the evolution if not the origin of life. 5 A more recent example concerns the formation of nucleotides from simple constituents.…”

Section: Introductionmentioning

confidence: 99%

Complexity in structure-directed prebiotic chemistry. Effect of a defective competing reactant in tetrapyrrole formation

et al. 2015

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Chemical reactions in prebiotic environments likely entailed complex combinatorial processes with mixtures of reactants. As a case study, the effect of a defective reactant has been examined in a chemical model for the prebiogenesis of tetrapyrrole macrocycles (uroporphyrins). The latter are formed by a multistep process that includes (1) condensation of a b-diketone and an a-aminoketone to form a pyrrole, (2) self-condensation of the pyrrole to form a bilane (tetrapyrromethane), (3) cyclization of the bilane to form a porphyrinogen, and (4) oxidation of the porphyrinogen to form the porphyrin. A defective b-diketone (acetylacetone) affords a pyrrole that can react with nascent oligopyrromethane chains and in so doing terminate chain growth. Quantitative studies show that the porphyrin yield decreases with the fourth power of the mole fraction of the non-defective reactant. Mass spectral examination of the reaction mixture revealed the presence of the pyrrole and of end-capped oligomers derived from the defective diketone. Taken together, the results show the poisoning effect of a small amount of defective reactant in repetitive, irreversible structure-directed reactions, which have been a mainstay in thinking about chemistry leading to the origin of life.Scheme 1 Abiotic pathway to tetrapyrrole macrocycles.Chart 1 Pyrrole structural features required for self-condensation (top) and pyrroles lacking such features (bottom).

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Abiotic formation of uroporphyrinogen and coproporphyrinogen from acyclic reactants

Cited by 44 publications

References 43 publications

A role for iron and oxygen chemistry in preserving soft tissues, cells and molecules from deep time

A role for iron and oxygen chemistry in preserving soft tissues, cells and molecules from deep time

Investigation on the Surface‐Confined Self‐Assembly Stabilized by Hydrogen Bonds of Urea and Amide Groups: Quantitative Analysis of Concentration Dependence of Surface Coverage

Complexity in structure-directed prebiotic chemistry. Effect of a defective competing reactant in tetrapyrrole formation

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