1. Prebiotic Chemistry and the Origin of Life
Prebiotic Chemistry and the Origin of Life. The possible role of UV radiation
Claudia Crestini, Dipatimento di Scienze e Tecnologie Chimiche, Tor Vergata University, Rome, Italy
Raffaele Saladino, Dipartimento di Agrobiologia ed Agrochimica, Università della Tuscia, Viterbo, Italy.
 WUTA08
1st Italian Workshop on UltraViolet Techniques and Applications

2. The RNA World Hypothesis
Time diagram for the origin of the first cell tra i vari processi un fenomeno rilevante sintesi biomolecole necessarie per la nascita del primo organismo chimica prebiotica
Tra le biomolecole fondamentali per l’origine della vita gli acifdi nucleici hanno un ruolo rilevante in quanto conservano e trasferiscono l’informazione geneticaPrebiotic chemistry section of Origin of informational polymers
Joyce, G.F. (2002) Nature 418,
Prebiotic chemistry: synthesis of biological molecules necessary for the birth of the first living cell
Origin of informational polymers
 Claudia Crestini - WUTA08

3. Heterotrophic theory A primordial soup of simple molecules arose first
driven by non biological energy like radiation or heat
assembled in complex molecules and
led to primitive life forms
Heterotrophic theory tra le teorie più studiate suggerita per la prima volta in the
 Claudia Crestini - WUTA08

4. A heterotrophic origin of life?
Reducing atmosphere
Biomolecules synthesis
Precursori chimici elementari si formano mediante reazioni nell’atmosfera prebiotica si concentrano nella prebiotic soup dove avvengono trasformazioni più complesse fino
Prebiotic soup
Complex molecules
 Claudia Crestini - WUTA08

5. Formamide as prebiotic probe
“Simulations based on Density Functional Theory show that
formamide is the most stable species with molecular formula “CHON”
Pauzat, F. et al. 6th EANA 2006
“This one-carbon molecule was detected in the gas phase of
interstellar medium” Crovisier, J. Astrobiology: Future Perspectives,
Kluwer Eds, 2004 Chapter 8, p
“in the long period comet Hale-Bopp“ Bockelee-Morvan,D. et al. Astr. Astrophys
“and tentatively in the solid phase on grains around the young stellar object W33A “
W.A. Schutte et al. Astr. Astrophys
 Claudia Crestini - WUTA08

6. Formamide. Phisical and Chemical properties
“Formamide has a high boiling point, without azeotropic effects, and a wide range of
uses as a solvent. It has an efficient solubilizing effect on nucleobases, nucleosides,
nucleotides, amino acids, proteins, sugars, metalsand salts”
Becker, B. J. Chem. Eng. 1970
Colloids and surfacesA: Physicochem Eng. Aspects 2003
219:
A comparison of micelle formation of ionic
surfactants in formamide, in N-methylformamide
and in N, N-dimethylformamide.
M.Salim Akhter, Sadeq M. Alawi
Langmuir Jan 20;20(2):
Solvation dynamics of formamide and
N, N-dimethylformamide in aerosol OT reverse micelles.
Shirota H, Segawa H.
 Claudia Crestini - WUTA08

7. Elemental formamide chemistry
Formata da ossidi per scarica elettrica o da hcn idrolisi che è uno dei precursori chimici
(A)
(B)
 Claudia Crestini - WUTA08

8. The mineral Honeycomb
Role of minerals metals and metal oxides in prebiotic chemistry
La reattività della formammide può essere tunata da metalli e ossidi metallici
 Claudia Crestini - WUTA08

9. The role of minerals and metal oxides on prebiotic processes
The role of minerals and metal oxides on prebiotic processes. A general overview
Minerals can accumulate the prebiotic precursors (concentration effect)
Minerals can act as catalytic environments, reducing the activation energy for the formation of products
Minerals can tune the selectivity of prebiotic syntheses
Minerals may act as a template
Minerals are benign environments to preserve newly formed biomolecules from degradation
 Claudia Crestini - WUTA08

10. Claudia Crestini - WUTA08
Bioorganic Med. Chem. 9 (2001) A Possible Prebiotic Synthesis of Purine, Adenine, Cytosine, and 4(3H)-Pyrimidinone From Formamide: Implications for the Origin of Life Raffaele Saladino, Claudia Crestini, Giovanna Costanzo, Rodolfo Negri and Ernesto Di Mauro
Sintetizzate contemporaneamente
 Claudia Crestini - WUTA08

11. Analyzing the reaction mechanism
Analyzing the reaction mechanism. 13C/15N-NMR Experiments “route of the purine ring”
Nella sintesi di alcune di queste molecole sono coinvolti anche hcn e ammonia che si formano…
 Claudia Crestini - WUTA08

12. Analyzing the reaction mechanism. “route of the pyrimidine ring”
Pyrimidine nucleobases require a redox stage for their synthesis
 Claudia Crestini - WUTA08

13. Toward an extraterrestrial synthesis of nucleobases
Extraterrestrial minerals, cda
Draco constellation
Anselm Kiefer
High Museum of Art
Atlanta, USA

14. Cosmic dust Claudia Crestini - WUTA08
Cdas are amorphous materials composed mainly by silica magnesium iron and other heavy metals
 Claudia Crestini - WUTA08

15. Cosmic dust analogues preparation
(Fayalite) 1)
Fe2SiO4* 2)
Mg0.5Fe1.5SiO4 * 3)
MgFeSiO4 * (Olivine)
SiO2, MgO,
FeO2 4)
Mg1.5Fe0.5 SiO4 *
Laser Ablation 5)
Mg2SiO4 * (Fosferite)
Cosmic dust not available. Laser ablation for cdas in collaboration
Cosmic dust analogue olivines (Mg,Fe)2SiO4 are synthesized by laser ablation technique (Nd-YAG 108 Wcm-2). Oxide pellets of MgO, FeO2, SiO2 are used as laser target vaporized in 10 mbar atmosphere of O2.
Brucato, J. R. et al in The Astronomy and Astrophysics Review, Volume 11,
Issue 2-3, pp (2003)
 Claudia Crestini - WUTA08

16. Synthesis and Degradation of Nucleic Acid Components by
ChemBioChem 6 (2005)
Synthesis and Degradation of Nucleic Acid Components by
Formamide and Cosmic Dust Analogues
Raffaele Saladino, Claudia Crestini, Veronica Neri, John R. Brucato, Luigi Colangeli, Fabiana Ciciriello, Giovanna Costanzo, and Ernesto Di Mauro
Fe Si Mg
fayalite
forsterite
olivine
CDAs qualitative composition
mAInly pyrimidines
DHU:5,6-DiHydroUracil
 Claudia Crestini - WUTA08

17. Synthesis and Degradation of Nucleic Acid Components by
ChemBioChem 6 (2005)
Synthesis and Degradation of Nucleic Acid Components by
Formamide and Cosmic Dust Analogues
Raffaele Saladino, Claudia Crestini, Veronica Neri, John R. Brucato, Luigi Colangeli, Fabiana Ciciriello, Giovanna Costanzo, and Ernesto Di Mauro
Yield defined as mg of product
per gram of formamide.
Fe Si Mg
fayalite
forsterite
olivine
mg/g
Selectivity tuned by the elemental composition of the catalyst. Cdas * cytosin in higher amount thant terrestrian analogues. Cytosyne decrease decreasing iron in the catalyst compositon in accord with the hypothesized redox step in the general mechanism for pyrimidine nucleobases formation
 Claudia Crestini - WUTA08

18. Moving towards nucleosides
Photocatalysts for the synthesis of nucleosides. Nucleosides are the building …

19. From Formamide: Implications for the Origin of Life
ChemBioChem 4 (2003)
One-pot TiO2-Catalyzed Synthesis of Nucleic Bases and Acyclonucleosides
From Formamide: Implications for the Origin of Life
Raffaele Saladino,a,* Claudia Crestini,b Umberto Ciambecchini,a Rodolfo Negri,c Giovanna Costanzo,c Ernesto Di Mauro c,
With tio2 a large array of nucleobases adenine, cytosine and tymine and 3 acyclonucleosides in which a purine nucleotide is linked to a sugar in the side chain
Adenine, cytosine and thymine
3 acyclonucleosides
 Claudia Crestini - WUTA08

20. Thymine synthetic pathway
R. H. Barker, 1975
In the synthesis of nucleobases and nucleosides formaldehyde generated in situ by hconh2 degradation plays a relevant role unica sintesi one pot della timina descritta in letteratura che è una delle basi più importanti
Unic known one pot synthesis of thymine!
 Claudia Crestini - WUTA08

21. Thymine from formamide
Present day biosynthesis of thymidine
La sintesi è simile alla via biosintetica alla timidina nella cellula
 Claudia Crestini - WUTA08

22. Nucleosides from formamide
Compd 9
Compd 10
In alta reasa
 Claudia Crestini - WUTA08
Compd 11

23. Sugars synthetic pathway. The formose reaction. Butlerow, 1861.
spiegare
Single headed arrows represent aldol
Condensations. Double-headed arrows
represent enolizations. Aldotreose can
undergo a reverse aldol condensation
 Claudia Crestini - WUTA08

24. A novel formose reaction
Unic known prebiotic syntesis of nucleosides!
Activated formaldehydeunica sintesi nota di nucleosidi in condizioni prebiotiche
 Claudia Crestini - WUTA08

25. Exploring the role of UV-radiation in prebiotic chemistry
Up to now a volcanic scenario. A similarscenario could occur by uv irradiatiation

26. UV radiation in prebiotic chemistry. Pioneering studies
Uv ray miller pionier dimer trimer diamminomalonitril hn cyclize key imidazole intermediate
Diamminomalononitril cyclization to a key imidazole intermediate
 Claudia Crestini - WUTA08

27. UV radiation in prebiotic chemistry. Pyrimidine From Cyanoacetaldehyde
30-50% yield hn
Pyrimidine by hn from cianoacetaldehydehn double bond isomerization for cytosine ring closure
Double bond isomerization for cytosine ring closure
M. P. Robertson, S. L. Miller Nature 1995, 972.
 Claudia Crestini - WUTA08

28. UV radiation in prebiotic chemistry. Glyoxal From formaldehyde
H. Mordehai BioSystems 1979, 11(4),
 Claudia Crestini - WUTA08

29. Exploring the role of UV-radiation on formamide prebiotic chemistry
Formamide chemistry nearly no data for uv radiation

30. Senanayake, S. D. and Idriss, H. (2006) PNAS. USA 103
Photocatalysis and the origin of life: Synthesis of nucleoside bases from Formamide on TiO2(001) single surface.
Senanayake, S. D. and Idriss, H. (2006) PNAS. USA 103
Confirmed our studies on uv radiation. All nucleobases synthesizaed our interest is to develop novel prebiotic chemistry of nucleic acids based on formamide under uv irradiation in the presence of ninerals or selected organic compounds that can act as photocatalysts we hope that the syncrotone facility can be used for this novel approach toesobiology.
Uncorrected peak areas of desorbing products
The surface structures of TiO2 (001) single crystal

31. Exploring the role of UV-radiation on formamide prebiotic chemistry
our interest is to develop novel prebiotic chemistry of nucleic acids based on formamide under uv irradiation in the presence of minerals or selected organic compounds that can act as photocatalysts.
we hope that the syncrotron facility can be used for this novel approach to esobiology
 Claudia Crestini - WUTA08

32. Thank you for the kind attention!