UV Study

Here's some more support for the idea that UV played a vital role in
every aspect of the OOL

Formation and Photo-Stability of Pyrimidine Derivatives from the UV
Irradiation
of Pyrimidine in Ices
Michel Nuevo1, Stefanie Milam1,2, Scott Sandford1, Jamie Elsila3
1NASA Ames Research Center, Moffett Field, CA 94035, USA; 2,3NASA
Goddard Space
Flight Center, Greenbelt, MD 20771, USA
256 Orig Life Evol Biosph (2009) 39:179=96392
The detection of amino acids in organic residues formed by the UV
photolysis of ices
mimicking interstellar and cometary environments (H2O, CO, CO2, CH3OH,
NH3, etc.)
showed that molecules of prebiotic interest can form easily in space
(Bernstein et al. 2002;
Mu=F1oz Caro et al. 2002). This result agrees with the detection of
amino acids in meteorites
(Engel and Macko 1997; Cronin and Pizzarello 1997) although their
distribution appears to
be different (Nuevo et al. 2008), and the (still debated) detection of
glycine in molecular
clouds (Kuan et al. 2003; Snyder et al. 2005), supporting a scenario
where the organic
molecules required for life are of extraterrestrial (interstellar or
proto-planetary) origin, before
being delivered by asteroids, comets, micrometeorites and interstellar
dust particles on Earth.
Nucleobases, the building blocks of DNA, constitute another family of
prebiotic
compounds likely to be formed in space. Larger than amino acids, they
are expected to be
formed with smaller abundances, and their detection in organic
residues requires a
specific chemical analytical protocol. Small functionalized polycyclic
aromatic hydrocarbons
(PAHs), whose structures are close to some of the nucleobases, as well
as
nucleobases themselves have been detected in meteorites (Stoks and
Schwartz 1979;
Martins et al. 2004). The formation of nucleobase-like compounds from
the UV
irradiation of PAHs mixed in ices has been studied in the laboratory
(Bernstein et al.
1999, 2001).
In this work, we present a study of the formation of organic compounds
from the UV
irradiation of pyrimidine at low temperature in ices (H2O, NH3).
Pyrimidine (C4H4N2) is
the base molecule for three of the five biological nucleobases
(cytosine, thymine and
uracil), as well as many other derivative compounds. This work aims at
studying how
pyrimidine is affected by UV photons when it is mixed with precometary
ice analogs. In
particular, we show how pyrimidine leads to the production of oxidized
and amino
compounds including nucleobases using high-performance liquid
chromatography (HPLC),
and study the photo-stability of pyrimidine and its photo-products
when subjected to UV
photons.

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