UV light generates guanine, inspires prebiotic research

Attempts to understand the building blocks of life on earth have been stymied by the elusiveness of the RNA base guanine (G). While RNA's other three bases–adenine (A), cytosine (C) and uracil (U)–can be generated by heating a simple precursor compound in the presence of certain naturally occurring catalysts, guanine has not been observed as a product of these reactions. Now researchers at the Georgia Institute of Technology and Sapienza University have shown for the first time that adding ultraviolet (UV) light to a model prebiotic reaction does the trick.1 The result is the knowledge that the chemical and environmental requirements to produce life are probably less restrictive than once thought.

Recent efforts to understand the prebiotic formation of the building blocks of RNA have focused on the chemical formamide (H2NCOH) as a potential starting material because it contains the four required elements–carbon, hydrogen, oxygen and nitrogen–and because of its stability, reactivity and low volatility compared to water. Previous reports have shown that these nucleic acid components (except guanine) can be synthesized by heating formamide to 160°C in the presence of mineral catalysts. The new research shows that subjecting a solution of formamide to UV during heating produces trace guanine, whose yield is boosted when minerals and photons are used together. In addition, production of adenine and a related molecule, hypoxanthine, also increased substantially when UV light was added along with heat.

Image courtesy Gary Meek

"These results potentially relax some of the requirements and reactions necessary to get life started, because formamide molecules would not have had to be in contact with a particular type of rock when heated on the prebiotic Earth, if the formamide was exposed to direct sunlight during heating," said Nicholas Hud, a professor in the Georgia Tech School of Chemistry and Biochemistry.

The study further demonstrated that guanine, adenine and hypoxanthine can be produced at 30°C less than previously reported, even in the absence of minerals, as long as photons are added.

"For these experiments, we built a very simple reaction chamber with an inexpensive 254 nm photon source to simulate conditions that could have been present on early Earth," explained Thomas Orlando, also a professor in Georgia Tech's School of Chemistry and Biochemistry. "We didn't need extremely sophisticated experimental systems or expensive lasers." Sophisticated mass spectrometers were needed, though, to analyze the resulting complex chemical mixtures.

1. H. Barks et al., ChemBioChem. 11 (9): 1240-1243 (2010)

More BioOptics World Current Issue Articles
More BioOptics World Archives Issue Articles

Get All the BioOptics World News Delivered to Your Inbox

Subscribe to BioOptics World Magazine or email newsletter today at no cost and receive the latest news and information.

 Subscribe Now
Related Articles

Wearable light therapy device for hair loss receives regulatory approval in Brazil

The iGrow hair growth system, a wearable low-level light therapy device for treating hair loss, is cleared for use in Brazil.

FDA authorizes emergency use of Zika virus molecular detection assay

The xMAP MultiFLEX Zika RNA assay combines optofluidics and digital signal processing to detect Zika virus in vitro.

Merz acquires laser tattoo removal device maker ON Light Sciences

Merz North America has acquired ON Light Sciences, which develops technologies to enhance laser-based dermatology procedures.

Shortwave-infrared device could improve ear infection diagnosis

An otoscope-like device that could improve ear infection diagnosis uses shortwave-infrared light instead of visible light.


Neuro15 exhibitors meet exacting demands: Part 2

Increasingly, neuroscientists are working with researchers in disciplines such as chemistry and p...

Why be free?

A successful career contributed to keeping OpticalRayTracer—an optical design software program—fr...

LASER Munich 2015 is bio-bent

LASER World of Photonics 2015 included the European Conferences on Biomedical Optics among its si...

White Papers

Understanding Optical Filters

Optical filters can be used to attenuate or enhance an image, transmit or reflect specific wavele...

How can I find the right digital camera for my microscopy application?

Nowadays, image processing is found in a wide range of optical microscopy applications. Examples ...



Twitter- BioOptics World

Copyright © 2007-2016. PennWell Corporation, Tulsa, OK. All Rights Reserved.PRIVACY POLICY | TERMS AND CONDITIONS