Guanine radical cation

Guanine radical cation
Identifiers
3D model (JSmol)	Interactive image;
ChemSpider	3037560;
PubChem CID	136111026;
	InChI InChI=1S/C5H5N5O/c6-5-9-3-2(4(11)10-5)7-1-8-3/h1H,(H4,6,7,8,9,10,11)/p+1 Key: UYTPUPDQBNUYGX-UHFFFAOYSA-O;
	SMILES C1=[NH+]C2=C(N1)C(=O)NC(=N2)N;
Properties
Chemical formula	C5H6N5O+
Molar mass	152.136 g·mol−1
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

A guanine radical cation, often noted as (G^•+), is a chemical species resulting from the DNA/RNA nucleobase guanine (G) following electron abstraction. Guanine radical cations are formed via chemical reactions with other molecules or, directly, under the effect of radiation.

From an electrical point of view, guanine radical cations are electron holes contributing to charge transport through the nucleic acids. More importantly, electron holes initially generated on other parts of the nucleic acid may migrate and ultimately be trapped by guanine sites, where they react.

The numerous downstream reaction products of (G^•+) provoke oxidative DNA damage, affecting various biological functions. In addition, several research projects explore their applications in fields such as photodynamic therapy and biosensor development. Both biological aspects and the technological uses involving (G^•+) are closely related to Guanine quadruplexes, whose building blocks are guanine tetrads.

The properties of (G^•+) and their reactivity are studied by spectroscopic, electrochemical, and conductometric techniques, as well as by quantum chemistry methods.