The Photoaddition of a Psoralen to DNA Proceeds via the Triplet State

Psoralens are natural compounds that serve in the light dependent treatment of certain skin diseases (PUVA therapy). They are DNA intercalators that upon photoexcitation form adducts with thymine bases. For one psoralen derivative, 4′-aminomethyl-4,5′,8-trimethylpsoralen (AMT), the photoreactions ar...

Full description

Saved in:
Bibliographic Details
Published in:Journal of the American Chemical Society 2019-08, Vol.141 (34), p.13643-13653
Main Authors: Diekmann, Janina, Gontcharov, Julia, Fröbel, Sascha, Torres Ziegenbein, Christian, Zinth, Wolfgang, Gilch, Peter
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Psoralens are natural compounds that serve in the light dependent treatment of certain skin diseases (PUVA therapy). They are DNA intercalators that upon photoexcitation form adducts with thymine bases. For one psoralen derivative, 4′-aminomethyl-4,5′,8-trimethylpsoralen (AMT), the photoreactions are characterized here by nanosecond UV–vis and IR absorption spectroscopy. The triplet state of AMT is identified as the reactive one. On the 1–10 μs time scale this local triplet state transforms into a triplet biradical bearing one single bond between the addends. Within ∼50 μs this biradical forms the final adduct featuring a cyclobutane ring. This kinetic behavior is in stark contrast to the closely related photoaddition of two thymine moieties within the DNA. Origins of the differences are discussed.
ISSN:0002-7863
1520-5126
DOI:10.1021/jacs.9b06521