title: Clemens von Sonntag and the early history of radiation-induced sugar damage in DNA.
abstract: OBJECTIVE
  This article reviews the early history of ionizing radiation-induced sugar damage in DNA in dedication to Prof. Clemens von Sonntag, who recently passed away. It covers the time between 1968 and 1978, during which most of the work on the ionizing radiation-induced damage to polyalcohols, carbohydrates and the 2'-deoxyribose moiety in DNA was performed. Methodologies using gas chromatography-mass spectrometry (GC-MS) were developed to identify and quantify the radiation-induced products that had previously remained elusive. Products were identified by GC-MS either directly or after reduction of samples with NaBH(4) or NaBD(4). Incorporation of deuterium atoms by NaBD(4)-reduction facilitated the identification of aldehyde, keto, carboxyl and deoxy groups in the molecules. Numerous products of a polyalcohol and carbohydrates were identified and quantified. Mechanisms of product formation were proposed. Several products of the 2'-deoxyribose moiety in DNA were identified, indicating that they were released from DNA strand, not bound to it. Alkali labile sites and products still remaining within DNA or bound to DNA as end groups were also elucidated by first reducing irradiated samples with NaBD(4) followed by alkali treatment and GC-MS analysis.
  
  
  CONCLUSIONS
  The knowledge of the products of the 2'-deoxyribose moiety in DNA led to the first mechanistic understanding of various pathways of hydroxyl radical-induced DNA strand breakage. To this date, some of these mechanisms still remain the most-widely studied mechanisms of DNA damage. Prof. von Sonntag's contributions to the understanding of the radiation chemistry of carbohydrates and DNA helped shape this field of science for years to come.
authors.affiliation: Biomolecular Measurement Division, National Institute of Standards and Technology , Gaithersburg, MD , USA.
authors.forename: Miral
authors.initials: M
authors.lastname: Dizdaroglu
mesh_terms: D004247:DNA / Q000737:chemistry / Q000266:history* / Q000528:radiation effects; D053960:DNA Breaks; D004249:DNA Damage; D003855:Deoxyribose / Q000737:chemistry / Q000528:radiation effects; D004896:Erythritol / Q000737:chemistry / Q000528:radiation effects; D005720:Gamma Rays / Q000009:adverse effects; D008401:Gas Chromatography-Mass Spectrometry; D005858:Germany; D049673:History, 20th Century; D008956:Models, Chemical; D011854:Radiochemistry / Q000266:history*
chemical_list: D003855:Deoxyribose; D004247:DNA; D004896:Erythritol
keywords: DNA damage; free radicals; radiation chemistry