Res. Chem. Intermed.
, Vol. 29, No. 3, pp. 325– 333 (2003)
Also available online - www.vsppub.com
Radical decomposition of
N,N-bis-(3-chloro-1,4-naphthoquinon-2-yl) amine in basic
conditions followed by EPR
, ALEXANDER I. SHAMES
and SHMUEL BITTNER
Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
Department of Physics, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel
Received 6 January 2003; accepted 22 January 2003
Abstract—EPR spectroscopy was used to assess the radicals produced upon basic decomposition
bis-(3-chloro-1,4-naphthoquinon-2-yl) amine (BClNQA). Three radicals have been trapped
and identi ed: N
-bis(3-chloro-1,4-naphthoquinone) hydrazine radical (6), 2-hydroxy-3-chloro-1,4-
naphthoquinoneanion radical (9) and 2-amino-3-chloro-1,4-naphthoquinone radical (8). The probable
reaction mechanism, the structure of intermediates as well as the reaction pro le are discussed.
: EPR; quinones; anion radical; basic fragmentation.
Quinonic drugs are widely used in chemotherapy, including that of cancer [1, 2],
bacterial  and fungal diseases . The current supposition is that radical forma-
tion by the quinones is responsible for their medicinal activity. Indeed, the most
characteristic feature of the quinones is their ability to undergo either chemical or
enzymatic reversible oxidation-reduction to form semiquinone (QH
quently reactive oxygen-radical species (ROS). These ROS react with DNA, pro-
teins, lipids and other cell structures . On the other hand, quinonic systems are
essential for life. Many biological chain systems, such as photosynthesis, oxida-
tive phosphorylation and blood coagulation, use quinones to transfer one or two
electrons . In vivo simulations of quinonic radicals can be achieved using chem-
ical [7, 8], electrochemical [9 – 12], photochemical  or ash photolytic meth-
ods [14, 15].
To whom correspondenceshould be addressed. Phone: (972-8) 646-1195. Fax: (972-8) 647-2943.