CIDNP and EPR Study of Phototransformation of Lappaconitine Derivatives in Solution

CIDNP and EPR Study of Phototransformation of Lappaconitine Derivatives in Solution Full article

Journal

Journal of Physical Chemistry B
ISSN: 1520-6106

Output data

Year: 2010, Volume: 114, Number: 13, Pages: 4646-4651 Pages count : 6 DOI: 10.1021/jp909166r

Authors

Polyakov Nikolay E. ¹ , Simaeva Olga A. ¹ , Taraban Marc B. ¹ , Leshina Tatyana V. ¹ , Konovalova Tatyana A. ² , Kispert Lowell D. ² , Nikitina Irina A. ^3,4 , Pankrushina Natalia A. ^3,4 , Tkachev Alexey V. ³

Affiliations

1	(Данные Web of science) Russian Acad Sci, Inst Chem Kinet & Combust, Novosibirsk 630090, Russia
2	(Данные Web of science) Univ Alabama, Dept Chem, Tuscaloosa, AL 35487 USA
3	(Данные Web of science) Novosibirsk Organ Chem Inst, Novosibirsk 630090, Russia
4	(Данные Web of science) NSU, Res & Educ Ctr Mol Design & Ecologically Safe Tec, Novosibirsk 630090, Russia

Chemically induced dynamic nuclear polarization (CIDNP) and electron paramagnetic resonance (EPR) techniques have been used to study the paramagnetic species formed during the photolysis of the alkaloid lappaconitine and its synthetic analogues in solution. Lappaconitine is a photosensitive antiarrhythmic and hypertension drug, whose major photoproduct (N-acetyl anthranilic acid) is also a potent photosensitizer. Both these compounds are lipophilic and might bind efficiently to cell membranes thereby causing phototoxic damage. Photolysis of natural lappaconitine (1) as well as its N(20) des-ethyl derivatives (N-Bz (H), N-Me (III), N-H (IV), and N(O)-Et (V)) results in cleavage of the ester bond with the formation of N-acetyl anthranilic acid (VIII) and corresponding enamine. The lappaconitine derivative V shows maximum photostability which correlates with reference data about its low toxicity. It was shown that the primary reaction step is electron transfer from the amino group to the anthranilic fragment of lappaconitine resulting in an intermediate biradical. The final products are formed via fragmentation of the neutral lappaconitine radicals.

Polyakov N.E. , Simaeva O.A. , Taraban M.B. , Leshina T.V. , Konovalova T.A. , Kispert L.D. , Nikitina I.A. , Pankrushina N.A. , Tkachev A.V.
CIDNP and EPR Study of Phototransformation of Lappaconitine Derivatives in Solution
Journal of Physical Chemistry B. 2010. V.114. N13. P.4646-4651. DOI: 10.1021/jp909166r WOS Scopus РИНЦ

Published online:	Mar 16, 2010
Published print:	Apr 8, 2010

Web of science	WOS:000276096600031
Scopus	2-s2.0-77950568573
Elibrary	15335812
OpenAlex	W1967978528