Photodegradation of methoxy substituted curcuminoids

Photodegradation of dimethoxy curcuminoids in acetonitrile solution was found to depend on the position of the methoxy group bonded to the phenyl ring. The rate of decomposition was expressed as the lifetime of the decomposing substrate, being the shortest in the case of the 3,5-diOCH3 and the longe...

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Bibliographic Details
Main Authors: Boris Sket, Petra Galer
Format: Article
Language:English
Published: Slovenian Chemical Society 2015-03-01
Series:Acta Chimica Slovenica
Subjects:
Online Access:https://journals.matheo.si/index.php/ACSi/article/view/1140
Description
Summary:Photodegradation of dimethoxy curcuminoids in acetonitrile solution was found to depend on the position of the methoxy group bonded to the phenyl ring. The rate of decomposition was expressed as the lifetime of the decomposing substrate, being the shortest in the case of the 3,5-diOCH3 and the longest for the 2,5-diOCH3 derivative. For the 3,5-diOCH3 curcuminoid, the major degradation products were 3,5-dimethoxy benzaldehyde, 3,5-dimethoxybenzoic acid and the Z and E isomers of dimethoxy cinnamic acid, together forming about 90% of the reaction mixture. Minor products found were 4,5-bis(3,5-dimethoxyphenyl)hex-2-endionic acid, and products with the molecular formula C23H24O6 and C23H22O6 attributed to the reaction of intramolecular 2+2 cycloaddition of the dimethoxy curcuminoid and the dioxygenated bicyclopentadione derivative (C23H24O8) derived from autoxidative transformation of the dimethoxy curcuminoid.
ISSN:1318-0207
1580-3155