Isolation and Photophysical Properties of Di- and Tri-substituted Natural Anthraquinones from Malaysian Morinda citrifolia
Document Type
Article
Publication Date
1-1-2018
Abstract
Five di- and tri-substituted natural anthraquinones, i.e. nordamnacanthal (1), damnacanthal (2), rubiadin (3), 1-methoxy-2-methyl-3-hydroxyanthraquinone (4) and 1-hydroxy-3-methoxyanthraquinone (5) were subjected to photophysical studies. The results indicated that steric hindrance and intramolecular hydrogen bonding are important factors that affect absorption and emission spectral of these natural anthraquinones. Besides that, emission properties were significantly enhanced with formation of intramolecular hydrogen bonding in 1,3-dihydroxy-2-aldehyde tri-substituted anthraquinone 1. This gave rise to formation of two additional quasi aromatic rings extending the π-conjugation system in the anthraquinone structure.
Keywords
Absorption spectral, anthraquinone, emission spectral, intramolecular hydrogen bonding, photophysical properties
Divisions
CHEMISTRY
Funders
University Malaya Research Grant (UMRG; RP002A-13Bio and RP002B-13Bio),University of Malaya HIR grant (UM.C/625/1/HIR/MOHE/ ARTS01),Government of Malaysia MOSTI e-ScienceFund (SF004-2014),Government of Malaysia MOHE fund (MO002-2014),Postgraduate Research Fund of University Malaya (PG089-2014A and PG035-2015A)
Publication Title
Sains Malaysiana
Volume
47
Issue
5
Publisher
Penerbit Universiti Kebangsaan Malaysia