Rapid identification of cyclic Tetrapyrrolic Photosensitisers for Photodynamic therapy using on-line hyphenated LC-PDA-MS coupled with photo-cytotoxicity assay

• Main Authors: Tan, P.J., Appleton, D.R., Mustafa, Mohd Rais, Lee, H.B.
• Format: Article
• Language: English
• Published: 2011
• Subjects: R Medicine
• Online Access: http://eprints.um.edu.my/3032/1/Rapid_Identification_of_Cyclic_Tetrapyrrolic.pdf; http://eprints.um.edu.my/3032/; http://onlinelibrary.wiley.com/doi/10.1002/pca.1324/full

Introduction � Photodynamic therapy is a treatment modality that involves site�directed generation of cytotoxic reactive oxygen species by light�activated photosensitisers. Objective � In order to rapidly identify new photosensitisers from natural extracts, we developed a liquid chromatography�photodiode array�mass spectrometry (LC�PDA�MS) method to rapidly identify plant extracts that contain photosensitisers, particularly those possessing a cyclic tetrapyrrole structure. Method � Six previously isolated compounds (1�6) were identified in bioactive fractions derived from 15 plant extracts on the basis of their chromatographic retention times, UV�visible profiles, accurate mass and fragmentation patterns. Results � Samples containing uncommon photosensitisers were rapidly identified using this method, and subsequent scale�up isolation efforts led to two new compounds (7 and 8) which were confirmed to be active photosensitisers in a photo�cytotoxicity assay. Conclusion � This method serves as a useful tool in prioritising samples that may contain new photosensitisers out of a larger group of photo�cytotoxic natural products extracts. Copyright © 2011 John Wiley & Sons, Ltd.