In vivo localization and identification of the antiplasmodial alkaloid dioncophylline A in the tropical liana Triphyophyllum peltatum by a combination of fluorescence, near infrared Fourier transform Raman microscopy, and density functional theory calculations

Near infrared Fourier transform (NIR FT) micro Raman spectroscopy in combination with density functional theory (DFT) calculations has been applied for an in vivo localization of the antiplasmodial naphthylisoquinoline alkaloid dioncophylline A ( 1 ) in the tropical liana Triphyophyllum peltatum . Fluorescence microscopy images suggest finding this active agent in 10 μm big inclusions located in the cortex of the stem or the beginning of the leaves. By means of spatially resolved FT Raman micro spectroscopy, we could detect dioncophylline A ( 1 ) in these inclusions. FT Raman spectroscopy is an extremely selective tool capable of differentiating between various structurally similar naphthylisoquinoline alkaloids. With the help of DFT calculations, we succeeded in assigning the differences found in the FT Raman spectra of the various naphthylisoquinolines to νCC vibrations of the naphthyl ring. The presented results are of relevance for the investigation and extraction of new antimalarial active agents. © 2006 Wiley Periodicals, Inc. Biopolymers 82: 295–300, 2006 This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com