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 mum 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 nuC=C vibrations of the naphthyl ring. The presented results are of relevance for the investigation and extraction of new antimalarial active agents.

[1]  G. Bringmann,et al.  The absolute stereostructure of dioncophylline a by anomalous X-ray dispersion of a 5-bromo derivative , 1997 .

[2]  William G. Fateley,et al.  Characteristic Raman frequencies of organic compounds , 1974 .

[3]  M. Halls,et al.  Harmonic frequency scaling factors for Hartree-Fock, S-VWN, B-LYP, B3-LYP, B3-PW91 and MP2 with the Sadlej pVTZ electric property basis set , 2001 .

[4]  J. Holenz,et al.  Naphthylisoquinoline alkaloids against malaria: evaluation of the curative potentials of dioncophylline C and dioncopeltine A against Plasmodium berghei in vivo , 1997, Antimicrobial agents and chemotherapy.

[5]  G. Bringmann,et al.  Dioncophylline C from the roots of Triphyophyllum peltatum, the first 5,1′-coupled dioncophyllaceae alkaloid , 1992 .

[6]  Gerhard Bringmann,et al.  In vitro inhibition of liver forms of the rodent malaria parasite Plasmodium berghei by naphthylisoquinoline alkaloids – structure-activity relationships of dioncophyllines A and C and ancistrocladine , 1997, Parasitology Research.

[7]  S. Langhoff,et al.  The Calculation of Accurate Harmonic Frequencies of Large Molecules: The Polycyclic Aromatic Hydrocarbons, a Case Study , 1997 .

[8]  J. Popp,et al.  FT-Raman investigation of alkaloids in the liana Ancistrocladus heyneanus. , 1998, Biospectroscopy.

[9]  Gerhard Bringmann,et al.  3D QSAR Investigations on Antimalarial Naphthylisoquinoline Alkaloids by Comparative Molecular Similarity Indices Analysis (CoMSIA), Based on Different Alignment Approaches , 2003, J. Chem. Inf. Comput. Sci..

[10]  M. A. Strehle,et al.  The application of a SERS fiber probe for the investigation of sensitive biological samples. , 2004, The Analyst.

[11]  G. Bringmann,et al.  Dioncopeltine A and dioncolactone A: Alkaloids from Triphyophyllum peltatum☆ , 1991 .

[12]  G. Bringmann,et al.  On the structure of the dioncophyllaceae alkaloids dioncophylline a (“triphyophylline”) and “O-Methyl-Triphyophylline” , 1990 .

[13]  K. Raynes.  Bisquinoline antimalarials: their role in malaria chemotherapy. , 1999, International journal for parasitology.

[14]  Jürgen Popp,et al.  Raman spectroscopy--a prospective tool in the life sciences. , 2003, Chemphyschem : a European journal of chemical physics and physical chemistry.

[15]  Derek A. Long,et al.  The Raman Effect , 2002 .