Planta Med 2014; 80 - P1L142
DOI: 10.1055/s-0034-1394799

Chemical characterization and antifungal photodynamic effect of methanolic extract and alkaloidal fraction isolated from callus culture of Annona squamosa (Annonaceae)

C Caramano de Lourenço 1, MJ Salvador 2
  • 1PPGBV, DBV, Institute of Biology, State University of Campinas (UNICAMP), Campinas (SP), Brazil
  • 2PPGBTPB e PPGBV, DBV, Institute of Biology, Facult of Pharmaceutical Science, State University of Campinas (UNICAMP), Campinas (SP), Brazil

Most secondary metabolites are present in small quantities in plants thus techniques of plant tissue culture are being implemented to increase the production of this compounds. The Annona squamosa is an arboreal species chemically characterized by the presence of alkaloids [1] those have been applied as natural photosensitizers in antimicrobial photodynamic inactivation (PDI) [2]. The aim of this study was to characterize chemically the methanolic extract and alkaloidal fraction isolated from callus culture of A. squamosa and to evaluate their photodynamic effects against yeast. The extract and fraction were obtained according to [3] and showed absortion from 390 to 660nm. Also, singlet molecular oxygen (1O2) production was examined by 1,3-diphenylisobenzofuran test and showed production of singlet oxygen. In antifungal assays, the methanol crude extract and alkaloidal fraction were tested, in sub-inhibitory concentration, against Candida albicans ATCC 10231 and Candida tropicalis ATCC 157. One plate (n = 6) was subjected to irradiation with a 660nm diode laser with an output power of 35 mW, distributed through the well cross section yielding an energy dosage of 28J/cm2, and one was not irradiated. Laser irradiation alone at 660nm, or non-irradiated samples in sub-inhibitory concentration didn't reduce the number of CFU/mL significantly, whereas the photoactivation of irradiated extracts, in sub-inhibitory concentrations, had a considerable antifungal effect. The chemical profiles of the extract and fraction were obtained by direct injection ESI-MS and HPLC-MS/MS confirmed by comparing the profile of the standard alkaloids. The alkaloids identified in these bioactive samples of callus culture were anonaine, assimilobine, liriodenine, lysicamine and palmatine. Further investigations are necessary to confirm the potential of these natural products as photosensitizers in PDI.

Acknowledgmens: CAPES, CNPq, FAEPEX-Unicamp and FAPESP.

Keywords: Annonaceae, Photodynamic Inativation, Alkaloids

References:

[1] Araya, H. et al. Squamocin-O(1) and squamocina-O(2), new adjacent bis-tetrahydrofuran acetogenins from the seeds of Annona squamosa. Phytochemistry, 8: 999 – 1004. 2002.

[2] Wainwright, M. Photosensitisers in biomedicine.John Wiley & Sons, 2009.

[3] Costa, E. V. et al. Alkaloids from the Bark of Guatteria hispida and their Evaluation as Antioxidant and Antimicrobial Agents. Journal of Natural Products, 73: 1180 – 1183, 2010.