The alkaloid Berberine from Coscinium fenestratum is an inhibitor of phytopathogenic organisms

Fractionation of the crude extract of Hamp, Coscinium fenestratum (Gaertn) Colebr. (Menispermaceae), by column chromatography yielded 21 fractions which were tested for inhibition of the fungus Sphaceloma ampelinum de Bary, the causal organism of grape scab disease. The anti fungal test revealed that the active compound inhibited fungal growth and spore budding of the fungus. Fraction 12 and 13 showed antifungal activity with a concentration of 1,000–10,000 ppm by the diffusion and dilution method. Twenty one fractions were identified on TLC by using two solvent systems. Chloroform: acetone: methanol (6: 2: 2 v/v) and butanol: glacial acetic acid: distilled water (6: 3: 1 v/v) were used for fractions 1–12 and fractions 13–21, respectively. Observation of the TLC under UV at a wave length of 365nm revealed that the main component of fraction 12 and 13 had an RF value of 0.64 and it was the same value as the compound in crude extract.

The alkaloid was extracted from the crude extract by a chemical procedure. It was tested for antifungal activity and identified by TLC as the previous procedure. The result indicated that the alkaloid showed inhibition of the phytopathogenic fungus. The dose response of the alkaloid on fungal growth expressed by linear regression, indicated a positive relation between concentration and inhibition zone. The Rf value of the alkaloid was 0.7 which was very close to the Rf value of the major component in fractions 12 and 13. NMR was conducted to identify the chemical structure which was confirmed as the alkaloid berberine. The result of this study concluded that berberine is active against this pathogenic fungus.

Acknowledgements: Kasetsart University Research Development Institute, Kasetsart University, Bangkok, Thailand; Institute de Ciencias Biomedicas de Abel Salazar, University of Porto, Potugal