Isolation of taxol producing endophytic fungus Alternaria brassicicola from non-Taxus medicinal plant Terminalia arjuna.

In the present study, an endophytic fungal strain was isolated from its non-Taxus host plant Terminalia arjuna and identified as Alternaria brassicicola based on its morphological characteristics and internal transcribed spacer sequence analysis. This fungus was grown in potato dextrose broth and analyzed for the presence of taxol by using chromatographic and spectrometric techniques. The ethyl acetate extract of A.brassicicola was subjected to column chromatography. Among the different fractions, the fraction 7 showed positive to taxol, which was further confirmed by UV absorption, HPLC, FTIR spectra and LC-ESI-MS by comparing with the authentic taxol (Paclitaxel). The peaks of fraction 7 obtained by UV spectroscopy, FTIR and HPLC analysis were quite similar to that of standard taxol confirming the presence of taxol. A parent ion peak of m/z 854.95 was observed in the LC-ESI-MS spectrum which was similar to paclitaxel with reported m/z of 854 [M+H]⁺ ion. A. brassicicola produced about 140.8 μg/l taxol as quantified through HPLC. Present study results suggest that the endophytic fungus A.brassicicola serves as a potential source for the production of taxol isolated from non-Taxus plant.