Alternaria alternata, an endophytic fungus capable of producing capsaicin (1) was isolated from Capsicum
annum. The endophyte was found to produce capsaicin upto three generations. Upscaling of the fermentation
broth led to the isolation of one known and one compound characterized as 2,4-di-tert-butyl
phenol (2) and alternariol-10-methyl ether (3) respectively. Compound 1 and 3 were identified and quantified
using liquid chromatography-electrospray ionization tandem mass spectrometry (LC–ESI–MS/MS)
system through multiple reaction monitoring (MRM). Furthermore, compound 3 displayed a range of
cytotoxicity against a panel of human cancer cell lines and was found to induce apoptosis evidenced
by Hoechst staining and loss of mitochondrial-membrane potential in HL-60 cells.