Detection of antifungal activity in Belamcanda chinensis by a single-cell bioassay method and isolation of its active compound, tectorigenin.

The antifungal activity of Belamcanda chinensis was evaluated by a single-cell bioassay method. An active fraction was separated by silica gel column chromatography and reverse-phase HPLC. The isolated compound was found to be identical to tectorigenin (5,7-dihydroxy-3-(4-hydroxy phenyl)-6-methoxy-4H-1-benzopyran-4-one) which has formerly appeared in the literature without any remarks on its antimicrobial activity. Antimicrobial activity was investigated against 17 strains of fungi and 6 strains of bacteria. This compound showed marked antifungal activity against dermatophytes of the genera Trichophyton, the minimum inhibitory concentration (MIC) being in the range of 3.12-6.25 mg/ml.