New antifungal prenylated flavanones from Colutea armata

Colucons A (1) and B (2), new prenylated flavanones, isolated from the EtOAc-soluble sub-fraction of the whole plant of Colutea armata Hemsl. & Lace along with four known compounds, namely, kenusanone J (3), hesperetin (4), tyrosol (5) and syringaldehyde (6), were reported for the first time from the species armata. Their structures were elucidated by spectroscopic techniques including H-1 and C-13 NMR (distortionless enhancement by polarization transfer), and 2D NMR experiments. Compounds 1-3 showed significant antifungal activity against Pseudallescheria boydii, Aspergillus niger, Trichophyton mentagrophytes, Macrophomina phaseolina and Candida glabrata, while compound 4 showed moderate antifungal activity.