Antimicrobial activity of confertifolin from<i>Polygonum hydropiper</i>

Confertifolin (6,6,9a-trimethyl-4,5,5a,6,7,8,9,9a-octahydronaphtho[1,2-c] furan-3 (1H)-one) was isolated from the essential oil of Polygonum hydropiper L. (Polygonaceae) leaves using column chromatography. Confertifolin showed activity both in bacteria and fungi. The lowest MIC for bacteria was observed against Enterococcus faecalis (31.25 μg/mL). Significant MIC for fungi was observed against Scopulariopsis sp (7.81 μg/mL), Curvularia lunata (7.81 μg/mL), Epidermophyton floccosum (7.81 μg/mL), Trichophyton mentagrophytes (16.62 μg/mL), Trichophyton rubrum (MTCC 296) (16.62 μg/mL), Aspergillus niger (31.25 μg/mL), Botrytis cinerea (31.25 μg/mL) Magnaporthe grisea (62.5 μg/mL), Trichophyton simii (125 μg/mL) and Trichophyton rubrum (clinical isolate) (125 μg/mL).