Antidermatophytic prenylated coumarins from asafetida

Abstract

Asafoetida is a resinous substances with a smell similar to garlic, which is obtained by drying the exudates from various species of Ferula growing in northern Iraq and Iran and surrounding countries. It is widely used in cooking in India and is used medicinally for gastro-intestinal complaints and for treating skin diseases. The botanical source of commercial samples of asafoetida is not easy to determine since several species of Ferula exist. Samples of asafetida with proven source were obtained from the pharmacognosy museum of King's College London and compared with some commercial samples obtained from Asian shops in the UK, India and Syria. Samples were examined by TLC and for antifungal activity using serial dilution assay in microtitre plates with two dermatophytes, Microsporeum gypseum and Trichophyton interdigitale [1]. The most active sample was obtained from India and on TLC conformed most closely with a museum sample from F. foetida Regel. From this sample nine prenylated coumarins were isolated and were tested against the two fungal species. Four of the compounds exhibited strong antifungal activity against the dermatophytes with 5,8 dihydroxyumbelliprenin 1 being most active with MIC of 10mM, the positive control miconazole having MIC of 0.5mM. No compounds of this type have previously shown antifungal activity.