Antiprotozoal and Antiglycation Activities of Sesquiterpene Coumarins from Ferula narthex Exudate

The exudate of Ferula narthex Boiss. (Apiaceae) is widely used in the Indian subcontinent as a spice and because of its health effects. Six sesquiterpene coumarins have been isolated from this exudate: feselol, ligupersin A, asacoumarin A, 8′-O-acetyl-asacoumarin A, 10′R-karatavacinol and 10′R-acetyl-karatavacinol. Based on its use in infectious and diabetic conditions, the isolated constituents were evaluated for antimicrobial and antiglycation activities. Some compounds showed activity against protozoal parasites, asacoumarin A being the most active one against Plasmodium falciparum K1 (IC(50) 1.3 μM). With regard to antiglycation activity, in the BSA-glucose test, ligupersin A displayed the highest activity (IC(50) 0.41 mM), being more active than the positive control aminiguanidine (IC(50) 1.75 mM). In the BSA-MGO assay, the highest activity was shown by 8′-O-acetyl-asacoumarin A (IC(50) 1.03 mM), being less active than aminoguanidine (IC(50) 0.15 mM). Hence, the antiglycation activity of the isolated constituents was due to both oxidative and non-oxidative modes of inhibition.