Anticandidal Activity of Extracts and a Novel Compound, Amnomopin, Isolated From Petriella setifera.

A novel triterpenoidal compound named 'amnomopin' (3β-diglucoside-5,12-28-oic acid), which is named IUPAC as 3-O-(2' ➔ 1″diglucoside)1,2,3,4,4a,5,6,6a,6b,7,9,10,11,12,12a,12b,13,14b-octadecahydro-10-hydroxy-2,2,6a,6b,9,9,12a-heptamethylpicene-4a-carboxylic acid, was isolated from the extract Petriella setifera. The total alcoholic extract of P. setifera showed a great activity against clinically isolated Candida species, including Candida albicans, Candida dubliniensis, Candida famata, Candida glabrata, Candida inconspicua, Candida kefyr, Candida krusei, Candida norvegensis, Candida parapsilosis and Candida tropicalis. Also, the new compound amnomopin was active against all the investigated Candida species. The highest anticandidal activity of P. setifera extract was obtained against C. kefyr (22.6 ± 1.5 mm), C. albicans and C. norvegensis (21.3 ± 0.63 mm) and C. krusei (20.6 ± 1.5 mm). Moreover, the minimum inhibitory concentrations of both the total extract and the isolated compound were low. The minimum inhibitory concentration of the compound isolated from P. setifera was 0.49 μg/mL against C. kefyr, 0.98 μg/mL against C. albicans and C. norvegensis and 1.95 μg/mL against C. krusei. The oral dosing of the extract and the isolated compound did not show any significant effect on the activity of alanine aminotransferase, aspirate aminotransferase and the levels of blood urea and serum creatinine.