NATURAL AND SEMISYNTHETIC COMPOUNDS FROM ARGENTINIAN POLYGONUM ACUMINATUM AGAINST HUMAN PATHOGENIC YEASTS

DI LIBERTO, M.; ZACCHINO, S.; DERITA, M.

PharmacologyOnline

SILAE

Año: 2016 vol. SI p. 58 - 59

1827-8620

In the last years, fungi have become the major cause of human infections, especially among immunocompromised hosts, having an enormous impact on morbidity and mortality. Although there are many available drugs for the treatment of systemic and superficial mycoses, they are not completely effective for their eradication. In addition, they all possess a certain degree of toxicity and quickly develop resistance due to inappropriate and abusive use. Therefore, there is an urgent need for the development of new antifungal chemical structures alternatives to the existing ones.1 In this context, exploring natural and semisynthetic products, turn out to be of great importance. Previously, we reported antifungal activities of polygodial isolated from Polygonum acuminatum Kunth and some molecules derivatives from this natural product, against a panel of human pathogenic fungi.2 In this work, we expanded the list of yeasts using clinical isolates of Candida and Cryptococcus strains. P. acuminatum was collected during the flowering season (March 2014) in Santa Fe province (Argentina) and deposited at the Herbarium FCA-UNL (Arturo Ragonese) with identifying data SF # MD97. Natural products polygodial (1) and p-methoxycinamoylpolygodial (2), as well as semisynthetic compounds confertifolin (3), drimenal (4) and isodrimenol (5) were obtained according to previous reports2 and tested against clinically isolated fungi from Centro de Referencia en Micología (CEREMIC) and Malbrán Institute. They included 9 strains of Candida spp. (5 of C. albicans and 4 of C. non-albicans) and 6 strains of Cryptococcus neoformans. Inocula of yeasts suspensions were obtained according to reported procedures and adjusted to 1 x 105 Colony Forming Units (CFU)/mL.3 MIC50 was defined as the lowest concentration of each compound that showed 50% growth reduction respect to the control and was determined using VERSA Max microplate reader (Molecular Devices, Sunnyvale, CA, USA). Amphotericin B was used as positive control and tests were performed by duplicate.