Antifungal activity of a compound isolated from strawberry (Fragaria ananassa) leaves.

MAMANÍ DE MARCHESE, FILIPPONE, CASTAGNARO, DÍAZ RICCI

Tucumán, Argentina

Congreso; Jornadas Científicas de la Sociedad e Biología de Tucumán; 2001

We report the isolation and purification of a non-eptidic antifungal compound we called “Fragarin II” to differentiate from a previously reported Fragarin I that shows antibacterial activity mainly. Fragarin II was obtained from leaves of healthy plants (vr. Chandles) ground in liquid nitrogen and treated with Tris-HCl 100 mM (pH 7.5) at 100ºC 10min. The extract separated by centrifugation (1000rpm 10 min) was subjected to a C1/C8-FLPC (UV 280nm) with an acetonitrile gradient (º-100%, 30 min) in Tris-HCl 5 mM/EDTA 0.5 mM (pH 7.5). The antimicrobial activity was detedted with the bacterium Clavibacter michiganensis ad the fungus Colletotrichum acutatum. The peak showing activity against both organisms aluting at 0% acetonitrile was passed through a DEAE-cellulose. The active fraction colleted at 50 mM was further purified in HPLC (Water, AP-1 Protein Pack DEAE 8HR column, UV 280nm) with NaCl gradient a-a.5M (20min). The active peak aluting at 250mM was designated Fragarin II and proved to be active against 10 distinct fungi, specially strawberry pathogens (Colletorichum sp.) The latter suggest that Fragarin II may be one of the chemical barrier of preformed compound against pathogens present in strawberry.