ANTIFUNGAL ACTIVITY OF COMPOUNDS FROM Zuccagnia punctata ON WHEAT AND MAIZE PATHOGENS

JIMENEZ, C.M.; SAMPIETRO, D. A.; SGARIGLIA, M.A.; SOBERÓN, J.R.; VATTUONE, M.A.

Mendoza

Congreso; XXX ANNUAL SCIENTIFIC MEETING TUCUMAN BIOLOGY ASSOCIATION; 2013

TUCUMAN BIOLOGY ASSOCIATION

Corn and wheat are vulnerable to ear rot caused by Fusarium. The most harmful species, F.graminearum and F.verticillioides, also contaminate grains with mycotoxins.The aim of this work was to isolate antifungals from the ethereal extract (EE) obtained from a tincture of Z.punctata and to quantify its bioactivities on F.graminearum sensu stricto and F.verticillioides. The tincture obtained from leaves of Z.punctata was partitioned with diethyl ether. EE was fractionated in a Silica gel column. Five pools were collected based on TLC and UV-VIS analysis. Antifungals were detected by bioautography assays, isolated by HPLC and identified by UV-VIS spectroscopy and GC-MS. The antifungal activity of the pure compounds was determined on F.graminearum sensu stricto (Fse) and F.verticilllioides (Fv) by microdilution assays and 50% inhibitory concentration (IC50) was calculated. Three antifungals were detected. Two were identified as: 2´,4´-dihydroxychalcone (DC) and 2´,4´-dihydroxy-3´-metoxychalcone (DMC). Spectrophotometric analysis suggested that the third compound is a flavone. The IC50 of DMC were 81 μg/ml (Fse) and 128 μg/ml (Fv) while those of DC were 132 μg/ml (Fse) and 185 μg/ml (Fv).The EE contained phenolic antifungals. They inhibited the growth of both pathogens, but DMC showed the highest bioactivity. Further research will be oriented towards the identification of the third antifungal.