Phytochemical profile of methanolic extracts from Chilca (Baccharis glutinosa) roots and its activity against Aspergillus ochraceus and Fusarium moniliforme

ABSTRACT

Aim: The present study aimed to identify the phytochemicals of methanolic extract from Baccharis glutinosa (chilca) roots (MEBg) and to evaluate its antifungal activity on two major fungal pathogens of agricultural importance. Methodology: The antifungal activity was evaluated by inhibition halo, minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC) and % sporulation against A. ochraceus and F. moniliforme. As a preliminary test, inhibition halo was tested using 1, 10, 100 and 270 mg ml-1 of MEBg. Different concentrations of MEBg were applied for MIC and MFC tests. Ketoconazole was used as positive control. The treatments were applied in triplicate. The phytochemical compounds of MEBg were determined by GC-MS analysis. Results: The MEBg produced an inhibition zone of 2 to 4 mm in the inhibition halo test, with concentrations of 100 and 270 mg ml-1 for A. ochraceus and F. moniliforme, respectively. Reduction in % sporulation above 50 was shown in concentrations over 8 mg ml-1. MEBg were reported to exhibit antifungal activities against A. ochraceus and F. moniliforme with the MIC values ranging from 2 to 5.6 mg∙ml-1 and the MFC from 12 to 15 mg ml-1. GC-MS analysis of Chilca extracts revealed that the most abundant metabolites were furfural compounds and organic acids. The most abundant furfural compounds were 5-(hydroxymethyl) furan-2-carbaldehyde (38.59%), furan-2-carbaldehyde (4.103%) and 5-methylfuran-2-carbaldehyde (2.1%). Interpretation: The MEBg revealed efficient antifungal activity, likely due to the presence of bioactive compounds, which could be used as an alternative for biological control of pathogenic fungi in maize and coffee crops.