Avaliação da ação antifúngica da própolis vermelha sobre o fungo Colletotrichum gloeosporioides causador da antracnose do mamão

Abstract

The production of papaya, of inestimable economic and cultural value to Brazil – which is among the largest global producers – faces significant challenges due to anthracnose, a disease caused by Colletotrichum gloeosporioides that causes severe lesions, compromising the appearance, nutritional integrity, and commercial value of the fruits. In this scenario, the implementation of effective and environmentally sustainable strategies is urgent. In this context, the present study investigated the antifungal activity of two alcoholic extracts: red propolis and its residue, aiming to explore their potential as a natural agent in controlling anthracnose, attributed to the richness in bioactive compounds, especially flavonoids and isoflavonoids. The methodology adopted included the characterization of the propolis and residue, including the determination of moisture and ash content, the identification of bioactive compounds by HPLC, and the analysis of functional groups by FTIR. Subsequently, C. gloeosporioides was isolated from papaya samples affected by the disease, and the in vitro evaluation of the antifungal activity of the extracts was performed, comparing them with the control without propolis. The results indicated that the red propolis presented a moisture content of 5.89%, consistent with high-quality standards, while its residue reached 24.26%, possibly due to the higher presence of impurities. The ash contents of both materials met the specifications of current legislation. The chromatographic analysis by HPLC allowed the qualitative identification of bioactive compounds in red propolis and its residue, highlighting the possible presence of kaempferol, coumarin, and luteolin. Additionally, unidentifiable peaks were observed that may be related to isoflavonoids of interest, such as formononetin and homopterocarpine. Complementarily, FTIR spectroscopy evidenced the occurrence of functional groups, suggesting the presence of relevant classes of compounds, including these isoflavonoids. The evaluation of antifungal activity indicated that the residue extract presented higher efficacy, although the inhibition zones appeared irregular in shape. These findings reinforce the potential of red propolis as a promising alternative in managing anthracnose, highlighting the importance of further investigations, including mass spectrometry, for a more detailed elucidation of the chemical composition and the mechanisms of action involved.