Antimicrobial Potential of Extracts from <em>Penicillium purpurogenum</em> Isolated from Aquatic Environment in the Amazon and Identification of Citrinin Derivatives

Abstract

Fungi of the genus Penicillium produce secondary metabolites used as a model for the synthesis and development of several compounds with bactericidal, fungicidal, antitumor, anti-inflammatory, antiviral activities, among others. Based on this information, a study was conducted to investigate the metabolomic profile and antimicrobial potential of Penicillium purpurogenum (CFAM – 214). The minimum inhibitory concentration (MIC) of extracts obtained from P. purpurogenum broth (CFAM - 214) in ISP2, SB, and YES against Candida albicans was 500 µg/mL, 31.25 µg/mL and 62, 5µg/mL, respectively. In the test against Candida tropicalis and Staphylococcus aureus, the MIC for extracts cultivated in SB was 250 µg/mL and 125 µg/mL, respectively. Due to the good performance of the P. purpurogenum extract in SB, large-scale cultivation was carried out that led to the isolation of two compounds, whose structures were determined by spectroscopic methods such as 1D NMR (1H NMR and 13C NMR) and 2D (HMBC and HSQC), HRMS and MS/MS. The isolated compounds were identified as two citrinin derivatives, dihydrocitrinin (1) and 1-methyl-dihydro citrinin (2).