Antifungal and Antiaflatoxigenic Methylenedioxy-Containing Compounds and Piperine-Like Synthetic Compounds

• Main Authors: Young-Sun Moon, Won-Sik Choi, Eun-Sil Park, In Kyung Bae, Sung-Deuk Choi, Ockjin Paek, Sheen-Hee Kim, Hyang Sook Chun, Sung-Eun Lee
• Format: Article
• Language: English
• Published: MDPI AG 2016-08-01
• Series: Toxins
• Subjects: aflatoxin; Aspergillus flavus; methylenedioxy compounds; piperine; reverse transcription-PCR
• Online Access: http://www.mdpi.com/2072-6651/8/8/240

Twelve methylenedioxy-containing compounds including piperine and 10 piperine-like synthetic compounds were assessed to determine their antifungal and antiaflatoxigenic activities against Aspergillus flavus ATCC 22546 in terms of their structure–activity relationships. Piperonal and 1,3-benzodioxole had inhibitory effects against A. flavus mycelial growth and aflatoxin B1 production up to a concentration of 1000 μg/mL. Ten piperine-like synthetic compounds were synthesized that differed in terms of the carbon length in the hydrocarbon backbone and the presence of the methylenedioxy moiety. In particular, 1-(2-methylpiperidin-1-yl)-3-phenylprop-2-en-1-one had potent antifungal and antiaflatoxigenic effects against A. flavus up to a concentration of 1 μg/mL. This synthetic compound was remarkable because the positive control thiabendazole had no inhibitory effect at this concentration. Reverse transcription-PCR analysis showed that five genes involved in aflatoxin biosynthesis pathways were down-regulated in A. flavus, i.e., aflD, aflK, aflQ, aflR, and aflS; therefore, the synthetic compound inhibited aflatoxin production by down-regulating these genes.