DISCOVERY OF ANTIFUNGAL COMPOUNDS FROM LOW VALUE/UNDERUTILIZED CROPS AND CROP CO-PRODUCTS
Location: Food and Feed Safety Research
Title: Fungicidal and bactericidal properties of bisabolol and dragosantol
Submitted to: Journal of Essential Oil Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 14, 2011
Publication Date: May 20, 2011
Citation: De Lucca II, A.J., Pauli, A., Schilcher, H., Sien, T., Bhatnagar, D., Walsh, T.J. 2011. Fungicidal and bactericidal properties of bisabolol and dragosantol. Journal of Essential Oil Research. 23:47-54.
Interpretive Summary: Plant produce many compounds, many of which are safe for human use. Among these natural compounds is bisabolol, which is present in chamomile oil and is used in the production of cosmetics. This compound can also be produced synthetically. The synthetic form is called dragosantol. We studied the ability of these compounds to kill selected species of two fungal genera (Aspergillus and Fusarium) which are problems in agriculture and medicine. We also studied their ability to kill two bacteria. The first bacteria, Pseudomonas aeruginosa is a common water-borne microbe that can cause disease in wounds. The second, Staphylococcus aureus, can infect cow udders, stopping milk production as well as being an opportunistic pathogen in humans. Both bisabolol and dragosantol were found to be potent fungicides. They also killed up to 90% of the two bacteria after only one hour after mixing with the compounds. The experiments show that these two compounds which are safe for human use, are also lethal to fungi and bacteria.
a-bisabolol, a natural plant sesquiterpene alcohol, and dragosantol, a racemic mixture of synthetic bisabolol, were studied for their fungicidal properties separately against the nongerminated and germinating conidia of several species of Aspergillus and Fusarium which are problems in agriculture and medicine. Bactericidal assays with Pseudomonas aeruginosa and Staphylococcus aureus were also performed. Results show that, compared to the controls, both compounds displayed statistically significant (p>0.001) lethality to the tested fungi. a-bisabolol and dragosantol produced approximately 98 percent viability reduction against the germinating conidia of A. flavus, A. fumigatus, A. niger, A. terreus, F. oxysporum, F. solani, and F. verticillioides (formerly F. moniliforme)at, or below, 10 µM. Except for F. oxysporum, the viability of the nongerminated conidia were not significantly reduced. Both compounds showed rapid and significant reduction in the viability counts of Ps. aeruginosa at 7.5 µM. Results show that a-bisabolol and dragosantol, which are used in the cosmetic industry, have potent fungicidal and bactericidal properties against the tested micro-organisms.