Antimicrobial activity of major active compounds of Litsea cubeba essential oils

Researchers at the Technical University of Munich in Germany examined the chemical composition of Litsea cubeba (may chang) essential oil and the biological activities of its active constituents. Their review was published in the Journal of Essential Oil Research.

• Two chemotypes of L. cubeba essential oil exists, one dominated by citral and limonene and the other by citronellal.
• L. cubeba essential oils exhibit broad antimicrobial activity against bacteria and fungi, with minimum inhibitory concentrations (MIC) ranging from 0.5 to 2,500 mcg/mL.
• Researchers attribute this antimicrobial activity to the monoterpene citral, which has an MIC of 50 to 1,000 mcg/mL against bacteria and fungi.
• Pseudomonas aeruginosa is the most resistant against citral, with the compound having MIC values above 1,000 mcg/mL when tested against it.
• At biocidal concentrations, citral affects the structure of the bacterial cell membrane as well as cell respiration, causing rapid energy depletion and cell death.
• Meanwhile, limonene exhibits insignificant antimicrobial activity; its MIC ranges from 1 to 20 mg/mL.

Because of the biological activities of their active components, L. cubeba essential oils are extensively studied for their potential food applications. The researchers said that these essential oils have shown promising results for fresh produce and fruit juices.

Journal Reference:

Thielmann J, Muranyi P. REVIEW ON THE CHEMICAL COMPOSITION OF LITSEA CUBEBA ESSENTIAL OILS AND THE BIOACTIVITY OF ITS MAJOR CONSTITUENTS CITRAL AND LIMONENE. Journal of Essential Oil Research. 06 May 2019;31(5):361–378. DOI: 10.1080/10412905.2019.1611671