Screening of fruit and leaf essential oils of Litsea cubeba Pers. from north-east India – chemical composition and antimicrobial activity

Abstract

Essential oils from the leaves and fruits of Litsea cubeba Pers. collected in the Assam and Arunachal Pradesh states in north-east India, were analyzed by gas chromatography (GC) and GC–mass spectrometry (GC–MS). On the whole, 117 components have been characterized. The two leaf oils (LC1, LC2) show sabinene as the main component; the other significant compounds for LC1 oil are α-pinene, terpinen-4-ol, α-terpineol and myrcene, whereas for LC2 1,8-cineole and α-pinene are the other most important compounds. The three fruit oils (LC3, LC4 and LC5) were characterized by different profiles, indeed LC3 and LC4 showed a similar composition with citronellol and citronellal the main components, accounting for 70% and 10% of total oils, respectively. LC5, instead, presents geranial (c. 44%) and neral (c. 40%) as the main components, whereas citronellal reaches only c. 3%. Essential oils were evaluated for their antimicrobial activity against Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Aspergillus niger. All microbial strains appeared sensitive to the cytotoxic activity of the essential oils under investigation. Leaf and fruit oils showed different levels of inhibition depending on their particular chemical composition; however, the LC5 sample was broadly the most effective.

Keywords:

• Litsea cubeba
• leaf and fruit essential oils
• antimicrobial activity
• sabinene
• citral

Acknowledgments

This work was supported by the Consiglio Nazionale delle Ricerche (C.N.R. Rome, Italy). We are also grateful to Mr. Agatino Renda (ICB-CNR, CT, Italy) for his skilful technical assistance. AKS acknowledges All India Council for Technical Education, New Delhi, India for financial assistance to purchase Shimadzu GC2014.