Chemical composition and antibacterial activity of foliage and resin essential oils of Araucaria cunninghamii Aiton ex D.Don and Araucaria heterophylla (Salisb.) Franco from India

• Araucaria cunninghamii and Araucaria heterophylla are ornamental tree species.
• Detailed GC/MS profile of the foliage and resin essential oils was developed.
• Foliage essential oils contained significant amounts of tricyclic and tetracyclic diterpenes.
• Resin essential oils were dominated by sesquiterpenes.
• The essential oils were antibacterial (MIC: 250–500 μg/mL and MBC: 1000–1000 μg/mL).

The essential oils of foliage and resin of Araucaria cunninghamii Aiton ex D.Don and Araucaria heterophylla (Salisb.) Franco were isolated by hydrodistillation and subsequently analyzed using gas chromatography (GC/FID) and GC–mass spectrometry (GC/MS). Altogether 113 constituents, representing 84.0–97.6% of the total oil compositions were identified. Major constituents of the foliage oil of A. cunninghamii were beyerene (34.6–44.4%), caryophyllene oxide (0.5–17.9%), α-pinene (3.3–16.2%), germacrene D (0.1–9.8%), kaurene (1.7–5.1%), and 13-epi-dolabradiene (4.2–4.8%). However, the resin oil of A. cunninghamii was characterized by higher amounts of (E)-caryophyllene (60.8%), caryophyllene oxide (13.4%), and (E)-β-farnesene (4.9%). The foliage oil of A. heterophylla was dominated by 13-epi-dolabradiene (42.7%), beyerene (22.2%), rimuene (13.7%), and dolabradiene (3.9%), whereas the resin oil of A. heterophylla contained α-copaene (29.9%), germacrene D (21.4%), γ-gurjunene (9.7%), δ-cadinene (7.1%), and sandaracopimara-8(14),15-diene (6.5%) as main constituents. The foliage and resin essential oils of both species showed minimum inhibitory concentration (MIC) in the range of 250–500 μg/mL and minimum bactericidal concentration (MBC) in the range of 1000 to >1000 μg/mL against tested bacterial strains.

Chemical constituents of foliage and resin essential oils of Araucaria cunnighamii and Araucaria heterophylla.Figure optionsDownload as PowerPoint slide