Essential Oil of Otanthus maritimus (L.) Hoffmanns. & Link From Algeria With High Content in (α/β)-Isocomene and α-epi-Bisabolol

Essential oils (EOs) are a potential source of biologically active molecules. Knowing exactly the constituents of an EO is fundamental to verifying its quality and predicting its biological potential and toxicity. Thus, the objective of this work is to determine the chemical constituents and the chemotype of the EO of Otanthus maritimus (L.) Hoffmanns. & Link growing wild in Zemmouri (Boumerdes, Algeria). EOs from the aerial flowering parts of two harvests, December and February, of O. maritimus, were isolated by hydrodistillation in a 0.19% and 0.14% yield, respectively. Gas chromatography-mass spectrometry analysis allows the identification of both EOs 36 constituents representing 87.35%-92.7% of the total oil composition dominated by irregular sesquiterpenes 35.05% and 29.34%, respectively. In the EO of the December harvest, the major compounds were α-isocomene (15.75%), β-isocomene (7.92%), artemisyl acetate (6.63%) and α-epi-bisabolol (6.16%). Whereas, α-isocomene (18.73%), artemisyl acetate (9.65%), α-epi-bisfabolol (8.96%), germacrene-D (7.13%) and β-isocomene (6.63%) were dominant in the EO of February harvest. This is the first report of the α-isocomene present as the first main component in the EO of this plant in parallel with an exceptional richness in α-epi-bisabolol, which has never been detected previously, which justifies that it is another different chemotype of O. maritimus from Algeria.