Integrative Investigation of Pancratium maritimum (Amaryllidaceae) Essential Oil: Chemical Profiling During Two Different Growth Stages, Allelopathi

ABSTRACT

The essential oil composition of the aerial parts of Pancratium maritimum L., a fragrant plant, growing in Djerba Island (South of Tunisia) in two development stages is discussed in this research, with a focus on its allelopathic properties and α‐amylase inhibition. In fact, phytochemicals in Pancratium maritimum essential oils during vegetative and flowering seasons were identified by gas chromatography‐FID and gas chromatography/mass spectrometry. An in vitro spectrophotometric assay based on a colorimetric method was used to test the α‐amylase inhibitory effect. Eventually, allelopathic effects against radish and lettuce seeds germination as well as roots and stems elongation were assessed by an in vitro test, and an in silico study via molecular docking was performed to identify a possible mechanism of action that correlated with the α‐amylase inhibitory and allelopathic effects. Results showed a significant difference between the two tested essential oils: phenylpropanoids (9.9%), alcohols (39.7%), and hydrogenated monoterpenes (5.49%) were abundant during flowering season; however, diterpene alcohols (20.76%) and hydrocarbons (14.68%) were among the predominant phytochemicals found in the vegetative stage. α‐Amylase Inhibition assay demonstrated that the inhibitory effect reached 86.2% at 2.5 mg/mL and 90.14% at 5 mg/mL. Allelopathic activity of Pancratium maritimum essential oil displayed high germination inhibition (70.85% for lettuce seeds) and it significantly inhibits the elongation of radish stems and lettuce roots by 93.63% and 90.7%, respectively, at a concentration of 4 mg/mL. In addition, primary oil components showed substantial inhibitory effect against human pancreatic α‐amylase and 4‐hydroxyphenylpyruvated oxygenase (HPPD), according to molecular docking study. These results highlight P. maritimum essential oil's potential as a hypoglycemic and allelopathic agent that affects radish and lettuce development and seed germination.