Essential Oil from Chiliadenus lopadusanus Growing Spontaneously in Lampedusa Island (Italy)

Chemical Composition, Antibacterial Screening and Cytotoxic Activity of Chiliadenus antiatlanticus (Asteraceae) Essential Oil

The chemical composition and in vitro antibacterial and cytotoxic activities of the essential oil (EO) of Chiliadenus antiatlanticus (Emb. & Maire) Gómiz, an asteraceous species endemic to the southwest of Morocco, were investigated. The EO yield was 1.07±0.28 %, twenty-seven metabolites were identified representing more than 96.4 % of the total composition. Camphor (35.7 %) and derivatives, borneol (4.9 %) and camphene (4.2 %) together with intermedeol (19.9 %), α-pinene (15.5 %) and (E)-pinocarveol (4.1 %) were the major constituents. An antibacterial activity was noticed against 24 strains (all Gram-positive) out of 71 at MICs values=100 μg/mL. The EO also showed significant toxicity towards liver HepG2 (55.8 % of cell viability) and melanoma B16 4A5 (41.6 % of cell viability) tumor cell lines at 100 μg/mL.

Farnesane-Type Sesquiterpenoids with Antibiotic Activity from Chiliadenus lopadusanus

Chiliadenus lopadusanus Brullo is an Asteraceae plant species endemic to Lampedusa island, the largest island of the Pelage archipelago, Italy. The organic extract of its whole aerial parts, showing antibiotic activity against Staphylococcus aureus and Acinetobacter baumannii, wasfractionated employing bioguided purification procedures affording three main farnesane-type sesquiterpenoids. They were identified by spectroscopic methods (NMR and ESIMS data) as the (E)-3,7,11-trimethyldodeca-1,6,10-triene-3,9-diol, (E)-10-hydroxy-2,6,10-trimethyldodeca-2,6,11- trien-4-one and (E)-10-hydroxy-2,6,10-trimethyl-dodeca-6,11-dien-4-one, commonly named 9-hydroxynerolidol, 9-oxonerolidol, and chiliadenol B, respectively. These three sesquiterpenes, isolated for the first time from C. lopadusanus, were tested on methicillin-resistant S. aureus and A. baumannii showing antibacterial and antibiofilm activities. This plant could be used as a source to isolate secondary metabolites as potential new antibiotics.

Essential Oil Composition of Summer and Winter Foliage of Chiliadenus bocconei

The composition of the essential oil (EO) obtained from dry leaves of Chiliadenus bocconei Brullo (Asteraceae subfam. Inulae), a Maltese endemic aromatic plant, collected in two different seasons, was evaluated in this work. The main EO components identified in the summer foliage were camphor (25.6%), borneol (27.1%) and τ-cadinol (13.9%). In the winter foliage τ-cadinol was the most represented compound (59.5%), followed by camphor (13.1). A comparison is also made between the EO composition of the two samples of C. bocconei and the EO obtained from different aerial parts of C. lopadusanus, an endemic plant of Lampedusa Island, another Mediterranean Island.

Essential Oils of Chiliadenus Lopadusanus (Asteraceae)

The essential oils from the leaves and flowers of Chiliadenus lopadusanus growing on Lampedusa Island were obtained by hydrodistillation and analyzed by GC-MS. The major component was camphor (39.4% in the leaves and 24.0% in the flowers), followed in the leaves by torreyol (6.7%), t-cadinol (5.2%) and 1,8-cineole (3.8%), while in the flowers by t-cadinol (15.2%), t-muurolol (5.1%) and torreyol (4.5%). Among the compounds identified, several seem to play a role in antibacterial, antifungal, allelopathic and spasmolytic activity. In addition, several compounds identified in this study seem to influence the attraction of Megachile ( Eutricharaea) apicalis (Megachilidae) and Halictus ( Seladonia) gemmeus (Halictidae), two hymenopteran here identified as pollinators of Chiliadenus lopadusanus.