Chemical Composition of the Leaf Oil ofLantana camara

Lantana camara Essential Oils from Vietnam: Chemical Composition, Molluscicidal, and Mosquito Larvicidal Activity

Lantana camara is a troublesome invasive plant introduced to many tropical regions, including Southeast Asia. However, the plant does hold promise as a source of essential oils that may be explored for potential use. Fresh water snails such as Pomacea canaliculata, Gyraulus convexiusculus, and Tarebia granifera can be problematic agricultural pests as well as hosts for parasitic worms. Aedes and Culex mosquitoes are notorious vectors of numerous viral pathogens. Control of these vectors is of utmost importance. In this work, the essential oil compositions, molluscicidal, and mosquito larvicidal activities of four collections of L. camara from north-central Vietnam have been investigated. The sesquiterpene-rich L. camara essential oils showed wide variation in their compositions, not only compared to essential oils from other geographical locations (at least six possible chemotypes), but also between the four samples from Vietnam. L. camara essential oils showed molluscicidal activities comparable to the positive control, tea saponin, as well as other botanical agents. The median lethal concentrations (LC₅₀ ) against the snails were 23.6-40.2 μg/mL (P. canaliculata), 7.9-29.6 μg/mL (G. convexiusculus), and 15.0-29.6 μg/mL (T. granifera). The essential oils showed good mosquito larvicidal activities with 24-h LC₅₀ values of 15.1-29.0 μg/mL, 26.4-53.8 μg/mL, and 20.8-59.3 μg/mL against Ae. aegypti, Ae. albopictus, and Cx. quinquefasciatus, respectively. The essential oils were more toxic to snails and mosquito larvae than they were to the non-target water bug, Diplonychus rusticus (24-h LC₅₀ =103.7-162.5 μg/mL). Sesquiterpene components of the essential oils may be acting as acetylcholinesterase (AChE) inhibitors. These results suggest that the invasive plant, L. camara, may be a renewable botanical pesticidal agent.

Chromatographic and spectroscopic determination of solvent-extracted Lantana camara leaf oil

Objective

This study aimed to determine the chemical profile of Lantana camara leaf oil.

Methods

The essential oil was extracted from dried leaf samples using the Soxhlet extraction method. The oil was separated from the solvent and the bioactive compounds were identified using gas chromatography–mass spectroscopy (GC-MS) and Fourier transform infrared spectroscopy (FTIR). The identified peaks in the mass spectrum were matched with the database of the US National Institute of Standards and Technology (NIST) library.

Results

The FT-IR results indicated the presence of alcohols, carboxylic acids, phenols, alkanes, ketones, and primary amine compounds. GC-MS identified 43 compounds representing 95% of the total leaf essential oil components. Some of the major isolated compounds included a pyrrolizine; 1-dodecanol; 1,2-nonadecanediol; phytol; 1,3-dioxolane; 4-undecene, 9-methyl, (Z)-; 1-eicosanol; and imidazole.

Conclusions

The identified constituents of the extracted oil have established pharmacologic and insecticidal activities, and these compounds are also used in the drink, food, and cosmetic industries. This extract is highly valuable for the medical treatment of various ailments.

Composition, Seasonal Variation, and Biological Activities of Lantana camara Essential Oils from Côte d'Ivoire

This work aims to study the variations in the composition of Lantana camara leaf, flower, and stem essential oils over two years. L. camara organs were harvested in Bregbo (East Côte d'Ivoire) each month from June 2015 to June 2017. The essential oils were obtained by hydrodistillation and characterized by GC-MS and ¹³C NMR. Eighty-four compounds accounting for 84.4-99.1% of the essential oils have been identified. The essential oils hydrodistillated from L. camara are dominated by sesquiterpenes such as (E)-β-caryophyllene and α-humulene, which were found in all samples. Some monoterpenes such as thymol, sabinene, and α-pinene were also present. Statistical analysis (principal component analysis and clustering) revealed a high variability in essential oil composition between the different organs and also within the studied periods, as the thymol proportion was higher during flowering and fruiting months. In addition, the stem, flower, and fruit essential oils were more concentrated in thymol than the leaf essential oils. The proportions of (E)-β-caryophyllene and α-humulene were strictly inverted with the thymol proportion throughout the harvest period or vegetative cycle. The antioxidant, anti-inflammatory and insecticidal activities of leaves and flowers essential oils were also studied. Results showed that L. camara leaf and flower essential oils displayed high antioxidant, anti-inflammatory and insecticidal activities.

Insecticidal activity of Lantana camara extract oil on controlling maize grain weevils

Postharvest losses are known to be one of the serious constraints upon food security among farmers poor resource in Africa. The use of botanical insecticide in pest management during storage against weevils is often encouraged because synthetic insecticides produce multiple side effects on human and environment. In this study, the insecticidal property of methanol, ethanol, and ethyl acetate extracts of Lantana camara leaf oil and powder for controlling maize weevils, Sitophilus zeamais, was studied. Gas chromatography–mass spectrometry and Fourier transform infrared spectroscopy (FTIR) were used to identify the chemical composition and functional group of solvent extract, respectively. Adult weevil repellency and mortality were studied by the effect of oil concentration at 0% (w/w), 2% (w/w), 3% (w/w), 5% (w/w), 7% (w/w), and 10% (w/w). Repellency effect was also conducted at 6, 12, and 24 h. The number of weevil death increased significantly as exposed time was increased. The extracted oil by the three-solvent fraction had direct repellent and toxic effect to the weevil. From all treatment applied, extracted by methanol fraction had showed highest percentage mortality (74%). The lowest mortality rate was observed in ethyl acetate extract (26%) at 2% (w/w) concentration. The effect of leaf powder and extracted oil on repellency and mortality for insects was due to the presence of bioactive and phytochemical molecules such as Phytol, Pyrroline, Paromomycin, Pyrrolizin, and 1-Eicosano. It was concluded that both L. camara leaf powder and extract oil can be used for the protection of stored maize from infestation S. zeamais.

The Chemical Diversity of Lantana camara: Analyses of Essential Oil Samples from Cuba, Nepal, and Yemen

The aerial parts of Lantana camara L. were collected from three different geographical locations: Artemisa (Cuba), Biratnagar (Nepal), and Sana'a (Yemen). The essential oils were obtained by hydrodistillation and analyzed by gas chromatography/mass spectrometry. A cluster analysis of 39 L. camara essential oil compositions revealed eight major chemotypes: β-caryophyllene, germacrene D, ar-curcumene/zingiberene, γ-curcumen-15-al/epi-β-bisabolol, (E)-nerolidol, davanone, eugenol/alloaromadendrene, and carvone. The sample from Cuba falls into the group dominated by (E)-nerolidol, the sample from Nepal is a davanone chemotype, and the sample from Yemen belongs to the β-caryophyllene chemotype. The chemical composition of L. camara oil plays a role in the biological activity; the β-caryophyllene and (E)-nerolidol chemotypes showed antimicrobial and cytotoxic activities.

A Chemical Marker Proposal for the Lantana genus: Composition of the Essential Oils from the Leaves of Lantana radula and L. canescens

Essential oil extracts from the leaves of two Lantana species ( L. radula Sw. and L. canescens Kunth), for which no prior analysis has been reported, were analyzed by GC-MS. This information was utilized to propose chemical markers for Lantana species so that identification between physically similar plant species can be achieved through chemical analysis. Results showed 33 constituents for L. canescens, among which β-caryophyllene (43.9%), β-cubebene (10.1%), elixene (8.6%), β-phellandrene (6.1%), α-caryophyllene (2.6%) and dehydro-aromadendrene (2.6%) were the principle components. L. radula revealed the presence of 21 compounds, the most abundant of which were β-cubebene (31.0%), β-caryophyllene (20.8%), elixene (10.0%), α-salinene (6.4%), β-phellandrene (6.1%), copaene (4.9%) cadinene (1.4%) and psi-limonene (1.4%). The high concentration of β-caryophyllene in the samples tested here and those in the literature make it a good candidate for a chemical marker for Lantana species, with β-cubebene, elixene and β-phellandrene following as minor compounds identified more sporadically in this genus. On the other hand, Lippia species, which are morphologically similar to those from the Lantana genus, would contain limonene, citral, carvacrol, β-myrcene, camphor and thymol as the main chemical markers. These chemical markers would be a powerful tool for maintaining quality control in the extraction of essential oils for use in medicinal applications, as well as in identification of plant specimens to a taxonomist.