humulene and gamma-terpinene

Giant fennel (Ferula communis L.) is well known in folk medicine for the treatment of various organ disorders. The biological importance of members of genus Ferula prompted us to investigate the leaves of the endangered Tunisian medicinal plant F. communis L. not previously investigated. An estimate of genetic diversity and differentiation between genotypes of breeding germplasm is of key importance for its improvement. Thus, four F. communis populations were RAPD fingerprinted (63 RAPD markers generated by 7 primers) and the composition of their leaf essential oils (EO) (134 EO compounds) was characterized by GC-MS. Cluster analysis based on the leaf volatiles chemical composition of F. communis accessions defined three chemotypes according to main compounds have been distinguished: α-eudesmol/β-eudesmol/γ-terpinene; α-eudesmol/α-pinene/caryophyllene oxide and chamazulene/α-humulene chemotypes. A high genetic diversity within population and high genetic differentiation among them, based on RAPDs, were revealed (H(pop)=0.320 and GST=0.288) caused both by the habitat fragmentation, the low size of most populations and the low level of gene flow among them. The RAPD dendrogram showed separation of three groups. Populations dominated by individuals from the β-eudesmol/γ-terpinene; chemotype showed the lowest gene diversity (H=0.104), while populations with exclusively α-pinene/caryophyllene oxide chemotype showed the highest value (H=0.285). The UPGMA dendrogram and PCA analysis based on volatiles yielded higher separation among populations, indicated specific adaptation of populations to the local environments. Correlation analysis showed a non-significant association between the distance matrices based on the genetic markers (RAPD) and chemical compounds of essential oil (P>0.05) indicating no influence of genetic background on the observed chemical profiles. These results reinforce the use of both volatile compounds and RAPD markers as a starting point for in situ conservation. The analysis of chemical constitution of oil of the populations from a specific region revealed predominance of specific constituents indicating possibility of their collection/selection for specific end uses like phytomedicines. Sufficient molecular and biochemical diversity detected among natural populations of this species will form the basis for the future improvement. The correlation between matrices of RAPD and essential oils was not significant. The conservation strategies o

Topics: Bicyclic Monoterpenes; Biodiversity; Cyclohexane Monoterpenes; Ferula; Gas Chromatography-Mass Spectrometry; Monocyclic Sesquiterpenes; Monoterpenes; Oils, Volatile; Plant Leaves; Plant Oils; Plants, Medicinal; Random Amplified Polymorphic DNA Technique; Sesquiterpenes; Sesquiterpenes, Eudesmane; Terpenes

This study was conducted to evaluate the phytochemical composition and larvicidal effect of leaf essential oil from Murraya exotica against early fourth-instar larvae of Aedes aegypti, Anopheles stephensi and Culex quinquefasciatus. Gas chromatography (GC) and gas chromatography mass spectrometry (GC-MS) analyses revealed that the essential oil contained 27 components. The major chemical components identified were β-humulene (40.62%), benzyl benzoate (23.96%), β-caryophyllene (7.05%) and α-terpinene (5.66%). The larval mortality was observed after 12 and 24 h of exposure period. The results revealed that essential oil showed varied levels of larvicidal activity against A. aegypti, A. stephensi and C. quinquefasciatus. After 12 h of exposure period, the larvicidal activities were LC₅₀ = 74.7 and LC₉₀ = 152.7 ppm (A. aegypti), LC₅₀ = 56.3 and LC₉₀ = 107.8 ppm (A. stephensi ), and LC₅₀ = 74.4 and LC₉₀ = 136.9 ppm (C. quinquefasciatus) and the larvicidal activities after 24 h of exposure period were LC₅₀ = 35.8 and LC₉₀ = 85.4 ppm (A. aegypti), LC₅₀ = 31.3 and LC₉₀ = 75.1 ppm (A. stephensi), and LC₅₀ = 43.2 and LC₉₀ = 103.2 ppm (C. quinquefasciatus). These results suggest that leaf essential oil from M. exotica is a promising and eco-friendly source of natural larvicidal agent against A. aegypti, A. stephensi and C. quinquefasciatus.

Topics: Aedes; Animals; Anopheles; Benzoates; Culex; Cyclohexane Monoterpenes; Insecticides; Larva; Monocyclic Sesquiterpenes; Monoterpenes; Murraya; Oils, Volatile; Plant Leaves; Plant Oils; Polycyclic Sesquiterpenes; Sesquiterpenes