humulene and beta-pinene

The hydro-distilled essential oil from aerial parts of

Topics: Bicyclic Monoterpenes; Cyclohexane Monoterpenes; Gas Chromatography-Mass Spectrometry; Lamiaceae; Monocyclic Sesquiterpenes; Oils, Volatile; Orthosiphon; Polycyclic Sesquiterpenes; Sesquiterpenes

Volatile terpenes represent the largest group of

Topics: Acyclic Monoterpenes; Anti-Bacterial Agents; Bacteria; Bicyclic Monoterpenes; Bridged Bicyclo Compounds; Cannabinoids; Cannabis; Gas Chromatography-Mass Spectrometry; Microbial Sensitivity Tests; Monoterpenes; Oils, Volatile; Plant Extracts; Polycyclic Sesquiterpenes; Sesquiterpenes; Terpenes

Essential oils hydrodistilled from the leaves and stem barks of Goniothalamus macrocalyx Ban., Goniothalamus albiflorus Ban. and Goniothalamus tamirensis Pierre ex Fin. & Gagnep. growing in Vietnam were analysed by gas chromatography (GC) and GC-coupled with mass spectrometry. α-Pinene (1.7-50.0%), β-pinene (tr-6.8%), β-myrcene (tr-1.5%), (E)-β-ocimene (tr-4.6%), β-caryophyllene (9.9-12.8%), aromadendrene (0.2-6.0%), α-humulene (1.7-6.9%), α-cadinol (1.2-14.5%), δ-cadinene (0.1-10.3%) and n-hexadecanoic acid (0.2-1.9%) were common to the oil samples. α-Pinene (50.0%) was the most abundant single constituent of the leaf oil of G. macrocalyx, whereas the major compounds of the stem were α-cadinol (14.5%), β-caryophyllene (10.3%) and octadecanoic acid (8.2%). Benzoic acid (18.4%), β-caryophyllene (12.4%) and α-pinene (10.3%) were present in the leaf of G. albiflorus, whereas limonene (21.2%), β-caryophyllene (12.8%) and α-phellandrene (9.3%) were identified in the stem. The leaf oil of G. tamirensis was characterised by abundance of α-pinene (33.4%), viridiflorol (18.5%) and β-caryophyllene (12.4%), whereas γ-gurjunene (11.2%), β-caryophyllene (10.9%) and δ-cadinene (10.3%) predominates in the stem oil.

Topics: Acyclic Monoterpenes; Alkenes; Azulenes; Bicyclic Monoterpenes; Bridged Bicyclo Compounds; Chromatography, Gas; Cyclohexane Monoterpenes; Gas Chromatography-Mass Spectrometry; Goniothalamus; Monocyclic Sesquiterpenes; Monoterpenes; Oils, Volatile; Plant Bark; Plant Leaves; Polycyclic Sesquiterpenes; Sesquiterpenes; Terpenes

Cotton plants accumulate gossypol and related sesquiterpene aldehydes, which function as phytoalexins against pathogens and feeding deterrents to herbivorous insects. However, to date little is known about the biosynthesis of volatile terpenes in this crop. Herein is reported that 5 monoterpenes and 11 sesquiterpenes from extracts of a glanded cotton cultivar, Gossypium hirsutum cv. CCRI12, were detected by gas chromatography-mass spectrometry (GC-MS). By EST data mining combined with Rapid Amplification of cDNA Ends (RACE), full-length cDNAs of three terpene synthases (TPSs), GhTPS1, GhTPS2 and GhTPS3 were isolated. By in vitro assays of the recombinant proteins, it was found that GhTPS1 and GhTPS2 are sesquiterpene synthases: the former converted farnesyl pyrophosphate (FPP) into β-caryophyllene and α-humulene in a ratio of 2:1, whereas the latter produced several sesquiterpenes with guaia-1(10),11-diene as the major product. By contrast, GhTPS3 is a monoterpene synthase, which produced α-pinene, β-pinene, β-phellandrene and trace amounts of other monoterpenes from geranyl pyrophosphate (GPP). The TPS activities were also supported by Virus Induced Gene Silencing (VIGS) in the cotton plant. GhTPS1 and GhTPS3 were highly expressed in the cotton plant overall, whereas GhTPS2 was expressed only in leaves. When stimulated by mechanical wounding, Verticillium dahliae (Vde) elicitor or methyl jasmonate (MeJA), production of terpenes and expression of the corresponding synthase genes were induced. These data demonstrate that the three genes account for the biosynthesis of volatile terpenes of cotton, at least of this Upland cotton.

Topics: Acetates; Alkyl and Aryl Transferases; Bicyclic Monoterpenes; Bridged Bicyclo Compounds; Cyclohexane Monoterpenes; Cyclohexenes; Cyclopentanes; Gas Chromatography-Mass Spectrometry; Gossypium; Intramolecular Lyases; Monocyclic Sesquiterpenes; Monoterpenes; Oxylipins; Phytoalexins; Polycyclic Sesquiterpenes; Polyisoprenyl Phosphates; Sesquiterpenes; Sesquiterpenes, Guaiane; Terpenes; Volatile Organic Compounds

Cotton (Gossypium hirsutum L.) plants damaged by insects emit a blend of volatiles, including monoterpenes and sesquiterpenes, which can directly repel herbivores and/or indirectly protect the plant by attracting natural enemies of the herbivores. To understand the molecular basis of terpene biosynthesis and regulation in cotton, two terpene synthase genes, GhTPS1 and GhTPS2, were heterologously expressed and characterized. Recombinant GhTPS1 accepted farnesyl pyrophosphate as substrate and produced (E)-β-caryophyllene and α-humulene. GhTPS2 was characterized as a monoterpene synthase which formed α-pinene and β-pinene using geranyl pyrophosphate as substrate. Quantitative real-time PCR analysis revealed that GhTPS1 and GhTPS2 gene expression was elevated after methyl jasmonate (MeJA) treatment in cotton leaves. Moreover, feeding of the green plant bug Apolygus lucorum, a major cotton pest in northern China, resulted in increased GhTPS2 expression in young leaves, suggesting that GhTPS2 might be involved in plant defense in cotton.

Topics: Acetates; Adaptation, Physiological; Alkyl and Aryl Transferases; Animals; Bicyclic Monoterpenes; Bridged Bicyclo Compounds; Carbon-Oxygen Lyases; China; Cyclopentanes; Gene Expression; Genes, Plant; Gossypium; Herbivory; Insecta; Monocyclic Sesquiterpenes; Monoterpenes; Oxylipins; Plant Diseases; Plant Leaves; Plant Proteins; Polycyclic Sesquiterpenes; Polyisoprenyl Phosphates; Sesquiterpenes; Terpenes