caryophyllene and zingiberene

The chemical composition of essential oils obtained from the hydrodistillation of different parts of Amomum maximum Roxb and Amomum muricarpum C. F. Liang & D. Fang (Zingiberaceae) grown in Vietnam are reported. The analysis was performed by means of gas chromatography-flame ionisation detectoorand gas chromatography coupled with mass spectrometry. The major compounds identified in the oils of A. maximum were β-pinene (20.4-40.8%), α-pinene (6.8-15.0%), β-elemene (2.5-12.8%) and β-caryophyllene (2.3-10.3%). Moreover, β-phellandrene (11.6%) was present in the root oil. The main compound identified in all the oil samples of A. muricarpum was α-pinene (24.1-54.7%) and β-pinene (9.2-25.9%). In addition, limonene (7.4%) and δ-3-carene (9.4%) were present in the leaves and stem oils, respectively. However, while β-phellandrene (8.3%) could be seen prominent in the root oil, the fruits contained significant amount of zingiberene (6.3%). The largest amount of τ-muurolol (13.0%) was found in the flower oil.

Topics: Amomum; Bicyclic Monoterpenes; Bridged Bicyclo Compounds; Cyclohexane Monoterpenes; Cyclohexenes; Gas Chromatography-Mass Spectrometry; Limonene; Monocyclic Sesquiterpenes; Monoterpenes; Oils, Volatile; Plant Leaves; Plant Oils; Plant Roots; Plant Stems; Polycyclic Sesquiterpenes; Sesquiterpenes; Terpenes; Vietnam; Volatile Organic Compounds

The variation of the essential-oil composition among ten wild populations of Stachys lavandulifolia VAHL (Lamiaceae), collected from different geographical regions of Iran, was assessed by GC-FID and GC/MS analyses, and their intraspecific chemical variability was determined. Altogether, 49 compounds were identified in the oils, and a relatively high variation in their contents was found. The major compounds of the essential oils were myrcene (0.0-26.2%), limonene (0.0-24.5%), germacrene D (4.2-19.3%), bicyclogermacrene (1.6-18.0%), δ-cadinene (6.5-16.0%), pulegone (0.0-15.1%), (Z)-hex-3-enyl tiglate (0.0-15.1%), (E)-caryophyllene (0.0-12.9), α-zingiberene (0.2-12.2%), and spathulenol (1.6-11.1%). For the determination of the chemotypes and the chemical variability, the essential-oil components were subjected to cluster analysis (CA). The five different chemotypes characterized were Chemotype I (germacrene D/bicyclogermacrene), Chemotype II (germacrene D/spathulenol), Chemotype III (limonene/δ-cadinene), Chemotype IV (pulegone), and Chemotype V (α-zingiberene). The high chemical variation among the populations according to their geographical and bioclimatic distribution imposes that conservation strategies of populations should be made appropriately, taking into account these factors. The in situ and ex situ conservation strategies should concern all populations representing the different chemotypes.

Topics: Acyclic Monoterpenes; Alkenes; Cyclohexane Monoterpenes; Cyclohexenes; Gas Chromatography-Mass Spectrometry; Iran; Limonene; Monocyclic Sesquiterpenes; Monoterpenes; Oils, Volatile; Polycyclic Sesquiterpenes; Sesquiterpenes; Sesquiterpenes, Germacrane; Stachys; Terpenes

Sorghum (Sorghum bicolor) plants damaged by insects emit a blend of volatiles, predominantly sesquiterpenes, that are implicated in attracting natural enemies of the attacking insects. To characterize sesquiterpene biosynthesis in sorghum, seven terpene synthase (TPS) genes, SbTPS1 through SbTPS7, were identified based on their evolutionary relatedness to known sesquiterpene synthase genes from maize and rice. While SbTPS6 and SbTPS7 encode truncated proteins, all other TPS genes were determined to encode functional sesquiterpene synthases. Both SbTPS1 and SbTPS2 produced the major products zingiberene, β-bisabolene and β-sesquiphellandrene, but with opposite ratios of zingiberene to β-sesquiphellandrene. SbTPS3 produced (E)-α-bergamotene and (E)-β-farnesene. SbTPS4 formed (E)-β-caryophyllene as the major product. SbTPS5 produced mostly (E)-α-bergamotene and (Z)-γ-bisabolene. Based on the genome sequences of sorghum, maize and rice and the sesquiterpene synthase genes they contain, collinearity analysis identified the orthologs of sorghum sesquiterpene synthase genes, except for SbTPS4, in maize and rice. Phylogenetic analysis implied that SbTPS1, SbTPS2 and SbTPS3, which exist as tandem repeats, evolved as a consequence of local gene duplication in a lineage-specific manner. Structural modeling and site-directed mutagenesis experiments revealed that three amino acids in the active site play critical roles in defining product specificity of SbTPS1, SbTPS2, SbTPS3 and their orthologs in maize and rice. The naturally occurring functional variations of sesquiterpene synthases within and between species suggest that multiple mechanisms, including lineage-specific gene duplication, subfunctionalization, neofunctionalization and pseudogenization of duplicated genes, have all played a role in the dynamic evolution of insect-induced sesquiterpene biosynthesis in grasses.

Topics: Alkyl and Aryl Transferases; Animals; Biological Evolution; Bridged Bicyclo Compounds; Catalytic Domain; Gene Duplication; Herbivory; Insecta; Monocyclic Sesquiterpenes; Mutagenesis, Site-Directed; Oryza; Phylogeny; Plant Proteins; Polycyclic Sesquiterpenes; Sesquiterpenes; Sorghum; Volatile Organic Compounds; Zea mays

Curcuma longa (Zingiberaceae) is a native plant of southern Asia and is cultivated extensively throughout the warmer parts of the world. Jianghuang and Yujin are rhizome and tuberous root of C. longa, respectively, which were traditionally used as two Chinese medicines. In this paper, pressurized liquid extraction (PLE) and gas chromatography-mass spectrometry (GC-MS) were developed for quantitative determination/estimation of eight characteristic compounds including beta-caryophyllene, ar-curcumene, zingiberene, beta-bisabolene, beta-sesquiphellandrenendrene, ar-turmerone, alpha-turmerone and beta-turmerone in Jianghuang and Yujin. A HP-5MS capillary column (30 m x 0.25 mm i.d.) coated with 0.25 microm film 5% phenyl methyl siloxane was used for separation and selected ion monitoring (SIM) method was used for quantitation. Hierarchical cluster analysis based on characteristics of eight identified peaks in GC-MS profiles showed that 10 samples were divided into two main clusters, Jianghuang and Yujin, respectively. Four components such as ar-curcumene, ar-turmerone, alpha-turmerone and beta-turmerone were optimized as markers for quality control of rhizome (Jianghuang) and tuberous root (Yujin), which are two traditional Chinese medicines, from Curcuma longa.

Topics: Chromatography, High Pressure Liquid; Cluster Analysis; Curcuma; Curcumin; Drugs, Chinese Herbal; Gas Chromatography-Mass Spectrometry; Ketones; Molecular Structure; Monocyclic Sesquiterpenes; Plant Tubers; Polycyclic Sesquiterpenes; Quality Control; Rhizome; Sesquiterpenes; Technology, Pharmaceutical; Toluene