Terpene

About: Terpene is a research topic. Over the lifetime, 2208 publications have been published within this topic receiving 51480 citations. The topic is also known as: terpenes.

Terpenes Emitted to Air from Forestry and the Forest Industry

Abstract: A major environmental concern with respect to hydrocarbon emissions is the formation of phytotoxic photooxidants. The work reported in this thesis focusses on the poorly studied anthropogenic terpene emissions from the industrial use of softwood. The advanced analytical determinations were made by adsorption sampling followed by thermal desorption and gas chromatography in the laboratory. Monoterpenes from forestry were analyzed for Scots pine (Pinus sylvestris) and Norway spruce (Picea abies). Near to a harvester, the total monoterpene concentrations reached ~1000 mg/m 3 , whereas the background level was ~1 mg/m 3 . Prominent monoterpenes were a-pinene, b-pinene, 3-carene, camphene, limonene, b-phellandrene, myrcene and terpinolene. Local formation of phytotoxic photooxidants may occur because of the short lifetimes of terpenes in air. Terpenes in process emissions and plumes from kraft pulp industries were found to have a uniform composition similar to that of pulpwood and of recovered sulphate turpentine. Predominant monoterpenes were a-pinene and 3-carene from Scots pine. The emitted terpenes give rise to photooxidants and to oxidation of co-emitted sulphur and nitrogen oxides. The monoterpenes in emissions from industries producing stone groundwood and thermomechanical pulp were similar in composition to that of the processed pulpwood from Norway spruce. The major monoterpenes were a-pinene (>50%) and b-pinene (~25%). The process emissions from a sulphite mill consisted mainly of p-cymene, formed from spruce monoterpenes by acid rearrangements. The terpene emissions from the barking of timber and pulpwood differed somewhat in composition from that of the wood. Increased proportions of b-phellandrene and myrcene were observed for Norway spruce. Oxidative decomposition and acid rearrangements of monoterpenes in the sampling cartridges were studied as major analytical difficulties. Pretreatment with thiosulphate and hydrogencarbonate prevented unwanted reactions of the terpenes.

Natürlich vorkommende Terpen-Derivate, XXXV. Synthese der Ferula-Terpene

Abstract: Ausgehend von dem Trimetyleyclohexadien-carbaldehyd 3 wurden die racemischen Terpene 1, 5, 6 und 8 synthetisiert. Der entscheidende Schritt ist die schwierige allylische Substitution. Naturally Occuring Terpene Derivatives, XXXVI. Synthesis of the Ferula-Terpenes Starting with the trimethyleyclohexadiene carbaldehyde 3 the racemic terpenes 1, 5, 6 and 8 has been synthesized. The crucial step is the difficult allylic substitution.

Volatile Flavor Compounds in Commercial Vinegar Beverages Derived from Fruits

Abstract: This study compared volatile flavor profiles of 4 commercial vinegar beverages (Italian vinegar beverage (IVB), Japanese vinegar beverage (JVB), Japanese Yuzu-Ponz (JYP), and Korean white wine vinegar beverage (KWVB)). Flavor components of vinegar beverages (VBs) were determined using SPME/GC/MSD. The profiles of VBs were as follows; IVB (11 acids, 17 esters, 10 alcohols, 8 aldehydes, 3 terpenes, 4 aromatic hydrocarbons, 9 ketones), JVB (7 acids, 8 esters, 9 alcohols, 7 aldehydes, 13 terpenes, 7 aromatic hydrocarbons, 1 ketones, 3 miscellaneous compounds), JYP (3 acids, 12 esters, 8 alcohols, 7 aldehydes, 63 terpenes, 6 aromatic hydrocarbons, 2 ketones, 5 miscellaneous compounds), KWVB (10 acids, 10 esters, 9 alcohols, 8 aldehydes, 2 terpenes, 5 aromatic hydrocarbons, 4 ketones, 2 miscellaneous compounds). IVB and JVB showed similar flavor compositions (acids, ketones and esters in particular), whereas major components in JYP and KWVB were terpenes (79.6%) and acids (81.0%), respectively. Five compounds including 2-phenylethyl acetate (floral, fruity, sweet odor), 2-phenylethanol (floral, rose odor), vitispirane (fruity odor), geranylacetone (fragrant odor) and acetic acid were identified as major components in balsamic vinegar beverages.

Volatile Metabolomic Composition of Vitex Species: Chemodiversity Insights and Acaricidal Activity.

Abstract: The Vitex genus (Lamiaceae) produces a plethora of metabolites that include ecdysteroids and terpenoids, some of which have demonstrated insect repellent properties. The volatile composition of several members of this genus has not been chemically defined, as many taxa are endemic to remote ecosystems. In this study, leaves were collected from the northeast of Brazil from Vitex capitata, V. megapotamica, V. gardneriana and V. rufescens plants and examined for their chemical profile via GC-MS/FID of essential oil extracts. The analyses showed a diversity of terpenoids. Of particular note were seven-member ring sesquiterpenes which were present in great abundance; a dendrogram showed clades separating by the production of (+)-bicyclogermacrene, aromadendrane and 5,10-cycloaromadendrane sesquiterpenoids for the four species. Comparison of volatile metabolite profiles to 13 other Vitex species showed strong similarities in the production of some monoterpenes, but varied by their production of larger terpenes, especially those with gem-dimethylcyclopropyl subunits on seven-member ring compounds. From this work, we suggest that the sesquiterpene skeleton with seven member rings is a good chemosystematic biomarker candidate for the Vitex genus. Separation using this biomarker was then validated using Inter-Simple Sequence Repeat (ISSR) profiling. Lastly, experiments examining the toxicity of these four oils against the coconut mite A. guerreronis showed that only the oil of V. gardneriana had strong acaricidal activity, with an LC50 of 0.85 mg/mL, thus demonstrating its potential for use as a natural pesticide.