Abstract The heat capacity of different mixtures terpenes (α-pinene, β-pinene, limonene oxide) and solvents (acetone, toluene, ethyl acetate) at atmospheric pressure (85.1 kPa atm in Medellin, Colombia) were measured using a microcalorimeter several terpene molar fractions from room temperature to value close the solvent boiling point. analyzed acetone + α-pinene 298.15 323.15 K, toluene oxide ...

Ips pini bark beetles use myrcene hydroxylases to produce the aggregation pheromone component, ipsdienol, from myrcene. The enantiomeric ratio of pheromonal ipsdienol is an important prezygotic mating isolation mechanism of I. pini and differs among geographically distinct populations. We explored the substrate and product ranges of myrcene hydroxylases (CYP9T2 and CYP9T3) from reproductively-i...

Epoxides have recently been identified as important intermediates in the gas phase oxidation of hydrocarbons, and their hydrolysis products have been observed in ambient aerosols. To evaluate the role of epoxides in the formation of secondary organic aerosols (SOA), the kinetics and mechanism of heterogeneous reactions of two model epoxides, isoprene oxide and α-pinene oxide, with sulfuric acid...

A recent outbreak of mountain pine beetle (MPB) has spread over more than 25 million hectares of pine forests in western North America, affecting pine species of sensitive boreal and mountain ecosystems. During initial host colonization, female MPB produce and release the aggregation pheromone trans-verbenol to coordinate a mass attack of individual trees. trans-Verbenol is formed by hydroxylat...

−− The kinetics of the gas-phase isomerization of β-pinene over an acid-activated bentonite clay has been investigated in a fixed-bed continuous flow reactor, at atmospheric pressure between 58 and 90 C. The major isomers produced were camphene, α-pinene and limonene. The reaction rates of β-pinene conversion and the apparent activation energy were determined. The kinetics of β-pinene isomeriza...

The aim of this study was to determine the volatile components Helichrysum arenarium (L.) Moench subsp. aucheri that belongs genus, belonging Asteraceae family, one important families for Turkey and generally known as ‘ölmez çiçek, altın otu or mantuvar’ in Turkey. To components, leaves flowers specimens were collected from Isparta Aksu Adana Feke villages Turkey, dried at room temperature. The...

Introduction & Aim: Plant growth regulators (PGR) have same effect as natural plant's hormones and can change the main components in plant samples. Chaerophyllum aureum L. is related to Apiaceae family. Experimental: In this paper the qualitative and quantitative composition of the volatile oils of ‎Chaerophyllum aureum L. were reported after using different...

Laboratory chambers, invaluable in atmospheric chemistry and aerosol formation studies, are subject to particle and vapor wall deposition, processes that need to be accounted for in order to accurately determine secondary organic aerosol (SOA) mass yields. Although particle wall deposition is reasonably well understood and usually accounted for, vapor wall deposition is less so. The effects of ...

The elemental composition of laboratory chamber secondary organic aerosol (SOA) from glyoxal uptake, α-pinene ozonolysis, isoprene photooxidation, single-ring aromatic photooxidation, and naphthalene photooxidation is evaluated using Aerodyne high-resolution time-of-flight mass spectrometer data. SOA O/C ratios range from 1.13 for glyoxal uptake experiments to 0.30–0.43 for α-pinene ozonolysis....

The following study deals with the chemical composition, antioxidant and antimicrobial activity of essential oils of Wedelia prostrata and their main constituents in vitro. A total of 70 components representing 99.26 % of the total oil were identified. The main compounds in the oil were limonene (11.38 %) and α-pinene (10.74 %). Antioxidant assays (1,1-diphenyl-2-picrylhydrazyl, superoxide anio...