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Triclosan (TCS), an antiseptic agent that facilitates the formation of microbial resistances, has been widely used and is therefore ubiquitously detectable in wastewater. However, structure and low water solubility limit both microbial transformation kinetic and removal efficiency of TCS. Therefore, the use of solubilizers or non-aqueous phases (NAP) appears to be a suitable approach for rapid, complete, and cost-effective treatment of highly contaminated TCS point sources such as sports clubs, hospitals, industrial wastewater treatment plants or synthesis effluents without dilution effects.The mixed culture TCSmix100 previously isolated and characterized, and able to completely mineralize TCS at stoichiometric chloride release, was investigated in presence or absence of solubilizers in lab-scale well stirred batch reactors. While TCS conversion was limited in solubilizer-free tests due to limited solubility of TCS crystals within the aqueous phase, solubilizers enhanced water solubility, mass transport and microbial kinetics. Thus, TCS transformation rate at initial 1.45 g TCS L−1 was further increased from a high level of 155–172 mg L−1 d−1 without solubilizers to 399 mg L−1 d−1 or to 888 mg L−1 d-1 providing β-pinene or α-pinene as NAPs, i.e., by a factor of 2.3–5.2, exceeding kinetic parameters of other strains described in literature by at least two orders of magnitude. These results clearly demonstrate the high TCS mineralization capacity of this biphasic treatment technologies and its applicability in treatment of highly contaminated TCS point-sources to eliminate recalcitrant contaminants at high levels before getting diluted.

Arizona Cypress is one of the drought-resistant, aromatic, and aesthetically pleasing trees having several pharmacological uses. Certain microorganisms contribute to the secondary metabolism and synthesis of bioactive compounds in aromatic and medicinal plants. This study aimed to determine the photosynthetic pigments, total phenolic content, antioxidant capacity, and essential oil composition of Arizona cypress under two irrigation regimes and microbial inoculations. We established a factorial experiment with three mycorrhizae inoculations (Rhizophagusirregularis, Funneliformismosseae, and a mixture of R.irregularis and F.mosseae), a rhizobacterium inoculation (Pseudomonasfluorescens), and two irrigation regimes (well-watered and water stress). Under the water stress regime, seedlings inoculated with F.mosseae (0.46%) and non-inoculated control plants (0.29%) had the highest and lowest essential oil contents, respectively. GC–MS analysis revealed that limonen, a-pinene, terpinen-4-ol, and umbellulone were the most abundant compounds in the seedlings and treatments under study. The water stress regime had a significant and dominant effect on essential oil and antioxidant capacity, whereas seedling growth and photosynthetic pigments tended to decrease under stress conditions. However, co-inoculation of seedlings with mycorrhizae and the bacterium resulted in an increase in phenolic compounds and carotenoids. Under conditions of water stress and mycorrhizal symbiosis, the results of the current study may help increase the level of valuable compounds in Arizona cypress for further pharmaceutical applications. [ABSTRACT FROM AUTHOR]

Saffron is a spice derived from the flower of Crocus sativus L., which has a special aroma, colour and odour influencing positively its economic value. In this context, ten saffron ecotypes were screened for their biochemical composition and antioxidant activity. The samples were also analysed using GC‐MS and LC‐MS to determine their content of volatile and phenolic compounds, respectively. The results revealed statistically significant differences among samples based on moisture (9.09%‐11.23%), total phenols (31.62‐62.71 mg EAG/g), total flavonoids (23.02‐40.02 mg ER/mg), total carotenoids (66.12‐155.05 μg/g), picrocrocin (88.99‐121.53), crocin (137.44‐228.39) and safranal (26.56‐53.04). The radical scavenging activity ranged from 17.09% to 29.53% for DPPH assay, and oscillated from 0.128 mmol AAE/g to 0.239 mmol AAE/g for ABTS test, while the ferric reducing antioxidant potency (FRAP) varied from 0.974 to 1.989 mmol Fe2+/g. Gas chromatography‐mass spectrometry (GC‐MS) analysis identified 66 volatile compounds, among which the Safranal and Isophorone were the most abondant. The ES1 from Taliouine recorded a very distinct volatile composition compared to the others ecotypes with 22 authentic volatile compounds. Moreover, liquid chromatography‐ mass spectrometry (LC‐MS) analysis revealed 14 phenolic compounds with picrocrocin and crocin were found to be the major compounds. The principal component analysis classified the investigated ecotypes into two mean distinctive sets with ES1 and ES9 were distinguished as a single items. The α‐pinene, β‐pinene, limonene, anethole, acetic acid, ketoisophorone, isophorone, safranal, thymoquinone, total flavonoids, FRAP and total carotenoids, are the main discriminant variables. The two‐dimensional analysis of the clustered heatmaps divided showed a relatively similar patterns as the principal component analysis (PCA) and confirmed the singularity of the sample ES1 based on its particular volatile profile dominated mainly by α‐terpinyl acetate, methyleugenol, copaene, anethole, limonene, methyl‐cyclopentane, which were not identified in the other samples even at minor levels. These findings herein found revealed the high quality of Moroccan saffron, which is very important for the species breeding and valorization. [ABSTRACT FROM AUTHOR]

[Objectives] This article simulated different temperature fluctuation conditions[-1 ℃, (-1±3)℃, (-1±5)℃], and explored the effect of precise temperature control technology on the preservation of fresh pork during ice-temperature storage. [Methods] The longest pig dorsal muscle was selected as the study object. Total viable counts, volatile base nitrogen, sensory evaluation and volatile organic compounds were determined to study the changes in the quality of fresh pork stored at ice temperature under precise temperature control. [Results] The results indicated that the quality and shelf life of fresh pork during ice-temperature storage were significantly affected by temperature fluctuations. After storage for 12 days, total viable counts in two fluctuating groups increased significantly, TVB-N content were significantly higher than that of -1 ℃ group. The sensory scores of two fluctuation groups were significantly reduced, and the odour was significantly different compared with -1 ℃ group. GC-IMS results showed that the contents of butanal, 2-heptanone, 2-pentanone, ethyl acetate, isoamyl acetate, isopropyl acetate, alpha pinene, styrene and methylpyrazine significantly increased in two fluctuating groups. There was no significant difference of the total viable counts, TVB-N and sensory indicators between two fluctuating groups in the middle and late storage period. [Conclusions] The shelf life of fresh pork in two fluctuation groups [(-1±3)℃ and(-1±5)℃] were shorter than that of -1 ℃ group by 2-3 days, and the stable ice-temperature storage (-1 ℃) was more conducive to maintaining the quality of fresh pork. [ABSTRACT FROM AUTHOR]

Orange peels (Citrus sinensis) are an abundant lignocellulosic residue that can be used as a carbon source to obtain solids with catalytic potential in the transformation of terpenes and their oxides into value-added products. This research seeks to evaluate the isomerization of a-pinene epoxide to campholenic aldehyde using a catalyst obtained from orange peels. The material OAC-Zn was obtained by activation of orange peel with ZnSO4.7H2O followed by thermal treatment at 500 °C; an additional solid was obtained from orange peel by pyrolysis at 500 °C (OC-500). XRD revealed the presence of ZnO and ZnS in OAC-Zn; TGA analysis indicated thermal stability in OAC-Zn and OC-500 materials; SEM images showed porous surfaces of different morphology, and the presence of microporosity in OC-500 and mesoporosity in the OAC-Zn that was confirmed by physical nitrogen adsorption. The elements C, O, Zn and S were identified in OAC-Zn by EDX analysis. The results of TPD-NH3 showed that the solids contained medium and weak acidity. Campholenic aldehyde was synthesized with a 96 % selectivity over the material OAC-Zn. [ABSTRACT FROM AUTHOR]

Terpene epoxides such as limonene dioxide are known as a very important intermediates for developing biological resins such as non-isocyanate polyurethanes. Recently, the dimethyldioxirane (DMDO) epoxidation technique has attracted attention and studies are being carried out to epoxidize terpenes. This study focuses on the epoxidation of hydrophobic terpene such as limonene and pinene by DMDO generated in-situ in a microemulsion system, examining the efficacy of cetyltrimethylammonium hydrogen sulfate (CTAHS) as a surfactant to homogenize the limonene and pinene in the aqueous reaction medium. The application of CTAHS showed a significant advantage for the epoxidation reaction. 100% limonene dioxide (LDO) and α-pinene oxide yields are obtained with molar ratios of only 1.6 for oxone/limonene and 0.9 for oxone/α-pinene respectively, after 30 min. The application of CTAHS resulted in a significant reduction in acetone content so that it just plays the role of a catalyst; Only an acetone/water volume ratio of up to 1:9 was sufficient to obtain these results. The reaction volume is therefore completely reduced and the amount of oxone required is almost 50% less than with the conventional biphasic organic solvent/water reaction medium. The separation of the epoxides from the aqueous medium and the surfactant (CTAHS) is easily done by liquid-liquid extraction. The main advantages of this technology are the use of acetone as a catalyst, which can be recycled indefinitely, the high selectivity of the epoxides without any by-products and the exclusion of the use of any organic solvent. [Display omitted] • Epoxidation of limonene and pinene by dioxirane generated from oxone. • Limonene dioxide and pinene oxide as bio-monomers or green monomers. • Green epoxides for the synthesis of green resins or polycarbonates. • Free-catalyst synthesis of green epoxides by dimethyl dioxirane. • Epoxidation of limonene and pinene in microemulsions by dioxirane. [ABSTRACT FROM AUTHOR]

Many recent secondary organic aerosol (SOA) studies mainly focus on biogenic SOA particles formed under low NO x conditions and thus are applicable to pristine environments with minor anthropogenic influence. Although interactions between biogenic volatile organic compounds and NO x are important in, for instance, suburban areas, there is still a lack of knowledge about the volatility and processes controlling the evaporation of biogenic SOA particles formed in the presence of high concentrations of NO x. Here we provide detailed insights into the isothermal evaporation of α -pinene SOA particles that were formed under low NO x and high NO x conditions to investigate the evaporation process and the evolution of particle composition during the evaporation in more detail. We coupled Filter Inlet for Gases and AEROsols-Chemical Ionization Mass Spectrometer (FIGAERO-CIMS) measurements of the molecular composition and volatility of the particle phase with isothermal evaporation experiments conducted under a range of relative humidity (RH) conditions from low RH (<7 % RH) to high RH (80 % RH). Very similar changes were observed in particle volatility at any set RH during isothermal evaporation for the α -pinene SOA particles formed under low NO x and high NO x conditions. However, there were distinct differences in the initial composition of the two SOA types, possibly due to the influence of NO x on the RO 2 chemistry during SOA formation. Such compositional differences consequently impacted the primary type of aqueous-phase processes in each type of SOA particle in the presence of particulate water. [ABSTRACT FROM AUTHOR]

The needles of the Aleppo pine (Pinus halepensis) (PA) are very abundant in the forest of the National Park of Tazekka (Ta-za-Morocco) and are unexploitable. Moreover, they constitute a potential danger because they facilitate the outbreak of wildfires. To solve this problem, we have considered turning these needles into a biomaterial that could be used as raw material for different uses, such as wastewater treatment. The biomaterial of the Aleppo pine is obtained from its needles which are harvested in spring, dried, cut, crushed, and sieved. The powder obtained is analyzed before and after the extraction of essential oil. The physicochemical and spectroscopic analyses show that this biomaterial is porous, hygroscopic, slightly acidic, moderately moist, and not very conducive. Its average density in the anhydrous state is 0.6. It is rich in carbon (79.91%) and oxygen (18.91%) in the form of aromatic compounds and ketone imprints; thus, relating the presence of cellulose, pectin, lignin, and hemicellulose. Its composition in mineral elements (Na, Mg, Ca, K, Cl, S) is deficient. Gas chromatographymass spectrometry (GC-MS) analysis of the oils extracted from the needle powder relates that it is a complex mixture of bioactive compounds such as mono-terpenoid α and β-pinene hydrocarbons. These results show that our biomaterial can be used as an adsorbent in wastewater treatment and the extracted essential oils can be used in the pharmacological, agro-food field. [ABSTRACT FROM AUTHOR]

We report Pd‐catalyzed cyclotrimerization of (+)‐α‐bromoenone, obtained from monoterpene β‐pinene, into an enantiopure cyclotrimer. This C3 symmetric compound has three bicyclo[3.1.1]heptane rings fused to its central benzene with each ring carrying a carbonyl group. The cyclotrimer undergoes diastereoselective threefold alkynylation with the lithium salts of five terminal alkynes (41–63 %, de=4–83 %). The addition enabled a rapid synthesis of a small library of novel chiral cavitands that, in shape, resemble a tripod stand. These molecular tripods include a tris‐bicycloannelated benzene head attached to three alkyne legs twisted in one direction to form a nonpolar cavity with polar groups as feet. Tripods with methylpyridinium and methylisoquinolinium legs, respectively, form inclusion complexes with anti‐inflammatory and chiral drugs (R)/(S)‐ibuprofen and (R)/(S)‐naproxen. The mode of binding shows drug molecules docked in the cavity of the host through ion‐ion, cation‐π, and C−H−π contacts that, in addition of desolvation, give rise to complexes having millimolar to micromolar stability in water. Our findings open the door to creating a myriad of enantiopure tripods with tunable functions that, in the future, might give novel chemosensors, catalysts or sequestering agents. [ABSTRACT FROM AUTHOR]

Ducrosia anethifolia Boiss is a medicinal and aromatic plant that is used as a food additive and drug in the areas of natural distribution. In this study, eight populations from different geographical regions of Iran were evaluated for their essential oil composition, total phenolics and flavonoids as well as for free radical scavenging activity during two consecutive years under water deficit. Analysis of variance was performed using a randomized block design at three levels of irrigation and 2 years, using the GLM procedure of SAS software and cluster analysis was used according to Ward's method using squared Euclidean dissimilarity. The highest essential oil and total phenolics/flavonoids content were obtained in the second year. GC–MS analysis was used to analyze the essential oil components. In normal conditions, cis-chrysanthenyl acetate (39.1–66.4%) and α-pinene (1.02–4.7%) were recognized as major compounds. The essential oil components were elevated under water stress. The highest increase in cis-chrysanthenyl acetate (21.32%) in response to water stress was observed in Abarkuh1. Elevation in total phenolic, flavonoid and antioxidant activity was also observed in plants subjected to water deficit. The highest content of phenolic acids was measured in Semirom (136.74 mg TAE/g DW), while the highest flavonoid content was in Kerman (6.05 mg QUE/g DW) in severe water stress condition. Finally, a high diversity in the studied populations can be used to select advantageous populations for other pharmaceutical and food purposes. [ABSTRACT FROM AUTHOR]

Secondary organic aerosol (SOA) contributes significantly to ambient fine particulate matter that affects climate and human health. Monoterpenes represent an important class of biogenic volatile organic compounds (VOCs) and their oxidation by nitrate radicals poses a substantial source of SOA globally. Here, we investigate the formation and properties of SOA from nitrate radical oxidation of two common monoterpenes, α-pinene and limonene. When two monoterpenes are oxidized simultaneously, we observe a ~50% enhancement in the formation of SOA from α-pinene and a ~20% reduction in limonene SOA formation. The change in SOA yields is accompanied by pronounced changes in aerosol chemical composition and volatility. These non-linear effects are not observed in a sequential oxidation experiment. Our results highlight that unlike currently assumed in atmospheric models, the interaction of products formed from individual VOCs should be accounted for to accurately describe SOA formation and its climate and health impacts. Tiny airborne particles play a critical role in two major environmental issues: climate change and air pollution. Our study highlights the important, yet often overlooked non-linear interaction of organic compounds on the formation of such particles. [ABSTRACT FROM AUTHOR]

Optically active polymers are of great interest as materials for dense enantioselective membranes, as well as chiral stationary phases for gas and liquid chromatography. Combining the versatility of norbornene chemistry and the advantages of chiral natural terpenes in one molecule will open up a facile route toward the synthesis of diverse optically active polymers. Herein, we prepared a set of new chiral monomers from cis-5-norbornene-2,3-dicarboxylic anhydride and chiral alcohols of various natures. Alcohols based on cyclic terpenes ((-)-menthol, (-)-borneol and pinanol), as well as commercially available alcohols (S-(-)-2-methylbutanol-1, S-(+)-3-octanol), were used. All the synthesized monomers were successfully involved in ring-opening metathesis polymerization, affording polymers in high yields (up to 96%) and with molecular weights in the range of 1.9 × 105–5.8 × 105 (Mw). The properties of the metathesis polymers obtained were studied by TGA and DSC analysis, WAXD, and circular dichroism spectroscopy. The polymers exhibited high thermal stability and good film-forming properties. Glass transition temperatures for the prepared polymers varied from −30 °C to +139 °C and, therefore, the state of the polymers changed from rubbery to glassy. The prepared polymers represent a new attractive platform of chiral polymeric materials for enantioselective membrane separation and chiral stationary phases for chromatography. [ABSTRACT FROM AUTHOR]

Cockroaches are urban pests that are very difficult to control. Using repellents is a green, safe and effective strategy for their control. In order to find novel cockroach repellents, the repellent activity of 45 bridged-ring terpenoid derivatives synthesized from β-pinene against Blattella germanica was tested. The relationship between the molecular structure of these bridged-ring terpenoid derivatives and their repellent activity against Blattella germanica was also analysed. The results show that some of the bridged-ring terpenoid derivatives exhibit good repellent activity against Blattella germanica, and six compounds (RR = 60.44–87.32%) show higher repellent activity against Blattella germanica than DEET (RR = 54.77%), making them promising for development as new cockroach repellents. Quantitative structure–activity relationship (QSAR) analysis revealed that the HOMO-1 energy, Kier and Hall index (order 2), Balaban index, and relative positive charged surface area of bridged-ring terpenoid derivatives have effects on repellent activity against Blattella germanica. The present study may provide a theoretical basis for the high-value use of β-pinene and can be helpful to the development of novel repellents against Blattella germanica. [ABSTRACT FROM AUTHOR]

The aryl hydrocarbon receptor (AhR) and aryl hydrocarbon receptor nuclear translocator (ARNT) belong to the bHLH-PAS (basic Helix–Loop–Helix–Period/ARNT/Single-minded) family of transcription factors, which participate in the sensing and transmitting stimuli of exogenous and endogenous chemical substances, and subsequently activates genes transcription involved in various detoxification and physiological functions. However, they have not been identified in Dendroctonus armandi, and their roles in the detoxification metabolism are unclear. In the present study, AhR and ARNT of D. armandi were characterized. Spatiotemporal expression profiling indicated that DaAhR and DaARNT were highly expressed in the adult and larval stages of D. armandi and mainly expressed in the midgut and Malpighian tubules of adults. Additionally, the expression of DaAhR and DaARNT significantly increased after exposure to (−)--pinene, (+)-3-carene, and (±)-limonene. Silencing DaAhR and DaARNT increased the susceptibility of D. armandi to (−)--pinene, (+)-3-carene, and (±)-limonene, and the activities of detoxification enzyme were also remarkably reduced. Moreover, DaCYP6DF1 and DaGSTs2 were significantly down-regulated after injections of dsAhR and dsARNT in the male and female adults, with the expression of DaCYP6DF1 decreasing by higher than 70%. The present study revealed that the transcription factors AhR and ARNT of D. armandi were induced by terpenoids and participated in the regulation of DaCYP6DF1 expression, which was associated with D. armandi's susceptibility to (−)--pinene and (±)-limonene. These results may provide a theoretical basis for the integrated control of D. armandi and improve our comprehension of insect toxicology. [ABSTRACT FROM AUTHOR]

Context: Due to the interesting potential of essential oils (EO) against cholinesterases and their close relation in Alzheimer's disease, the EO of Lepechinia betonicifolia (Lam) Epling (Lamiaceae), a native shrub from Ecuador, was assessed. Chemical profiling and enantiomeric distribution were also recorded for the first time. Objective: To analyse the chemical profile including the enantiomeric composition and anticholinesterase effect exerted by EO of L. betonicifolia. Materials and methods: The EO of L. betonicifolia fresh aerial parts was obtained by hydrodistillation in a Clevenger-type apparatus. Physical properties were determined according to standard norms. The chemical composition was determined by GC-MS and GC-FID. Enantioselective GC-MS analysis was carried out by using a capillary chiral column. Anticholinesterase effect was assessed by Ellman's method with acetylthiocoline as substrate and Ellman's reagent (DTNB) to detect its hydrolysis at 405nm for 60 min. Donepezil was used as a reference drug. EO was dissolved in methanol to reach 10 mg/mL concentration and two more 10° dilutions were included. Results: Thirty-nine constituents were identified corresponding to 97.55% of the total oil composition. The main components were b-pinene (30.45%), sabinene (27.98%), a-pinene (4.97%), b-phellandrene (4.79%), E-caryophyllene (4.44%) and limonene (3.84%). L. betonicifolia EO exerted a strong inhibitory effect over the AChE enzyme with an IC50 value of 74.97 ± 1.17 lg/mL. Discussion and conclusions: Current chemical characterisation and anticholinesterase effect of EO of L. betonicifolia encourage us to propose this EO as a candidate for the preparation of functional foods or as adjuvant therapy for Alzheimer's disease. [ABSTRACT FROM AUTHOR]

Terpenes have many applications and are widely found in nature, but recent progress in synthetic biology has enabled the use of microorganisms as chassis cells for the synthesis of these compounds. Candida glycerinogenes (C. glycerinogenes) is an industrial strain that may be developed as a chassis for the synthesis of terpenes since it has a tolerance to hyperosmolality and high sugar, and has a complete mevalonate (MVA) pathway. However, monoterpenes such as pinene are highly toxic, and the tolerance of C. glycerinogenes to pinene was investigated. We also measured the content of mevalonate and squalene to evaluate the strength of the MVA pathway. To determine terpene synthesis capacity, a pathway for the synthesis of pinene was constructed in C. glycerinogenes. Pinene production was improved by overexpression, gene knockdown and antisense RNA inhibition. Pinene production was mainly enhanced by strengthening the upstream MVA pathway and inhibiting the production of by-products from the downstream pathway. With these strategies, yield could be increased by almost 16 times, to 6.0 mg/L. Overall, we successfully constructed a pinene synthesis pathway in C. glycerinogenes and enhanced pinene production through metabolic modification. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the influence of cryogrinding pretreatment on the recovery of essential oil, phenolics and pigments from myrtle leaves. The duration of cryogrinding (3, 6 and 9 min) in combination with the duration of hydrodistillation (30, 60 and 90 min) for the isolation of essential oils and the duration of hydroethanolic extraction (5, 10 and 15 min) for the isolation of phenols and pigments were studied as independent factors in a full factorial design. The major volatile components detected in myrtle leaf essential oil were myrtenyl acetate, 1,8-cineole, α-pinene and linalool. The most abundant phenols detected were myricetin derivatives (myricetin 3-O-galactoside and myricetin 3-O-rhamnoside), galloylquinic acid, myricetin and digalloylquinic acid, while the major pigments were chlorophyll b, pheophytin a and lutein. A 3 min cryogrinding pretreatment significantly increased the yield and concentrations of essential oil volatile compounds and reduced the distillation time to 30 min. A 9 min cryogrinding pretreatment and 15 min extraction resulted in at least 40% higher concentrations of phenolic compounds and pigments in the extracts when compared to the untreated control. According to the results obtained, cryogrinding can significantly increase the yield of myrtle EO and extracts and also modulate their composition. [ABSTRACT FROM AUTHOR]

Copper(II)-containing aluminum phosphate material (CuAPO-5) was synthesized hydrothermally and used as a multiphase catalyst for the oxidation of α-pinene to verbenone. The catalysts were analyzed using X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area techniques, X-ray photoelectron spectroscopy (XPS), and ammonia temperature programmed reduction (NH3-TPD). Scanning electron microscopy (SEM), X-ray energy spectrometry (EDS), inductively coupled plasma emission spectroscopy (ICP-OES), Fourier infrared spectroscopy (FT-IR), and ultraviolet-visible spectroscopy (UV-vis) were performed to characterize the material. The effects of reaction temperature, reaction time, n(α-pinene)/n(TBHP), and solvent on the catalytic performance of CuAPO-5 were investigated. The results show that all the prepared catalysts have AFI topology and a large specific surface area. Copper is evenly distributed in the skeleton in a bivalent form. The introduction of copper increases the acid content of the catalyst. Under the optimized reaction conditions, 96.8% conversion of α-pinene and 46.4% selectivity to verbenone were achieved by CuAPO-5(0.06) molecular sieve within a reaction time of 12 h. CuAPO-5(0.06) can be recycled for five cycles without losing the conversion of α-pinene and the selectivity to verbenone. [ABSTRACT FROM AUTHOR]

The Oseberg Viking ship burial is one of the most extensive collections of Viking wooden artefacts ever excavated in Norway. In the early twentieth century, many of these artefacts were treated with alum in order to preserve them, inadvertently leading to their current degraded state. It is therefore crucial to develop new bioinspired polymers which could be used to conserve these artefacts and prevent further disintegration. Two hydroxylated polymers were synthesised (TPA6 and TPA7), using α-pinene- and oleic acid-derived monomers functionalised with an acrylate moiety. Characterisation using biomolecular hydrodynamics (analytical ultracentrifugation and high precision viscometry) has shown that these polymers have properties which would potentially make them good wood consolidants. Conformation analyses with the viscosity increment (ν) universal hydrodynamic parameter and ELLIPS1 software showed that both polymers had extended conformations, facilitating in situ networking when applied to wood. SEDFIT-MSTAR analyses of sedimentation equilibrium data indicates a weight average molar mass Mw of (3.9 ± 0.8) kDa and (4.2 ± 0.2) kDa for TPA6 and TPA7 respectively. Analyses with SEDFIT (sedimentation velocity) and MultiSig however revealed that TPA7 had a much greater homogeneity and a lower proportion of aggregation. These studies suggest that both these polymers—particularly TPA7—have characteristics suitable for wood consolidation, such as an optimal molar mass, conformation and a hydroxylated nature, making them interesting leads for further research. [ABSTRACT FROM AUTHOR]

Conventional headspace (HS) method could not meet the requirement of analyzing low-abundance volatile compounds in high water content samples. A HS-low water absorption trap technique coupled with gas chromatography–mass spectrometry was introduced to remove the large amount of water vapor; therefore, the low-abundance volatile compounds could be detected with better analytical sensitivity. With this method, a total of 81 volatile compounds were identified from fresh Artemisia annua L. by mass spectral library search, retention index and accurate mass measurement, which could make the qualitative results more accurate and reliable. These compounds belonged to different species, including terpene, cycloparaffin, aliphatic aldehyde, aromatic ketone, aromatic aldehyde and so on. The 2,5,6-trimethyl-1,3,6-heptatriene (8.23%) was the most principal compound, followed by γ-muurolene (6.80%), β-caryophyllenea (6.24%), 1,8-cineol (5.76%), 2-carene (5.65%), borneol (5.57%), isocaryophyllene (4.91%), bornylene (4.78%), camphene (4.30%) and β-pinene (4.26%) as the main components. The results indicated that this method presents a great potential for the trace analysis of volatile compounds in complex high water content samples. [ABSTRACT FROM AUTHOR]

The chemical profiles of Rosmarinus officinalis L. essential oils, collected from five distinct geographical regions in Palestine, were determined using GC-MS. The major phytochemical classes of R. officinalis EOs were monoterpene hydrocarbon (24.81–78.75%) and oxygenated monoterpenoids (19.01–73.78%), with 1,8-cineole (4.81–37.83%), α-pinene (13.07–51.36%), and camphor (11.95–24.30%) being the most abundant components of the studied oils. Using the DPPH assay, the antioxidant activity of EOs revealed that EO from the Jenin region had the highest antioxidant activity, with an IC50 value of 10.23 ± 0.11 µg/mL, followed by samples from Tulkarm (IC50 = 37.15 ± 2.3 µg/mL) and Nablus (IC50= 38.9 ± 0.45 µg/mL). With MICs of 12.5, 12.5, 6.25, 6.25, and 6.25 µg/mL against MRSA, S. aureus, E. coli, K. pneumonia, and P. vulgaris, respectively, the EO extracted from the Jenin region of Palestine had the greatest antibacterial activity. Furthermore, EOs from Jenin and Nablus demonstrated stronger anti-candida action than the pharmaceutical formulation Fluconazole, with MICs of 0.781, 0.781, and 1.56 µg/mL, respectively. [ABSTRACT FROM AUTHOR]

The purposes of this investigatory study were to determine the chemical composition of the essential oils (EOs) of Origanum compactum from two Moroccan regions (Boulemane and Taounate), as well as the evaluation of their biological effects. Determining EOs' chemical composition was performed by a gas chromatography–mass spectrophotometer (GC-MS). The antioxidant activity of EOs was evaluated using free radical scavenging ability (DPPH method), fluorescence recovery after photobleaching (FRAP), and lipid peroxidation inhibition assays. The anti-inflammatory effect was assessed in vitro using the 5-lipoxygenase (5-LOX) inhibition test and in vivo using the carrageenan-induced paw edema model. Finally, the antibacterial effect was evaluated against several strains using the disk-diffusion assay and the micro-dilution method. The chemical constituent of O. compactum EO (OCEO) from the Boulemane zone is dominated by carvacrol (45.80%), thymol (18.86%), and α-pinene (13.43%). However, OCEO from the Taounate zone is rich in 3-carene (19.56%), thymol (12.98%), and o-cymene (11.16%). OCEO from Taounate showed higher antioxidant activity than EO from Boulemane. Nevertheless, EO from Boulemane considerably inhibited 5-LOX (IC50 = 0.68 ± 0.02 µg/mL) compared to EO from Taounate (IC50 = 1.33 ± 0.01 µg/mL). A similar result was obtained for tyrosinase inhibition with Boulemane EO and Taounate EO, which gave IC50s of 27.51 ± 0.03 μg/mL and 41.83 ± 0.01 μg/mL, respectively. The in vivo anti-inflammatory test showed promising effects; both EOs inhibit and reduce inflammation in mice. For antibacterial activity, both EOs were found to be significantly active against all strains tested in the disk-diffusion test, but O. compactum EO from the Boulemane region showed the highest activity. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) for O. compactum EO from the Boulemane region ranged from 0.06 to 0.25% (v/v) and from 0.15 to 0.21% (v/v) for O. compactum from the Taounate region. The MBC/MIC index revealed that both EOs exhibited remarkable bactericidal effects. [ABSTRACT FROM AUTHOR]

[Display omitted] • A synthetic route to novel high-energy–density biofuels from α-pinene. • Alkylation of α-pinene with lignin-based phenols followed by hydrodeoxygenation. • Potential biomass-based high-energy–density fuels with favorable properties. The present work investigated the alkylation performance of various lignin-based phenols as carbon-increasing blocks for α-pinene to create novel biomass-based high-energy–density fuels (HEDFs). H 3 PW 12 O 40 (HPW) was identified as an effective catalyst for the Friedel-Crafts alkylation of α-pinene and phenol substrates, with guaiacol showing the highest activity followed by phenol, anisole, 4-methylguaiacol, 4-ethylguaiacol, and 4-propylguaiacol. Moreover, guaiacol also displayed the best selectivity for monoalkylated products. Blended alkylated products of phenol, anisole, and guaiacol could be fully hydrodeoxygenated under the catalysis of HPW and Pd/C. However, the dialkylated components from 4-methylguaiacol, 4-ethylguaiacol, and 4-propylguaiacol were challenging to hydrodeoxygenation under the same conditions. After vacuum distillation, all refined products from different phenol substrates exhibited promising fuel properties, suggesting the potential for developing high-energy–density biofuels from α-pinene and lignin-based phenols using the approach outlined in this work. [ABSTRACT FROM AUTHOR]

Essential oils possess significant antimicrobial and antioxidant properties and are increasingly used as natural substitutes for food preservation. Therefore, this study investigated the potential application of rosemary essential oil (REO) and REO nano-emulsion in the dairy plant. The antimicrobial effects of REO and REO nano-emulsion were determined by an agar well diffusion assay after chemical profiling by Gas Chromatography-Mass Spectrometry (GC–MS). The REO nano-emulsion was characterized by a Transmission Electron Microscope (TEM). The REO chemical profile revealed the presence of 42 chemical compounds, including 1, 8-cineole (9.72 %), and α-pinene (5.46 %) as major active components. REO nano-emulsion demonstrated significant antimicrobial activity compared to REO (P < 0.05) with a MIC value of 0.0001 mg/ml against Listeria monocytogenes and Aspergillus flavus and 0.001 mg/ml against Pseudomonas aeruginosa and Bacillus cereus. REO nano-emulsion enhanced the oxidative stability of pasteurized fresh cream, revealing a non-significant difference compared with that inoculated with butylated hydroxy anisol (BHA; synthetic antioxidant) (P ˃ 0.05). Fortified cream and Karish cheese with REO nano-emulsion were evaluated organoleptically, and the results showed higher grades of overall acceptability when compared to control samples with a statistically significant difference (P < 0.05). Viability studies were estimated using the previously mentioned microorganisms in fortified fresh cream and Karish cheese with REO nano-emulsion. Results of the fortified cream showed a complete reduction of L. monocytogenes , A. flavus , and B. cereus on days 5, 7, and 10, respectively, and a 96.93 % reduction of P. aeruginosa by the end of the storage period. Regarding Karish cheese viability studies, C. albicans , A. flavus , and P. aeruginosa exhibited complete reduction on days 10, 10, and 15 of storage, respectively. In conclusion, REO nano-emulsion was recommended as a natural, safe, and effective antimicrobial and antioxidant additive in the dairy industry. • GC-MS analysis of Rosemary Essential Oil (REO) reveled 1, 8-Cineole (9.72%) and α-pinene (5.46%) as predominant constituents • REO nano-emulsion showed significant antimicrobial activity against L. monocytogenes, A. flavus, P. aeruginosa, and B. cereus • REO nano-emulsion improved the oxidative stability of fortified cream, with no significant difference from BHA • REO nano-emulsion significantly improved the overall acceptability of fortified cream and Karish cheese • Complete reduction of the inoculated microorganisms on Karish cheese and cream fortified with REO nano-emulsion [ABSTRACT FROM AUTHOR]

• Co complex was encapsulated in ZIF-8 micropores via bottle around the ship method. • The heterogeneous catalyst was used in alkene epoxidation with high selectivity. • The heterogeneous catalyst showed higher activity compared to ZIF-8 and Co complex. • Reaction mechanism was studied and the involvement of radical species was approved. A novel and stable heterogeneous catalyst for alkene epoxidation reaction, named as CoDMG@ZIF-8, has been synthesized by facile encapsulation of Co(III) complex i.e. [Co(DMGH)(DMGH 2)Cl 2 ] (abbreviated as CoDMG, DMGH 2 denotes for dimethylglyoxime and DMGH denotes for dimethylglyoxime mono anion) inside the ZIF-8 micropores via a solvothermal process. Based on the results of fourier transform-infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) technique and field emission scanning electron microscopy (FE-SEM), it was observed that the catalyst has maintained the structure, crystallinity and morphology of the parent ZIF-8 as well. Furthermore, CHN, DRS (diffuse reflectance spectra), energy dispersive X-ray (EDX), induced coupled plasma (ICP-OES), thermal gravimetric (TGA) and nitrogen adsorption-desorption (BET method) analyses have confirmed the encapsulation of the CoDMG complex. The epoxidation reaction was performed using tert‑butyl hydroperoxide (TBHP) in CH 3 CN solvent in the presence of catalyst. By optimizing the reaction parameters, a total conversion of 96 % with 82 % selectivity towards the epoxide product, was achieved. It was found that both CoDMG complex and ZIF-8 exhibited lower efficiency individually, while the encapsulation of this complex inside the ZIF-8 micropores has resulted to superior activity. Finally, the epoxidation of various alkenes such as cyclohexene, 2-norbornene, α-pinene, styrene and 1-hexene under the optimized reaction condition, have been studied and the catalytic mechanism was also proposed. [Display omitted] [ABSTRACT FROM AUTHOR]

• Absorption cross sections of major atmospheric inorganic gases and VOCs are quantified. • The cross section of 3-carene, myrcene, and ethylbenzene in deep-UV are proposed first time. • Absorption cross sections confirm and update previous literature spectra. • The application to trace gas detection in the deep-UV is discussed. Absorption of deep-ultraviolet photons gives rise to intense vibronic transitions in molecules and can be exploited for sensitive and selective quantification of trace gases. Accurate absorption cross sections at appropriate resolution are essential for such applications, but are not well characterised for even major atmospheric species like nitric oxide (NO) and key biogenic and anthropogenic volatile organic compounds (BVOCs and AVOCs). This study reports new absorption cross section spectra from 197 to 235 nm for NO at 1 atm and 293 K and important aromatic AVOCs (benzene, toluene, ethylbenzene, and o-, m-, and p-xylene) and BVOCs (α-pinene, β-pinene, limonene, 3-carene, and myrcene) at 1 atm across a temperature range of 293 K to 296 K. Measurements were made with a xenon flashlamp spectrometer using a flow cell configuration for gas mixtures and a static cell arrangement for vapour-phase VOC samples. The resolution of the spectrum at 253.7 nm was approximately 0.3 nm. Both configurations showed excellent agreement in magnitude and spectral features with well-established literature cross sections. Flow cell measurements were validated against the absorption cross section of sulfur dioxide (SO 2) and static cell measurements against that of isoprene. Our absorption cross sections of NO and m-xylene reconcile large differences in the magnitude and spectral structure of previous cross sections. The deep-UV absorption cross sections of 3-carene, myrcene and ethylbenzene are reported for the first time, and confirmed for α-pinene, β-pinene, and limonene. We discuss the potential and challenges of using deep-UV absorption for quantifying these gases ambient air monitoring, emissions monitoring, and breath analysis. [ABSTRACT FROM AUTHOR]

β-Pinene, unlike α-pinene, is easily and quantitatively metalated with butyllithium/TMEDA. The resulting allyllithium•TMEDA is easily isolated, with the racemic material crystallizing preferentially, even from 92 % ee solutions. The complex is indefinitely stable in C 6 D 6 , and has been fully characterized. Reaction with formaldehyde favors alkylation at the less substituted allyl position with modest regioselectivity (2:1), and the corresponding Grignard reagent (made by transmetalation with MgBr 2) reacts very regioselectively at the more substituted position with formaldehyde and diphenyl disulfide (99-92 %, resp.). The two phenyl sulfide isomers are observed to equilibrate when exposed to heat or UV light. This easy metalation provides access to a versatile chiral-pool-derived allyl nucleophile. [Display omitted] • Readily accessible chiral (92 % ee) allylmetallic. • Dramatic regiochemical outcomes between Li and MgX. • Unexpected equilibration of allyl phenyl sulfide regioisomers. [ABSTRACT FROM AUTHOR]

Monoterpenes are volatile organic compounds that play important roles in atmospheric chemistry, plant physiology, communication, and defense. This review compiles the monoterpene emission flux data reported for different regions and plant species and highlights the role of abiotic environmental factors in controlling the emissions of biogenic monoterpenes and their emission fluxes for terrestrial plant species (including seasonal variations). Previous studies have demonstrated the role and importance of ambient air temperature and light in controlling monoterpene emissions, likely contributing to higher monoterpene emissions during the summer season in temperate regions. In addition to light and temperature dependence, other important environmental variables such as carbon dioxide (CO2), ozone (O3), soil moisture, and nutrient availability are also known to influence monoterpene emissions rates, but the information available is still limited. Throughout the paper, we identify knowledge gaps and provide recommendations for future studies.

In this study, a couple of tetradentate Pt(II) enantiomers ((−)-1 and (+)-1) and a couple of tetradentate Pt(IV) enantiomers ((−)-2 and (+)-2) containing fused 5/6/6 metallocycles have been synthesized by controlling reaction conditions. Two valence forms could transform into each other through mild chemical oxidants and reductants. Single-crystal X-ray diffraction confirms the structures of (−)-1 and (−)-2. The coordination sphere of the Pt(II) cation in (−)-1 displays a distorted square-planar geometry and a platinum centroid helix chirality. In contrast, the structure of (−)-2 reveals a distorted octahedral geometry. The solution and the solid of (−)-1 are highly luminescent. Complex (−)-1 shows a prominent aggregation-induced emission enhancement (AIEE) behavior in DMSO/water solution with emission quantum yield (Φem) up to 73.2%. Furthermore, highly phosphorescent Pt(II) enantiomers exhibit significant circularly polarized luminescence (CPL) with a dissymmetry factor (glum) of order 10−3 in CH2Cl2 solutions at room temperature. Symmetrically appreciable CPL signals are observed for the enantiomers (−)-1 and (+)-1.

Background: The robust model cyanobacterium Synechocystis PCC 6803 is increasingly explored for its potential to use solar energy, water and atmospheric CO2 for the carbon-neutral production of terpenes, the high-value chemicals that can be used for the production of drugs, favors, fragrances and biofuels. However, as terpenes are chemically diverse, it is extremely difcult to predict whether Synechocystis is a suitable chassis for the photosynthetic production of various terpenes or only a few of them. Results: We have performed the frst-time engineering and comparative analysis of the best-studied cyanobacterium Synechocystis PCC 6803 for the photosynthetic production of fve chemically diverse high-value terpenes: two monoterpenes (C10H16) limonene (cyclic molecule) and pinene (bicyclic), and three sesquiterpenes (C15H24) bisabolene (cyclic), farnesene (linear) and santalene (cyclic). All terpene producers appeared to grow well and to be genetically stable, as shown by the absence of changes in their production levels during the 5--9-month periods of their sub-cultivation under photoautotrophic conditions). We also found that Synechocystis PCC 6803 can efciently and stably produce farnesene and santalene, which had never been produced before by this model organism or any other cyanobacteria, respectively. Similar production levels were observed for cells growing on nitrate (the standard nitrogen source for cyanobacteria) or urea (cheaper than nitrate). Furthermore, higher levels of farnesene were produced by cloning the heterologous farnesene synthase gene in a RSF1010-derived replicating plasmid as compared to the well-used slr0168 neutral cloning site of the chromosome. Conclusions: Altogether, the present results indicate that Synechocystis PCC 6803 is better suited to produce sesquiterpenes (particularly farnesene, the most highly produced terpene of this study) than monoterpenes (especially pinene). [ABSTRACT FROM AUTHOR]

In this study, we investigate the influence of isoprene on the volatility of secondary organic aerosol (SOA) formed during the photo-oxidation of mixtures of anthropogenic and biogenic precursors. The SOA particle volatility was quantified using two independent experimental techniques (using a thermal denuder and the Filter Inlet for Gas and Aerosols iodide high-resolution time-of-flight Chemical Ionisation Mass Spectrometer – FIGAERO-CIMS) in mixtures of α -pinene/isoprene, o -cresol/isoprene, and α -pinene/ o -cresol/isoprene. Single-precursor experiments at various initial concentrations and results from previous α -pinene/ o -cresol experiments were used as a reference. The oxidation of isoprene did not result in the formation of detectable SOA particle mass in single-precursor experiments. However, isoprene-derived products were identified in the mixed systems, likely due to the increase in the total absorptive mass. The addition of isoprene resulted in mixture-dependent influence on the SOA particle volatility. Isoprene made no major change to the volatility of α -pinene SOA particles, though changes in the SOA particle composition were observed and the volatility was reasonably predicted based on the additivity. Isoprene addition increased o -cresol SOA particle volatility by ∼5/15 % of the total mass/signal, respectively, indicating a potential to increase the overall volatility that cannot be predicted based on the additivity. The addition of isoprene to the α -pinene/ o -cresol system (i.e. α -pinene/ o -cresol/isoprene) resulted in slightly fewer volatile particles than those measured in the α -pinene/ o -cresol systems. The measured volatility in the α -pinene/ o -cresol/isoprene system had an ∼6 % higher low volatile organic compound (LVOC) mass/signal compared to that predicted assuming additivity with a correspondingly lower semi-volatile organic compound (SVOC) fraction. This suggests that any effects that could increase the SOA volatility from the addition of isoprene are likely outweighed by the formation of lower-volatility compounds in more complex anthropogenic–biogenic precursor mixtures. Detailed chemical composition measurements support the measured volatility distribution changes and showed an abundance of unique-to-the-mixture products appearing in all the mixed systems accounting for around 30 %–40 % of the total particle-phase signal. Our results demonstrate that the SOA particle volatility and its prediction can be affected by the interactions of the oxidized products in mixed-precursor systems, and further mechanistic understanding is required to improve their representation in chemical transport models. [ABSTRACT FROM AUTHOR]

Simple Summary: The limit screening method (LMS method) and product-tolerance engineering was proposed and applied. AcrB, flgFG, motB and ndk were found to be associated with an enhanced tolerance of E. coli to pinene. Using the I-SceI cleavage system, the promoters of acrB, flgFG, and ndk genes were replaced with P37, and pinene production was eventually increased 2.1 times. In general, a combination of shotgun, product-tolerance, and I-SceI cleavage systems provides a more convenient and efficient way of enhancing the synthesis of target products in a host strain. Tolerance breeding through genetic engineering, sequence and omics analyses, and gene identification processes are widely used to synthesize biofuels. The majority of related mechanisms have been shown to yield endogenous genes with high expression. However, the process was time-consuming and labor-intensive, meaning there is a need to address the problems associated with the low-throughput screening method and significant time and money consumption. In this study, a combination of the limit screening method (LMS method) and product-tolerance engineering was proposed and applied. The Escherichia coli MG1655 genomic DNA library was constructed using the shotgun method. Then, the cultures were incubated at concentrations of 0.25%, 0.5%, 0.75% and 1.0% of pinene with different inhibitory effects. Finally, the genes acrB, flgFG, motB and ndk were found to be associated with the enhanced tolerance of E. coli to pinene. Using the I-SceI cleavage system, the promoters of acrB, flgFG and ndk genes were replaced with P37. The final strain increased the production of pinene from glucose by 2.1 times. [ABSTRACT FROM AUTHOR]

Bark beetles mainly rely on detoxification enzymes to resist the host tree's defense against oleoresin terpenes. Cytochrome P450 enzymes (CYPs) play an important role in the detoxification of plant allelochemicals and pesticides in insect. One P450 gene (DaCYP4BQ1) is associated with the response of (+)-α-pinene in Dendroctonus armandi. However, the regulatory mechanism of this P450 gene response to (+)-α-pinene is still unknown. In this study, spatiotemporal expression profiling indicated that CYP4BQ1 was highly expressed in adult and larval stages of D. armandi, and it was predominantly expressed in fat body, midgut, and Malpighian tubules of adults. Moreover, the expression of CYP4BQ1 significantly increased after exposure to (+)-α-pinene, and depletion of it decreased the tolerance of adults to (+)-α-pinene. In addition, (+)-α-pinene treatment induced the expression of the transcription factors cap 'n' collar isoform C (CncC) and its binding factor muscle aponeurosis fibromatosis (Maf), elevated the level of hydrogen peroxide (H2O2), and increased the activities of antioxidant enzymes. Silencing CncC suppressed CYP4BQ1 expression and enhanced the susceptibility of beetles to (+)-α-pinene. Similarly, application of the reactive oxygen species (ROS) scavenger N-acetylcysteine reduced the production and accumulation of H2O2, suppressed the expression of CncC, Maf, and CYP4BQ1 and led to decreased tolerance of adults to (+)-α-pinene. In contrast, ingestion of the CncC agonist curcumin elevated CYP4BQ1 expression and enhanced (+)-α-pinene tolerance. The results demonstrate that, in D. armandi, (+)-α-pinene induces CYP4BQ1 via activation of the ROS/CncC signaling pathway. [ABSTRACT FROM AUTHOR]

Terpenoids are a large variety of natural products with remarkable diverse biological functions, and have a wide range of applications in flavors, pharmaceuticals, biofuels, pigments, and so on. However, limited production of terpenoids from natural resources constrains their use of bulk commodity products. In vivo synthetic biosystem, harnessing living organisms to produce terpenoids, has been broadly used and in-depth reviewed for terpenoids production, which has inherent weaknesses, such as slow reaction rate, low product yield, toxic intermediates, and high separation cost. In vitro synthetic biosystem, harboring numerous enzymes and/or coenzymes assembled into an in vitro enzymatic bioreactions, can obviate part of problems associated with in vivo style. In this review, the general design of in vitro synthetic biosystem is presented with seven supporting examples: mevalonate, isoprene, limonene, pinene, farnesene, amorpha-4,11-diene and taxadiene. The efforts for the large-scale implementation of in vitro synthetic biosystem have been addressed to enzymes engineering, computational modeling and cofactors recycle. The review also discusses the challenges and solutions for the large-scale implementation of in vitro synthetic biosystem around enzymes stability and cofactors recycle. This review may suggest in vitro synthetic biosystems become a realistic option for the production of diverse valuable terpenoids, even expand to other commodity chemicals. [ABSTRACT FROM AUTHOR]

The NO 3 radical represents a significant nighttime oxidant which is present downstream of polluted environments. Existing studies have investigated the formation of secondary organic aerosol (SOA) from NO 3 radicals, focusing on the yields, general composition, and hydrolysis of organonitrates; however, there is limited knowledge about how the composition of NO 3 -derived SOA evolves as a result of particle-phase reactions. Here, SOA was formed from the reaction of α -pinene with NO 3 radicals generated from N 2 O 5 , and the resulting SOA was aged in the dark. The initial composition of NO 3 -derived α -pinene SOA was slightly dependent upon the concentration of N 2 O 5 injected (excess of NO 3 or excess of α -pinene) but was largely dominated by dimer dinitrates (C 20 H 32 N 2 O 8-13). Oxidation reactions (e.g., C 20 H 32 N 2 O 8→ C 20 H 32 N 2 O 9→ C 20 H 32 N 2 O 10) accounted for 60 %–70 % of the particle-phase reactions observed. Fragmentation reactions and dimer degradation pathways made up the remainder of the particle-phase processes occurring. The exact oxidant is not known, although suggestions are offered (e.g., N 2 O 5 , organic peroxides, or peroxynitrates). Hydrolysis of –ONO 2 functional groups was not an important loss term during dark aging under the relative humidity conditions of our experiments (58 %–62 %), and changes in the bulk organonitrate composition were likely driven by evaporation of highly nitrogenated molecules. Overall, 25 %–30 % of the particle-phase composition changes as a function of particle-phase reactions during dark aging, representing an important atmospheric aging pathway. [ABSTRACT FROM AUTHOR]

A new theory suggests that flammable gases generated by heated vegetation, in particular the volatile organic compounds (VOC) common to Mediterranean plants, may, under certain topographic and wind conditions, accumulate in locations where, after the arrival of the ignition source, they rapidly burst into flames as explosions. Hence, there is a need for the development of a system that can monitor the development of these compounds. In this work, a sensor's array is proposed as a method for monitoring the amount of eucalyptol and α-pinene, the major VOC compounds of the Eucalyptus and Pine trees. The detection of the target compounds was assessed using the impedance spectroscopy response of thin films. Combinations of layers of polyelectrolytes, such as poly(allylamine hydrochloride) (PAH), polyethyleneimine (PEI), poly(sodium 4-sytrenesulfonate) (PSS) graphene oxide (GO), and non/functionalized multiwall nanotubes (MWCNT-COOH or MWCNT), namely, PAH/GO, PEI/PSS, PEI/GO, PAH/MWCNT, PAH/MWCNT-COOH, films, and TiO2 and ZnO sputtered films, were deposited onto ceramic supports coated with gold interdigitated electrodes. The results showed that concentrations of the target VOCs, within the range of 68 to 999 ppmv, can be easily distinguished by analyzing the impedance spectra, particularly in the case of the ZnO- and PAH/GO-film-based sensors, which showed the best results in the detection of the target compounds. Through principal component analysis (PCA), the best set of features attained for the ZnO and PAH/GO based sensor devices revealed a linear trend of the PCA's first principal component with the concentration within the range 109 and 807 ppmv. Thus, the values of sensitivity to eucalyptol and α-pinene concentrations, which were (2.2 ± 0.3) × 10−4 and (5.0 ± 0.7) × 10−5 per decade, respectively, as well as resolutions of 118 and 136 ppbv, respectively, were identified. [ABSTRACT FROM AUTHOR]

Verbenone and carvone are allylic monoterpenoid ketones with many applications in the fine chemicals industry that can be obtained, respectively, from the allylic oxidation of α-pinene and limonene over a silica-supported iron hexadecachlorinated phthalocyanine (FePcCl16-NH2-SiO2) catalyst and with t-butyl hydroperoxide (TBHP) as oxidant. As there are no reported analyses of the environmental impacts associated with catalytic transformation of terpenes into value-added products that include the steps associated with synthesis of the catalyst and several options of raw materials in the process, this contribution reports the evaluation of the environmental impacts in the conceptual process to produce verbenone and carvone considering two scenarios (SI-raw-oils and SII-purified-oils). The impact categories were evaluated using ReCiPe and IPCC methods implemented in SimaPro 9.3 software. The environmental impacts in the synthesis of the heterogeneous catalyst FePcCl16-NH2-SiO2 showed that the highest burdens in terms of environmental impact come from the use of fossil fuel energy sources and solvents, which primarily affect human health. The most significant environmental impacts associated with carvone and verbenone production are global warming and fine particulate matter formation, with fewer environmental impacts associated with the process that starts directly from turpentine and orange oils (SI-raw-oils) instead of the previously extracted α-pinene and limonene (SII-purified-oils). As TBHP was identified as a hotspot in the production process of verbenone and carvone, it is necessary to choose a more environmentally friendly and energy-efficient oxidizing agent for the oxidation of turpentine and orange oils. [ABSTRACT FROM AUTHOR]

In order to investigate and analyze constituents of essential oils from peels and anti-tumor activities of Citrus maxima cv. Mansailong from Xishuangbanna, C. sinensis Osbeck from Yuanjiang, and C. aurantiifolia from Dehong in Yunnan. Essential oils of peels of C. maxima cv. Mansailong from Xishuangbanna, C. sinensis Osbeck from Yuanjiang, and C. aurantiifolia from Dehong were extracted by steam distillation, qualitative and quantitative component analysis were carried out by GC-MS, and the inhibition of tumor proliferation by pericarp essential oil was studied by MTT method. The results were as follows: the extraction rate of essential oil from C. aurantiifolia was the highest, followed by that from C. sinensis Osbeck, and the lowest from C. maxima cv. Mansailong. And 24, 11 and 13 components were identified from essential oils of peels of C. maxima cv. Mansailong from Xishuangbanna, C. sinensis Osbeck from Yuanjiang, and C. aurantiifolia from Dehong, respectively. Myrcene and terpinene were the common components of the three essential oils. Both C. maxima cv. Mansailong and C. sinensis Osbeck essential oil contained active monomers compounds in β-pinene and 3, 7-dimethyl-1, 6-octadiene-3-alcohol, limonene, α-terpineol, and important spice ingredients, dimethyl benzyl acetate and methyl dihydrojasmonate, C. maxima cv. Mansailong essential oil contained limonene up to 72.097%, citral was the active ingredient in C. aurantiifolia from Dehong essential oil. Three essential oils showed certain anti-tumor activities against MKN-45 cell line of gastric cancer, MCF-7 cell line of human breast cancer and HCT-116 cell line of colorectal cancer in a dose-dependent manner. The results provide scientific reference for the development and utilization of the three endemic Cirtus L. in Yunnnan. [ABSTRACT FROM AUTHOR]

A new library of pinane-based 1,4-amino alcohols was synthesised and utilised as chiral ligands in enantioselective diethylzinc addition to benzaldehyde. Aldol condensation of (+)-nopinone, derived from (–)-β-pinene, with 2-pyridinecarboxaldehyde gave the key intermediate α,β-unsaturated ketone, which was transformed in diastereoselective reduction, followed by hydrogenation, resulting in 1,4-amino alcohols. On the other hand, epoxidation of the α,β-unsaturated ketone, followed by reduction and then hydrogenation of the pyridine ring, afforded a mixture of 4-amino-2,3-epoxy-1-ols. Stereoselective hydride reduction of the epoxy ketone and subsequent condensation of the resulting products with substituted benzyl bromides provided quaternary ammonium salts, which were subjected to hydride reduction and then hydrogenation, affording 4-amino-2,3-epoxy-1-ol derivatives containing an N -benzylpiperidine moiety. The inhibition of nucleophile-initiated opening of the oxirane ring was interpreted by a systematic series- of comparative Hartree–Fock modelling study using the 6-31+G(d,p) basis set. The antiproliferative activities of 4-amino-2,3-epoxy--1-ol derivatives were examined, and structure–activity relationships were studied from the aspects of the stereochemistry of the oxirane ring, saturation, and substituent effects on the piperidine ring system. [ABSTRACT FROM AUTHOR]

Myrtle (Myrtus communis L.) is an important medicinal plant, of which all parts have pharmaceutical and nutritional applications and which is distributed throughout the southwest regions of Iran. The aerial parts of myrtle were collected at different phenological stages (vegetative, flowering, unripe fruit and ripening fruit stages, after the fully mature fruit dispersal stage) from Fars Province of Iran and were analyzed with GC–FID and GC–MS. All the data were submitted to multivariate statistical analysis, showing many differences among the various plant parts and their phenological stages. Monoterpene hydrocarbons (18.9–50.5%) and oxygenated monoterpenes (38.2–72.4%) were the most abundant class in the volatile emissions, with α-pinene, 1,8-cineole, limonene, linalool, α-terpineol, linalyl acetate and geranyl acetate being the main constituents in the majority of the examined samples. α-Pinene content ranged from 8.88% at the after fully mature fruit dispersal stage (leaves) to 32.84% at the flowering stage in the leaves. Limonene, which is the dominant component at the flowering stage, was 23.97% in the flowers, while the limonene amount was 0.14–1.42% at other harvest stages. The greatest 1,8-cineole amount was obtained prior to flowering, 45.98%, while the lowest amount was obtained at the flowering stage, in the flowers. The total phenol and flavonoid contents varied between different myrtle parts: the highest total phenol and flavonoid contents were obtained for the extract made of the before-flowering stage in leaves (66.52 mg GAE/g and 7.49 mg QE/g extracts). Overall, the study indicated that collecting myrtle at the vegetative and flowering stages, especially the leaves organs, would be of considerable importance. [ABSTRACT FROM AUTHOR]

Rosemary (Rosmarinus officinalis L.) is a popular herb in cooking, traditional healing, and aromatherapy. This study was conducted to evaluate the effects of meteorological conditions plant growth stage and genetic factors on the yield, quantitative and qualitative composition, on the antioxidant and antimicrobial activities of rosemary essential oil from two Tunisian locations (El Fahs and Matmata) during two successive years. The composition of the essential oils obtained by hydrodistilation from rosemary plants were carried out annually using GC and GC/MS. Results showed the the main constituents were camphor (18.2–28.1%), 1,8-cineole (6.4–18.0%), α-pinene (9.7–13.5%), borneol (4.4–9.5%), and camphene (5.1–8.7%). The principal component and heatmapper analyses showed group segregation of the two studied varities based on major essential oil compounds. Additionally, in vitro antimicrobial and antioxidant activities showed that rosemary essential oils had an important ability in scavenging DPPH, as well as a higher bactericidal effect. The seasonal variation, growth stage and genetic pools seemed to be a factors of significant variation of the composition, antimicrobial and the antioxidant activities of the rosemary essential oils. These finding would be taken to use the chemotaxonomy tools to develop a program for Rosmary protection conservation and identification based on essential oil composition. [ABSTRACT FROM AUTHOR]

Secondary organic aerosol (SOA) forms a major part of the tropospheric submicron particle mass. Still, the exact formation mechanisms of SOA have remained elusive. It is now admitted that highly oxygenated organic molecules (HOMs) can contribute to a large fraction of SOA formation. In this study, we performed a set of chamber experiments to investigate the SOA formation, and the HOMs uptake and processing directly formed by OH‐radical initiated oxidation of α‐pinene under two different aerosol seed conditions. Numerous HOM compounds were identified using advanced online and offline analytical techniques, and grouped into four classes according to their different uptake behaviors. For the first time, individual HOMs uptake coefficients ranging from 1.1 × 10−2 to 1.5 × 10−1 were experimentally determined and analyzed using a resistance model which considers uptake limitations by individual gas‐ and/or particle‐phase processes. This study demonstrates that the uptake coefficients of HOMs strongly depend on their molar mass and their respective O/C ratio. Results show that aerosol seed composition and phase state affect the initial uptake of HOMs. Furthermore, the study demonstrates that the acidity and/or different seed phase‐state can significantly enhance the subsequent uptake through occurring acidity‐driven reactions reflected in a reactive behavior, particularly under (NH4)HSO4 seed conditions, promoting up to 3 times a higher SOA mass formation including the formation of highly oxidized organosulfates (HOOS). Overall, the present study implies that HOMs and their subsequent chemical processing can play an important role in both the early growth of newly formed particles and SOA formation when particle acidity is high. Plain Language Summary: Tropospheric organic aerosol (OA) compounds represent a large part of submicron particulate matter. A big fraction of OA is formed from oxidation of emitted gaseous volatile organic compounds such as α‐pinene. Oxidation products are less‐volatile compounds that tend to condense on aerosol particles. Recently identified "highly oxygenated organic molecules" (HOMs) are formed by gas‐phase autoxidation processes and exhibit very low vapor pressures. Therefore, HOMs are expected to efficiently contribute to secondary organic aerosol (SOA). However, up to now, SOA formation potential of HOMs is still not well described because of lacking experimental investigations and analysis. Consequently, this study aims to investigate the mentioned HOMs partitioning and subsequent SOA formation from the OH‐radical initiated oxidation of α‐pinene under both Na2SO4 and (NH4)HSO4 aerosol seed conditions through complex chamber experiments. For the first time, individual HOMs uptake coefficients were determined experimentally. Further investigations demonstrated that the uptake coefficients of HOMs strongly depend on their molar mass, as well as on their respective O/C ratio. Finally, the results show that aerosol acidity and/or phase state significantly enhances the HOMs uptake and promotes up to three times higher SOA mass formation under (NH4)HSO4 seed conditions compared to that under neutral seed conditions. Key Points: Uptake coefficients of numerous highly oxygenated organic molecules (HOMs) were experimentally determined for the first timeHOMs uptake and secondary organic aerosol formation were significantly enhanced by acidic (NH4)HSO4 seedHighly oxidized organosulfates formation were observed under acidic (NH4)HSO4 seed conditions [ABSTRACT FROM AUTHOR]

Particulate matter (PM) largely consists of secondary organic aerosol (SOA) that is formed via oxidation of biogenic and anthropogenic volatile organic compounds (VOCs). Unambiguous identification of SOA molecules and their assignment to their precursor vapors is a challenge that has so far only succeeded for a few SOA marker compounds, which are now well characterized and (partly) available as authentic standards. In this work, we resolve the complex composition of SOA by a top-down approach based on a newly created aerosolomics database, which is fed by non-target analysis results of filter samples from oxidation flow reactor experiments. We investigated the oxidation products from the five biogenic VOCs α-pinene, β-pinene, limonene, 3-carene, and trans-caryophyllene and from the four anthropogenic VOCs toluene, o-xylene, 1,2,4-trimethylbenzene, and naphthalene. Using ultra-high performance liquid chromatography coupled to a high-resolution (Orbitrap) mass spectrometer, we determine the molecular formula of 596 chromatographically separated compounds based on exact mass and isotopic pattern. We utilize retention time and fragmentation mass spectra as a basis for unambiguous attribution of the oxidation products to their parent VOCs. Based on the molecular-resolved application of the database, we are able to assign roughly half of the total signal of oxygenated hydrocarbons in ambient suburban PM2.5 to one of the nine studied VOCs. The application of the database enabled us to interpret the appearance of diurnal compound clusters that are formed by different oxidation processes. Furthermore, the application of a hierarchical cluster analysis (HCA) on the same set of filter samples enabled us to identify compound clusters that depend on sulfur dioxide mixing ratio and temperature. This study demonstrates how aerosolomics tools (database and HCA) applied on PM filter samples can improve our understanding of SOA sources, their formation pathways, and temperature-driven partitioning of SOA compounds. [ABSTRACT FROM AUTHOR]

Metadynamics simulation has been used to determine the conformational energy landscapes of several helical quinoline oligoamides bearing β‐pinene‐derived pyridine at either the C or N‐terminus. Based on the experimental results, the helix‐sense preference for four types of foldamers with the chiral terminal group has been verified. To compare to the key factors inducing handedness to helix‐sense preference, a terminal group with three hydrogen bond sites is designed and corresponding foldamers are built. The calculated results show that the delocalization effect and steric hindrance are mainly responsible for a particular helix‐sense preference for the investigated foldamers. The more hydrogen bonds between the terminal group and oligoamide units are formed, the more stable foldamers are. [ABSTRACT FROM AUTHOR]

The Aristotelia alkaloids are a family of monoterpene indole alkaloids possessing a characteristic azabicyclononane scaffold, which has been assembled by several synthetic methods. Herein we review those approaches that have adopted a biomimetic approach to unite heterocyclic synthons with chiral-pool monoterpenes. Throughout this discussion, the tendency of monoterpenes like α-pinene and limonene to undergo racemization is highlighted, revealing the challenges in developing stereospecific syntheses of these alkaloids. Finally, we provide a brief discussion of how these synthetic efforts have enabled the structural confirmation and elucidation of the Aristotelia alkaloids' absolute configurations, including our own recent efforts to employ bioactivity data to deduce the naturally occurring configuration of the quinoline alkaloid aristoquinoline. 1 Introduction 2 Mercury-Mediated Ritter-Like Reactions 3 Brønsted Acid Mediated Ritter-Like Reactions 4 Synthesis of Aristoquinoline: Ritter-Like Reaction Approach 5 Aza-Prins-Type Reaction in the Synthesis of Aristotelia Alkaloids 6 Determination of Naturally Occurring Absolute Stereochemistry 7 Conclusions [ABSTRACT FROM AUTHOR]

Selective Oxygen Atom Transfer to α-pinene, β-pinene, (R)-limonene and camphene by dioxo-Mo(VI)Ln complex {Ln = 2-aminothiazole-4-carboxylic acid} anchored on TiO2 nanotubes (TiO2-NT) using O2 as oxidant and UV light was studied at ambient conditions. The Catalytic system was characterized by FTIR, 1H NMR and 13C, and elemental analysis. Molecular oxygen reoxidizes the (Mo(IV)=O) reduced unit in the darkness, forming an oxo-peroxo-Mo intermediate. The catalyst under UV radiation transfers two oxygen atoms to the olefin. The α-pinene is found to be the most reactive monoterpene. [ABSTRACT FROM AUTHOR]

In this research, β-tetra-brominated meso-tetraphenylporphyrinatomanganese(III) acetate [MnTPPBr4(OAc)] (MnPor) was anchored onto a magnetite imidazole-modified graphene oxide nanosheet (Fe3O4.GO.Im). The obtained catalyst (Fe3O4.GO.Im@MnPor) was characterized through Fourier transform infrared (FT-IR) and diffuse reflectance UV–Visible spectrophotometry (DR UV–Vis), powder X-ray diffractometry (XRD), field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) spectroscopy, thermogravimetric analysis (TGA) and atomic absorption spectroscopy. The characterization was performed to determine the amount of manganese porphyrin loaded on the GO support. The new immobilized catalyst was employed for the efficient epoxidation of different alkenes with urea hydrogen peroxide (UHP) and acetic acid (HOAc) as oxidant activators under mild conditions. Olefins were oxidized efficiently to their corresponding epoxide with 63–100% selectivity in the presence of Fe3O4.GO.Im@MnPor. Moreover, an remarkable turnover frequency (93) was achieved for the oxidation of α-pinene. The graphene oxide-bound Mn-porphyrin was recovered from the reaction mixture by magnetic decantation and reused several times. [ABSTRACT FROM AUTHOR]

A series of experiments was designed and conducted in the Manchester Aerosol Chamber (MAC) to study the photo-oxidation of single and mixed biogenic (isoprene and α -pinene) and anthropogenic (o -cresol) precursors in the presence of NO x and ammonium sulfate seed particles. Several online techniques (HR-ToF-AMS, semi-continuous GC-MS, NO x and O 3 analyser) were coupled to the MAC to monitor the gas and particle mass concentrations. Secondary organic aerosol (SOA) particles were collected onto a quartz-fibre filter at the end of each experiment and analysed using liquid chromatography–ultrahigh-resolution mass spectrometry (LC-Orbitrap MS). The SOA particle chemical composition in single and mixed precursor systems was investigated using non-targeted accurate mass analysis of measurements in both negative and positive ionization modes, significantly reducing data complexity and analysis time, thereby providing a more complete assessment of the chemical composition. This non-targeted analysis is not widely used in environmental science and has never been previously used in atmospheric simulation chamber studies. Products from α -pinene were found to dominate the binary mixed α -pinene–isoprene system in terms of signal contributed and the number of particle components detected. Isoprene photo-oxidation was found to generate negligible SOA particle mass under the investigated experimental conditions, and isoprene-derived products made a negligible contribution to particle composition in the α -pinene–isoprene system. No compounds uniquely found in this system sufficiently contributed to be reliably considered a tracer compound for the mixture. Methyl-nitrocatechol isomers (C 7 H 7 NO 4) and methyl-nitrophenol (C 7 H 7 NO 3) from o -cresol oxidation made dominant contributions to the SOA particle composition in both the o -cresol–isoprene and o -cresol– α -pinene binary systems in negative ionization mode. In contrast, interactions in the oxidation mechanisms led to the formation of compounds uniquely found in the mixed o -cresol-containing binary systems in positive ionization mode. C 9 H 11 NO and C 8 H 8 O 10 made large signal contributions in the o -cresol–isoprene binary system. The SOA molecular composition in the o -cresol– α -pinene system in positive ionization mode is mainly driven by the high-molecular-weight compounds (e.g. C 20 H 31 NO 4 and C 20 H 30 O 3) uniquely found in the mixture. The SOA particle chemical composition formed in the ternary system is more complex. The molecular composition and signal abundance are both markedly similar to those in the single α -pinene system in positive ionization mode, with major contributions from o -cresol products in negative ionization mode. [ABSTRACT FROM AUTHOR]