(1R)-(+)-Alpha-Pinene

Molecular Identification, Expression, and Functional Analysis of a General Odorant-Binding Protein 1 of Asian Citrus Psyllid.[Pubmed:30566599]

Environ Entomol. 2019 Feb 13;48(1):245-252.

For insects, odorant-binding proteins (OBPs) play an essential role in binding and transporting semiochemicals through the sensillum lymph to olfactory receptor neurons within the antennal sensilla. In the present study, the full-length cDNA encoding a general odorant-binding protein 1 (DcitOBP1, accession number KY475564) was cloned from the antennae of Diaphorina citri using RACE-PCR, and qRT-PCR analysis revealed that the DcitOBP1 gene was expressed mainly in the antennae of D. citri. In molecular docking assay, the results showed that DcitOBP1 protein has better binding affinities to the 12 selected host-plant volatile compounds. Then, the recombinant DcitOBP1 protein was expressed in Escherichia coli. After removed His-Tag, the binding properties of purified DcitOBP1 protein to the selected host-plant volatile compounds were investigated in a fluorescence ligand-binding assay, similar, but more obviously binding properties of DcitOBP1 protein result were obtained, the dissociation constant (KD) value of DcitOBP1/1-NPN complex was 6.440 +/- 0.521, and the DcitOBP1 protein showed high binding affinities (IC50 < 100 muM) to six of the selected ligands, namely methyl salicylate, alpha-phellandrene, (1R)-(+)-Alpha-Pinene, 3-carene, beta-caryophyllene, and alpha-caryophyllene. Additionally, the behavior bioassays were also showed that D. citri had significant behavioral responses toward to alpha-caryophyllene, beta-caryophyllene, (1R)-(+)-Alpha-Pinene, and alpha-phellandrene. Our investigation infer that the DcitOBP1 protein might play a crucial role in host-plant volatile odorants' perception in D. citri, and these results also have been supplied previous insight evidence into the physiological functions of the DcitOBP1 protein of D. citri.

Sweet attraction: sugarcane pollen-associated volatiles attract gravid Anopheles arabiensis.[Pubmed:29466989]

Malar J. 2018 Feb 21;17(1):90.

BACKGROUND: Anopheles arabiensis is a key vector for the transmission of human malaria in sub-Saharan Africa. Over the past 10,000 years, humans have successfully cultivated grasses and altered the landscape, creating An. arabiensis favourable environments that contain excellent habitats for both larvae and adults. Sugarcane is the most expanding agricultural system in sub-Saharan Africa, and is linked to the increased threat of malaria in rural communities. The prolific production and wind dispersal of sugarcane pollen, together with standing pools of water, often provide, as a result of irrigation, a nutrient-rich environment for the offspring of gravid malaria mosquitoes. RESULTS: In the present study, sugarcane pollen-associated volatiles from two cultivars are shown to attract gravid An. arabiensis in a still air two-port olfactometer and stimulate egg laying in an oviposition bioassay. Through combined gas chromatography and electroantennographic detection, as well as combined gas chromatography and mass spectrometric analyses, we identified the bioactive volatiles and generated a synthetic blend that reproduced the full behavioural repertoire of gravid mosquitoes in the Y-tube assay. Two subtractive odour blends, when compared with the full blend, were significantly more attractive. These three and four-component subtractive blends share the compounds (1R)-(+)-Alpha-Pinene, nonanal and benzaldehyde, of which, (1R)-(+)-Alpha-Pinene and nonanal are found in the attractive odour blends from rice plants and maize pollen. In pairwise comparisons, the rice synthetic odour blend was more attractive to gravid mosquitoes than either of the pollen blends, whereas the pollen blends did not differ in attraction. CONCLUSIONS: The attraction of gravid females to sugarcane pollen volatiles demonstrated in this study, together with the previously found grass-associated volatiles, raise the potential of developing a bioactive chimeric blend to attract gravid malaria mosquitoes. This is discussed in relation to the development of novel and cost-effective vector control measures.

Repellency of alpha-pinene against the house fly, Musca domestica.[Pubmed:26209937]

Phytochemistry. 2015 Sep;117:469-475.

Musca domestica L. is a non-biting nuisance fly that is capable of transmitting a large variety of pathogens to humans and non-human animals. Natural compounds and their derivatives, which are often less toxic than entirely synthetic compounds, may be used as repellents against M. domestica as part of comprehensive pest control and disease mitigation programs. This work investigates the repellent properties of the natural compound alpha-pinene against M. domestica. Adult house flies of both sexes avoided the volatile plant-derived terpenes (1S)-(-)-alpha-pinene 1 and (1R)-(+)-Alpha-Pinene 2 in constant air flow laboratory conditions, with 1 exhibiting a stronger repellent effect. House flies also avoided tarsal contact with filter paper saturated with 1. Furthermore, both 1 and 2 are electrophysiologically active on in situ female house fly antennal preparations. These findings demonstrate that alpha-pinene exhibits natural baseline repellency against the house fly, elicits a specific physiological response in this fly, and that functional or structural modification of 1 in particular may yield novel fly repellents with desirable properties.

Characterization of volatile components of Zingiber roseum essential oil using capillary GC on modified cyclodextrins.[Pubmed:23513734]

Nat Prod Commun. 2013 Feb;8(2):221-4.

The essential oil from different parts of Zingiber roseum plants was extracted by hydrodistillation, and analyzed using enantio-GC, capillary-GC and GC-MS. Two chiral selectors, 6-tert-butyldimethylsilyl-2,3-diethyl-beta-cyclodextrin (TBDE-beta-CD), and 2,3,6-methyl-beta-cyclodextrin (PM-beta-CD) doped into 14% cyanopropylphenyl/86% dimethylpolysiloxane, and 35% diphenyl/65% dimethylpolysiloxane, respectively were compared in order to clarify the stereochemistry and enantioselectivity of terpenoids using chiral gas chromatography. The enantiomeric excess for (1R)-(+)-Alpha-Pinene, (1R)-(+)-beta-pinene, and (R)-(+)-limonene were characteristic for the rhizome. In TBDE-beta-cyclodextrin coated chiral columns, a significant increase in separation factor (alpha) for beta-pinene, limonene, linalool and alpha-terpineol enantiomers was observed when compared with methyl substituted beta-cyclodextrin. The increase in chain length of the alkyl substituents may be the possible cause for enantiomer separation in beta-cyclodextrin cavity. In addition, enantioreversal of alpha-pinene enantiomers in 6-tert-butyldimethylsilyl-2,3-diethyl-beta-cyclodextrin was noticed as a unique feature. The enantiomeric compositions of Z. roseum fruit and flower essential oils were similar, but, in contrast, the rhizome oil contained an entirely different composition. Therefore, these results aid in the authentication of the natural origin of Z. roseum essential oils.