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Solidago virgaurea L. popularly called Goldenrod is a member of the Asteraceae family. S. virgaurea sample were obtained from Binsar, Almora (Indian state of Uttarakhand). The essential oil from the aerial part was distilled out using steam distillation, and GC and GC-MS were employed for analysis. A total of 27 constituents from aerial part were identified constituting 92.92% of total oil composition. The aerial parts of S. virgaurea were found to contain limonene (25.57%), α-humulene (12.19%), linalool oxide (8.65%), benzyl salicylate (6.40%), 1,4-cineole (6.22%) and humulene epoxide (II) (5.93%). The antibacterial activity of this essential oil was studied using disk diffusion and broth microdilution methods on five human pathogen bacteria and six plant pathogenic bacteria. There was moderate to good antibacterial activity in the oil sample extracted from the entire aerial portion of the plant. We did the antileishmanial activity of essential oils with Leishmania donovani (Dd8) promastigotes and intracellular amastigotes. EO was safer on the J774.A1 macrophages and lethal to promastigotes and intracellular amastigotes at different concentrations (10, 50, and 100 μg/ mL). These findings support the traditional uses of S. virgaurea and suggest its potential as a natural remedy for bacterial infections and leishmaniasis. [ABSTRACT FROM AUTHOR]

Melanaphis sacchari Zehntner (Hemiptera: Aphididae) is currently the most destructive pest insect of the sorghum crop (Sorghum bicolor L. Moench) and has caused economic losses worldwide. Strategies using natural products such as plant extracts can offer alternatives for the control of this pest. In this investigation, we evaluated the insecticidal effect of the hexane extract of Ricinus communis L. and Momordica charantia L. seeds on M. sacchari in contact bioassays. The results showed that the extract of R. communis presented a mortality rate of 100% in 48 h at 10,000 ppm, while M. charantia presented 80% in 72 h, at 10,000 ppm. Gas chromatography—mass spectrometry (GC–MS) identified the major compounds as squalene in R. communis (51.57%) and linalool oxide in M. charantia (30.45%). The hexanic extracts of these plant species could be considered an ecologically friendly alternative to control this pest, given the use of synthetic chemical insecticides. [ABSTRACT FROM AUTHOR]

The effects of the level of berry thinning (30% and 50% berry removal) on the quality and sensory properties of Shine Muscat grapes were investigated. As berry thinning increased, the total soluble solids content increased and titratable acidity decreased. Berry thinning increased berry size and cluster weight but caused no change in individual berry weight. Phenolic concentrations as measured by total phenolic, proanthocyanidin, and polymeric tannin concentrations tended to increase with an increase in berry thinning. Gas chromatographic analysis indicated that C6-compounds were the significant constituents of volatile alcohols and aldehydes; linalool was the most abundant monoterpene. Odor activity analysis indicated that (E)-2-hexen-1-ol, (E)-2-hexenal, 1-hexanal, (Z)-3-hexenal, (E)-β-damascenone, linalool, and (E)-linalool oxide were active odorants. Berry thinning increased the accumulation of linalool contributing to high sensory flavor scores in thinned berries. Furthermore, its oxidized derivative-linalool oxide-contributed to enhancing the Muscat flavor. In conclusion, berry thinning induced compositional changes in Shine Muscat grape berries by accelerating the ripening rate, contribution to improved sensory properties. [ABSTRACT FROM AUTHOR]

Nineteen host plant volatiles (HPVs) were screened for attractivity to adult codling moth Cydia pomonella (L.) as a fourth component of core blends (3K) including (E,Z)‐2,4‐ethyl decadienoate, (E)‐4,8‐dimethyl‐1,3,7‐nonatriene and acetic acid. Each new quaternary combination was compared with a previously reported attractive bisexual lure (4K), consisting of the 3K blend plus 6‐ethenyl‐2,2,6‐trimethyloxan‐3‐ol (pyranoid linalool oxide, pyrLOX). All lure evaluations were conducted in apple, Malus domestica (Borkhausen). Several compounds were found to significantly lower total and/or female catches when added to the 3K blend, including (Z)‐3‐hexenol, (E)‐2‐hexanal and hexyl butanoate (female and total moths), and (Z)‐3‐hexenyl acetate and linalool (female moths). Other compounds when added to the 3K blend did not increase or decrease moth catches, including methyl salicylate, (E)‐β‐ocimene, limonene, β‐caryophyllene, butyl hexanoate, farnesol, terpineol, terpinen‐4‐ol and α‐pinene. A few added compounds significantly increased moth catches compared with the 3K blend, including β‐pinene (male moths), (Z)‐jasmone (male and total moths), (E)‐β‐farnesene and β‐myrcene (female and total moths), and (E,E)‐α‐farnesene (male, female, and total moths). In addition, each of these five compounds when added to the 3K core blend performed similarly to the 4K lure (male, females, and total moths). Further studies should expand these results through tests of these and other new blends with a range of component ratios and total loading amounts. Field trials should also be replicated within all host crops of codling moth and across major geographical production regions. [ABSTRACT FROM AUTHOR]

The monoterpenes linalool and its oxides are the key aroma-active compounds in Osmanthus fragrans Lour. flowers. The glycosides of these monoterpenes accumulate throughout flowering, leading to considerable storage of potential aroma constituents that account for the majority of non-volatile aroma compounds. However, the UDP-glycosyltransferase (UGT) responsible for the glycosylation of linalool and its oxides has not been clarified. Four candidate OfUGTs (UGT85A82, UGT85A83, UGT85AF3, and UGT85A84) with high homology to the known terpenoid UGTs were screened by transcriptome sequencing. Over-expression of the candidate OfUGTs in tobacco showed that UGT85A84 glycosylated linalool oxides in planta. Since the transcript levels of UGT85A84 were positively correlated with glycoside accumulation, the recombinant UGT85A84 protein was subjected to reactions with aglycones and sugar donors. Two formate adducts were exclusively detected in UDP-Glc with linalool and linalool oxide reactions by liquid chromatography-mass spectrometry (LC-MS), indicating that UDP-Glc was the specific sugar donor. The kinetic parameters demonstrated that UGT85A84 glycosylated both linalool and lianlool oxides in vitro. Further analysis demonstrated that the transcription levels of MEP pathway genes might play an important role in mediating terpenoid glycosylation. Our findings unraveled the mechanism underlying the glycosylation of essential aroma compounds in flowers. This study will facilitate the application of potential aroma contributors in future industries.

Field studies were conducted to evaluate new kairomone blends in combination with pear ester (E,Z)‐2,4‐ethyl decadienoate (PE) and acetic acid (AA) for their attraction of male and female codling moth, Cydia pomonella (L.), in apple, Malus domestica Borkhausen. The addition of decanal to either AA or PE alone significantly increased total and female moth catches. However, the addition of decanal did not improve the attraction of PE + AA. The addition of either the pyranoid (PyrLOX) or furanoid (FurLOX) linalool oxide but not linalool (LOL) increased moth catches with PE but did not increase catches with PE + AA. Similarly, the addition of PyrLOX plus decanal did not improve PE + AA. The addition of (E)‐4,8‐dimethyl‐1,3,7‐nonatriene (DMNT) to either AA, PE + AA or PE + AA+decanal did not significantly increase moth catches. However, the addition of PyrLOX to traps with PE + AA and DMNT (4‐component lure) significantly increased moth catches compared with PE + AA alone or any of the ternary blends of these volatiles. Females accounted for 60%–80% of the total catch with this 4‐component lure. The 4‐component blend with PyrLOX was a more attractive lure than similar blends that substituted LOL, or a binary blend of LOL and FurLOX for PyrLOX. The 4‐component blend caught nearly fourfold more total and female moths than the purported attractant N‐butyl sulphide when it was used in combination with PE + AA. These results indicate that significant improvements in monitoring, mating disruption and mass trapping of codling moth are possible. Further studies are needed to assess the new attractive blend's effectiveness in combination with sex pheromone lures and to evaluate whether other host plant volatiles can be added or substitute for DMNT or LOX when used in combination with PE + AA. [ABSTRACT FROM AUTHOR]

Larvae and adults of Altica cyanea (Weber) (Coleoptera: Chrysomelidae) feed on the rice-field weed Ludwigia octovalvis (Jacq.) Raven (Onagraceae), commonly known as willow primrose, which is considered a biocontrol agent of the weed. Volatile organic compounds from undamaged plants, plants after 4, 12, and 36 h of continuous feeding by A. cyanea larvae or adult females and after mechanical damaging were identified by GC-MS and GC-FID analyses. Twenty nine compounds were identified from undamaged plants. 2 Z-Penten-1-ol, geraniol, and 1-tridecanol were present in all plants damaged by larvae. In contrast, feeding by adults caused the release of 2 Z-penten-1-ol only after 12 and 36 h; whereas geraniol and 1-tridecanol appeared only after 36 h. Farnesyl acetone was detected after 12 and 36 h of feeding by larvae and after 36 h of feeding by adults. Farnesene was detected after 36 h of feeding by larvae and adults. Linalool was unique after 36 h of feeding by larvae. In Y-shaped glass tube olfactometer bioassays, A. cyanea females were attracted to volatiles after 36 h of feeding by larvae or adults compared to volatiles released by undamaged plants. The insects were attracted to five synthetic compounds: 3-hexanol, α-pinene, linalool oxide, geraniol, and phytol. Synthetic blends were more attractive than individual compounds. Compared to undamaged plants, volatiles released by plants, damaged by conspecific individuals, were more attractive to A. cyanea females, due to elevated emissions of 3-hexanol, α-pinene, linalool oxide, geraniol, and phytol. [ABSTRACT FROM AUTHOR]

Subcritical water extraction (SWE) of monoterpenes from coriander seeds and effect of extraction conditions were investigated varying temperature (170–200 °C) and time (5–20 min). Monoterpenes was influenced by differences in their chemical structures and SWE conditions. The extraction efficiency of linalool was decreased with the increasing extraction temperature and extraction time, whereas linalool oxide was increased due to conversion of linalool to linalool oxide by hydrothermal oxidation. Geraniol, which has the same chemical formula as linalool, was extracted at a high temperature (170 °C) owing to the different placement of hydroxyl groups. The efficiency of SWE for geraniol (1.22 ± 0.22 mg/g) and linalool oxide (0.30 ± 0.09 mg/g) was higher than that of conventional extraction methods (hexane, methanol, hot water, and hydrodistillation). Therefore, SWE can be used to effectively and selectively extract monoterpenes by exploiting temperature changes in short extraction time. [Display omitted] • Monoterpenes were efficiently selectively extracted using subcritical water extraction. • Major compounds extracted were oxygenated monoterpenes in subcritical water. • Linalool converted to linalool oxide under subcritical-water condition above 170 °C. • Monoterpene contents by SWE were higher than conventional extraction methods. [ABSTRACT FROM AUTHOR]

The essential oils from the cladodes of Opuntia littoralis, Opuntia ficus-indica and Opuntia prolifera growing wild on Santa Catalina Island, California, were obtained by hydrodistillation and analysed by gas chromatography-mass spectrometry (GC–MS). Terpenoids were the dominant class of volatiles in O. littoralis, with the two main components being the furanoid forms of cis-linalool oxide (10.8%) and trans-linalool oxide (8.8%). Fatty acid-derived compounds dominated the essential oil of O. ficus-indica with linoleic acid (22.3%), palmitic acid (12.7%), lauric acid (10.5%) and myristic acid (4.2%) as major fatty acids. O. prolifera oil was composed of 46.6% alkanes and the primary hydrocarbon component was heptadecane (19.2%). Sixteen compounds were common to all the three Opuntia species. [ABSTRACT FROM AUTHOR]

Linalool oxides are of interest to the flavour industry because of their lavender notes. Corynespora cassiicola DSM 62475 has been identified recently as a production organism because of high stereoselectivity and promising productivities [Mirata et al. () J Agric Food Chem 56(9):3287-3296]. In this work, the stereochemistry of this biotransformation was further investigated. Predominantly (2R)-configured linalool oxide enantiomers were produced from (R)-(−)-linalool. Comparative investigations with racemic linalool suggest that predominantly (2S)-configured derivatives can be expected by using (S)-(+)-configured substrate. Substrate and product inhibited growth even at low concentrations (200 mg l). To avoid toxic effects and supply sufficient substrates, a substrate feeding product removal (SFPR) system based on hydrophobic adsorbers was established. Applying SFPR, productivity on the shake flask scale was increased from 80 to 490 mg l day. Process optimisation increased productivity to 920 mg l day in a bioreactor with an overall product concentration of 4.600 mg l linalool oxides. [ABSTRACT FROM AUTHOR]

Abstract: Linalool oxide is a monoterpene that is found in some species of aromatic plants. The effects of the inhalation of linalool oxide (0.65%, 1.25%, 2.5% and 5.0% w/w) in the elevated plus-maze and light/dark box tests as animal models of anxiety were investigated in adult male mice and compared with the effects of the reference anxiolytic diazepam (0.5 and 2.0mg/kg), administered intraperitoneally. Additionally, the effects of inhaled linalool oxide were investigated in the rotarod test. Linalool oxide significantly increased the number of visits to the open arms of the elevated plus-maze and the amount of time spent there as well as the total number of entries. In the light/dark box test, inhalation of linalool oxide led to an increase in the time spent by the mice in the brightly-lit chamber and in the number of times the animal crossed from one compartment to another. Performance on the rotarod was unaffected. Thus, inhaled linalool oxide was found to have anxiolytic properties in both animal models, without causing any motor deficit. These results suggest that inhalation of linalool oxide may be a useful means of counteracting anxiety. [Copyright &y& Elsevier]

Field observations revealed that flowers of Osmanthus fragrans attract few insect species despite their strong scent and vivid coloration (yellowish orange). Floral volatiles of the plant were thus examined for suspected repellency to Pieris rapae, a potential visitor that never visits this flower. The influence of odor components on the foraging behavior of adult butterflies was assessed by two behavioral bioassays: proboscis extension reflex (PER) in response to olfactory stimuli and the frequency of visits to artificial flowers. In the PER bioassays, a binary mixture composed of a test material and 2-phenylethanol (a positive standard compound) was used, and the negative effect of test materials was appraised based on the degree of suppression caused compared with the original PER performance evoked by 2-phenylethanol alone. Isopentane extract of the flower exhibited significant deterrency in the PER test and remarkable repellency in the flower-visiting experiment, thereby suggesting the presence of a repellent(s) in the floral volatiles. Fractionation of the extract by silica gel column chromatography yielded an active fraction (based on PER performance), which, upon GC and GC-MS analyses, was found to consist of γ-decalactone, β-ionone, and linalool oxide (LO) isomers (furanosides and pyranosides) as major components together with small amounts of linalool and α-ionone. γ-Decalactone was strongly deterrent in the PER test, and β-ionone and all LO isomers were weakly deterrent, while the other compounds exhibited no deterrency. In the flower-visiting tests, γ-decalactone showed notable repellency, whereas β-ionone had no repellent effect. Among the LO isomers, at least furanosides ( cis/trans mixture) and cis-pyranoside were found to be weakly repellent. On the other hand, the butterfly showed strong to weak EAG responses to LO furanosides, cis-LO pyranoside, γ-decalactone, and β-ionone in decreasing order of intensity. The present results clearly indicate that the repellency of a compound is correlated with its deterrent effect on PER but not necessarily with antennal sensitivity. [ABSTRACT FROM AUTHOR]