A Turn-On and Colorimetric Probe Based on Isophorone Skeleton for Detecting Nerve Agent Mimic Diethyl Chlorophosphite

A new turn-on probe (SWJT-20) based on isophorone fluorophore for the detection of nerve agent mimic diethyl chlorophosphite (DCP) was designed and synthesized. SWJT-20 could rapidly respond to DCP within 2 s using UV-Vis or fluorescent spectra, accompanied by a significant change in the solution color under visible light or UV light, which could be observed by the naked eyes. The detection limit of SWJT-20 to DCP was as low as 8.3 nM, which is lower than those of most reported fluorescent probes for DCP detection. Additionally, SWJT-20 could quantitatively measure DCP using ratio changes in A₄₂₇/A₆₄₅ in absorption spectra. Furthermore, facile paper as sensors with the visualization of colorimetric/fluorometric responses based on SWJT-20 has been fabricated. Notably, this probe could detect DCP vapor through gas diffusion experiments.

Adsorption and controlled release of three kinds of flavors on UiO-66

Delivery systems for controlled release of fragrances are significantly essential in the flavor and fragrance industry due to a limited life span (premature evaporation and degradation) of fragrance compounds. Recently, several adsorption materials such as porous materials have been developed in delivery systems for targeted fragrance release. In this work, UiO-66, a member of metal-organic framework (MOF) family with high porosity and greater adsorbability, was selected as a prospective alternative to traditional porous adsorbents for controlled release of fragrances. Isophorone, eugenol, and β-ionone with strong aroma are widely used as perfume flavors, soap flavor, cosmetic flavors, and even as a food-flavoring agents, and were chosen as representative fragrances for adsorption and controlled release studies. The adsorption and release behavior of fragrances on UiO-66 was evaluated by high-performance liquid chromatography (HPLC). The UiO-66 with high surface area (1,076 m2/g) achieved effective storage and controlled release for isophorone, eugenol, and β-ionone. The adsorption rates of isophorone, eugenol, and β-ionone can reach 99.4%, 99.9%, and 60.2%, respectively. Additionally, the release of these fragrances from UiO-66 can sustain over 20 days. UiO-66 exhibited higher release rate over eugenol with desorption rates of 95.2% than that of β-ionone (52.6%) and isophorone (49.6%), respectively, suggesting a good adsorption-release selectivity of UiO-66 to different fragrances. This study further confirms the usability of UiO-66 in fragrance release and extends the application of MOF porosity in aroma release.

Honey Norisoprenoids Attract Bumble Bee, Bombus terrestris, in New Zealand Mountain Beech Forests

Three varieties of honey of different dominant floral origin were found to attract social Hymenoptera, including the large earth bumble bee, Bombus terrestris, in a New Zealand mountain beech forest. This study was undertaken to identify volatile organic compounds that induce the attraction of bumble bees to honeybee ( Apis mellifera) honey. We analyzed the chemical composition of the volatile organic compounds produced in three distinct varieties of honey (i.e., manuka, honeydew, and clover honey). The composition of the chemical profile of the three honey varieties differed in the quality and in the ratio of compounds in the headspace. o-Methoxyacetophenone was the main compound in the headspace of all three honey varieties. Among the 40 compounds identified in the headspace in the three varieties, only seven shared compounds (i.e., benzaldehyde, benzyl alcohol, phenylacetaldehyde, 2-phenylethanol, isophorone, 4-oxoisophorone, and o-methoxyacetophenone) were present in the headspace of the three honey varieties. The relative attractiveness of various blends of the seven common compounds found in the three honey varieties was tested for the attraction to bumble bees in a mountain beech forest. A binary blend of isophorone and 4-oxoisophorone at a ratio of 90:10 was the most attractive blend for both bumble bee workers and queens. A small number of honey bee workers were also attracted to the former binary blend. Our study represents the first identification of a honey-derived attractant for bumble bees and honey bees. The potential application of our finding for monitoring of bumble bees or to enhance crop pollination and help to tackle the current concern of a global pollination crisis is discussed.

Improvement of the selectivity of isophorone hydrogenation by Lewis acids

The selective hydrogenation of isophorone (3,5,5-trimethyl-2- cyclohexen-1-one) to produce 3,3,5-trimethylcyclohexanone (TMCH), an important organic solvent and pharmaceutical intermediate, is of significance in industry. However, the over-hydrogenation to produce the by-product 3,3,5-trimethylcyclohexanol causes issues. Up to now, it is still a challenge to hydrogenate isophorone to TMCH with high selectivity. In this work, we found that Lewis acids could inhibit the hydrogenation of C=O bond on isophorone, thus greatly improving the selectivity towards TMCH. In addition, added solvents like supercritical CO2 also had a positive impact on the selectivity. Both the conversion and selectivity could be increased to more than 99% when suitable Lewis acid and solvent were employed. Nevertheless, Lewis acid also exhibited some inhibition on the hydrogenation of the C=C bond of isophorone. Hence, a relatively weak Lewis acid, ZnCl2, is suitable for the selective hydrogenation.

The Combined Influence of Air Pollution and Home Learning Environment on Early Cognitive Skills in Children

Cognitive skills are one component of school readiness that reflect a child’s neurodevelopment and are influenced by environmental and social factors. Most studies assess the impact of these factors individually, without taking into consideration the complex interactions of multiple factors. The objective of this study was to examine the joint association of markers of environmental pollution and of social factors on early cognitive skills in an urban cohort of children. For this, we chose isophorone in ambient air as a marker of industrial air pollution. Low quality home learning environments was chosen as a marker of the social factors contributing to cognitive development. Using a subpopulation from the Early Childhood Longitudinal Study, Birth Cohort (N = 4050), isophorone exposure was assigned using the 2002 National Air Toxics Assessment. Home learning environment was assessed with a modified version of the Home Observation for Measurement of the Environment (HOME) Inventory, and standardized math assessment scores were used as a measure of early cognitive skills. Multiple linear regression was used to estimate the effect of both exposures on math scores. After adjustment for confounders, children living in areas with ambient isophorone in the upper quintile of exposure (>0.49 ng/m³) had math scores that were 1.63 points lower than their less exposed peers [95% CI: −2.91, −0.34], and children with lower HOME scores (at or below 9 out of 12) had math scores that were 1.20 points lower than children with better HOME scores [95% CI: −2.30, −0.10]. In adjusted models accounting for identified confounders and both exposures of interest, both high isophorone exposure and low HOME score remained independently associated with math scores [−1.48, 95% CI: −2.79, −0.18; −1.05, 95% CI: −2.15, 0.05, respectively]. There was no statistical evidence of interaction between the two exposures, although children with both higher isophorone exposure and a low HOME score had a decrement in math scale score beyond the additive effect of each exposure. This was primarily observed among male children. These findings suggest that aspects of both the physical and social environments are independently associated with children’s early cognitive skills. Future research aiming to improve children’s early cognitive skills and subsequent school readiness should address both domains.