RESUMEN

Cedrol-like compounds are of pharmacological interest due to their diverse range of medicinal effects and are used globally in traditional medicines and cosmetics. Many cedrol tautomers are known from molecular studies but few have been studied in crystalline form by X-ray diffraction. Acicular white crystals collected from the wood of eastern red cedar (Juniperus virginiana) are determined to be (+)-cedrol hemihydrate, namely, (1S,2R,5S,7R,8R)-2,6,6,8-tetramethyltricyclo[5.3.1.01,5]undecan-8-ol hemihydrate, C15H26O·0.5H2O, a novel packing of two unique cedrol molecules (Z' = 2) with a single water molecule [space group P212121; a = 6.1956 (1), b = 14.5363 (1), and c = 30.9294 (4) Å]. The hydrogen bonding forms a one-dimensional spiral chain running along the a axis, following the chirality of the cedrol molecule, through hydrogen-bonding interactions with a right-handed helical configuration in graph-set notation Δ-C33(6) > a > c > b. The crystal packing and symmetry are different from crystalline isocedrol due to the different hydrogen-bonding geometry.

RESUMEN

A new species of the parasitic wasp Coptera Say was previously distinguished from other species via correspondence between ecological (host) differences and DNA barcodes. A description and figures for Coptera tonic sp. nov., along with revisions to existing keys that allow it to be distinguished from other Nearctic species without the aid of molecular characters, is provided in this work.

RESUMEN

Fast pyrolysis is a promising route to transform biomass into bio-oil for further refining into transportation fuels and chemicals. However, bio-oil applications suffer from several challenges due to its adverse properties. This study reports improving bio-oil properties through co-pyrolysis of biomass with methane over molybdenum/zinc (MoZn/ZHSM-5) and HZSM-5 catalysts that promote deoxygenation, decarbonylation, hydrogen transfer and aromatization reactions. The co-pyrolysis was conducted at 650 °C and 750 °C in a micro-scale reactor and a bench-scale reactor. The highest bio-oil yield, energy content, and energy yield of 53.4%, 10.2 MJ/kg, and 29.9%, respectively, were obtained with methane over MoZn/HZSM-5 at 650 °C. Acids, alcohols, aldehydes, benzene derivatives, BTEXs, furans, ketones, PAHs, and phenols were detected in bio-oils while phenols dominated under most conditions. Oxygenated compounds decreased using MoZn/HZSM-5 with methane at 750 °C. The results demonstrate that methane used with catalysts can reduce oxygenated compounds and improve properties and yield of bio-oil.

Asunto(s)

RESUMEN

The chemical profile and antioxidant capacity of Juniperus virginiana, J. excelsa, and J. sabina essential oil (EO) fractions as a function of time was the subject of this study. The hypothesis was that, capturing EO in sequential timeframes during hydrodistillation would generate fractions containing unique compositions and antioxidant capacity. In J. virginiana, the highest limonene (43%) was found in the 0⁻5 min oil fraction, with safrole (37%) being highest in the 10⁻20 and 20⁻40 min fractions, and elemol (34%) being highest in the 160⁻240 min fraction. In J. excelsa, α-pinene (34-36%) was the highest in the 0⁻5 min fraction and in the control (non-stop 0⁻240 min distillation) oil, limonene (39%) was the highest in the 0⁻10 min fractions and cedrol (50-53%) was the highest in the 40⁻240 min fractions. In J. sabina, sabinene (80%) was highest in the 0⁻3 min fraction. The highest antioxidant capacity of J. virginiana was demonstrated by the 5⁻10 min fraction; the one in J. sabina by the 3⁻10 min fraction; and, the one in J. excelsa, by the control. The kinetics regression models that were developed can predict EO composition of the three juniper species eluted at different timeframes. Various industries could benefit from the results from this study.

Asunto(s)

RESUMEN

In the Tulsa area, the Cupressaceae is largely represented by eastern red cedar (Juniperus virginiana L.). The encroachment of this species into the grasslands of Oklahoma has been well documented, and it is believed this trend will continue. The pollen is known to be allergenic and is a major component of the Tulsa atmosphere in February and March. This study examined airborne Cupressaceae pollen data from 1987 to 2016 to determine long-term trends, pollen seasonal variability, and influence of meteorological variables on airborne pollen concentrations. Pollen was collected through means of a Burkard sampler and analyzed with microscopy. Daily pollen concentrations and yearly pollen metrics showed a high degree of variability. In addition, there were significant increases over time in the seasonal pollen index and in peak concentrations. These increases parallel the increasing population of J. virginiana in the region. Pollen data were split into pre- and post-peak categories for statistical analyses, which revealed significant differences in correlations of the two datasets when analyzed with meteorological conditions. While temperature and dew point, among others were significant in both datasets, other factors, like relative humidity, were significant only in one dataset. Analyses using wind direction showed that southerly and southwestern winds contributed to increased pollen concentrations. This study confirms that J. virginiana pollen has become an increasing risk for individuals sensitive to this pollen and emphasizes the need for long-term aerobiological monitoring in other areas.

Asunto(s)