Hydrodistillation Extraction Kinetics Regression Models for Essential Oil Yield and Composition in \u3ci\u3eJuniperus virginiana, J. excelsa\u3c/i\u3e, and \u3ci\u3eJ. sabina\u3c/i\u3e

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

Oil yield and composition of Juniperus oxycedrus L. from Bulgaria and Serbia

Juniperus oxycedrus L. (Cupressaceae) is widely distributed in countries with a Mediterranean climate. The species is known for its large morphological and chemical variation and its debatable taxonomic status. The objective was to compare the essential oil content and composition of J. oxycedrus plants from Bulgaria and Serbia, and secondly, to quantify morphological variations of leaves. Тhe essential oil content in dried juniper leaves varied from 0.059% (Кopaonik, Serbia) to 0.240% (Markovo, Bulgaria). Around 40 EO constituents were identified, belonging to the groups of monoterpenes, sesquiterpenes, diterpenes, and phenylpropanoids. The monoterpene hydrocarbons and oxygenated monoterpenes were the predominant groups of compounds representing 36.8-66.2% of the total oil, with α-pinene, limonene, sabinene, β-pinene, β-myrcene being the major constituents of this group. Overall, α-pinene was the major oil constituent in plants from all locations. The second largest group was the one of sesquiterpenes (sesquiterpene hydrocarbons, oxygenated sesquiterpenes), ranging from 19.3 tо 33.6%. There was no significant difference between the mean leaf width of the six combinations of location and tree sex, and the overall mean width was 1.24 mm. However, there was a significant difference between the mean leaf lengths. This study contradicts recent reports that the European populations of J. oxycedrus east of Italy belong to a newly identified species J. deltoides. The same reports claimed that ”the leaf oil of J. deltoides was lower in α-pinene and higher in limonene compared to J. oxycedrus”. In this study, none of the studied populations had a higher concentration of limonene than that of α-pinene. Therefore, this study demonstrated that the flora of the two countries includes indeed J. oxycedrus

Juniper essential-oil composition and bioactivity as a function of species and sex

There are 10 species of juniper (Juniperus L., Cupressaceae) in the European flora, six of which (J. communis, J. oxycedrus, J. pygmaea, J. sabina, J. sibirica, and J. excelsa) are found in the Flora of Bulgaria. Of these, J. excelsa is monoecious and the other five species are dioecious. The objective of this study was to compare the essential oil (EO) composition, antioxidant, antimicrobial, and insecticidal activities of the male (M) and female (F) plants from the five dioecious species. A secondary objective was to compare extraction methods; Clevenger vs semi-commercial steam distillation on the EO yield, profile, and bioactivity of the juniper species. The concentration of α-pinene, β-caryophyllene, δ-cadinene, and δ-cadinol was different between the oils of M and F plants within all five species. Male and F plants of J. pygmaea, J. sabina, and J. sibirica had significantly different concentrations of sabinene within the respective species. In some cases, the EO of M and F plants had different antioxidant and antimicrobial activities. The extraction method, Clevenger vs semi-commercial steam distillation was also significant on the antioxidant capacity of the EOs within most juniper species. Overall, the EO obtained from the semi-commercial extraction was more consistent within a species with respect to antioxidant capacity compared with the oils obtained using the Clevenger-type extraction. However, the oils obtained via Clevenger extraction showed greater antioxidant capacity within a species compared with those from semi-commercial extraction. In two separate experiments, seven of the juniper oils (J. communis-F, J. communis-M, J. oxycedrus-M, J. pygmaea-F, J. pygmaea-M, J. sibirica-F, and J. sibirica-M) were tested for repellent and insecticidal activities against Rhopalosiphum padi (bird cherry-oat aphid) и Sitobion avenae (English grain aphid). All of the tested oils had significant repellent and insecticidal activities against the two aphid species at concentrations of the EO in the solution at 1%, 2.5%, and 5%. The results suggest that when reporting EO composition, antioxidant, antimicrobial, and insecticidal activity of juniper EO, the sex of the tree and the extraction method needs to be indicated along with the species. The results may benefit industry utilizing juniper leaf oil for new product development

Hydrodistillation Extraction Kinetics Regression Models for Essential Oil Yield and Composition in \u3ci\u3eJuniperus virginiana, J. excelsa\u3c/i\u3e, and \u3ci\u3eJ. sabina\u3c/i\u3e

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

Biological Activity of Essential Oils of Four Juniper Species and Their Potential as Biopesticides

The objective of this study was to assess the biological activity of essential oils (EOs) of four Juniperus species obtained via two different distillation methods and their potential as biopesticides. The studied factors were juniper species (Juniperus communis L., J. oxycedrus L., J. pygmaea C. Koch., and J. sibirica Burgsd), plant sex (male (M) and female (F)), and distillation method (hydrodistillation via a standard Clevenger apparatus (ClevA) and semi-commercial (SCom) steam distillation). The hypothesis was that the EO will have differential antioxidant, antimicrobial, and insecticidal activities as a function of plant species, plant sex, and distillation method. The two distillation methods resulted in similar EO composition within a given species. However, there were differences in the EO content (yield) due to the sex of the plant, and also differences in the proportions of some EO components. The concentration of α-pinene, β-caryophyllene, δ-cadinene and δ-cadinol was dissimilar between the EO of M and F plants within all four species. Additionally, M and F plants of J. pygmaea, and J. sibirica had significantly different concentrations of sabinene within the respective species. The EOs obtained via ClevA extraction showed higher antioxidant capacity within a species compared with those from SCom extraction. All of the tested EOs had significant repellent and insecticidal activity against the two aphid species Rhopalosiphum padi (bird cherry-oat aphid) and Sitobion avenae (English grain aphid) at concentrations of the EO in the solution of 1%, 2.5%, and 5%. The tested EOs demonstrated moderate activity against selected pathogens Fusarium spp., Botrytis cinerea, Colletotrichum spp., Rhizoctonia solani and Cylindrocarpon pauciseptatum. The results demonstrate that the standard ClevA would provide comparable EO content and composition in comparison with SCom steam distillation; however, even slight differences in the EO composition may translate into differential bioactivity

Hydrodistillation Extraction Kinetics Regression Models for Essential Oil Yield and Composition in Juniperus virginiana, J. excelsa, and J. sabina

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

Chemical profile of Juniperus excelsa M. Bieb. essential oil within and between populations and its weed seed suppression effect.

The aims of this study were to (1) establish the intrapopulation and seasonal variation of Juniperus excelsа essential oil (EO); (2) compare the J. excelsa concrete and resinoid composition with its EO composition; and (3) investigate the potential herbicidal activity of J. excelsa EO against seeds of Papaver rhoeas L., Consolida orientalis (J.Gay) Schrödinger, Anthemis arvensis L., Avena fatua L., and Agrostemma githago L. Four independent studies were performed to meet these objectives. Twenty-eight individual trees were analyzed from two populations to establish intrapopulation and interpopulation variability of EOs yield and composition. In the seasonal dynamic study of leaf EO, samples from the same three trees and in the same population were collected in January, March, May, July, October, and December and their EO yield and composition determined. The EOs (intrapopulation and seasonal) were extracted by hydrodistillation, while the EO for the herbicidal test was obtained by steam distillation in a semi-commercial (SCom) apparatus. Overall, the EO yield varied significantly from 0.93% to 2.57%. α-Pinene (8.85-35.94%), limonene (11.81-50.08%), and cedrol (3.41-34.29%) were the predominant EO compounds in all samples (intrapopulation variability); however, trans-2,4-decadienol and β-caryophyllene were predominant in some individual trees. Four chemical groups were identified in the samples collected from two natural populations (intrapopulation). This is the first report on the compositions of J. excelsa concrete and resinoid. Cedrol (15.39%), 7-hydroxy-4-methyl-coumarin (17.63%), 1-octacosanol (36.85%), tritriacontane (16.08%), and tiacontanoic acid were the main compounds in the concrete and resinoid. Juniperus excelsa EO suppressed seed germination and seedling growth of P. rhoeas, C. orientalis, A. arvensis, A. fatua, and A. githago, demonstrating its potential to be used for the development of new biopesticides. The highest EO yield with high content of limonene and cedrol was obtained from samples harvested during the winter months (December, January, and March)

ANOVA <i>p</i>-values that show the significance of the main and interaction effects of Tree and Month on 10 response variables of <i>Juniperus excelsa</i> in Bulgaria (seasonal variability).

Significant effects that require multiple means comparison are shown in bold.</p