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).

Chemical profile, antioxidant and antimicrobial activity of Pinus heldreichii Christ. Distributed in Bulgaria

Pinus heldreichii Christ. (Bosnian pine), a Tertiary relict and Balkan sub-endemic, has not been comprehensively studied for its essential oil (EO) profile and bioactivity of its different plant parts. This study aimed to determine the EO yield, composition and antimicrobial activity from different parts of P. heldreichii at three different populations (mountains) in Bulgaria. Furthermore, the study assessed the antioxidant activities of plant tissue, including leaves (needles), twigs wood, male and female cones. The EOs yield from different plant parts ranged from 0.09 % (leaves) to 0.74 % (wood of twigs), with monoterpenes being the predominant class. Limonene, α-pinene, β-caryophyllene, germacrene D, β-pinene, and β-myrcene were detected in the EO extracted from all analyzed trees. However, these compounds were not found in the EO extracted from all plant parts of the same trees. Four chemical groups (chemotypes) were identified for EO from twigs, and three chemotypes were identified for EO from leaves. The chemotypes were based on the percent ratio of the main EO constituents (>5 %). Leaves tissue showed the highest values in terms of polyphenols and flavonoids, as well as higher ABTS radical scavenging activity, while the highest antimicrobial activity against Staphylococcus aureus subsp. aureus was seen in the EOs obtained from twigs. This is the first study to identify several chemotypes based on leaf and twigs EO of P. heldreichii distributed in Bulgarian flora. Furthermore, the EO of twigs tips (TT), male cones (MC), and wood of one-two-year-old twigs (WT) of the same trees were reported for the first time. The total polyphenol, flavonoid content, and radical scavenging activity of tissues of annual twigs wood and biennial twigs wood, leaf tissue, MC tissue, and the twigs tips tissue is also reported for the first time in the accessible literature. These findings highlight the potential of P. heldreichii to provide EOs with varying compositions and bioactivities, making them suitable for nutraceutical, pharmacological, and potentially food additive applications. Furthermore, the identification of chemotype accessions in this study suggests their selection for the development of new forest crop as a source for natural products with desirable composition and bioactivity.

Phytochemical and biological investigations on Centranthus kellereri (Stoj., Stef. & T. Georgiev) Stoj. & Stef. and C. ruber (L.) DC. and their potential as new medicinal and ornamental plants

INTRODUCTION

Centranthus kellereri is a Bulgarian endemic plant species, found only in two locations in the world: The Balkans Mountains (Stara Planina), above the town of Vratsa, and The Pirin Mountains, above the town of Bansko, Bulgaria. Being endemic and endangered species precluded any significant research on it. The hypothesis of this study was that the populations of C. kellereri may represent genetically, phytochemically, and morphologically distinct forms and these will differentiate from C. ruber. Furthermore, C. kellereri possibly imperfect embryology may preclude its more widespread distribution under natural conditions.

RESULTS

This study revealed the phytochemical profile, antioxidant activity, embryology, surface microstructural morphological traits, and genetic differences between the C. kellereri plants from the only two natural populations and compares them to the ones of the related and better-known plant C. ruber. The essential oil (EO) content in aboveground plant parts and in roots was generally low and the EO composition varied significantly as a function of plant part, year of sampling, location, and species. Methylvaleric acid was a major EO constituent in the C. kellereri EO, ranging between 60.2% and 71.7% of the total EO. The EO included monoterpenes, sequiterpenes, long-chain alkanes and fatty acids. Phytochemical analyses of plant tissue revealed the occurrence of 32 compounds that were tentatively identified as 6 simple phenolics, 18 flavonoids, 1 quinone, 1 lipid, 1 alkaloid, 2 diterpenes, and 3 triterpenes. There were differences in detected compounds between the C. kellereri plants at the two locations and between the roots and shoots in both species. The total phenols and flavonoids varied between the two species but were also dissimilar between the plants from the two populations of C. kelleri. Free radical scavenging activity, measured with ABTS and DPPH in aqueous and methanol extracts, had similar values; however, overall, C. kellereri from Vratsa showed the highest antioxidant activity while C. ruber had the lowest activity. Genetic analyses showed a clear differentiation between C. kellereri and C. ruber, and between the two populations of C. kellereri. Embryological studies revealed the peculiarities of the male and female generative spheres of the two species that were defined as being sexually reproducing. The pollen had high viability; however, the low viability of seeds demonstrated possible high sensitivity of C. kellereri to the environmental conditions, perhaps the main factor modifying and restricting the population sizes. The SEM analyses exposed differences in surface microstructural traits between the species (C. kellereri and C. ruber) but also between the two populations of C. kellereri. The observed dissimilarities in genetic makeup, micromorphological characteristics, and phytochemical composition strongly indicate that the two populations can be classified as distinct subspecies or varieties of C. kellereri; var. pirinensis and var. balkanensis. Further research is needed to introduce C. kellereri into culture and develop it as a high-value specialty crop or ornamental in order to conserve C. kellereri natural populations. C. kellereri may be utilized as a source for phytochemicals of interest and as an ornamental plant like C. ruber; however, it may have a greater environmental plasticity and adaptation as evidenced by its current locations.

Reproductive Capacity and Scanning Electron Microscopy (SEM) Analyses of the Micromorphological Surfaces of Three Endemic Satureja Species from Bulgaria

Satureja pilosa Velen., S. coerulea Janka and S. kitaibelii Wierzb. ex Heuff. are Balkan endemic species, and they are distributed in restricted territories, primarily found in dry grasslands, rocky slopes, and stony habitats. This study presents the results of the first embryological and micromorphological analyses of three Satureja species (S. pilosa, S. kitaibelii, and S. coerulea) from the Bulgarian flora. The aim of this study was to establish the features of the male and female reproductive sphere, as well as surface characteristics of leaves, stem, and calyx in order to understand the mode of reproduction, character, size and state of species populations and delimitation. For the embryological study, flowers and flower buds in different developmental stages were collected from plants of natural populations and treated with the classic paraffin method. Reproductive capacity was assessed using the following approaches: (1) acetocarmine test for pollen viability, (2) tetrazolium test (TTZ) for seed viability, and (3) germination test. The surfaces characteristics of leaves, stem, and calyx were analyzed by scanning electron microscopy (SEM). As a result, the study revealed the structures of the male (M) and female (F) generative spheres as well as the processes of gamete development, pollination, and endosperm and embryo formation. It was found that the three Satureja species exhibited a high pollen viability but low seed viability and germination. The SEM analysis showed both common and distinct micromorphology features regarding epidermis, calyx and stem surfaces among the three Satureja species. Notably, the S. coerulea surfaces (leaves, calyx, stem) were clearly distinguishable from the other two Satureja species. Regarding the nutlet surfaces, it was observed that the exocarp surfaces of S. coerulea and S. kitaibelii have a reticulate convex type surface and comprise two types of cells: (1) highly bulging, bubble-like cells; and (2) flat cells with numerous striations. On the other hand, the exocarp of S. pilosa displayed rectangular or polygonal shapes without bubble-like cells, and it had a tabular to slightly convex type surface. Additionally, nutlets (seeds) of both S. coerulea and S. pilosa exhibited distinct papilla formations resembling non-glandular trichomes seen on the ends of the nutlets for S. coerulea and over the entire surface for S. pilosa. The characteristics of the embryological structures and processes, along with the absence of apomixis, characterized the three studied Satureja species as sexually reproducing. The established balanced processes and stable structures contribute to their high reproductive potential and population stability. However, these traits may also decrease their adaptability to environmental changes.

Determining the optimum mixture of three essential oils for potato sprout suppression at room temperature storage

As a staple crop, potatoes (Solanum tuberosum) play an important role in meeting daily caloric needs. To ensure adequate supplies for year-round consumption, potato quality must be maintained throughout lengthy storage periods. Towards this end, potato sprouting during storage must be minimized. Due to changing regulations regarding chemical means of potato sprout suppression, increased focus has turned to alternative products including essential oils (EO) as sprout suppressants in recent years. The complex composition of various EOs promises numerous options for sprout suppression. Furthermore, blends of several EOs may achieve enhanced sprout suppressant properties if synergistic interactions are present. We evaluated Syzygium aromaticum, Artemisia herba-alba, and Laurus nobilis EOs and blends thereof as sprout suppressants in potato cultivar Ranger Russet stored at room temperature and also tested for their antifungal activity against Colletotrichum fragariae, a causal organism of anthracnose disease in strawberries including other vegetables and fruits. A. herba-alba EO was an effective sprout suppressant when used alone and suppressed sprouting over the 90-day storage period. Interactions between A. herba-alba and S. aromaticum affected sprout length whereas interactions between A. herba-alba and L. nobilis EOs affected sprout number. An optimum blend of 50% - 82.31% A. herba-alba, 17.69% - 50% L. nobilis, and 0% - 1.01% S. aromaticum EOs could more effectively minimize tuber sprout length and number than any of the three whole EOs used alone. Among these three EOs, only S. aromaticum EO showed antifungal activity against C. fragariae in bioautography assay. These results exhibit the potential of EOs blends as a novel tactic in potato sprout suppression as well as potential natural product-based fungicides in managing C. fragariae.

Essential Oil Composition of Seven Bulgarian Hypericum Species and Its Potential as a Biopesticide

Hypericum species and especially H. perforatum L. are well known for their therapeutic applications. The present study assessed the essential oil (EO) composition, and antifungal and aphid suppression activity of seven Bulgarian Hypericum species. The EOs were analyzed by GC-MS-FID. Two experiments were conducted. In the first experiment, H. perforatum, H. maculatum, and H. hirsutum were used. Additionally, the EO composition of H. perforatum extracted via hydrodistillation (ClevA) and via commercial steam distillation (Com) were compared. The second experiment compared the EOs of H. perforatum, H. cerastoides, H. rumeliacum, H. montbretii, and H. calycinum (flowers and leaves) extracted via hydrodistillation and collected with n-hexane. Overall, the EO constituents belonged to four classes, namely alkanes, monoterpenes, sesquiterpenes, and fatty acids. The main class for compounds in H. maculatum and H. perforatum (section Hypericum) were sesquiterpenes for both experiments except for H. perforatum (Com). Hypericum montbretii (section Drosocarpium) EO had monoterpenes (38.09%) and sesquiterpenes (37.09%) as major groups, while H. hirsutum EO (section Taeniocarpium) contained predominately alkanes (67.19%). Hypericum hirsutum EO contained cedrol (5.04%), found for the first time in Hypericum species. Fatty acids were the main compounds in H. cerastoides (section Campylopus), while monoterpenes were the most abundant class in H. rumeliacum and H. calycinum EOs. α-Pinene and germacrene D were the major EO constituents of all analyzed Hypericum species except for H. hirsutum and H. cerastoides. Hypericum perforatum EO (Com) had significant repellent and insecticidal activity against two aphid species, Rhopalosiphum padi (Bird Cherry-oat aphid) and Sitobion avenae (English grain aphid) at concentrations of 0%, 1%, 2.5%, 3.5%, 4.5%, and 5%. The tested EOs did not show significant activity against selected economically important agricultural fungal pathogens Fusarium spp., Botrytis cinerea, Colletotrichum spp., Rhizoctonia solani, and Aspergillus sp. The EO of the Hypericum species found in the Bulgarian flora could be utilized for the development of new biopesticides for aphid control.

Metabolic Profiles, Genetic Diversity, and Genome Size of Bulgarian Population of Alkanna tinctoria

Alkanna tinctoria (L.) Tausch Boraginaceae is a medicinal plant whose root is used for its antimicrobial and anti-inflammatory properties. A. tinctoria roots have been subject to numerous studies. However, the aerial parts have been explored less. The objective of the present study was to compare the chemical profile of aerial parts and roots as well as the total alkannin content in roots of 11 populations of the species from different floristic regions of Bulgaria. Methanolic extracts from 22 samples were analyzed by GC/MS. Phenolic, fatty, and organic acids, sterols, polyols, fatty alcohols, and sugars were identified. Ononitol (4-O-methyl-myo-inositol) was found as the main compound in the aerial parts. The total alkannin content in the roots was evaluated by the spectrophotometric method and compared with that of the commercial product. Populations with high alkannin content and rich in other bioactive compounds were identified. A relatively low genetic diversity in the studied populations was observed. The present study is the first comprehensive study on metabolite profiles and genetic diversity of the Bulgarian populations of A. tinctoria. The occurrence of ononitol in the aerial parts of the species is reported for the first time, as well as the phenolic acid profiles of the species in both aerial parts and roots. The results showed that aerial parts of the plant are also promising for use as a source of valuable biologically active substances.

Effects of Essential Oil Fumigation on Potato Sprouting at Room-Temperature Storage

As a global staple, potato plays an important role in meeting human dietary needs and alleviating malnutrition. Potato sprouting during storage is a major issue that threatens food security by increasing food waste and must therefore be controlled. Biopesticides, including essential oils (EOs), have a history of use as potato sprout suppressants, and interest in their use has been renewed in response to stricter regulations on CIPC, the dominant chemical sprout suppressant over the last half-century. We evaluated twenty-one EOs as potential sprout suppressants in cv. Ranger Russet potatoes at room-temperature storage. Treatment with Artemisia herba-alba EO was the most effective at suppressing both sprout length and sprout number over a 90-day storage period. GC—MS—FID analysis of A. herba-alba EO revealed the presence of α-thujone, hexadecenoic acid, β-thujone, camphor, sabinene, and camphene at amounts >1%. Cistus ladanifer, Ocimum basilicum, Ormenis mixta, and Salvia sclarea EOs significantly reduced sprout length for shorter storage periods, whereas Cinnamomum zeylanicum (bark) and Laurus nobilis EOs also significantly reduced sprout number. Syzygium aromaticum (clove) EO did not significantly suppress sprouting at room temperature. These results indicate the potential of certain EOs to be used as sprout suppressants for room-temperature potato storage, providing needed alternatives for both organic and conventional potato industries.

Evaluation of Essential Oils as Sprout Suppressants for Potato (Solanum tuberosum) at Room Temperature Storage

Chlorpropham (CIPC) has been the dominant method of chemical sprout suppression for the last half-century. However, stricter regulations including outright bans on its use in several countries has prompted investigation into alternative products to replace it. Growing interest in organic foods has increased focus on the use of biopesticides, including essential oils (EOs), as potential sprout suppressants in stored potato. We evaluated the potential of ten EOs for sprout suppression in potato cultivar Ranger Russet at room temperature. Treatment with Cymbopogon citratus EO was found to be the most effective sprout suppressant, completely suppressing sprouting over the 90-day storage period. The EOs of Myrtus communis and Melaleuca quinquenervia significantly reduced sprout length relative to the control but did not have any effect on sprout number. These findings demonstrate the potential of select EOs as effective potato sprout suppressants that could replace CIPC use in this industry while also giving more power to organic potato producers and processors to control sprouting in their operations.

Melissa officinalis L. as a Sprout Suppressor in Solanum tuberosum L. and an Alternative to Synthetic Pesticides

The goal of this research was to screen plant essential oils (EOs) as sprout inhibitors or suppressors in potato (Solanum tuberosum L.). Three controlled environment experiments were conducted to screen 18 EOs and several pure compounds as sprout inhibitors. The EOs were applied using the wicked method on potato cv. Gala in 19 L plastic containers. The results indicated that Melissa officinalis L. EO inhibited sprouting, while Coriandrum sativum L. seed oil and the EO blend of Lavandula angustifolia Mill. and Salvia sclarea L. suppressed sprouting. The EOs of interest were analyzed using gas chromatography coupled to mass spectrometry (GC-MS) and/or a flame ionization detector (GC-FID); the detailed chemical profiles are provided. The M. officinalis EO was fractionated into seven fractions, and these were tested on minitubers. We identified two fractions (F and A) that suppressed potato sprouting better than the whole oil. The GC-MS-FID analyses of M. officinalis EO fraction A identified myrcene, Z-ocimene, E-ocimene, trans-caryophyllene, and α-humulene as the main constituents, while the main constituents of fraction F were α-terpineol, β-citronellol, and geraniol. The pure isolated compounds, together with the major compound in M. officinalis EO (citral), were tested for sprout suppression on three potato cultivars (Ranger Russet, Terra Rosa, and Dakota TrailBlazer), which revealed that β-citronellol reduced the sprout length and the number of sprouts in all three cultivars, while citral and (+)-α-terpineol reduced the sprout length and the number of sprouts in Ranger Russet relative to the two controls in all three cultivars. Myrcene had a stimulating effect on the number of sprouts in Cv. Terra Rosa. However, none of the pure compounds suppressed sprouting completely or were comparable to the EO of M. officinalis.

Green extraction of hemp (Cannabis sativa L.) using microwave method for recovery of three valuable fractions (essential oil, phenolic compounds and cannabinoids): a central composite design optimization study

BACKGROUND

Solvent-free microwave-assisted extraction (MAE) is a green extraction method capable of boosting the yield and quality profile of hemp essential oil when compared with other conventional extraction techniques. During this process, two by-products are produced, namely the aqueous residue containing bioactive phenolics and the residual deterpenated biomass, which can be used for further extraction and purification of phytocannabinoids. To date, the hemp industry has not utilized these products, although they can be valuable for the food, cosmetic, nutraceutical and pharmaceutical market.

RESULTS

This study assessed and optimized the variables affecting MAE efficiency, namely microwave irradiation power, extraction time and added water, which were studied using a central composite design approach, and results were used to optimize the extraction process for recovering three valuable fractions: essential oil, polyphenols and phytocannabinoids. The products obtained using the optimized conditions were characterized in terms of yield, chemical profile and antioxidant potential. Moreover, the by-products obtained during the optimized run were further analyzed in terms of their biological activity using both enzymatic and non-enzymatic assays. The aqueous residue demonstrated a powerful α-glucosidase inhibition, a good activity in terms of superoxide radical scavenging activity, a modest efficacy in terms of inhibition of advanced glycation end products formation and no activity in terms of lipase inhibition. The residual deterpenated biomass did not possess significant biological activity.

CONCLUSION

This work demonstrated valorization of industrial hemp essential oil and its by-products, obtained by a sustainable and eco-friendly extraction method, through an almost waste-free approach. Cannabinoids as well as other valuable bioactive compounds such as glycosidic flavones may be recovered from the residues of the essential oil extraction, representing interesting substances in the pharmaceutical, cosmetic and nutraceutical fields. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Variability in Biological Activities of Satureja montana Subsp. montana and Subsp. variegata Based on Different Extraction Methods

Winter savory (Satureja montana L.) is a well-known spice and medicinal plant with a wide range of activities and applications. Two subspecies of S. montana, subsp. montana and subsp. variegata, were used for the preparation of seven different extracts: steam distillation (essential oil (EO) and hydrolate (HY)), subcritical water (SWE), ultrasound-assisted (UAE-MeOH and UAE-H₂O), and microwave-assisted (MAE-MeOH and MAE-H₂O) extraction. The obtained EOs, HYs, and extracts were used for an in vitro evaluation of the antioxidant activity (DPPH, ABTS, reducing power, and superoxide anion methods) and in vitro antimicrobial activity against Bacillus cereus, Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Salmonella Typhimurium, Saccharomyces cerevisiae, and Candida albicans. The antimicrobial screening was conducted using disk-diffusion assessment, minimal inhibitory concentration, time–kill kinetics modeling, and pharmacodynamic study of the biocide effect. The total phenolic content (TPC) was highest in EO, followed by SWE, MAE, and UAE, and the lowest was in HY. The highest antimicrobial activity shows EO and SWE for both varieties, while different UAE and MAE extracts have not exhibited antimicrobial activity. The natural antimicrobials in the S. montana extract samples obtained by green extraction methods, indicated the possibility of ecologically and economically better solutions for future in vivo application of the selected plant subspecies.

Terpenes and Cannabinoids Yields and Profile from Direct-Seeded and Transplanted CBD-Cannabis sativa

Following recent legalization, the production of hemp (Cannabis sativa L.) for high-value plant compounds became a major crop in many countries across the world. In this study, we profiled popular plant compounds being extracted for emerging markets, terpenes and cannabinoids, developed in two different planting systems of a single, high-cannabidiol (CBD), low-Δ⁹-tetrahydrocannabinol (Δ⁹-THC), dioecious hemp cultivar 'Culver' in central Oregon, U.S.A. One system is the current conventional system of an open, all-female, clonal transplant (OFCT) production system. This is compared to a dioecious, densely seeded (DDS) production system. Overall, the essential oil (EO, chiefly terpenes) and cannabinoid profiles of plants harvested from the two systems were comparable. In comparison to the DDS plots, the EO obtained from colas of the OFCT plots had higher concentrations of α-pinene, myrcene, limonene, β-bisabolene, γ-cadinene, caryophyllene oxide, guaiol, 10-epi-γ-eudesmol, β-eudesmol, bulnesol, epi-α-bisabolol, α-humulene, and CBD, although lower concentrations of 1,8-cineole, (E)-caryophyllene, γ-elemene, α-selinene, selina-4(15),7(11)-diene, selina-3,7(11)-diene, and germacrene B. Of the various plant parts (female leaves and chaff, male flowers) tested in the DDS plots, the highest EO yield was obtained from the chaff. The main EO constituents of female leaves were (E)-caryophyllene (14-21%), caryophyllene oxide (13-16%), α-humulene (5-6%), humulene epoxide II (3.5-3.8%), epi-α-bisabolol (2.7-5.5%), CBD, and α-eudesmol (1.1-2.6%). The principal EO constituents of female chaff from the DDS system were (E)-caryophyllene (∼21%), α-humulene (6.6%), β-selinene (4.5%), α-selinene (3.6%), selina-3,7(11)-diene (9.8%), selina-4(15),7(11)-diene (6.3%), caryophyllene oxide (5.2%), and cannabichromene (3.1%). The major EO constituents of the male flowers were CBD (19.3%), caryophyllene oxide (11%), α-humulene (4.1%), epi-α-bisabolol (3.9%), selina-3,7(11)-diene (3.4%), and β-selinene (3.4%). Cannabinoids were not detected in the EO distilled for 30 min, but they were present in the EO from 240 min of distillation. The EO content of female leaves and male flowers was relatively low, whereas the EO content of the female chaff from the DDS system was significantly greater. Breaking with conventional knowledge, the EO of male flowers may accumulate up to 19% CBD. Distillation of plants from both production systems converted CBD-A to CBD, CBDV-A to CBDV, CBG-A to CBG, and THC-A to THC as a result of the thermal decarboxylation of acidic cannabinoids but otherwise did not affect the total cannabinoid content. Most of the cannabinoids remained in the distilled biomass after the extraction of terpenes (EO). Therefore, the distilled, terpene-free biomass represents a high-value product that could be further extracted for cannabinoids or used as a component in various products.

Essential Oil Yield, Composition, and Bioactivity of Sagebrush Species in the Bighorn Mountains

Sagebrush (Artemisia spp.) are dominant wild plants in large areas of the U.S., Canada and Mexico, and they include several species and subspecies. The aim was to determine if there are significant differences in essential oil (EO) yield, composition, and biological activity of sagebrush within the Bighorn Mountains, U.S. The EO yield in fresh herbage varied from 0.15 to 1.69% for all species, including 0.25-1.69% in A. tridentata var. vaseyana, 0.64-1.44% in A. tridentata var. tridentata, 1% in A. tridentata var. wyomingensis, 0.8-1.2% in A. longifolia, 0.8-1% in A. cana, and 0.16% in A. ludoviciana. There was significant variability in the EO profile between species, and subspecies. Some EO constituents, such as α-pinene (0-35.5%), camphene (0-21.5%), eucalyptol (0-30.8%), and camphor (0-45.5%), were found in most species and varied with species and subspecies. The antioxidant capacity of the EOs varied between the species and subspecies. None of the sagebrush EOs had significant antimicrobial, antimalarial, antileishmanial activity, or contained podophyllotoxin. Some accessions yielded EO with significant concentrations of compounds including camphor, eucalyptol, cis-thujone, α-pinene, α-necrodol-acetate, fragranol, grandisol, para-cymene, and arthole. Therefore, chemotypes can be selected and possibly introduced into culture and be grown for commercial production of these compounds to meet specific industry needs.

Wheat and Barley Grass Juice Addition to a Plant-Based Feed Improved Growth and Flesh Quality of Common Carp (Cyprinus carpio)

Simple Summary

Several plant extract additives are being increasingly used in aquaculture for their positive effects on fish growth and immunity. Plant extract additives are called phytogenics. The chemical composition of the additives influences their biological activity. The plant extracts used in this study were wheat grass juice and barley grass juice. Their inclusion in a plant-based diet for common carp improved growth performance and flesh quality. The positive effects of the plant extracts could be attributed to their contents of unsaturated fatty acids, essential amino acids, sugars and organic acids.

Abstract

Phytogenics are plant extract additives used for their bioactive properties. The objective of this study was to assess the effect of plant extracts, wheat grass juice (WGJ) and barley grass juices (BGJ) addition to fish diet on growth and meat quality of common carp. Fish (51 ± 33 g initial weight) were fed for four weeks with three plant-based diets: (1) control feed (Con), (2) control feed supplemented with 2% WGJ (Con+WGJ), and (3) control feed supplemented with 2% BGJ (Con+BGJ). The results showed that the inclusion of the two juices in the plant-based feed stimulated the growth and improved meat quality by lowering the fat and ash content. Feed conversion ratio and condition factor were not affected. There were no significant differences in Fe and Zn contents of meat; however, Cu decreased, while Mn was lower in the Con+WGJ group and higher in the Con+BGJ group compared to Con. A high content of unsaturated fatty acids (FA, oleic acid and linoleic acid) and desirable ratios of saturated/unsaturated FA (0.27–0.29) and Ω6/Ω3 (2.5–2.78) were found in all groups. The juices were characterized in terms of lipid profile and polar compounds by GC-MS technique. The observed positive effects can be attributed to the rich composition of juices that included unsaturated FA, amino acids, sugars and organic compounds.

Chemical Composition, Antioxidant, and Antimicrobial Activity of Dracocephalum moldavica L. Essential Oil and Hydrolate

Steam distillation was used for the isolation of Dracocephalum moldavica L. (Moldavian dragonhead) essential oil (DMEO). This aromatic herbaceous plant is widespread across the Northern Hemisphere regions and has been utilized in health-improving studies and applications. In addition to the DMEO, the hydrolate (DMH), a byproduct of the distillation process, was also collected. The DMEO and DMH were analyzed and compared in terms of their chemical composition, as well as their in vitro biological activities. The main component in DMEO was geranyl acetate, while geranial was dominant in DMH. The DMEO demonstrated better antioxidant and antimicrobial activities compared with the DMH against Staphylococcus aureus, Escherichia coli, Salmonella Typhimurium, and Listeria monocytogenes, which represent sources of food-borne illness at the global level. The DMEO and DMH show promise as antioxidant and antimicrobial additives to various products.

Chemical Profile and Antimicrobial Activity of the Essential Oils of Helichrysum arenarium (L.) Moench. and Helichrysum italicum (Roth.) G. Don

This study compared the essential oils (EO) composition of Helichrysum arenarium (Bulgarian populations) with that of the cultivated species H. italicum. The EO composition of H. arenarium and H. italicum were analyzed via gas chromatography. In general, 75 components were identified in H. arenarium EO and 79 in H. italicum EO. The predominant constituents in H. arenarium EO were α-pinene (34.64–44.35%) and sabinene (10.63–11.1%), which affirmed the examined population as a new chemical type. Overall, the main EO constituents of H. italicum originating in France, Bosnia and Corsica were neryl acetate (4.04–14.87%) and β-himachalene (9.9–10.99%). However, the EOs profile of H. italicum introduced from the above three countries differed to some extent. D-limonene (5.23%), italicene, α-guaiene and neryl acetate (14.87%) predominated in the H. italicum introduced from France, while α-pinene (13.74%), δ-cadinene (5.51%), α-cadinene (3.3%), β-caryophyllene (3.65%) and α-calacorene (1.63%) predominated in plants introduced from Bosnia. The EOs of the plants introduced from France and Corsica had similar chemical composition and antimicrobiological activity.

Assessment of the Fertilization Capacity of the Aquaculture Sediment for Wheat Grass as Sustainable Alternative Use

Periodic removal of sediment from aquaculture ponds is practiced to maintain their productivity and animal welfare. The recovery of sediment as a plant fertilizer could alleviate the costs of sediment removal. The objective of this study was to test the effects of a dried sediment, extracted from an aquaculture pond used for common carp cultivation, on the growth and physiology of potted wheat grass and the quality of the juice obtained from wheat grass. The results showed that sediment application did not produce significant morphological changes, although the values for plant height (16.94-19.22 cm), leaf area (19.67-139.21 mm²), and biomass (3.39-4.26 g/plant) were higher in sediment-grown plants. However, at a physiological level, the effect was negative, decreasing photosynthesis (0.82-1.66 μmol CO₂ m²s^-1), fluorescence ΦPSII (0.737-0.782), and chlorophyll content (1.40-1.83 CCI). The juice yield was reduced in the sediment treatments (46-58 g/100 g), while the quality was improved by increasing the content of phenols (2.55-3.39 µg/mL gallic acid equivalent), flavonoids (1.41-1.85 µg/mL quercetin equivalent), and antioxidant activity (47.99-62.7% inhibition of; 2,2-diphenyl-1-picrylhydrazyl). The positive results obtained in this study can be attributed to the moderate nutrient content of the sediment and a negligible concentration of heavy metals.

Phytochemical Investigation and Reproductive Capacity of the Bulgarian Endemic Plant Species Marrubium friwaldskyanum Boiss. (Lamiaceae)

Marrubium friwaldskyanum Boiss (Lamiaceae) is a Bulgarian endemic species. Overall, the essential oil (EO) composition of M. friwaldskyanum was different from that of the other Marrubium species reported in the literature. The main EO constituents of M. friwaldskyanum were (E)-caryophyllene, germacrene D, and caryophyllene oxide. The effect of the harvest stage was significant only on α-copaene, (E)-caryophyllene, caryophyllene oxide, and τ-muurolol. The concentration of α-copaene (1.26-1.83% range of the total oil), (E)-caryophyllene (31-41%), caryophyllene oxide (6.4-11.8%), and τ-muurolol (1.3-2.8%) were the highest at 2-3 pair of leaves or before flowering and lower at flowering. The harvest stage did not significantly affect the concentrations of the other six identified EO compounds β-bourbonene (1.1%), α-humulene (2.8%), germacrene D (23.3%), bicyclogermacrene (2.85%), δ-cadinene (1.1%), and spathulenol (2.8%). In a separate experiment, grinding of the biomass prior to EO extraction had a significant effect only on the concentrations of D-limonene (0.24-3.3%) and bicyclogermacrene (3.6-9.1%). Grinding in water or without water, maceration, and addition of Tween^®20 had rather small effects on the EO profile. The identified EO constituents and their mean concentrations in this experiment were (E)-caryophyllene (25.4%), germacrene D (17.6%), caryophyllene oxide (9.1%), spathulenol (6.5%), τ-muurolol (5.0%), carvacrol (3.9%), α-copaene (2.5%), β-bourbonene (2.5%), δ-cadinene (2.4%), α-humulene (1.8%), and Z-β-farnesene (1.3%). Embryological studies observed anther and the development of the male gametophyte and ovule and development of the female gametophyte of M. friwaldskyanum. Furthermore, pollen and seed viability assays were conducted, and mass spectrometry-based metabolomics analysis of an extract from shoots revealed the presence of 45 natural products, identified as flavonoids, phenolic acids, and (tri)terpenoids. Overall, the phytochemistry and some of the microscopic analyses distinguished this endemic species from other species in Marrubium.

Allelopathic Effects of Essential Oils on Seed Germination of Barley and Wheat

In this study, we evaluated the allelopathic effects of essential oils (EOs) from six different plant species, namely, lavender (Lavandula angustifolia), hyssop (Hyssopus officinalis), English thyme (Thymus vulgaris), lovage (Levisticum officinale), costmary (Chrysanthemum balsamita), and cumin (Cuminum cyminum), on seed germination and seedling growth of barley (Hordeum vulgare) and wheat (Triticum aestivum). The main constituents of the EOs of L. angustifolia were 47.0% linalool acetate and 28.4% linalool; H. officinalis' main constituents were 39.8% cis-pinocamphone, 9.8% trans-pinocamphone, 11.4% β-pinene, and 7.5% β-phellandrene; T. vulgaris' were 38.2% para-cymene, 25.6% thymol, and 13.6% γ-terpinene; L. officinale's were 64.8% α-terpinyl acetate and 14.7% β-phellandrene; C. balsamita's were 43.7% camphor, 32.4% trans-thujone, and 11.6% camphene; C. cyminum's were 49.6% cumin aldehyde, 10.4% para-cymene, 11.6% α-terpinen-7-al, and 9.1% β-pinene. All six EOs exhibited an allelopathic effect and suppressed the seed germination and seedling development of wheat and barley; however, the concentrations that exhibited a suppressing effect were different among the plants. C. cyminum EO completely suppressed both barley and wheat germination at 10-, 30-, and 90-µL application rates, making it the most effective treatment among the tested EOs. C. balsamita's and H. officinalis' EOs at 30 and 90 µL application rates completely suppressed barley and wheat radicles per seed, radicle length (mm), seedling height (mm), and germination (%). L. angustifolia's EOs at 30- and 90-µL and T. vulgaris' EO at 90 µL application rates also completely suppressed barley and wheat radicles per seed, radicle length (mm), seedling height (mm), and germination (%). C. balsamita's, H. officinalis', L. angustifolia's, and T. vulgaris' EOs at a 10 µL application rate reduced barley radicle length, seedling height, and % germination relative to the control. Wheat seed germination % was completely suppressed by the application of L. angustifolia's and T. vulgaris' EOs at 30 and 90 µL, while T. vulgaris' EO at 10 µL rate reduced the germination relative to the control. Interestingly, C. balsamita and H. officinalis at 10 µL did not reduce wheat germination; however, they did reduce the number of radicles per seed, radicle length (mm), seedling height (mm), germination (%), and vigor index. Furthermore, L. officinale's EO reduced the measured indices (radicles per seed, radicle length, seedling height, and vigor index) at the 10, 30, and 90 µL application rates relative to the non-treated control; however, none of the application rates of L. officinale's EO had a suppression effect on wheat germination. This study demonstrated the allelopathic effects of the EOs of six different herbal plant species on seed germination of barley and winter wheat. The results can be utilized in the development of commercial products for controlling pre-harvest sprouting of wheat and barley. Further research is needed to verify the results under field conditions.

Valorization of CBD-hemp through distillation to provide essential oil and improved cannabinoids profile

Hemp (Cannabis sativa L.) synthesizes and accumulates a number of secondary metabolites such as terpenes and cannabinoids. They are mostly deposited as resin into the glandular trichomes occurring on the leaves and, to a major extent, on the flower bracts. In the last few years, hemp for production of high-value chemicals became a major commodity in the U.S. and across the world. The hypothesis was that hemp biomass valorization can be achieved through distillation and procurement of two high-value products: the essential oil (EO) and cannabinoids. Furthermore, the secondary hypothesis was that the distillation process will decarboxylate cannabinoids hence improving cannabinoid composition of extracted hemp biomass. Therefore, this study elucidated the effect of steam distillation on changes in the content and compositional profile of cannabinoids in the extracted biomass. Certified organic CBD-hemp strains (chemovars, varieties) Red Bordeaux, Cherry Wine and Umpqua (flowers and some upper leaves) and a T&H strain that included chopped whole-plant biomass, were subjected to steam distillation, and the EO and cannabinoids profile were analyzed by gas chromatography-mass spectrometry (GC-MS) and HPLC, respectively. The distillation of hemp resulted in apparent decarboxylation and conversion of cannabinoids in the distilled biomass. The study demonstrated a simple method for valorization of CBD-hemp through the production of two high-value chemicals, i.e. EO and cannabinoids with improved profile through the conversion of cannabidiolic acid (CBD-A) into cannabidiol (CBD), cannabichromenic acid (CBC-A) into cannabichromene (CBC), cannabidivarinic acid (CBDV-A) into cannabidivarin (CBDV), cannabigerolic acid (CBG-A) into cannabigerol (CBG), and δ-9-tetrahydrocannabinolic acid (THC-A) into δ-9-tetrahydrocannabinol (THC). In addition, the distilled biomass contained CBN while the non-distilled did not. Distillation improved the cannabinoids profile; e.g. the distilled hemp biomass had 3.4 times higher CBD in variety Red Bordeaux, 5.6 times in Cherry Wine, 9 times in variety Umpqua, and 6 times in T&H compared to the original non-distilled samples, respectively. Most of the cannabinoids remained in the distilled biomass and small amounts of CBD were transferred to the EO. The CBD concentration in the EO was as follows: 5.3% in the EO of Umpqua, 0.15% in the EO of Cherry Wine and Red Bordeaux and 0.06% in the EO of T&H. The main 3 EO constituents were similar but in different ratio; myrcene (23.2%), (E)-caryophyllene (16.7%) and selina-3,7(11)-diene (9.6%) in Cherry Wine; (E)-caryophyllene (~ 20%), myrcene (16.6%), selina-3,7(11)-diene (9.6%), α-humulene (8.0%) in Red Bordeaux; (E)-caryophyllene (18.2%) guaiol (7.0%), 10-epi-γ-eudesmol (6.9%) in Umpqua; and (E)-caryophyllene (30.5%), α-humulene (9.1%), and (E)-α-bisabolene (6.5%) in T&H. In addition, distillation reduced total THC in the distilled biomass. Scanning electron microscopy (SEM) analyses revealed that most of the glandular trichomes in the distilled biomass were not disturbed (remained intact); that suggest a possibility for terpenes evaporation through the epidermal membrane covering the glandular trichomes leaving the cannabinoids in the trichomes. This explained the fact that distillation resulted in terpene extraction while the cannabinoids remained in the distilled material.

Comparative study on the chemical composition of laurel (Laurus nobilis L.) leaves from Greece and Georgia and the antibacterial activity of their essential oil

Laurel (Laurus nobilis L.) is a plant species from Lauraceae family, and is native to the Mediterranean region. The goal of this study was to compare chemical composition of laurel leaves and antibacterial activity of its essential oil (EO) from wild-grown trees in Greece and Georgia. The laurel leaves from the two native habitats had dissimilar concentrations of phenolic acids. Of the conjugated flavonols and flavons, kaempferol (1981.3 μg/g) and apigenin (1433.6 μg/g) were the major representatives in the leaves from Greece, while luteolin (839.1 μg/g) and kaempferol (688.1 μg/g) were the major ones in the leaves from Georgia, respectively. The EO content was 1.42% and 4.54% in the leaves from Greece and Georgia, respectively. The main EO constituents of the Greek laurel plants were 1,8-cineole (30.8%), α-terpinyl acetate (14.9%), α-terpineol (8.0%), sabinene (7.9%), and terpinen-4-ol (6.0%). The main EO constituents of the Georgian laurel plants were 1,8-cineole (29.2%), α-terpinyl acetate (22.6%), sabinene (12.2%), and methyleugenol (8.1%). The EO antimicrobial activities against 20 microorganisms were determined. Among the Gram-positive bacteria, the Enterococcus faecalis strain was the most sensitive, followed by Staphylococcus aureus ATCC 6538. Among the Candida species, C. albicans ATCC 10231 was the most sensitive to the laurel leaf EOs.

Chemical Characterization and Antibacterial Activity of Essential Oil of Medicinal Plants from Eastern Serbia

The objective of this study was to evaluate wild growing Satureja kitaibelii, Thymus serpyllum, Origanum vulgare, Achillea millefolium and Achillea clypeolata with respect to their essential oil (EO) content, composition and antimicrobial activity. The five species were collected at Mt. Rtanj and the village of Sesalac, Eastern Serbia. The main EO constituents of Lamiaceae plants were p-cymene (24.4%), geraniol (63.4%) and germacrene D (21.5%) in Satureja kitaibelii, Thymus serpyllum and Origanum vulgare ssp. vulgare, respectively. A. millefolium EO had multiple constituents with major ones being camphor (9.8%), caryophyllene oxide (6.5%), terpinen-4-ol (6.3%) and 1,8-cineole (5.6%), while the main EO constituents of A. clypeolata were 1,8-cineole (45.1%) and camphor (18.2%). Antimicrobial testing of the EO showed that Staphylococcus aureus (Gram-positive) was more sensitive to all of the tested EOs than Escherichia coli (Gram-negative). S. kitaibelii EO showed the highest antimicrobial activity against both tested bacterial strains. This is the first study to characterize the EO composition and antimicrobial activity of these five medicinal species from Eastern Serbia in comparison with comprehensive literature data. The results can be utilized by the perfumery, cosmetics, food and pharmaceutical industries, but also for healing purposes in self-medication.

Industrial, CBD, and Wild Hemp: How Different Are Their Essential Oil Profile and Antimicrobial Activity?

Hemp (Cannabis sativa L.) is currently one of the most controversial and promising crops. This study compared nine wild hemp (C. sativa spp. spontanea V.) accessions with 13 registered cultivars, eight breeding lines, and one cannabidiol (CBD) hemp strain belonging to C. sativa L. The first three groups had similar main essential oil (EO) constituents, but in different concentrations; the CBD hemp had a different EO profile. The concentration of the four major constituents in the industrial hemp lines and wild hemp accessions varied as follows: β-caryophyllene 11-22% and 15.4-29.6%; α-humulene 4.4-7.6% and 5.3-11.9%; caryophyllene oxide 8.6-13.7% and 0.2-31.2%; and humulene epoxide 2, 2.3-5.6% and 1.2-9.5%, respectively. The concentration of CBD in the EO of wild hemp varied from 6.9 to 52.4% of the total oil while CBD in the EO of the registered cultivars varied from 7.1 to 25%; CBD in the EO of the breeding lines and in the CBD strain varied from 6.4 to 25% and 7.4 to 8.8%, respectively. The concentrations of δ9-tetrahydrocannabinol (THC) in the EO of the three groups of hemp were significantly different, with the highest concentration being 3.5%. The EO of wild hemp had greater antimicrobial activity compared with the EO of registered cultivars. This is the first report to show that significant amounts of CBD could be accumulated in the EO of wild and registered cultivars of hemp following hydro-distillation. The amount of CBD in the EO can be greater than that in the EO of the USA strain used for commercial production of CBD. Furthermore, this is among the first reports that show greater antimicrobial activity of the EO of wild hemp vs. the EO of registered cultivars. The results suggest that wild hemp may offer an excellent opportunity for future breeding and the selection of cultivars with a desirable composition of the EO and possibly CBD-rich EO production.

Comparative Study on the Phytochemical Composition and Antioxidant Activity of Grecian Juniper (Juniperus excelsa M. Bieb) Unripe and Ripe Galbuli

Grecian juniper (Juniperus excelsa M. Bieb.) is an evergreen tree and a rare plant found in very few locations in southern Bulgaria. The aim of this study was to evaluate the phytochemical content and antioxidant potential of J. excelsa unripe and ripe galbuli from three different locations in Bulgaria. The essential oil content ranged between 1.9% and 5.1%, while the lipid fraction yield was between 4.5% and 9.1%. The content of total chlorophyll was 185.4-273.4 μg/g dw. The total carotenoid content ranged between 41.7 and 50.4 μg/g dw of ripe galbuli, and protein content was between 13.6% and 16.4%. Histidine (5.5 and 8.0 mg/g content range) and lysine (4.0 and 6.1 mg/g) were the major essential amino acids. The antioxidant potential of the 95% and 70% ethanol extracts was analyzed using four different methods. A positive correlation between the antioxidant potential and phenolic content of the galbuli was found. The results obtained in this study demonstrated the differences in phytochemical composition and antioxidant capacity of J. excelsa galbuli as a function of maturity stage and collection locality.