Several organic compounds released into the aquatic environment have a detrimental impact on humans and other organisms. There is a lack of knowledge about natural hormones and herbicides on ...non-target organisms, including cyanobacteria. In this study, the response of Microcystis aeruginosa to four phytohormones, indole-3-acetic acid (IAA; 10−5), zeatin (ZT; 10−5), abscisic acid (ABA; 10−7), and brassinolide (BRL; 10−9 mol/L), exposed to terpinolene (TPN; (0.44, 0.88, 1.17, or 1.62 mmol/L) at the cellular and genetic levels were investigated. The results showed that TPN could inhibit the growth and photosynthetic activities and stimulate microcystins (MCs) of M. aeruginosa at various levels through the co-occurrence of oxidative stress, antioxidant defense activities, and an imbalance of the antioxidative system. Hormones played critical roles in the growth promotion and photosynthetic activity by enhancing the antioxidant defense mechanisms and MCs production of M. aeruginosa under TPN stress in both hormone and TPN dose-dependent manner. The growth performance and photosynthetic activities of M. aeruginosa were significant with IAA (p < 0.01) and BSL (p < 0.05) compared to ZT and ABA, as TPN concentrations increased. Hormones stimulated the MCs production significantly BSL (p < 0.05) at various levels and protected the cells against TPN-induced oxidative stress and expression of mcyB and mcyD genes involve in MCs synthesis. Our results indicated that hormone contamination in eutrophic lakes might increase the risk of Microcystis aeruginosa bloom and microcystin production with the TPN association.
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•Terpinolene (TPN) could inhibit the growth of Microcystis aeruginosa.•Hormones promote the growth of M. aeruginosa under TPN stress.•Alleviate the oxidative damage by inducing SOD and CAT enzyme activities•Hormones stimulate the production and release of cell toxins at higher TPN doses.
Bioherbicide terpinolene is widely employed in the agricultural field because of its unique phytotoxic properties. However, little is known about the toxicity of bioherbicide on harmful algal blooms ...(HABs) and its mechanisms. Therefore, in this study, the inhibiting effect of bioherbicide terpinolene on the growth and physiological change of Microcystis aeruginosa was determined. Results showed that the cell density and photosynthetic activity of microalgae were significantly inhibited by terpinolene. Activities of nitrate reductase (NR) and glutamine synthetase (GS) were decreased separately by 25.38% and 42.75% after 4 d of exposure to 1.47 mM terpinolene, suggesting the inhibiting effect of terpinolene on algal nitrogen metabolism. However, the transcript abundance of genes related to membrane protein cytochrome c oxidase subunit II (COX II) and ATP-binding cassette transporters (ABC transporter) were enhanced separately by 3.15 and 1.69-fold compared with control, suggesting the resistance response of cells to terpinolene stress. Additionally, terpinolene not only increased the content of endogenous phytohormones including indole-3-acetic acid (IAA), zeatin, and brassinolide, but also inhibited the expression of genes related to calcium-binding protein (CaBPs), one kind of calcium (Ca2+) sensors, suggesting its regulation on algal signal molecules. These findings helped to understand the ecotoxicity of terpinolene and guide the rational use of bioherbicide in agriculture.
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•Terpinolene affected the expression of gene related to membrane proteins•Terpinolene stimulated the antioxidant system of M. aeruginosa•Terpinolene inhibited the activity of nitrogen metabolism-related enzymes•Content of endogenous IAA, zeatin, and brassinolide were increased by terpinolene
The isomerization of β-pinene is an important reaction to synthesize spices, such as camphene, limonene, terpinene, and terpinolene, among which terpinene and terpinolene are particularly difficult ...to be obtained. Herein, MOR zeolite modified by both inorganic base (NaOH) and organic base (TEAOH) was conducted, which showed high catalytic activity for the isomerization of β-pinene to high-added value spices of terpinene and terpinolene. Different from the zeolite catalyst modified by solely inorganic base or organic base, both high conversion of β-pinene and high selectivity for terpinene and terpinolene could be achieved over the dual-modified zeolite catalyst. Based on the various characterizations, catalytic reaction results and comparison studies, the roles of inorganic base and organic base were revealed and possible reaction mechanism was described. The modification by inorganic base was mainly to introduce additional mesopores in the MOR zeolite, which had important influence on the conversion of β-pinene through accelerating the diffusion and mass transfer of various bulky organic molecules in the reaction system. The modification by organic base was mainly to tune the Brønsted/Lewis (B/L) acid property, which had important impact on the selectivity of products. In contrast, the zeolite modified by solely inorganic base mainly showed Lewis acidity, which led to camphene and limonene as the main products; the zeolite modified by solely organic base mainly showed Brønsted acidity, which produced camphene, terpinene and terpinolene as the main products. The dual-modified zeolite catalyst by inorganic/organic bases could achieve 99.5% conversion of β-pinene with the total selectivity for terpinene and terpinolene as high as 70.9%. In addition, the catalyst showed high reaction-recycling stability, which could maintain the catalytic performance up to 10 recycles.
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•Synergistic roles of B/L acids and hierarchical structures.•Catalytic synthesis terpinene and terpinolene by β-pinene isomerization.•Inorganic/organic bases dual-modified MOR zeolite catalyst.•Efficient heterogeneous catalyst with excellent recycling stability.
Terpinolene, a monoterpene that is naturally found in a variety of herbs, is widely used as a flavoring agent in the industry. Although it's well established in the literature that terpinolene is an ...important component of plant extracts, the biological properties and the potential therapeutic use of this compound remain poorly explored.
This work aimed to answer the following guiding question: "What are the biological activities of terpinolene demonstrated through in silico, in vitro, and in vivo assays?".
A systematic review was carried out in four electronic databases (Embase, Web of Science, Scopus, and PubMed) according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, using the following search terms: terpinolene “AND” activity “OR” properties “OR” therapeutic “OR” treatment. This search included manuscripts published between 1960 and June 2020. Study selection was conducted by two independent reviewers according to predefined criteria.
The initial search found a total of 2449 articles. However, only 57 of them were selected as they met the inclusion criteria and answered the guiding question. The analysis of these studies indicated that terpinolene presents a series of biological effects, from which the antioxidant, larvicide, and insecticide activities stand out. Despite the evidence demonstrating that terpinolene has the potential to be used in a broad pharmacological context, the mechanisms underlying its cellular and molecular effects remain to be better elucidated. In addition, the in vivo efficacy and safety of the administration of this compound have been poorly evaluated through either preclinical and clinical trials. Therefore, this study highlights the importance of characterizing the biological aspects and mechanisms of action of this natural compound.
The data summarized in the present systematic review demonstrates the pharmacological potential of terpinolene. Nevertheless, most studies included in this review provide a superficial characterization of terpinolene biological effects and therefore, further research elucidating its mechanism of action and potential therapeutic benefits through preclinical and clinical trials are required. Nevertheless, due to its wide range of different biological activities, terpinolene will certainly attract the interest of scientific research, which could significantly contribute to the development of new products with both therapeutic and environmental applications.
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Abstract
Vaping is gaining in popularity. However, there is still much that remains unknown about the potential risk and harms of vaping. Formation of oxidative products is one of such areas that are ...not well understood. In this study, we used an in-situ thermal desorption GC/MS method to investigate the formation of oxidative products of several monoterpenes at or below typical vaping temperatures. Among the five tested monoterpenes, the unchanged portion of the parent compound in the vapour varied from 97 to 98% for myrcene to 11–28% for terpinolene. The majority of formed oxidative products in the vapour have a molecular weight of 134 (loss of two hydrogens), 150 (insertion of one oxygen and loss of two hydrogen atoms) or 152 (insertion of one oxygen atom). Three products, likely to be p-(1-propenyl)-toluene, β-pinone and fenchol were also observed. This is the first in-situ thermal desorption GC/MS study to investigate the possible formation of oxidative products of monoterpenes, one of the major components in vaping liquids, at temperatures that are relevant to the vaping process. Although the toxicity of inhaling these oxidative products is not clear yet, allergic and irritation reactions associated with oxidized monoterpene oils are well documented. Therefore, potential adverse effects of inhaling these oxidative products during vaping could be investigated to help support human risk assessment.
Saturejahortensis is one of the representative plants from the Lamiaceae family, and its essential oil has been used in various applicative fields, from the food industry to aromatherapy. The changes ...that occur in heated samples at different temperatures (160, 175, 190 ºC) over different periods (0.5 and 2.5 h) in Saturejahortensis essential oil composition and chemical properties were evaluated. The results showed that the major chemical composition constituents of the investigated essential oil are γ-terpinene + α-terpinolene and carvacrol + p-cymene and the thermal behavior is dependent on the content. This composition drastically changes through the heating of the samples and causes significant changes in thermal behavior. The present study demonstrated that the concentration of carvacrol in S.hortensis essential oil is increasing after heating treatment, and the sample heated at 190 ºC for 2.5 h contained more than 91% carvacrol. This simple treatment is a rapid way to obtain carvacrol from the essential oil that has high potential as a natural preservative suitable for the food industry and alternative and complementary medicine.
•Foliar application of 24-epibresinolide under different drought stress was assessed on sage plants.•The highest H2O2 content was found in plants subjected to severe stress without 24-epibrassinolide ...treatment.•Essential oil content was positively correlated with total dry matter accumulation and proline content.•The essential oils were mainly consisted of α-Terpinolene, α-Thujone, cis-Sabinene hydrate, γ-Terpinene, and β-Thujone.•α-Terpinolene reached to 49.81 % of the essential oil in plants subjected to moderate water deficit.
Water deficit stress is one of the most dramatic environmental agents, reduces the growth and efficiency of cultivated plants. Brassinostroids are ubiquitous steroidal compounds playing vital roles in the processes of growth and development, pharmaceutically important metabolite production, stress responses and adaptation in plants. Therefore, in the current study the impact of foliar application of 24-epibresinolide (0, 100 mg L−1) under different water deficit stress (100 % field capacity (FC), 60 % FC, and 30 % FC) was assessed on field grown sage plants at two different locations of East Azarbaijan (Ahar and Kaleybar) in a factorial experiment arranged in randomized complete block design (RCBD). The results of combined ANOVA showed that triple interaction of locations, 24-epibrassinolide treatment and water deficit stress on total dry matter, chlorophyll b and proline contents were statistically significant. Water deficit had adverse effects on plant height, leaf relative water content (RWC), dry matter accumulation, and photosynthetic pigments in both cultivated sites, but spraying with 24-epibrassinolide led to an increase in these traits under water scarcity. The highest H2O2 content was found in plants subjected to water stress of 30 % FC without 24-epibrassinolide treatment cultivated in Ahar (a cold semi-arid) region compared to Kaleybar (a cold semi-humid) site. Mean comparison showed that brassinolide treatment and deficit irrigation of 60 % FC significantly increased (by 33 % and 42.5 %) the essential oil percentage of plants as compared to the respective control, respectively. Essential oil content was positively correlated with dry matter accumulation (r0.05 = 0.41) and proline (r0.01 = 0.66) content under the employed treatments. Based on the GC–MS analysis, about 28 volatile constituents were detected in the essential oil, which were mainly consisted of α-Terpinolene, α-Thujone, cis-Sabinene hydrate, γ-Terpinene, α-Thujene, Camphor, and β-Thujone. The highest content of cis-Sabinene hydrate was found in plants treated with 24-epibrassinolide at Ahar studied site, which was about 10.6-fold higher than that of Kaleybar.
The mountain pine beetle (Dendroctonus ponderosae; MPB) is an eruptive bark beetle species affecting pine forests of western North America. MPB are exposed to volatile monoterpenes, which are ...important host defense chemicals. We assessed the toxicity of the ten most abundant monoterpenes of lodgepole pine (Pinus contorta), a major host in the current MPB epidemic, against adult MPB from two locations in British Columbia, Canada. Monoterpenes were tested as individual volatiles and included (-)-β-phellandrene, (+)-3-carene, myrcene, terpinolene, and both enantiomers of α-pinene, β-pinene and limonene. Dose-mortality experiments identified (-)-limonene as the most toxic (LC
: 32 μL/L), and (-)-α-pinene (LC
: 290 μL/L) and terpinolene (LC
: >500 μL/L) as the least toxic. MPB body weight had a significant positive effect on the ability to survive most monoterpene volatiles, while sex did not have a significant effect with most monoterpenes. This study helps to quantitatively define the effects of individual monoterpenes towards MPB mortality, which is critical when assessing the variable monoterpene chemical defense profiles of its host species.
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