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The structural, conformational, and spectroscopic properties in the gas phase of 20 bicyclic monoterpenes and monoterpenoids have been analyzed by a new accurate, reduced-cost computational strategy. In detail, the revDSD-PBEP86 double-hybrid functional in conjunction with the D3BJ empirical dispersion corrections and a suitable triple-zeta basis set provides accurate geometrical parameters, whence equilibrium rotational constants, which are further improved by proper account of core–valence correlation. Average deviations within 0.1% between computed and experimental rotational constants are reached when taking into account the vibrational corrections obtained by the B3LYP functional in conjunction with a double-zeta basis set in the framework of second-order vibrational perturbation theory. In addition to their intrinsic interest, the studied terpenes further extend the panel of systems for which the proposed strategy has provided accurate results at density functional theory cost. Therefore, a very accurate yet robust and user-friendly tool is now available for systematic investigations of the role of stereo-electronic effects on the properties of large systems of current technological and/or biological interest by experimentally oriented researchers. [ABSTRACT FROM AUTHOR]

Monoterpenes are commonly known for their role in the flavors and fragrances industry and are also gaining attention for other uses like insect repellant and as potential renewable fuels for aviation. Corynebacterium glutamicum, a Generally Recognized as Safe microbe, has been a choice organism in industry for the annual million ton-scale bioproduction of amino acids for more than 50 years; however, efforts to produce monoterpenes in C. glutamicum have remained relatively limited. In this study, we report a further expansion of the C. glutamicum biosynthetic repertoire through the development and optimization of a mevalonate-based monoterpene platform. In the course of our plasmid design iterations, we increased flux through the mevalonate-based bypass pathway, measuring isoprenol production as a proxy for monoterpene precursor abundance and demonstrating the highest reported titers in C. glutamicum to date at 1504.6 mg/L. Our designs also evaluated the effects of backbone, promoter, and GPP synthase homolog origin on monoterpene product titers. Monoterpene production was further improved by disrupting competing pathways for isoprenoid precursor supply and by implementing a biphasic production system to prevent volatilization. With this platform, we achieved 321.1 mg/L of geranoids, 723.6 mg/L of 1,8-cineole, and 227.8 mg/L of linalool. Furthermore, we determined that C. glutamicum first oxidizes geraniol through an aldehyde intermediate before it is asymmetrically reduced to citronellol. Additionally, we demonstrate that the aldehyde reductase, AdhC, possesses additional substrate promiscuity for acyclic monoterpene aldehydes.

Nighttime oxidation of monoterpenes (MT) via the nitrate radical (NO3) and ozone (O3) contributes to the formation of secondary organic aerosol (SOA). This study uses observations in Atlanta, Georgia from 2011 to 2022 to quantify trends in nighttime production of NO3 (PNO3) and O3 concentrations and compare to model outputs from the EPA's Air QUAlity TimE Series Project (EQUATES). We present urban‐suburban gradients in nighttime NO3 and O3 concentrations and quantify their fractional importance (F) for MT oxidation. Both observations and EQUATES show a decline in PNO3, with modeled PNO3 declining faster than observations. Despite decreasing PNO3, we find that NO3 continues to dominate nocturnal boundary layer (NBL) MT oxidation (FNO3 = 60%) in 2017, 2021, and 2022, which is consistent with EQUATES (FNO3 = 80%) from 2013 to 2019. This contrasts an anticipated decline in FNO3 based on prior observations in the nighttime residual layer, where O3 is the dominant oxidant. Using two case studies of heatwaves in summer 2022, we show that extreme heat events can increase NO3 concentrations and FNO3, leading to short MT lifetimes (<1 hr) and high gas‐phase organic nitrate production. Regardless of the presence of heatwaves, our findings suggest sustained organic nitrate aerosol formation in the urban SE US under declining NOx emissions, and highlight the need for improved representation of extreme heat events in chemistry‐transport models and additional observations along urban to rural gradients. Plain Language Summary: Monoterpenes are important precursors of secondary organic aerosol (SOA), which influence air quality and climate. At night, they react with the nitrate radical (NO3) and ozone (O3). Trends in these two oxidants and their role on air quality in the southeastern United Sates (SE US) is partially dictated by changes in nitrogen oxide (NOx = NO + NO2) emissions which have declined in recent years. We find that NO3 dominates present‐day monoterpene loss in the summer, and may continue to do so even as NOx concentrations decrease in the future. We show that heatwaves in the SE US further elevate both O3 and NO3 concentrations at night, with a larger relative importance for NO3. We compare observations to a regional air quality model, and find the model overpredicts both oxidant concentrations. This overprediction may impact model‐based studies of future nighttime chemistry. Key Points: Nitrate radical (NO3) continues to control nocturnal boundary layer monoterpene oxidation in the urban SE USRegional model overpredicts oxidant concentrations and fractional NO3 contribution to monoterpene lossExtreme heat events increase nighttime NO3 concentrations, monoterpene oxidation rates, and gas‐phase organic nitrate production [ABSTRACT FROM AUTHOR]

Peptic ulcers, recognized for their erosive impact on the gastrointestinal mucosa, present a considerable challenge in gastroenterology. Epidemiological insights underscore the global prevalence of peptic ulcers, affecting 5–10+% of individuals, with a yearly incidence of 0.3 to 1.9 cases per thousand. Recent decades have witnessed a decline in complications, attributed to improved diagnostics and therapeutic advancements. The review deepens into H. pylori -associated and NSAID-induced ulcers, emphasizing their distinct prevalence in developing and industrialized nations, respectively. Despite advancements, managing peptic ulcers remains challenging, notably in H. pylori -infected individuals facing recurrence and the rise of antibiotic resistance. The pathophysiology unravels the delicate balance between protective and destructive factors, including the intricate molecular mechanisms involving inflammatory mediators such as TNF-α, ILs, and prostaglandins. Genetic and ethnic factors, rare contributors, and recent molecular insights further enhance our understanding of peptic ulcer development. Diagnostic approaches are pivotal, with upper gastrointestinal endoscopy standing as the gold standard. Current treatment strategies focus on H. pylori eradication, NSAID discontinuation, and proton pump inhibitors. Surgical options become imperative for refractory cases, emphasizing a comprehensive approach. Advances include tailored H. pylori regimens, the emergence of vonoprazan, and ongoing vaccine development. Challenges persist, primarily in antibiotic resistance, side effects of acid suppressants, and translating natural compounds into standardized therapies. Promising avenues include the potential H. pylori vaccine and the exploration of natural compounds, with monoterpenes showing therapeutic promise. This review serves as a compass, guiding healthcare professionals, researchers, and policymakers through the intricate landscape of peptic ulcer management. [ABSTRACT FROM AUTHOR]

To investigate the biocatalytic potential of Amazonian actinomycetes for monoterpenes biotransformation. To carry out the present study, eleven actinomycetes of the genus Streptomyces isolated from inga-cipó (Inga edulis Mart.) rhizospheres were tested for their ability to bioconvert the substrates R-(+)-limonene, S-(-)-limonene, 1S-(-)-α-pinene, and (-)–β–pinene as sole carbon and energy source. According to gas chromatography-mass spectrometry analysis, three strains, LabMicra B270, LaBMicrA B310, and LaBMicrA B314, were able to biotransform 1S-(-)-α-pinene after 96 h of growth. However, Streptomyces LaBMicrA B270 was the most promising since it converted after only 72 h all the 1S-(-)-α-pinene mainly into cis-verbenol (74.9±1.24%) and verbenone (18.2±1.20%), compounds that have important biological activities and great industrial interest as additives in foods and cosmetics. These findings can stimulate the development of natural aromas using naturally abundant monoterpenes, ratify the potential of microorganisms from almost unexplored niches such as the Amazonian rhizosphere, and reinforce the importance of preserving those niches. [ABSTRACT FROM AUTHOR]

• Essential oils from Cerrado plants are active against Aedes aegypti. • Alpinia zerumbet and E. langsdorffii oils show larvicide potential for Ae. aegypti. • Eugenia langsdorffii exhibits new larvicidal properties against mosquitos. The Aedes aegypti mosquito serves as the primary vector for transmitting viral diseases such as dengue, Zika, chikungunya, and urban yellow fever. Essential oils comprising volatile organic compounds derived from a single plant species have demonstrated repellent activity against various mosquito species, including Ae. aegypti. Despite their potential therapeutic benefits, only limited studies have explored the larvicidal activity of essential oil from plants occurring in Cerrado. To address this gap, the present study evaluated the larvicidal efficacy of different essential oils (EO) sourced from native and cultivated plants in the Cerrado biome against Ae. aegypti larvae. Essential oils were extracted from Alpinia zerumbet (Pers.) B.L.Burtt & R.M.Sm., Baccharis retusa DC., Blepharocalyx salicifolius (Kunth) O. Berg, Cymbopogon densiflorus (Steud.) Stapf , Eugenia langsdorffii O. Berg , Myracrodruon urundeuva Allemão. Notably, B. retusa is dioecious; hence, it was categorized into male and female plants each with a separated extraction of leaves and flowers. Among the essential oils tested, those derived from A. zerumbet and E. langsdorffii exhibited the highest activity, resulting in 100 % mortality of Ae. aegypti larvae at a 100 mg/L concentration. The calculated LC 50 values were 36.6 mg/L and 53.5 mg/L for A. zerumbet and E. langsdorffii, respectively, with the corresponding LC 90 values of 66.3 mg/L and 103.9 mg/L. Analysis of the major components revealed the presence of 1,8-cineole, sabinene, terpinen-4-ol, and γ-terpinene in A. zerumbet essential oil, while limonene, δ-cadinol, myrcene, and spathulenol were predominant in E. langsdorffii essential oil. However, further studies are required to identify the active components responsible for the observed larvicidal activity and elucidate their mode of action. [ABSTRACT FROM AUTHOR]

Terpenes serve important functions in enhancing plant thermotolerance. Cinnamomum camphora mainly has eucalyptol (EuL), camphor (CmR), linalool (LnL) and borneol (BeL) chemotypes basing on the uppermost monoterpenes. To reveal the thermotolerance mechanisms of these uppermost monoterpenes (eucalyptol, camphor, linalool, and borneol) in C. camphora, we surveyed the ROS metabolism and photosynthesis in the 4 chemotypes fumigated with the corresponding uppermost monoterpene after fosmidomycin (Fos) inhibiting monoterpene synthesis under high temperature at 38°C (Fos+38°C+monoterpene), and investigated the related gene expression in EuL and CmR. Meanwhile, the thermotolerance differences among the 4 uppermost monoterpenes were analyzed. In contrast to normal temperature (28°C), ROS levels and antioxidant enzyme activities in the 4 chemotypes increased under 38°C, and further increased in the treatment with Fos inhibiting monoterpene synthesis at 38°C (Fos+38°C), which may be caused by the alterations in expression of the genes related with nonenzymatic and enzymatic antioxidant formation according to the analyses in EuL and CmR. Compared with Fos+38°C treatment, Fos+38°C+monoterpene treatments lowered ROS levels and antioxidant enzyme activities for the increased non-enzymatic antioxidant gene expression and decreased enzymatic antioxidant gene expression, respectively. High temperature at 38° C reduced the chlorophyll and carotenoid content as well as photosynthetic abilities, which may result from the declined expression of the genes associated with photosynthetic pigment biosynthesis, light reaction, and carbon fixation. Fos+38°C treatment aggravated the reduction. In contrast to Fos+38°C treatment, Fos+38°C+monoterpene treatments increased photosynthetic pigment content and improved photosynthetic abilities by up-regulating related gene expression. Among the 4 uppermost monoterpenes, camphor showed strong abilities in lowering ROS and maintaining photosynthesis, while eucalyptol showed weak abilities. This was consistent with the recovery effects of the gene expression in the treatments with camphor and eucalyptol fumigation. Therefore, the uppermost monoterpenes can enhance C. camphora thermotolerance as signaling molecules, and may have differences in the signaling functions. [ABSTRACT FROM AUTHOR]

Citri Exocarpium Rubrum black tea (CER tea) is a novel blend tea infusion combining tea and CER. Due to its potential health benefits and unique flavor, it has gained popularity among consumers. Nevertheless, the aroma characteristics and key odorants of it remain to be distinguished and cognized. The HS‐SPME and GC/MS techniques were employed to analyze the alterations in volatile constituents throughout the critical stages of CER tea production. A total of 200 chemical compounds exhibited notable disparities during the processing procedures. Among them, terpenes and esters were the most abundant compounds in CER tea, which might be the key material basis for the aroma quality of CER tea. It is worth noting that 124 metabolites were significantly increased in the kneading stage and drying stage, including benzeneacet aldehyde, trans‐nerolidol, and D‐limonene, with contained floral and fruity odors, which might be closely related to the aroma of CER tea. Monoterpenes might be important contributors to the aroma of CER tea. This study provided a theoretical basis for the quality improvement of CER tea. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate whether and how albiflorin, a natural monoterpene glycoside, affects the release of glutamate, one of the most important neurotransmitters involved in neurotoxicity, from cerebrocortical nerve terminals (synaptosomes) in rats. The results showed that albiflorin reduced 4-aminopyridine (4-AP)-elicited glutamate release from synaptosomes, which was abrogated in the absence of extracellular Ca2+ or in the presence of the vesicular glutamate transporter inhibitor or a P/Q-type Ca2+ channel inhibitor, indicating a mechanism of action involving Ca2+-dependent depression of vesicular exocytotic glutamate release. Albiflorin failed to alter the increase in the fluorescence intensity of 3,3-diethylthiacarbocyanine iodide (DiSC3(5)), a membrane-potential-sensitive dye. In addition, the suppression of protein kinase A (PKA) abolished the effect of albiflorin on glutamate release. Albiflorin also reduced the phosphorylation of PKA and synaptosomal-associated protein of 25 kDa (SNAP-25) and synapsin I at PKA-specific residues, which correlated with decreased available synaptic vesicles. The results of transmission electron microscopy (TEM) also observed that albiflorin reduces the release competence of synaptic vesicles evoked by 4-AP in synaptosomes. In conclusion, by studying synaptosomally released glutamate, we suggested that albiflorin reduces vesicular exocytotic glutamate release by decreasing extracellular Ca2+ entry via P/Q-type Ca2+ channels and reducing PKA-mediated synapsin I and SNAP-25 phosphorylation. [ABSTRACT FROM AUTHOR]

This article discusses the isolation and identification of four new compounds from the leaves of Turpinia montana Kurz, a medicinal plant used in Vietnam. The compounds were analyzed using techniques such as NMR spectroscopy and mass spectrometry. The study provides valuable information for further research on the phytochemical properties of Turpinia montana. The document describes the experimental procedures, results, and spectral data for the compounds, as well as acknowledging the financial support received for the research. Supplementary figures showing the spectra of the compounds are also included. [Extracted from the article]

Objective(s): Hyperglycemia, a prevalent metabolic condition observed in diabetes, leads to oxidative damage, inflammatory responses, and other consequences. Natural compounds alleviate the adverse impacts of diabetes. We aimed to explore the effects of alpha-pinene (AP) as a monoterpene on oxidative damage and inflammation caused by high glucose (HG) in the human hepatocellular liver carcinoma (HepG2) cell line. Materials and Methods: The HepG2 cells were subjected to non or HG concentration (50 mM) and treated with or without AP (8, 16, and 32 µg/ml) for 48 hr. The effect of treatments on cellular viability, malondialdehyde (MDA), glutathione (GSH), and activity of anti-oxidant enzymes, including glutathione peroxidase (GPx), catalase (CAT), superoxide dismutase (SOD), was determined. The gene expression levels of nuclear factor-κβ (NF-κB), tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and dipeptidyl peptidase-4 (DPP-4) were estimated using quantitative real-time polymerase chain reaction (qRT-PCR). Results: HG exposure significantly increased cell death, MDA formation, and depletion of GSH content and GPx, CAT, and SOD activity (P<0.05). We have also seen a significant induction in NF-κB, TNF-α, IL-6, and DPP-4 gene expression in hepatocytes under HG conditions (P<0.05). Interestingly, co-treatment with AP in a dose-dependent manner improved cell death and altered levels of MDA and GSH, and activity of GPx and CAT (P<0.05). AP could also modulate the gene expression of NF-κB and inflammatory biomarkers dose-dependently (P<0.05). Conclusion: Our findings suggested the protective effect of AP on hepatocytes under HG conditions through attenuating oxidative stress markers and suppression of inflammatory pathways. [ABSTRACT FROM AUTHOR]

Pistacia palaestina Boiss. is a common tree in the Mediterranean maquis. The leaves of this plant accumulate defensive monoterpenes, whose levels greatly increase in galls induced by the aphid Baizongia pistaciae. We previously found a significant chemopolymorphism in monoterpene content among individual trees, but the chirality of these monoterpenes was unknown. Although most plant species specifically accumulate one enantiomeric form of a given compound, P. palaestina individuals display chemopolymorphism in the chirality of the key monoterpenes accumulated. We report here a marked enantiomeric variation for the limonene, α‐ and β‐pinene, camphene, sabinene, δ‐3‐carene, and terpene‐4‐ol content in leaves and galls of nine different naturally growing P. palaestina trees. Interestingly, insect‐induced gall monoterpene composition is an augmentation of the specific enantiopolymorphism originally displayed by each individual tree. [ABSTRACT FROM AUTHOR]

Background: Volatile organic compounds (VOCs) play a crucial role in understanding soil ecology and the atmospheric environment. However, the biochemical cycles of VOCs in soil systems and their relationship to atmospheric VOC exchange remain unclear. The soil system serves as a primary site for the generation, emission, and uptake of VOCs, yet these processes lack sufficient understanding. Scope: This review aims to provide a comprehensive overview of the exchange of VOCs between the soil and the atmosphere. We explore the mechanisms governing the generation, emission, and uptake of VOCs in soils, quantitatively summarizing available data on emission and uptake. Additionally, we highlight common and specific VOCs emitted by various soil sources (litter, roots, bare soil, and soil microbes) and examine their interactions. Conclusions: The composition and emission rates of VOCs display significant variability across different soils, attributed in part to variations in the contributions of different VOC sources within the soils. Litter and roots predominantly release terpenes, benzenoids, and alcohols, while bare soil and microbes emit higher proportions of alkanes, esters, and alcohols. Despite often being overlooked, soils serve as essential sinks for VOCs, and global environmental changes may reshape patterns of soil VOC sources and sinks. [ABSTRACT FROM AUTHOR]

The aim of this study was to validate the preventive effects of koumine (KM), a monoterpene indole alkaloid, on gouty arthritis (GA) and to explore its possible mechanisms. C57BL/6 mice were intraperitoneally administered KM (0.8, 2.4 or 7.2 mg/kg), colchicine (3.0 mg/kg) or sterile saline. One hour later, a monosodium urate (MSU) suspension was injected into the right hind paws of the mice to establish an acute gout model. Inflammation symptoms were evaluated at 0, 3, 6, 12 and 24 h, and the mechanical withdrawal threshold was evaluated at 0, 6 and 24 h. After 24 h, the mice were euthanized, and the joint tissue, kidney and blood were collected for subsequent experiments. Histological examination and antioxidant enzyme, kidney index and serum uric acid (UA) measurements were taken. The expression levels of the signalling pathway components were determined. KM effectively alleviated the symptoms of redness, swelling and pain; counteracted inflammatory cell infiltration; and increased antioxidant enzyme levels, reduced kidney index and serum UA levels through regulating UA excretion in MSU‐induced mice. The expression of toll‐like receptor 4 (TLR4)/nuclear factor kappa‐B (NF‐κB)/nucleotide‐binding oligomerization domain, leucine‐rich repeat and pyrin domain‐containing 3 (NLRP3) signalling pathway proteins and mRNA were reduced in the KM group. These results suggest that KM may be effective in alleviating GA through the TLR4/NF‐κB/NLRP3 pathway. [ABSTRACT FROM AUTHOR]

Mechanical peeling is more efficient and environmentally friendly compared to manual peeling. However, comparative studies on the quality of mechanically peeled pepper and manually peeled pepper are limited. This study utilized GC-MS to investigate the effects of immersion, steaming, and peeling machinery speed on the volatile composition of white pepper. A total of thirteen monoterpenes and seven sesquiterpenes were detected, with 3-carene, D-limonene, and sabinene being the most abundant monoterpenoids and β-caryophyllene, δ-elemene, and α-copaene being the most abundant sesquiterpenes. The total volatiles increased with longer steaming times and higher peeling machinery speeds. Compared to manual peeling or steaming followed by mechanical peeling, the volatile content of pepper was higher when using mechanical peeling alone. Additionally, relative odor activity values showed that 3-carene and D-limonene were the main contributors to flavor, with 3-carene, β-caryophyllene, and α-copaene being key volatiles responsible for flavor distinctions. This research aims to provide theoretical support for developing a superior and environmentally friendly mechanical method to replace manual labor. [ABSTRACT FROM AUTHOR]

Key message: Inventory and seasonal variation of terpene emissions from tropical trees in French Guiana: implications for environmental and ecological roles. A limited understanding of foliar terpene emissions from different tree species is prominent in diverse tropical forests. We conducted a study in French Guiana, screening BVOC emissions from 36 tropical woody species. We focused on 32 species in the dry season and 33 in the wet season, documenting terpene emissions for the first time in some of these tree species. Our findings show that 93.8% emitted terpenes in the dry season, while only 33.3% did so in the wet season. Terpene emissions ranged from 0.01 to 80.9 μg g−1 h−1 in the dry season and 0 to 11.7 μg g−1 h−1 in the wet season, consistent with previous reports. We identified and quantified 23 terpene compounds, including 19 monoterpenes and 4 sesquiterpenes. Additionally, 2 non-terpenoid compounds were detected: 2,2,4,6,6-pentamethylheptane (with no detected emissions in the dry season) and toluene. Among the monoterpenes, the most abundant were α-terpinolene, limonene, α-pinene, β-ocimene, and sabinene. As for sesquiterpenes, β-caryophyllene, α-caryophyllene, and α-copaene were observed during the dry season, while during the wet season, α-terpinolene predominated, followed by limonene, α-pinene, sabinene, β-caryophyllene, and α-copaene. Isoprene was detected in most of the species studied in both seasons. Sesquiterpene emissions displayed a notable phylogenetic pattern, whereas total terpenes and monoterpenes did not; however, total terpenes and monoterpenes exhibited a significant seasonal influence. Our study demonstrates that seasonality strongly influences BVOC production in tropical trees, with higher emissions in the dry season. These findings imply that various factors and conditions influence tree emissions in this tropical forest, affecting their ecological, environmental, and climatic roles, as well as the implementation of atmospheric chemistry models. [ABSTRACT FROM AUTHOR]

Terpenes and terpenoids content in cannabis plant was already studied in the past with three used methods. Since these works did not compare the content of these substances under the same conditions, we tried to make this comparison exactly. Three different gas chromatography/mass spectrometry (GS/MS) methods—hexane-based liquid extraction (Lis), static headspace extraction (HS), and headspace solid-phase microextraction (SPME)—were compared to identify volatile compounds in four different cannabis chemotypes—Green fields chemotype, Titan chemotype, Black Domina chemotype, and Neptune chemotype. The main compounds focused on were monoterpenes/monoterpenoids and sesquiterpenes/sesquiterpenoids. For a final evaluation of the comparison of the three methods of analysis, hexane extraction gives comparable results (which is advantageous for quantitative analysis), although the other two methods allowed the identification of more substances. This means that the same method should be used everywhere for the quantitative evaluation of constituents in cannabis. [ABSTRACT FROM AUTHOR]

Introduction: Despite the rising concern with fungal resistance, a myriad of molecules has yet to be explored. Geraniol, linalool, and citronellal are monoterpenes with the same molecular formula (C10H18O), however, neither the effect of these compounds on inflammatory axis induced by Candida spp. nor the antibiofilm Structure-Activity Relationship (SAR) have been well-investigated. Herein we analyzed geraniol, linalool and citronellal antifungal activity, cytotoxicity, and distinctive antibiofilm SAR, also the influence of geraniol on Candida spp induced dysregulated inflammatory axis, and in vivo toxicity. Methods: Minimal inhibitory (MIC) and fungicidal (MFC) concentrations against Candida spp were defined, followed by antibiofilm activity (CFU-colony forming unit/mL/g of dry weight). Cytotoxic activity was assessed using human monocytes (THP-1) and oral squamous cell (TR146). Geraniol was selected for further analysis based on antifungal, antibiofilm and cytotoxic results. Geraniol was tested using a dual-chamber co-culture model with TR146 cells infected with C. albicans, and THP-1 cells, used to mimic oral epithelium upon fungal infection. Expression of Candida enzymes (phospholipase-PLB and aspartyl proteases-SAP) and host inflammatory cytokines (interleukins: IL-1ß, IL-6, IL-17, IL-18, IL-10, and Tumor necrosis factor-TNF) were analyzed. Lastly, geraniol in vivo toxicity was assessed using Galleria mellonella. Results: MIC values obtained were 1.25-5 mM/mL for geraniol, 25-100 mM/mL for linalool, and 100-200 mM/mL for citronellal. Geraniol 5 and 50 mM/mL reduced yeast viability during biofilm analysis, only 500 mM/mL of linalool was effective against a 72 h biofilm and no biofilm activity was seen for citronellal. LD50 for TR146 and THP-1 were, respectively: geraniol 5.883 and 8.027 mM/mL; linalool 1.432 and 1.709 mM/mL; and citronellal 0.3006 and 0.1825 mM/mL. Geraniol was able to downregulate expression of fungal enzymes and host proinflammatory cytokines IL-1ß, IL-6, and IL-18. Finally, safety in vivo parameters were observed up to 20 mM/Kg. Discussion: Despite chemical similarities, geraniol presented better antifungal, antibiofilm activity, and lower cytotoxicity when compared to the other monoterpenes. It also showed low in vivo toxicity and capacity to downregulate the expression of fungal enzymes and host pro-inflammatory cytokines. Thus, it can be highlighted as a viable option for oral candidiasis treatment. [ABSTRACT FROM AUTHOR]

Molecular hybridization is a widely used strategy in drug discovery and development processes that consists of the combination of two bioactive compounds toward a novel entity. In the current study, two libraries of hybrid derivatives coming from the linkage of sesquiterpene counterparts dihydroartemisinin and artesunic acid, with a series of monoterpenes, were synthesized and evaluated by cell viability assay on primary and metastatic melanoma cell lines. Almost all the obtained compounds showed micromolar antimelanoma activity and selectivity toward the metastatic form of this cancer. Four hybrid derivatives containing perillyl alcohol, citronellol, and nerol as monoterpene counterpart emerged as the best compounds of the series, with nerol being active in combination with both sesquiterpenes, dihydroartemisinin and artesunic acid. Preliminary studies on the mechanism of action have shown the dependence of the pharmacological activity of newly synthesized hybrids on the formation of carbon- and oxygen-centered radical species. This study demonstrated the positive modulation of the pharmacodynamic effect of artemisinin semisynthetic derivatives dihydroartemisinin and artesunic acid due to the hybridization with monoterpene counterparts. [ABSTRACT FROM AUTHOR]

Sage (Salvia officinalis L.) is a medicinal and aromatic plant (MAP) belonging to the Lamiaceae family. Its morphological, productive and chemical characteristics are affected by abiotic and biotic factors. The use of biostimulants seems to be one of the most interesting innovative practices due to fact they can represent a promising approach for achieving sustainable and organic agriculture. Despite a large application in horticulture, the use of biostimulants on MAPs has been poorly investigated. On this basis, a field experiment in a 2-year study was done to assess the effect of foliar treatments with different types of biostimulants (containing seaweeds, fulvic acids and protein hydrolysates) and two frequencies of application on morphological, productive, and chemical characteristics of S. officinalis grown organically in Mediterranean environment. Morphological, productive, and chemical parameters were affected by the factors. The biostimulant application generated higher plant height, chlorophyll content, relative water content, biomass yield and essential oil yield compared to control plants. In addition, more frequent application of biostimulants produced higher biomass and essential oil yield. The application of fulvic acid and protein hydrolysates every week produced the highest total fresh yields (between 3.9 and 8.7 t ha-1) and total dry yields (between 1.3 and 2.5 t ha-1). The essential oil yield almost doubled (33.9 kg ha-1) with a higher frequency of protein hydrolysates application. In this study, 44 essential oil compounds were identified, and the frequency factor significantly influenced the percentage of 38 compounds. The highest percentage of some of the most representative monoterpenes, such as 1,8-cineole, a-thujone and camphor, were observed in biostimulated plants, with average increases between 6% and 35% compared to control plants. The highest values for total phenolics, rosmarinic acid, antioxidant activity were obtained in control plants and with a lower frequency of biostimulant applications. This study emphasizes how biostimulant applications may be used to improve sage production performance and essential oil parameters when produced in agricultural organic system. At the same time, biostimulants application caused a decrease in total phenolic, antioxidant activity and rosmarinic acid values. [ABSTRACT FROM AUTHOR]

This study was conducted to determine the sea fennel essential oil (SFEO) yield, composition, and antioxidant activity of leaves, stem, inflorescences, and umbels from seeds of wild sea fennel (SF) (Crithmum maritimum L.) from the Montenegro coast. The chemical composition of isolated essential oil was determined by GC/MS and GC/FID analyses. The antioxidant activity was determined using the DPPH assay. The maximum SFEO yield was found in umbels with seeds (4.77 mL/100 g p.m.). The leaves contained less EO (0.52 mL/100 g p.m.) than immature inflorescence (0.83 mL/100 g p.m.) The minimum EO content was found in the stem (0.08%). Twenty components were isolated from SFEO leaves, twenty-four from inflorescence, thirty-four components from the stem, and twenty-one components from umbels with seeds. Limonene (62.4–72.0%), γ-terpinene (9.5–14.0%), α-pinene (1.4–5.8%), and sabinene (1–6.5%) were found to be the main components of the SFEO from monoterpene hydrocarbons as dominant grouped components (86% to 98.1%). SF plant parts showed differences in chemical profiles, especially in specific and low-represented ingredients. (E)-anethole (4.4%), fenchone (0.5%), and trans-carveol (0.2%) were present only in umbel with seeds, while the β-longipipene (0.5%), (E)-caryophyllene (0.5%), and (2E)-decenal (0.2%) were found only in the stems. The degree of DPPH radical neutralization increased with incubation time. The SFEO isolated from the stems showed stronger antioxidant activity during the incubation times of 20 and 40 min (EC50 value of 5.30 mg/mL and 5.04 mg/mL, respectively) in comparison to the SFEO isolated from the other plant parts. The lowest antioxidant activity was obtained with the SFEO leaves (155.25 mg/mL and 58.30 mg/mL, respectively). This study indicates that SFEO possesses significant antioxidant activities and is animportant component in the food and pharmaceutical industries. It is important to preserve the existing gene pool and biodiversity with rational use SF for the extraction of high-quality essential oils. [ABSTRACT FROM AUTHOR]

This study investigates the impact of methyl jasmonate (MeJA) on the volatile oil composition of Schizonepeta tenuifolia and elucidates the function of the StTPS45 gene, a key player in terpenoid biosynthesis. The effect of different concentrations of MeJA (0, 50, 100, 200, and 300 μmol/L) on the growth of S. tenuifolia adventitious bud clusters was analyzed over a 20 d period. Using gas chromatography–mass spectrometry (GC-MS), 17 compounds were identified from the adventitious bud clusters of S. tenuifolia. Significant changes in the levels of major monoterpenes, including increased contents of (+)-limonene and (+)-menthone, were observed, particularly at higher concentrations of MeJA. Analysis of transcriptome data from three groups treated with 0, 100, and 300 μmol/L MeJA revealed significant changes in the gene expression profiles following MeJA treatment. At 100 μmol/L MeJA, most terpene synthase (TPS) genes were overexpressed. Additionally, gene expression and functional predictions suggested that StTPS45 acts as germacrene D synthase. Therefore, StTPS45 was cloned and expressed in Escherichia coli, and enzyme activity assays confirmed its function as a germacrene D synthase. Molecular docking and structural prediction of StTPS45 further suggested specific interactions with farnesyl diphosphate (FPP), aligning with its role in the terpenoid synthesis pathway. These findings provide valuable insights into the modulation of secondary metabolite pathways by jasmonate signaling and underscore the potential of genetic engineering approaches to enhance the production of specific terpenoids in medicinal plants. [ABSTRACT FROM AUTHOR]

Developing effective and targeted drug delivery systems is crucial in searching for improved pain management strategies. Here, it is shown the preparation of a nanocarrier using chitosan hydrogel, and polymeric nanocapsules loaded with linalool for enhancing transdermal permeation and targeted delivery of this antinociceptive monoterpene for the pain treatment. Extensive characterization was conducted to evaluate the properties of the nanocarrier, and several in vitro studies were performed to investigate the release kinetics of linalool from the nanocarrier and its permeation through the layers of the skin. As results, the prepared polymeric nanocarrier exhibited an average size of 160 ± 9 nm, with a polydispersion index of 0.12 ± 0.01. The kinetic study revealed that the nanocarrier effectively controlled and prolonged the release of linalool, following a pseudo‐second order model (R2 = 0.98). To evaluate the permeation of the nanocarrier through the transdermal barrier, swine ear skin was employed. The nanocarrier efficiently penetrated the transdermal barrier and successfully delivered linalool to the skin layers. Additionally, an in vivo toxicity study indicated no toxicity for the nanocarrier at the tested concentrations (<0.950 μg mL−1). The release kinetics showed a controlled and sustained release of the linalool, suggesting its potential for prolonged therapeutic effects. [ABSTRACT FROM AUTHOR]

Background: Several members of the Lamiaceae family of plants produce large amounts of essential oil [EO] that find extensive applications in the food, cosmetics, personal hygiene, and alternative medicine industries. There is interest in enhancing EO metabolism in these plants. Main body: Lavender produces a valuable EO that is highly enriched in monoterpenes, the C10 class of the isoprenoids or terpenoids. In recent years, substantial effort has been made by researchers to study terpene metabolism and enhance lavender EO through plant biotechnology. This paper reviews recent advances related to the cloning of lavender monoterpene biosynthetic genes and metabolic engineering attempts aimed at improving the production of lavender monoterpenes in plants and microbes. Conclusion: Metabolic engineering has led to the improvement of EO quality and yield in several plants, including lavender. Furthermore, several biologically active EO constituents have been produced in microorganisms. [ABSTRACT FROM AUTHOR]

Profiles of the volatile organic compound (VOC) content of essential oils (EOs) extracted from young and old Juniperus communis L. needles were generated via gas chromatography combined with mass spectrometry (GC‐MS) and flame ionization detection (GC‐FID) and subsequently processed using multivariate statistical methods. These were then used to differentiate the EOs according to needle age and geographical origin. From a total 49 of VOCs identified, statistically significant differences (p<0.05) between young‐ and old‐needle EOs were found for 21 VOCs. Most of the EOs from the young needles showed higher (p<0.05) contents of α‐ and β‐pinene and sesquiterpenes (β‐ and γ‐elemene, germacrene D and B, α‐muurolene, and δ‐cadinene) and their oxygenated derivatives (α‐ and τ‐cadinol), while most of the monoterpenes (α‐thujene, sabinene, terpinolene, β‐myrcene, β‐phellandrene, and p‐cymene) were present in higher quantities (p<0.05) in the EOs from the old needles. The volatiles germacrene D, α‐ and β‐pinene, α‐cadinol, and sabinene were identified via stepwise and canonical discriminant analysis as the most valuable for EO discrimination according to needle age and geographical origin. Recognition and prediction ability tests of the EOs achieved 100 % accuracy in EO classification according to the above mentioned criterion. [ABSTRACT FROM AUTHOR]

Intraspecific variation of specialized metabolites in plants, such as terpenoids, are used to determine chemotypes. Tansy Tanacetum vulgare exhibits diverse terpenoid profiles that affect insect communities. However, it is not fully known whether patterns of their chemical composition and associated insects vary beyond the community scale. Here, we investigated the geographic distribution of mono‐ and sesquiterpenoid chemotypes in tansy leaves and their relationships with specific insect communities across Germany. We sampled tansy leaves from ten plants with and five plants without aphids in each of 26 sites along a north–south and west–east transect in Germany. Hexane‐extracted metabolites from leaf tissues were analyzed by gas chromatography‐mass spectrometry (GC‐MS). Plant morphological traits, aphid occurrence and abundance, and occurrence of ants were recorded locally. The effect of plant chemotype, plant morphological parameters, and abiotic site parameters such as soil types, temperature and precipitation on insect occurrences were analyzed. Plants clustered into four monoterpenoid and four sesquiterpenoid chemotype classes. Monoterpene classes differed in their latitudinal distribution, whereas sesquiterpenes were more evenly distributed across the transect. Aphid and ant occurrence was influenced by monoterpenoids. Plants of monoterpenoid class 1 were colonized by aphids and ants significantly more often than expected by chance, whereas in other classes there were no significant differences. Aphid abundance was affected by soil type, and average annual temperature positively correlated with the occurrence of ants. We found significant geographic patterns in the distribution of tansy chemodiversity and show that monoterpenoids affect aphid and ant occurrence, while the soil type can influence aphid abundance. We show that geographic variation in plant chemistry influences insect community assembly on tansy plants. [ABSTRACT FROM AUTHOR]

Combination of crop protectants is an important approach to increase insecticidal efficacy and reduce the application rates. In this study, the insecticidal efficacy of spinosad and seven monoterpenes, alone and in binary combinations, was evaluated against Sitophilus oryzae (L.) (Coleoptera: Curculionidae) in stored wheat. Spinosad was tested at application rates of 0.1 and 0.5 mg/kg while monoterpenes were tested at 0.5, 1.0 and 2.0 g/kg. Mortality of adults after 7, 14 and 21 days, progeny reduction after 45 and 90 days, and grain weight loss were recorded for all treatments. The results showed that the complete mortality (100.0%) of S. oryzae adults was observed in wheat treated with 0.5 mg/kg of spinosad + 2.0 g/kg of carvone or P-cymene or menthone after 21 days. At the same time, no progeny of S. oryzae was resulted in the combined treatments (0.5 mg/kg of spinosad + 2.0 g/kg of carvone or 0.5 mg/kg of spinosad + 2.0 g/kg of P-cymene) after 45 and 90 days. The same trends were observed for grains weight loss as the binary treatments at highest application rates preserved the wheat seeds free from damage caused by S. oryzae for 90 days. [ABSTRACT FROM AUTHOR]

New strategies have to be introduced for the management of agricultural and public health insects to overcome the problems associated with long-term use of synthetic insecticides. Plant-based natural products are among the possible and available alternatives to be applied for insect management. Among the plant secondary metabolites, monoterpenes have been widely studied for their applications in insect control. In this review, we focus on the studies describing the insecticidal and grain protection activities of monoterpenes against stored product insects. In addition, the biosynthesis and chemistry of monoterpenes as well as their possible modes of action and commercialization opportunities are summarized. The present review emphasizes the importance of monoterpenes as target-specific, biodegradable, environmentally safe grain protectants as well as their possible practical use as a tool in integrated pest management programs. [ABSTRACT FROM AUTHOR]

The chemical composition of Sedum ewersii Ledeb., a plant indigenous to Kazakhstan and traditionally utilized in folk medicine, was comprehensively investigated, with a focus on its various plant parts. Fresh samples collected in May 2023 from the Almaty region underwent hydrodistillation to extract volatile components, followed by analysis using gas chromatography coupled with mass spectrometric detection, which identified a total of 71 compounds across different plant parts, including the root (underground part), root (aerial part), leaf, stem, and flowering aerial part. The predominant biologically active compound identified across all plant parts was Ethyl α-D-glucopyranoside. Monoterpenes, recognized as primary secondary metabolites, were notably abundant in each plant part, with varying compositions: the root (underground part) contained 28.58% aliphatic monoterpenes, 54.41% oxygenated monoterpenoids, 1.42% diterpenoids, and 15.59% other compounds; the root (aerial part) exhibited 1.34% aliphatic monoterpenes, 31.28% oxygenated monoterpenoids, 6.16% diterpenoids, and 61.22% other compounds; the stem and leaves showed 3.06% aliphatic monoterpenes, 21.49% oxygenated monoterpenoids, 17.99% diterpenoids, and 57.46% other compounds; and the flowering aerial part displayed 8.20% aliphatic monoterpenes, 53.18% oxygenated monoterpenoids, 23.75% diterpenoids, and 14.87% other compounds. Diterpenes, particularly Phytol, were prominently present in the leaf, stem, and flowering aerial parts. Additionally, a diverse array of organic acids, ketones, and phenolic compounds were identified across the plant parts, each potentially offering distinct pharmacological benefits. The presence of exclusive compounds in specific plant parts, such as Dihydroxyacetone in the root (aerial part), underscored the pharmacological diversity of S. ewersii. This study provides valuable insights into the chemical diversity and pharmacological potential of S. ewersii, suggesting promising applications in pharmaceutical and medicinal fields. Further research aimed at elucidating the individual and synergistic pharmacological effects of these compounds is crucial to fully harness the therapeutic benefits of this plant. [ABSTRACT FROM AUTHOR]

Monoterpene indole alkaloids (MIAs) are a group of plant-derived natural products with high-value medicinal properties. However, their availability for clinical application is limited due to challenges in plant extraction. Microbial production has emerged as a promising strategy to meet the clinical demands for MIAs. The biosynthetic pathway of cis-trans nepetalactol, which serves as the universal iridoid scaffold for all MIAs, has been successfully identified and reconstituted. However, bottlenecks and challenges remain to construct a high-yielding platform strain for cis-trans nepetalactol production, which is vital for subsequent MIAs biosynthesis. In the present study, we focused on engineering of Pichia pastoris cell factories to enhance the production of geraniol, 8-hydroxygeraniol, and cis-trans nepetalactol. By targeting the biosynthetic pathway from acetyl-CoA to geraniol in both peroxisomes and cytoplasm, we achieved comparable geraniol titers in both compartments. Through protein engineering, we found that either G8H or CPR truncation increased the production of 8-hydroxygeraniol, with a 47.8-fold and 14.0-fold increase in the peroxisomal and cytosolic pathway strain, respectively. Furthermore, through a combination of dynamical control of ERG20 , precursor and cofactor supply engineering, diploid engineering, and dual subcellular compartmentalization engineering, we achieved the highest ever reported production of cis-trans nepetalactol, with a titer of 4429.4 mg/L using fed-batch fermentation in a 5-L bioreactor. We anticipate our systematic metabolic engineering strategies to facilitate the development of P. pastoris cell factories for sustainable production of MIAs and other plant natural products. • Construction of geraniol-producing strains both in peroxisomes and cytoplasm. • Protein engineering increased 8-hydroxygeraniol titer by over 14- fold. • Dynamical regulation of ERG20 for enhanced production of monoterpenoids. • A platform for MIAs biosynthesis with the highest cis-trans nepetalactol titer. [ABSTRACT FROM AUTHOR]

Detecting volatile organic compounds (VOCs) emitted from different plant species and their organs can provide valuable information about plant health and environmental factors that affect them. For example, limonene emission can be a biomarker to monitor plant health and detect stress. Traditional methods for VOC detection encounter challenges, prompting the proposal of novel approaches. In this study, we proposed integrating electrospinning, molecular imprinting, and conductive nanofibers to fabricate limonene sensors. In detail, polyvinylpyrrolidone (PVP) and polyacrylic acid (PAA) served here as fiber and cavity formers, respectively, with multiwalled carbon nanotubes (MWCNT) enhancing conductivity. We developed one-step monolithic molecularly imprinted fibers, where S(−)-limonene was the target molecule, using an electrospinning technique. The functional cavities were fixed using the UV curing method, followed by a target molecule washing. This procedure enabled the creation of recognition sites for limonene within the nanofiber matrix, enhancing sensor performance and streamlining manufacturing. Humidity was crucial for sensor working, with optimal conditions at about 50% RH. The sensors rapidly responded to S(−)-limonene, reaching a plateau within 200 s. Enhancing fiber density improved sensor performance, resulting in a lower limit of detection (LOD) of 137 ppb. However, excessive fiber density decreased accessibility to active sites, thus reducing sensitivity. Remarkably, the thinnest mat on the fibrous sensors created provided the highest selectivity to limonene (Selectivity Index: 72%) compared with other VOCs, such as EtOH (used as a solvent in nanofiber development), aromatic compounds (toluene), and two other monoterpenes (α-pinene and linalool) with similar structures. These findings underscored the potential of the proposed integrated approach for selective VOC detection in applications such as precision agriculture and environmental monitoring. [ABSTRACT FROM AUTHOR]

Background: Limonene has a variety of applications in the foods, cosmetics, pharmaceuticals, biomaterials, and biofuels industries. In order to meet the growing demand for sustainable production of limonene at industry scale, it is essential to find an alternative production system to traditional plant extraction. A promising and eco-friendly alternative is the use of microbes as cell factories for the synthesis of limonene. Results: In this study, the oleaginous yeast Yarrowia lipolytica has been engineered to produce d- and l-limonene. Four target genes, l- or d-LS (limonene synthase), HMG (HMG-CoA reductase), ERG20 (geranyl diphosphate synthase), and NDPS1 (neryl diphosphate) were expressed individually or fused together to find the optimal combination for higher limonene production. The strain expressing HMGR and the fusion protein ERG20-LS was the best limonene producer and, therefore, selected for further improvement. By increasing the expression of target genes and optimizing initial OD, 29.4 mg/L of l-limonene and 24.8 mg/L of d-limonene were obtained. We also studied whether peroxisomal compartmentalization of the synthesis pathway was beneficial for limonene production. The introduction of d-LS and ERG20 within the peroxisome improved limonene titers over cytosolic expression. Then, the entire MVA pathway was targeted to the peroxisome to improve precursor supply, which increased d-limonene production to 47.8 mg/L. Finally, through the optimization of fermentation conditions, d-limonene production titer reached 69.3 mg/L. Conclusions: In this work, Y. lipolytica was successfully engineered to produce limonene. Our results showed that higher production of limonene was achieved when the synthesis pathway was targeted to the peroxisome, which indicates that this organelle can favor the bioproduction of terpenes in yeasts. This study opens new avenues for the efficient synthesis of valuable monoterpenes in Y. lipolytica. [ABSTRACT FROM AUTHOR]

Our study aimed to compare the essential oil (EO) concentration and composition of several Apiaceae species growing in the Northern region of Vietnam. The yields of EOs from materials ranged from 0.03% (root EO of Angelica acutiloba and aerial parts EO of Heracleum bivittatum)−0.27% (leaf EO of Xyloselinum vietnamense). Gas chromatography-mass spectrometry (GC-MS) allowed the identification of 74 components in the EOs of six Apiaceae species, making up 94.4%–100.0% of the oils. In EO from Angelica acutiloba , (Z)-ligustilide accounted for an extremely large proportion (94.9%). EO of Angelica pubescens was dominated by six characteristic components including α-pinene (21.5%), β-phellandrene (18.1%), p -cymene (12.2%), 3-methylnonane (8.7%), o -cymene (8.1%), and D-sylvestrene (6.2%). The EO from Cryptotaenia japonica was characterized by high amounts of α-selinene (48.7%), β-selinene (23.7%), and trans -β-farnesene (5.4%). The EOs from leaves and stems of Xyloselinum vietnamense were characterized by high concentrations of sabinene (69.8% and 33.8%), 4-terpineol (8.7% and 7.4%) and β-pinene (4.0% and 6.5%) while EOs from aerial parts and root of Xyloselinum leonidii comprise four characteristic monoterpenes including α-pinene (28.2% and 52.8%), β-pinene (7.9% and 10.3%), β-phellandrene (7.6% and 15.3%), and sabinene (3.0% and 4.1%). Additionally, cryptone is also one of the major components in the EO of Xyloselinum leonidii (13.2% in the aerial parts oil and 2. 8% in the root oil). In the EOs isolated from the aerial parts and root of Heracleum bivittatum , α-pinene (22.5% and 70.2%) and β-pinene (43.2% and 20.0%) were the predominant monoterpenes. Sabinene appeared in the EO from aerial parts of Heracleum bivittatum with a relatively high concentration (13.5%) while bornyl acetate (5.1%) was also one of the main components in the EO from its aerial parts but was not detected in other Apiaceae species in the present study. These databases help identify and control the quality of plant material studied from the family Apiaceae growing in Vietnam. [ABSTRACT FROM AUTHOR]

Monoterpenes are a class of volatile organic compounds that play crucial roles in imparting floral and fruity aromas to Muscat-type grapes. However, our understanding of the regulatory mechanisms underpinning monoterpene biosynthesis in grapes, particularly following abscisic acid (ABA) treatment, remains elusive. This study aimed to explore the impact of exogenous ABA on monoterpene biosynthesis in Ruiduhongyu grape berries by employing Headspace Solid-Phase Micro-Extraction Gas Chromatography–Mass Spectrometry (HS-SPME/GC–MS) analysis and transcriptome sequencing. The results suggested significant differences in total soluble solids (TSS), pH, and total acid content. ABA treatment resulted in a remarkable increase in endogenous ABA levels, with concentrations declining from veraison to ripening stages. ABA treatment notably enhanced monoterpene concentrations, particularly at the E_L37 and E_L38 stages, elevating the overall floral aroma of grape berries. According to the variable gene expression patterns across four developmental stages in response to ABA treatment, the E_L37 stage had the largest number of differential expressed genes (DEGs), which was correlated with a considerable change in free monoterpenes. Furthermore, functional annotation indicated that the DEGs were significantly enriched in primary and secondary metabolic pathways, underlining the relationship between ABA, sugar accumulation, and monoterpene biosynthesis. ABA treatment upregulated key genes involved in the methylerythritol phosphate (MEP) pathway, enhancing carbon allocation and subsequently impacting terpene synthesis. This study also identified transcription factors, including MYB and AP2/ERF families, potentially modulating monoterpene and aroma-related genes. Weighted gene co-expression network analysis (WGCNA) linked ABA-induced gene expression to monoterpene accumulation, highlighting specific modules enriched with genes associated with monoterpene biosynthesis; one of these modules (darkgreen) contained genes highly correlated with most monoterpenes, emphasizing the role of ABA in enhancing grape quality during berry maturation. Together, these findings provide valuable insights into the multifaceted effects of exogenous ABA on monoterpene compounds and grape berry flavor development, offering potential applications in viticulture and enology. [ABSTRACT FROM AUTHOR]

The hormonal decline during menopause increases women's risk of chronic diseases. D-limonene, a monoterpene found in the human diet, possesses biological properties related to hypolipemic, antioxidant, anti-inflammatory, and gut microbiota-modulating activities, primarily observed in preclinical studies. Postprandial responses include physiological adaptations to the stress of a nutrient surplus, providing an opportunity to assess metabolic resilience, being a suitable strategy for exploring post-menopause-associated metabolic alterations. Here, we investigated the effects of D-limonene supplementation (2 g/day) on postprandial metabolism in postmenopausal women (n = 9) challenged with a standardized mixed meal in a 3-week single-arm clinical study. Our findings revealed that D-limonene did not induce marked differences in postprandial responses to the dietary challenge. The supplementation with D-limonene induced no alterations in serum lipid/lipoprotein profile or glycemia/insulinemia. D-limonene supplementation did not affect the transient postprandial inflammatory response regarding changes in gene expression of peripheral blood mononuclear cells (PBMC) and circulating inflammatory markers. Nevertheless, D-limonene reduced postprandial levels of lithocholic acid, a gut microbiota-derived bile acid, and regulated the plasma concentrations of selected amino acids, carbohydrate metabolism-derived metabolites, and organic acids. In conclusion, our data do not support the claim that short-term D-limonene supplementation beneficially affects the postprandial metabolism of postmenopausal women. [ABSTRACT FROM AUTHOR]

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Background: Colorectal cancer (CRC) is one of the most common and deadly cancers worldwide. Different factors, such as environmental and genetic factors and lifestyle, affect it. Owing to the presence of phenolic, alkaloid, antioxidant, and terpenoid compounds, herbal compounds can be effective in the treatment of various cancers. Thymol is a natural monoterpene phenol that is abundant in some plants and exerts several biological effects. The aim of this study was to investigate the apoptotic, anti-proliferative effect and EGFR gene expression under the influence of thymol-loaded nanoliposome in SW84 and SW111 cell lines derived from colorectal cancer. Materials and methods: The lipid thin-film hydration method was used to synthesize thymol-loaded liposomes, and their characterization was performed using TEM, DLS, and HPLC analyses. SW84 and SW1111 cells were treated with thymol- and thymol-loaded liposomes at different doses, the inhibition of cell proliferation was evaluated using an MTT assay, the rate of apoptosis induction was assessed using flow cytometry, and EGFR gene expression was measured using real-time PCR. Results: The nanoparticles produced were spherical, uniform, and 200 ± 10 nm in size. HPLC analysis showed that approximately 98% thymol was loaded into the nanoliposome. The results of the MTT assay showed that thymol and thymol-nanoliposomes decreased the proliferation of SW84 and SW1111 cells in a concentration-dependent manner. The IC50 of thymol and thymol-nanoliposomes were 18 and 14.2 µg/ml for the SW48 cell line (P = 0.04) and 10.5 and 6.4 µg/ml for the SW1116 cell line (P = 0.001). Thymol-nanoliposomes significantly inhibited the proliferation of cancer cells compared to free thymol. Flow cytometry showed an increase in the percentage of apoptotic cells, especially in the thymol-nanoliposome group in the treated cells. Real-time PCR results also showed that thymol and thymol-nanoliposome both caused a decrease in the expression of EGFR genes in both cell lines, but this effect of decreasing gene expression was significantly higher in the thymol-nanoliposome group. Conclusions: Our results showed that thymol-nanoliposomes reduced proliferation, increased apoptosis, and decreased EGFR expression in colorectal cancer-derived cell lines. [ABSTRACT FROM AUTHOR]

Monoterpenoid indole alkaloids (MIAs) represent a large class of plant natural products with marketed pharmaceutical activities against a wide range of indications, including cancer, malaria and hypertension. Halogenated MIAs have shown improved pharmaceutical properties; however, synthesis of new-to-nature halogenated MIAs remains a challenge. Here we demonstrate a platform for de novo biosynthesis of two MIAs, serpentine and alstonine, in baker's yeast Saccharomyces cerevisiae and deploy it to systematically explore the biocatalytic potential of refactored MIA pathways for the production of halogenated MIAs. From this, we demonstrate conversion of individual haloindole derivatives to a total of 19 different new-to-nature haloserpentine and haloalstonine analogs. Furthermore, by process optimization and heterologous expression of a modified halogenase in the microbial MIA platform, we document de novo halogenation and biosynthesis of chloroalstonine. Together, this study highlights a microbial platform for enzymatic exploration and production of complex natural and new-to-nature MIAs with therapeutic potential.

Abstract Background Several members of the Lamiaceae family of plants produce large amounts of essential oil [EO] that find extensive applications in the food, cosmetics, personal hygiene, and alternative medicine industries. There is interest in enhancing EO metabolism in these plants. Main body Lavender produces a valuable EO that is highly enriched in monoterpenes, the C10 class of the isoprenoids or terpenoids. In recent years, substantial effort has been made by researchers to study terpene metabolism and enhance lavender EO through plant biotechnology. This paper reviews recent advances related to the cloning of lavender monoterpene biosynthetic genes and metabolic engineering attempts aimed at improving the production of lavender monoterpenes in plants and microbes. Conclusion Metabolic engineering has led to the improvement of EO quality and yield in several plants, including lavender. Furthermore, several biologically active EO constituents have been produced in microorganisms.

Abstract The hormonal decline during menopause increases women's risk of chronic diseases. D-limonene, a monoterpene found in the human diet, possesses biological properties related to hypolipemic, antioxidant, anti-inflammatory, and gut microbiota-modulating activities, primarily observed in preclinical studies. Postprandial responses include physiological adaptations to the stress of a nutrient surplus, providing an opportunity to assess metabolic resilience, being a suitable strategy for exploring post-menopause-associated metabolic alterations. Here, we investigated the effects of D-limonene supplementation (2 g/day) on postprandial metabolism in postmenopausal women (n = 9) challenged with a standardized mixed meal in a 3-week single-arm clinical study. Our findings revealed that D-limonene did not induce marked differences in postprandial responses to the dietary challenge. The supplementation with D-limonene induced no alterations in serum lipid/lipoprotein profile or glycemia/insulinemia. D-limonene supplementation did not affect the transient postprandial inflammatory response regarding changes in gene expression of peripheral blood mononuclear cells (PBMC) and circulating inflammatory markers. Nevertheless, D-limonene reduced postprandial levels of lithocholic acid, a gut microbiota-derived bile acid, and regulated the plasma concentrations of selected amino acids, carbohydrate metabolism-derived metabolites, and organic acids. In conclusion, our data do not support the claim that short-term D-limonene supplementation beneficially affects the postprandial metabolism of postmenopausal women. Graphical Abstract

Objective(s): This study was conducted to explore the impact of 1, 8-cineole (eucalyptol) on the biochemical, molecular, and histological changes caused by lead acetate in the liver of adult male Wistar rats. The research also investigated the potential involvement of the TLR4 signaling pathway in this effect. Materials and Methods: Rats were orally administered lead acetate (25 mg/kg-day) for 14 consecutive days and received 1, 8-cineole (100 mg/kg-day) during the same period. Results: 1, 8-cineole prevented an increase in the malondialdehyde level, a decrease in the glutathione level, and a decrease in the activity of superoxide dismutase and glutathione peroxidase enzymes in the liver of rats treated with lead acetate. This monoterpene also prevented an increase in the expression of pro-inflammatory cytokines and significantly reduced the infiltration of inflammatory cells in the liver parenchyma. Additionally, 1, 8-cineole discouraged the increase in toll-like receptor 4 (TLR4), myeloid differentiation primary response 88 (MyD88), and nuclear factor kappa B (NF-κB) expression in the liver and stopped a rise in serum AST and ALT enzymes. Conclusion: 1, 8-cineole can prevent liver damage caused by lead acetate by reducing oxidative stress and inflammation. This hepatoprotection is probably achieved by inhibiting TLR4/MyD88/NF-κB signaling. [ABSTRACT FROM AUTHOR]

This study aimed to examine the antifungal effects of nine monoterpenes on Sclerotinia sclerotiorum via the mycelial growth rate method. The effects of carvacrol on the morphological structures of hyphae were investigated by scanning electron microscopy (SEM). The oxalic acid (OA), total protein contents, and the activity of cell wall-degrading enzymes, including chitinase, cellulase and β-1,3-glucanase, were assessed. The results showed that the antifungal rates of carvacrol, thymol and eugenol reached 100% at a concentration of 400 mg/L, and the EC50 values of carvacrol, thymol, and eugenol were 43.40, 56.22, and 86.63 mg/L, respectively. The treatment of S. sclerotiorum with carvacrol had no significant effect on sclerotia formation, but the mycelial surface was shrivelled, uneven and broken, with cytoplasm flowing out. The OA content of S. sclerotiorum was significantly reduced to 133.78 µg/mL after treatment with carvacrol. Additionally, the total protein content of S. sclerotiorum mycelia in the carvacrol treatment group was significantly reduced to 15.67 µg/mL compared with that of the control group, and the activity of cellulase in the carvacrol treatment group was significantly higher than that in the control group.

Abstract Background The fruity aromatic bouquet of coffee has attracted recent interest to differentiate high value market produce as specialty coffee. Although the volatile compounds present in green and roasted coffee beans have been extensively described, no study has yet linked varietal molecular differences to the greater abundance of specific substances and support the aroma specificity of specialty coffees. Results This study compared four Arabica genotypes including one, Geisha Especial, suggested to generate specialty coffee. Formal sensory evaluations of coffee beverages stressed the importance of coffee genotype in aroma perception and that Geisha Especial-made coffee stood out by having fine fruity, and floral, aromas and a more balanced acidity. Comparative SPME–GC–MS analyses of green and roasted bean volatile compounds indicated that those of Geisha Especial differed by having greater amounts of limonene and 3-methylbutanoic acid in agreement with the coffee cup aroma perception. A search for gene ontology differences of ripening beans transcriptomes of the four varieties revealed that they differed by metabolic processes linked to terpene biosynthesis due to the greater gene expression of prenyl-pyrophosphate biosynthetic genes and terpene synthases. Only one terpene synthase (CaTPS10-like) had an expression pattern that paralleled limonene loss during the final stage of berry ripening and limonene content in the studied four varieties beans. Its functional expression in tobacco leaves confirmed its functioning as a limonene synthase. Conclusions Taken together, these data indicate that coffee variety genotypic specificities may influence ripe berry chemotype and final coffee aroma unicity. For the specialty coffee variety Geisha Especial, greater expression of terpene biosynthetic genes including CaTPS10-like, a limonene synthase, resulted in the greater abundance of limonene in green beans, roasted beans and a unique citrus note of the coffee drink.

Background: Pinus koraiensis cone essential oil (PEO) contains functional compounds such as monoterpene hydrocarbons, and the administration of PEO reduced methane (CH4) emissions during growing phase of goats. However, the mode of action of PEO driven CH4 reduction is not known, especially how the administration of PEO can affect rumen microbiota and host metabolism in goats during the fattening phase. This study aimed to elucidate the potential microbial and host responses PEO supplementation in goats using metataxonomics (prokaryotes and protozoa) and metabolomics (rumen fluid and serum). Results: Ten fattening Korean native goats were divided into two dietary groups: control (CON; basal diet without additives) and PEO (basal diet + 1.5 g/d of PEO) with a 2 × 2 crossover design and the treatment lasted for 11 weeks. Administration of PEO reduced CH4 concentrations in the exhaled gas from eructation by 12.0–13.6% (P < 0.05). Although the microbial composition of prokaryotes (bacteria and archaea) and protozoa in the rumen was not altered after PEO administration. MaAsLin2 analysis revealed that the abundance of Selenomonas, Christensenellaceae R-7 group, and Anaerovibrio were enriched in the rumen of PEO supplemented goats (Q < 0.1). Co-occurrence network analysis revealed that Lachnospiraceae AC2044 group and Anaerovibrio were the keystone taxa in the CON and PEO groups, respectively. Methane metabolism (P < 0.05) was enriched in the CON group, whereas metabolism of sulfur (P < 0.001) and propionate (P < 0.1) were enriched in the PEO group based on microbial predicted functions. After PEO administration, the abundance of 11 rumen and 4 serum metabolites increased, whereas that of 25 rumen and 14 serum metabolites decreased (P < 0.1). Random forest analysis identified eight ruminal metabolites that were altered after PEO administration, among which four were associated with propionate production, with predictive accuracy ranging from 0.75 to 0.88. Additionally, we found that serum sarcosine (serum metabolite) was positively correlated with CH4 emission parameters and abundance of Methanobrevibacter in the rumen (|r|≥ 0.5, P < 0.05). Conclusions: This study revealed that PEO administration reduced CH4 emission from of fattening goats with altered microbial interactions and metabolites in the rumen and host. Importantly, PEO administration affected utilizes various mechanisms such as formate, sulfur, methylated amines metabolism, and propionate production, collectively leading to CH4 reduction. The knowledge is important for future management strategies to maintain animal production and health while mitigate CH4 emission. [ABSTRACT FROM AUTHOR]

Frequent and variant infections are caused by the virtue of opportunistic fungi pathogens. Candidiasis, aspergillosis, and mucormycosis are pathogenic microorganisms that give rise to vast fungal diseases that alternate between moderate to fatal in severity. The use of fluconazole as an antifungal drug was limited due to the acquired resistance in some types of Candida and other fungal species. This study aims to consolidate fluconazole's biological effectiveness against several pathogenic fungi. Six active monoterpenes (MTs) of carvacrol, linalool, geraniol, α-terpinene, citronellal, and nerolidol were selected and encapsulated in nanostructure lipid carrier (NLC) with (NLC-Flu-MTs) and/without (NLC-MTs) fluconazole in one nanoformulation to determine if they will act synergistically or not? The synthesized nanoformulation NLC-Flu-MTs and NLC-MTs exhibited very good particle size of 144.5 nm and 138.6 nm for size and zeta potential values of (− 23.5 mV) and (− 20.3 mV), respectively. Transmission electron microscope investigation confirmed that the synthesized NLCs have regular and spherical shape. The abundance and concentration of the six released monoterpenes were determined, as a novel approach, using GC–MS with very good results and validity. In-vitro antifungal screening was done before and after nano co-delivery against seven pathogenic, and aggressive fungi of Candida tropicalis, Candida krusei, Candida glabrata, Geotrichum Candidum, Candidaalbicans, Aspergillus Niger, and mucor circinelloides. Inhibition Zone diameter (IZD) and the minimum inhibitory concentration (MIC) were measured. Nanoformulations NLC-Flu-MTs and NLC-MTs manifested potential and unique biological susceptibility against all the tested microorganisms with reduced (MIC) values, especially against Candida Tropicalis (MIC = 0.97 µg/ml) which represents 16-fold of the value shown by NLC-MTs (MIC = 15.6 µg/ml) and 64-fold of fluconazole free before nanoformulation (MIC = 62.5 µg/ml). The efficiency of nanomaterials, particularly NLC-Flu-MTs, has become evident in the diminishing value of MIC which affirmed the synergism between fluconazole and the other six monoterpenes. [ABSTRACT FROM AUTHOR]

Gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS) analyses were conducted on essential oil extracted from Saudi Arabian Artemisia judaica L. (A. judaica) aerial parts, resulting in the identification of 58 constituents, representing 93.0% of the total oil composition. The oil primarily consisted of monoterpenes (38.6%), sesquiterpenes (14.1%), and other compounds such as ethyl esters and cyclic ketones (40.3%). The main components identified were piperitone (16.5%), ethyl cinnamate (12.9%), and camphor (9.7%). Multivariate statistical analyses (MVAs), including principal component analysis (PCA) and agglomerative hierarchical clustering (AHC) analysis, were employed to compare the chemical makeup of this oil with 20 other A. judaica oils from various regions. The study revealed distinct clusters, highlighting unique chemotypes and geographic variations. Particularly, the oil from the current study demonstrated a specialized chemical profile with significant concentrations of specific compounds, contributing significantly to its distinctiveness. Further cytotoxicity testing on RAW264.7 macrophages suggested that concentrations below 20 μg/mL of A. judaica oil are suitable for future pharmacological investigations. This study provides valuable insights into the chemical diversity, geographic variations, and potential biomedical applications of these essential oils. [ABSTRACT FROM AUTHOR]

The present study provides a comprehensive analysis of the chemical composition of essential oils from species of the Myrcia genus and their applications. The compiled results highlight the chemical diversity and biological activities of these oils, emphasizing their potential importance for various therapeutic and industrial applications. The findings reveal that Myrcia essential oils present a variety of bioactive compounds, such as monoterpenes and sesquiterpenes, which demonstrate antimicrobial activities against a range of microorganisms, including Gram-positive and Gram-negative bacteria, as well as yeasts. Furthermore, this study highlights the phytotoxic activity of these oils, indicating their potential for weed control. The results also point to the insecticidal potential of Myrcia essential oils against a range of pests, showing their viability as an alternative to synthetic pesticides. Additionally, species of the genus Myrcia have demonstrated promising hypoglycemic effects, suggesting their potential in diabetes treatment. This comprehensive synthesis represents a significant advancement in understanding Myrcia essential oils, highlighting their chemical diversity and wide range of biological activities. However, the need for further research is emphasized to fully explore the therapeutic and industrial potential of these oils, including the identification of new compounds, understanding of their mechanisms of action, and evaluation of safety and efficacy in different contexts. [ABSTRACT FROM AUTHOR]

Species belonging to the genus Echinophora (Apiaceae) have been used by humanity since ancient times as flavoring agents, preservatives, and medicines for the treatment of a broad spectrum of conditions, including respiratory, digestive and kidney disorders, fungi infections, wounds, and gastric ulcers. Phytochemical studies on this botanical genus mainly investigate the essential oil composition and reveal the species as a rich source of volatile compounds, including monoterpenes and phenylpropanoids. Among the non-volatile secondary metabolites, flavonoids, coumarins, phenolic acids, phytosterols, and polyacetylenes have been identified. Pharmacological studies revealed Echinophora extracts and essential oils exhibit different biological properties, including antibacterial, antifungal, anticancer, insecticidal, anti-inflammatory, and hepatoprotective activities. However, compared to other genera, the biological activity and chemical diversity of this genus are not well studied. In future decades, it is highly likely that the small genus Echinophora will play an important role in drug discovery and drug development. [ABSTRACT FROM AUTHOR]

GC/MS analysis of Murraya koenigii (L.) Spreng. and Murraya paniculata (L.) Jacq. leaves revealed the identification of 73 components, with an evident greater contribution of monoterpenes hydrocarbons to their total volatiles. α-Pinene (37.5%) and β-caryophyllene (27.4%) were the most abundant compounds in M. koenigii leaves and β-phellandrene (40.7%) in M. paniculata leaves, using headspace. β-Phellandrene (33.7%) was the major constituent by M. koenigii leaves where germacrene D (23.8%), and δ-elemene (22.0%) were predominant in M. paniculata leaves, using steam distillation. M. koenigii leaves oil showed quite remarkable cholinesterase inhibitory activity, where oil of M. paniculata leaves showed strong inhibitory activity against AChE (IC50=13.2 ± 0.9 µg/mL) and BChE (IC50=5.1 ± 0.3 µg/mL). Germacrene D, α-zingiberene, and δ-elemene showed higher affinity to BChE than AChE as revealed from docking scores (S = −5.65 to −6.03 Kcal/mol) for BChE and (S = −5.56 to −6.25 Kcal/mol) for AChE. [ABSTRACT FROM AUTHOR]