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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]

In pharmaceutical discovery, the "magic methyl" effect describes a substantial improvement in the pharmacological properties of a drug candidate with the incorporation of methyl groups. Therefore, to expedite the synthesis of methylated drug analogs, late-stage, undirected methylations of C(sp3)-H bonds in complex molecules would be valuable. However, current methods for site-selective methylations are limited to activated C(sp3)-H bonds. Here we describe a site-selective, undirected methylation of unactivated C(sp3)-H bonds, enabled by photochemically activated peroxides and a nickel(II) complex whose turnover is enhanced by an ancillary ligand. The methodology displays compatibility with a wide range of functional groups and a high selectivity for tertiary C-H bonds, making it suitable for the late-stage methylation of complex organic compounds that contain multiple alkyl C-H bonds, such as terpene natural products, peptides, and active pharmaceutical ingredients. Overall, this method provides a synthetic tool to explore the "magic methyl" effect in drug discovery.

The production of e-cigarette aerosols through vaping processes is known to cause the formation of various free radicals and reactive oxygen species (ROS). Despite the well-known oxidative potential and cytotoxicity of fresh vaping emissions, the effects of chemical aging on exhaled vaping aerosols by indoor atmospheric oxidants are yet to be elucidated. Terpenes are commonly found in e-liquids as flavor additives. In the presence of indoor ozone (O3), e-cigarette aerosols that contain terpene flavorings can undergo chemical transformations, further producing ROS and reactive carbonyl species. Here, we simulated the aging process of the e-cigarette emissions in a 2 m3 FEP film chamber with 100 ppbv of O3 exposure for an hour. The aged vaping aerosols, along with fresh aerosols, were collected to detect the presence of ROS. The aged particles exhibited 2- to 11-fold greater oxidative potential, and further analysis showed that these particles formed a greater number of radicals in aqueous conditions. The aging process induced the formation of various alkyl hydroperoxides (ROOH), and through iodometric quantification, we saw that our aged vaping particles contained significantly greater amounts of these hydroperoxides than their fresh counterparts. Bronchial epithelial cells exposed to aged vaping aerosols exhibited an upregulation of the oxidative stress genes, HMOX-1 and GSTP1, indicating the potential for inhalation toxicity. This work highlights the indirect danger of vaping in environments with high ground-level O3, which can chemically transform e-cigarette aerosols into new particles that can induce greater oxidative damage than fresh e-cigarette aerosols. Given that the toxicological characteristics of e-cigarettes are mainly associated with the inhalation of fresh aerosols in current studies, our work may provide a perspective that characterizes vaping exposure under secondhand or thirdhand conditions as a significant health risk.

A simple aqueous host:guest sensing array can selectively discriminate between different types of citrus varietal from peel extract samples. It can also distinguish between identical citrus samples at varying stages of ripening. The discrimination effects stem from detection of changes in the terpenoid composition of the peel extracts by the host:guest array, despite the overwhelming excess of a single component, limonene, in each sample. The hosts are insensitive to limonene but bind other monoterpenes strongly, even though they are similar in structure to the major limonene component. This work demonstrates the capability of host:guest arrays in sensing target molecules in environments with the competing agents present at high abundances in the sample matrix.

Reduced defense against large herbivores has been suggested to be part of the island syndrome in plants. However, empirical evidence for this pattern is mixed. In this paper, we present two studies that compare putative physical and chemical defense traits from plants on the California Channel Islands and nearby mainland based on sampling of both field and common garden plants. In the first study, we focus on five pairs of woody shrubs from three island and three mainland locations and find evidence for increased leaf area, decreased marginal leaf spines, and decreased concentrations of cyanogenic glycosides in island plants. We observed similar increases in leaf area and decreases in defense traits when comparing island and mainland genotypes grown together in botanic gardens, suggesting that trait differences are not solely driven by abiotic differences between island and mainland sites. In the second study, we conducted a common garden experiment with a perennial herb-Stachys bullata (Lamiaceae)-collected from two island and four mainland locations. Compared to their mainland relatives, island genotypes show highly reduced glandular trichomes and a nearly 100-fold reduction in mono- and sesquiterpene compounds from leaf surfaces. Island genotypes also had significantly higher specific leaf area, somewhat lower rates of gas exchange, and greater aboveground biomass than mainland genotypes across two years of study, potentially reflecting a broader shift in growth habit. Together, our results provide evidence for reduced expression of putative defense traits in island plants, though these results may reflect adaptation to both biotic (i.e., the historical absence of large herbivores) and climatic conditions on islands.

Marine-derived Streptomyces have long been recognized as a source of novel, pharmaceutically relevant natural products. Among these bacteria, the MAR4 clade within the genus Streptomyces has been identified as metabolically rich, yielding over 93 different compounds to date. MAR4 strains are particularly noteworthy for the production of halogenated hybrid isoprenoid natural products, a relatively rare class of bacterial metabolites that possess a wide range of biological activities. MAR4 genomes are enriched in vanadium haloperoxidase and prenyltransferase genes, thus accounting for the production of these compounds. Functional characterization of the enzymes encoded in MAR4 genomes has advanced our understanding of halogenated, hybrid isoprenoid biosynthesis. Despite the exceptional biosynthetic capabilities of MAR4 bacteria, the large body of research they have stimulated has yet to be compiled. Here we review 35 years of natural product research on MAR4 strains and update the molecular diversity of this unique group of bacteria.

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.

Terpenes are diverse specialized metabolites naturally found within plants and have important roles in inter-species communication, adaptation and interaction with the environment. Their industrial applications span a broad range, including fragrances, flavors, cosmetics, natural colorants to agrochemicals and therapeutics, yet formal chemical synthesis is economically challenging due to structural complexities. Engineering terpene biosynthesis could represent an alternative in microbial biotechnological workhorses, such as Saccharomyces cerevisiae or Escherichi coli, utilizing sugars or complex media as feedstocks. Host species that metabolize renewable and affordable carbon sources may offer unique sustainable biotechnological alternatives. Methylotrophs are bacteria with the capacity to utilize one-carbon feedstocks, such as methanol or formate. They colonize the phyllosphere (above-ground area) of plants, and many accumulate abundant carotenoid pigments. Methylotrophs have the capacity to take up and use a subset of the rare earth elements known as lanthanides. These metals can enhance one-carbon (methylotrophic) metabolism. Here, we investigated whether manipulating the metabolism enables and enhances terpene production. A carotenoid-deficient mutant potentially liberates carbon, which may contribute to bioproduct accumulation. To test this hypothesis, terpene-producing bacterial strains regulated by two distinct promoters were generated. Wildtype Methylobacterium extorquens, ∆Meta1_3665, a methylotrophic mutant lacking the carotenoid pathway, and an E. coli strain were transformed with an exogenous terpene pathway and grown both in the presence and absence of lanthanides. The extraction, and the comparison of analytical profiles, provided evidence that engineered cultured M. extorquens under control of a native, inducible methylotrophic promoter can yield the sesquiterpene patchoulol when supplemented with lanthanide. In contrast, using a moderate-strength constitutive promoter failed to give production. We demonstrated colonization of the phyllosphere with the engineered strains, supporting the future engineering of selected species of the plant microbiome and with promising implications for the synthetic biology of small molecules.

The resident human skin microbiome is responsible for the production of most of the human scents that are attractive to mosquitoes. Hence, engineering the human skin microbiome to synthesize less of mosquito attractants or produce repellents could potentially reduce bites and prevent the transmission of deadly mosquito-borne pathogens. In order to further characterize the human skin volatilome, we quantified the major volatiles of 39 strains of skin commensals (Staphylococci and Corynebacterium). Importantly, to validate the behavioral activity of these volatiles, we first assessed landing behavior triggered by human skin volatiles. We demonstrated that landing behavior is gated by the presence of carbon dioxide and L-(+)-lactic acid. This is similar to the combinatorial coding triggering mosquito short range attraction. Repellency behavior to selected skin volatiles and terpenes was tested in the presence of carbon dioxide and L-(+)-lactic acid. In a 2-choice landing behavior context, the skin volatiles 2- and 3-methyl butyric acids reduced mosquito landing by 62.0-81.6% and 87.1-99.6%, respectively. Similarly, the terpene geraniol was capable of reducing mosquito landing behavior by 74.9%. We also tested the potential repellency effects of terpenes in mosquitoes at short-range using a 4-port olfactometer. In these assays, geraniol reduced mosquito attraction (69-78%) to a mixture of key human kairomones carbon dioxide, L-(+)-lactic acid, and ammonia. These findings demonstrate that carbon dioxide and L-(+)-lactic acid change the valence of other skin volatiles towards mosquito landing behavior. Moreover, this study offers candidate odorants to be targeted in a novel strategy to reduce attractants or produce repellents by the human skin microbiota that may curtail mosquito bites, and subsequent mosquito-borne disease.

Chlororaphens A and B are structurally unique non‐canonical C17 sesquiterpenoids from Pseudomonas chlororaphis that are made by two SAM‐dependent methyltransferases and a type I terpene synthase. This study addresses the mechanism of their formation in isotopic labelling experiments and DFT calculations. The results demonstrate an astonishing complexity with distribution of labellings within a cyclopentane core that is reversely connected to two acyclic fragments in chlororaphen A and B. In addition, the uptake of up to 14 deuterium atoms from D2O was observed. These findings are explainable by a repeated late stage multistep rearrangement sequence. The absolute configurations of the chlororaphens and their biosynthetic intermediates were elucidated in stereoselective labelling experiments. [ABSTRACT FROM AUTHOR]

Background: Solid tumors often develop hypoxic regions, leading to aggressive behavior and increased drug resistance. Methods: The chemical composition of Cymbopogon citratus essential oil (EO) was analyzed using GC-MS. Alginate nanoparticles containing the EO and its primary component, citral, were synthesized via the ionic gelation method. Encapsulation was confirmed using ATR-FTIR analysis. The anticancer efficacy of C. citratus EO, citral, and their respective alginate nanoparticles was evaluated under normoxic (21% oxygen) and hypoxic (1% oxygen) conditions on breast cancer (MDA-MB-231) and melanoma (A-375) cell lines. Additionally, qPCR and flow cytometry were used to assess apoptosis gene expression ratios (Bax/Bcl-2) and levels of apoptosis. Results: Citral (80.98%) was identified as the major component of the EO. Alginate nanoparticles containing C. citratus EO and citral (C. citratus-AlgNPs and citral-AlgNPs) were synthesized with particle sizes of 195 ± 4 nm and 222 ± 9 nm, and zeta potentials of -22 ± 3 mV and − 17 ± 1 mV, respectively. Both samples demonstrated significantly greater efficacy under hypoxic conditions. Citral and C. citratus-AlgNPs had IC50 values of 27 (19–39) µg/mL and 25 (4-147) µg/mL, respectively, against MDA-MB-231 and A-375 cells. Flow cytometry showed increased apoptosis under hypoxic conditions, with the highest rates observed for citral-AlgNPs and C. citratus-AlgNPs (84 ± 5 and 92 ± 5% in MDA-MB-231 and A-375 cells, respectively). Conclusion: This study demonstrates that alginate nanoparticles enhance the anticancer activity of C. citratus-AlgNPs and citral, particularly under hypoxic conditions, highlighting their potential for hypoxia-targeted cancer therapies. [ABSTRACT FROM AUTHOR]

Summary: Stomatal closure during drought inhibits carbon uptake and may reduce a tree's defensive capacity. Limited carbon availability during drought may increase a tree's mortality risk, particularly if drought constrains trees' capacity to rapidly produce defenses during biotic attack.We parameterized a new model of conifer defense using physiological data on carbon reserves and chemical defenses before and after a simulated bark beetle attack in mature Pinus edulis under experimental drought. Attack was simulated using inoculations with a consistent bluestain fungus (Ophiostoma sp.) of Ips confusus, the main bark beetle colonizing this tree, to induce a defensive response.Trees with more carbon reserves produced more defenses but measured phloem carbon reserves only accounted for c. 23% of the induced defensive response. Our model predicted universal mortality if local reserves alone supported defense production, suggesting substantial remobilization and transport of stored resin or carbon reserves to the inoculation site.Our results show that de novo terpene synthesis represents only a fraction of the total measured phloem terpenes in P. edulis following fungal inoculation. Without direct attribution of phloem terpene concentrations to available carbon, many studies may be overestimating the scale and importance of de novo terpene synthesis in a tree's induced defense response. [ABSTRACT FROM AUTHOR]

Background: Achieving cost-competitiveness remains challenging for industrial biomanufacturing. With whole-cell biocatalysis, inefficiency presents when individual cells vary in their production levels. The problem exacerbates when the basis for such production heterogeneity is heritable. Here, evolution selects for the low- and non-producers, as they have lowered/abolished the cost of bioproduction to fitness. With the scale of population expansion required for industrial bioproduction, the asymmetrical enrichment can be severe enough to compromise the performance, and hence commercial viability of the bioprocess. Clearly, addressing production heterogeneity is crucial, especially in improving the stability of bioproduction across the cell generations. In this respect, we designed a growth-coupling strategy for terpenoid bioproduction in Escherichia coli. By knocking out the native 1-deoxy-D-xylulose 5-phosphate reductoisomerase (dxr) gene and introducing the heterologous mevalonate pathway, we created a chassis that relies solely on the latter for synthesis of all terpenoids. We hypothesise that the need to sustain the biosynthesis of endogenous life-sustaining terpenoids will impose a minimum level of productivity, which concomitantly improves the bioproduction of our target terpenoid. Results: Following the confirmation of lethality of a dxr knockout, we challenged the strains with a continuous plasmid-based bioproduction of linalool. The Δdxr strain achieved an improved productivity profile in the first three days post-inoculation when compared to the parental strain. Productivity of the Δdxr strain remained observable near the end of 12 days, and after a disruption in nutrient and oxygen supply in a separate run. Unlike the parental strain, the Δdxr strain did not evolve the same deleterious mutations in the mevalonate pathway, nor a viable subgroup that had lost its resistance to the antibiotic selection pressure (a plausible plasmid loss event). We believe that this divergence in the evolution trajectories is indicative of a successful growth-coupling. Conclusion: We have demonstrated a proof of concept of a growth-coupling strategy that improves the performance, and stability of terpenoid bioproduction across cell generations. The strategy is relatively broad in scope, and easy to implement in the background as a 'fail-safe' against a fall in productivity below the imposed minimum. We thus believe this work will find widespread utility in our collective effort towards industrial bioproduction. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

α-Pinene (PEN) is a phyto compound present in terpene plants. In traditional medicine, PEN has been used for its anti-inflammatory, pain-relieving, and bronchodilator properties. The effect of PEN in combination with temozolomide (TMZ) in glioblastoma multiforme (GBM) cells has been evaluated. The action of the PEN + TMZ combination on cell migration, soft-agar, and cell death was determined in LN229 and U87MG human glioblastoma cells. In combination, PEN with TMZ showed a synergistic inhibitory effect in the GBM cells. The PEN + TMZ treatment showed a higher fluorescent intensity and reduced the percentage of wound area closure compared to the compound alone. The compounds in combination also resulted in a reduction in single-cell colony formation. To conclude, the study showed that plant-derived PEN enhanced the effectiveness of standard chemotherapeutic, TMZ, in LN229 and U87MG cells. [ABSTRACT FROM AUTHOR]

Aim: Environmental exposure constitutes a significant determinant in the pathogenesis of metabolic syndrome (MetS). Nevertheless, the contribution of environmental factors to MetS remains ambiguous. The present study was aimed at investigating the correlation between serum terpenes and the risk of MetS in the general population. Methods: A cross‐sectional study was conducted among 1266 individuals from the 2013–2014 National Health and Nutrition Examination Survey (NHANES). Serum terpenes and MetS risk were analyzed using a weighted logistic regression model. Weighted quantile sum (WQS) regression was utilized to explore the relationship between the mixture of serum terpenes and MetS. The restricted cubic spline (RCS) method was employed to assess the dose–response relationship between them. All data and analyses were conducted using the "Survey" package in R software (Version 4.3.2). Results: The study population, with an average age of 46.82 ± 0.46 years and a body mass index (BMI) of 28.97 kg/m2, consisted of 48.15% males and 67.99% Whites. Among the participants, 35.78% were diagnosed with MetS. The weighted logistic regression showed that tertiles of serum levels of α‐pinene, β‐pinene, and limonene were positively correlated with MetS risk with a OR value of 1.90 (1.14, 3.16), 2.02 (1.23, 3.31), and 2.35 (1.33, 4.13) and elevated triglycerides (TGs) with a OR of 2.36 (1.63, 3.43), 3.51 (2.30, 5.38), and 3.96 (2.55, 6.15) (all ptrend < 0.05). The WQS regression indicated a positive association between serum terpene mixture and MetS risk (OR = 1.65, 95% CI: 1.18–2.3), increased TG (OR = 2.69, 95% CI: 1.94–3.71), and reduced high‐density lipoprotein cholesterol (HDL‐C) (OR = 1.46, 95% CI: 1.03–2.07) (all ptrend < 0.01). The RCS analysis further supported the dose–response relationship. Conclusion: This study suggested potential adverse effects of terpene exposure on human health, emphasizing the importance of environmental interventions in maintaining health. [ABSTRACT FROM AUTHOR]

Coniferous trees produce secondary or defense chemicals, such as terpenes, against pest insects. Terpenes could serve as constitutive or induced defensive mechanisms, defending the tree from invasive herbivores. The Mediterranean pine shoot beetle Tomicus destruens colonizes stems and branches of Pinus brutia trees and even can kill mature trees during periodic outbreaks. We investigated whether terpene profiles of needle and stem of P. brutia trees differ between health and those infested by T. destruens. We selected 20 healthy and T. destruens-infested trees and analyzed the monoterpenes and sesquiterpenes of their needles and phloem. We found higher concentrations of tricyclene, camphene and p-cymene in the phloem of infested trees. Similarly, the needles of infested trees had higher concentrations of α-pinene, β-pinene, myrcene, limonene, trans-β-caryophyllene and α-humulene than healthy trees. These results show that the monoterpene and sesquiterpene profiles of P. brutia trees differed between healthy and infested trees, suggesting that volatile terpenes may be an important part of plant-induced responses against T. destruens. [ABSTRACT FROM AUTHOR]

The root of Paeonia lactiflora pall. is a significant component of traditional Chinese medicine, with terpenoids and their glycosides, such as paeoniflorins, serving as key active ingredients known for their anti-inflammatory, hepatoprotective, and analgesic properties. By generating a transcriptome and functionally characterizing 32 terpene synthases (TPSs) from P. lactiflora, we successfully constructed 24 pESC-Trp-PlTPS expression vectors. Through expression in Saccharomyces cerevisiae engineered strains, we identified four mono-TPSs and five sesqui-TPSs that produce 18 compounds, including eight monoterpenes and ten sesquiterpenes in vitro. This includes a bifunctional enzyme (PlTPS22). Additionally, PlTPS21 was characterized as a pinene synthase with α-pinene as its main product. The expression pattern of PlTPS21 aligns closely with the accumulation patterns of paeoniflorins and α-pinene in the plant, suggesting that PlTPS21 is a key enzyme in the biosynthesis of paeoniflorin. [ABSTRACT FROM AUTHOR]

The unimolecular reactions of protonated myrcene and linalool were investigated by collision‐induced dissociation and density functional theory calculations. Experiments on a triple quadrupole mass spectrometer showed that protonated myrcene undergoes two major unimolecular reactions losing propene and isobutene, and two minor reactions of ethene and propane loss. In each case, the product ion consists of a substituted five‐member ring. Protonation of myrcene was found to form four distinct protomers, three of which can be significantly populated in the ion source. The observed fragmentation reactions were calculated and found to depend on the starting protomer. Each pathway consisted of several hydrogen‐migration and ring‐forming/opening steps on the way to the observed products. Likewise, protonation of linalool also produces three distinct protomers, with the global minimum being formed by protonation of a central double bond. The major reaction is water loss to form protonated myrcene, but two minor channels were also observed resulting in loss of acetone and isobutene. The calculated minimum energy reaction pathways were found to be consistent with the relative abundances of the ions in the experimental breakdown diagrams. [ABSTRACT FROM AUTHOR]

This study employs a high‐dimensional consensus mass spectral (HDCMS) similarity scoring technique to discriminate isomers collected using an electron ionization mass spectrometer. The HDCMS method was previously introduced and applied to the discrimination of mass spectra of constitutional isomers, methamphetamine and phentermine, collected with direct analysis real‐time mass spectrometry (DART‐MS). The method formulates the problem of discriminating mass spectra in a mathematical Hilbert space and is hence called "high dimensional." It requires replicate mass spectra to build a Gaussian model and evaluate the inner products between these functions. The resulting measurement variability is used as a signature by which to discriminate spectra. In this work, HDCMS is tested on electron impact ionization (EI) mass spectra of 7 terpene and terpene‐related (C10H16 and C10H14) isomers with experimental retention indices that differ by less than 30 and with traditional cosine similarity scores greater than 0.9, on a scale of 0 to 1, when compared with at least one other compound in the test set. Using identical instrument parameters, 15 replicate gas chromatography–electron ionization–mass spectrometry (GC‐EI‐MS) spectra of each isomer were collected and separated into distinct library and query sets. The HDCMS algorithm discriminated each isomer, indicating the method's potential. Because the method requires replicate measurements, observations from a simple heuristic study of the number of replicates required to discriminate these isomers is presented. The paper concludes with a discussion of compound discrimination using HDCMS and the benefits and drawbacks of applying the method to EI‐MS data. [ABSTRACT FROM AUTHOR]

The essential oils were isolated from Thymus serpyllum L. leaves, stem, flowers and whole plant using hydrodistillation technique and % yield was determined. The chemical constituents were studied using Gas Chromatography-Mass Spectrometry and Gas Chromatography-Flame Ionisation Detection. The analysis revealed the presence of 38 compounds in the essential oils obtained from different plant parts. Identification of compounds was achieved by detailed analysis of mass spectrum and retention indices. The major constituents of essential oil from the whole plant were thymol (35.25%), p-cymene (27.57%), thymol acetate (8.03%) and γ-terpinene (6.92%). In leaves they were thymol (45.59%), p-cymene (24.26%), thymol acetate (6.41%), and β-bisabolene (5.91%); whereas in flowers these were thymol (68.74%) and thymol acetate (7.40%) and in the stem, these were thymol (55.15%) and thymol acetate (8.01%). Specifically, it is the first report wherein essential oil constituents of T. serpyllum L. whole plant, leaves, flowers, and stems have been analyzed separately. Further, fundamental analysis of complex mass fragmentation patterns of terpenes and terpenoids using EI-MS has been achieved and the logical reason for the fragmentation pattern has been elaborated. Detailed elaboration of the mass fragmentation pattern may strengthen the EI-MS-based compound identification of terpenes and terpenoids from essential oils. [ABSTRACT FROM AUTHOR]

Objective: About 3% of patients with lupus develop severe diffuse alveolar hemorrhage (DAH) with pulmonary vasculitis. C57BL/6 (B6) mice with pristane‐induced lupus also develop DAH, but BALB/c mice are resistant. DAH is independent of Toll‐like receptor signaling and other inflammatory pathways. This study examined the role of the MEK1/2 pathway (MEK1/2–ERK1/2, JNK, p38). Methods: B6 and BALB/c mice were treated with pristane with or without inhibitors of MEK1/2 (trametinib/GSK1120212 [GSK]), ERK1/2 (SCH772984 [SCH]), JNK, or p38. Effects on lung hemorrhage and hemostasis were determined. Results: GSK and SCH abolished DAH, whereas JNK and p38 inhibitors were ineffective. Apoptotic cells were present in lung samples from pristane‐treated mice but not in mice receiving pristane and GSK, and endothelial dysfunction was normalized. Expression of the ERK1/2‐regulated transcription factor early growth response 1 increased in pristane‐treated B6, but not BALB/c, mice and was normalized by GSK. Pristane also increased expression of the anticoagulant genes Tfpi and Thbd in B6 mice. The ratio of Tfpi to tissue factor (F3) to Tfpi increased in B6 (but not BALB/c) mice and was normalized by GSK. Circulating thrombomodulin protein levels increased in B6 mice and returned to normal after GSK treatment. Consistent with augmented endothelial anticoagulant activity, pristane treatment increased tail bleeding in B6 mice. Conclusion: Pristane treatment promotes lung endothelial injury and DAH in B6 mice by activating the MEK1/2–ERK1/2 pathway and impairing hemostasis. The hereditary factors determining susceptibility to lung injury and bleeding in pristane‐induced lupus are relevant to the pathophysiology of life‐threatening DAH in systemic lupus erythematosus and may help to optimize therapy. [ABSTRACT FROM AUTHOR]

The study explored the chemical composition, antioxidant activity, and potential antihyperlipidemic effects of Allspice (Pimenta dioica) leaf essential oil. The oil yield from hydro-distillation was 1.61 ± 0.35% (v/w), with major compounds identified by GC-MS analysis as eugenol (72.06 ± 3.93%), β-pinene (9.29 ± 3.33%), chavicol (6.95 ± 0.6%), limonene (3.05 ± 0.71%), and 3-octenol (1.55 ± 1.07%). The oil's antioxidant activity (426 ± 3.5 mg TE g−1) was attributed to polyphenols. It also reduced porcine pancreatic lipase activity, suggesting potential in managing dietary lipids. Molecular docking showed strong binding to CES1, with eugenol, limonene, β-pinene, and octenol outperforming the control (probucol). ADME-Tox predictions indicated favorable pharmacological profiles with controlled lipophilicity and toxicity. [ABSTRACT FROM AUTHOR]

A collection of ring distorted analogue of Nootkatone including 6 CTD (Complex to Diversity) compounds and 9 SAR (Structure Activity Relationship) compounds were synthesized utilizing the carbonyl group as a starting reaction point. [ABSTRACT FROM AUTHOR]

This study assessed the adoption level of essential oil extraction practices among lemon growers in the Pothwar region of Punjab, Pakistan. A well-structured questionnaire was used to collect data from 138 smallholders using the interview method by trained remunerators. Descriptive statistics and econometrics; logit and Poisson regression were employed for data analysis. Results of farmers' perceptions of adopting new practices indicated that 10.1% of the farmers are not adopting any one, 22.5% are adopting any three, and 26.8% are adopting all four practices. Moreover, farmers' age, farming experience, land holding, skill, training participation, and receptivity proved to be statistically significant determinants in improving the likelihood of adopting all four practices under the logit and Poisson models, respectively. Hence, it is recommended that the provision of an effective package in the form of literature concerning essential oil extraction practices to the doorsteps of smallholders during demonstration sessions, along with adequate professional training, could help in improving farmers' perceptions toward adoption and strengthening the essential oil sector. [ABSTRACT FROM AUTHOR]

Volatile components in red orange essential oil extracted by two cold pressing processes (cup pressing and lime method) were analyzed by gas chromatography quadrupole time-of-flight mass spectrometry (GC-Q/TOF). A total of 93 components were identified, 89 and 84 compounds were identified for the two types of red orange essential oils, respectively. Among the 93 components, there were 29 terpenes, 20 alcohols, 20 aldehydes, 5 esters, 2 ketones, 12 hydrocarbons, and 5 other compounds. There were 80 compounds shared by the two essential oils. The total volatile component content of red orange essential oil by cup pressing method was significantly higher than that by lime method. The highest content of these compounds was terpenes which total content was over 80%. In addition, the compounds with higher content were D-limonene, γ-terpinene, β-myrcene, linalool and α-pinene. According to principal component analysis (PCA), there was a significant difference in the volatile components of the two types of red orange essential oils. The relative odor activity value (ROAV) method indicated that linalool was the most important aroma component of the two red orange essential oils. And the citrus aroma properties of red orange essential oil extracted by cup pressing method was significantly stronger than that extracted by lime method. Linalool, thymol, β-myrcene, D-limonene, citronellal, and γ- terpinene were confirmed to the key aroma components of the red orange essential oils. [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Geoscience is the property of Natural Gas Geoscience and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Carrot is a highly significant vegetable cultivated worldwide and possesses a unique aroma with abundant edible and medicinal values. However, it remains largely unknown whether jasmonic acid could regulate aroma formation in carrot. Here, an integrated analysis of the volatile metabolome and transcriptome of carrot roots exposed to different concentrations of methyl jasmonate (MeJA) was performed. The results revealed 1,227 volatile organic compounds and 972 differential accumulated metabolites, with terpenes representing the largest portion. MeJA treatment evidently increased the relative odor activity values as well as the accumulation of most volatile compounds. In addition, 4,787 differentially expressed genes were identified and subjected to function enrichment analysis, indicating a role of terpene biosynthesis and metabolism in response to MeJA application. A network consisting of 4,680 transcription factor-structural pairs that showed highly significant positive correlations was constructed, which may be utilized as genetic targets for examining terpene accumulation and aroma formation elicited by methyl jasmonate. The results from the present work substantially improved our understanding of MeJA-mediated aroma formation in carrot. [ABSTRACT FROM AUTHOR]

Phytol is a diterpene constituent of many essential oils, belonging to the group of unsaturated acyclic alcohols. Although phytol possesses antimycobacterial and anti-inflammatory effects, no reports of a gastrointestinal action are available from the literature. Due to the well-known shortcomings of classical anti-ulcer drugs (e.g. side effects or relapses), natural products may offer an attractive alternative. In this study, a potential gastroprotective activity of phytol was evaluated using acute and chronic ulcer models in rats. Phytol 12.5, 25 and 50 mg/kg, administered orally 1 h prior to induction of gastric lesions by absolute ethanol, inhibited the lesion area by 96, 90 and 95%, respectively. When lesions were induced by ischemia and reperfusion, phytol 12.5 and 25 mg/kg per os decreased the lesion areas by 89 and 46%, respectively. In the third acute ulcer model (lesions induced by ibuprofen), phytol 12.5 mg/kg reduced the lesion area by 55%. Phytol restored the decreased level of reduced glutathione, the increased levels of myeloperoxidase and malondialdehyde and the decreased levels of catalase and superoxide dismutase in rats with gastric ulcer induced by ethanol to levels obtained in vehicle group. Finally, in a chronic model in which gastric ulcer was induced by acetic acid directly instilled into the stomach, phytol administered orally over a time period of 7 days at 12.5, 25, 50 and 100 mg/kg reduced lesion areas by 84, 81, 83 and 68%. Our data suggest a gastroprotective and cicatrizing effect of phytol, possibly associated with its antioxidant effect. [ABSTRACT FROM AUTHOR]

Mycobacterium tuberculosis (Mtb) releases the unusual terpene nucleoside 1-tuberculosinyladenosine (1-TbAd) to block lysosomal function and promote survival in human macrophages. Using conventional approaches, we found that genes Rv3377c and Rv3378c, but not Rv3376, were necessary for 1-TbAd biosynthesis. Here, we introduce linear models for mass spectrometry (limms) software as a next-generation lipidomics tool to study the essential functions of lipid biosynthetic enzymes on a whole-cell basis. Using limms, whole-cell lipid profiles deepened the phenotypic landscape of comparative mass spectrometry experiments and identified a large family of approximately 100 terpene nucleoside metabolites downstream of Rv3378c. We validated the identity of previously unknown adenine-, adenosine-, and lipid-modified tuberculosinol-containing molecules using synthetic chemistry and collisional mass spectrometry, including comprehensive profiling of bacterial lipids that fragment to adenine. We tracked terpene nucleoside genotypes and lipid phenotypes among Mycobacterium tuberculosis complex (MTC) species that did or did not evolve to productively infect either human or nonhuman mammals. Although 1-TbAd biosynthesis genes were thought to be restricted to the MTC, we identified the locus in unexpected species outside the MTC. Sequence analysis of the locus showed nucleotide usage characteristic of plasmids from plant-associated bacteria, clarifying the origin and timing of horizontal gene transfer to a pre-MTC progenitor. The data demonstrated correlation between high level terpene nucleoside biosynthesis and mycobacterial competence for human infection, and 2 mechanisms of 1-TbAd biosynthesis loss. Overall, the selective gain and evolutionary retention of tuberculosinyl metabolites in modern species that cause human TB suggest a role in human TB disease, and the newly discovered molecules represent candidate disease-specific biomarkers. Mycobacterium tuberculosis releases 1-tuberculosinyladenosine to block lysosomal function and promote survival in human macrophages. This study identifies over 100 such terpene nucleoside metabolites, revealing how ancestral M. tuberculosis complex bacteria acquired the genes needed to make these unique bioactive lipids. [ABSTRACT FROM AUTHOR]

Background: Platycodon grandiflorum (P. grandiflorum) is a commonly used medicinal plant in China. Transcriptome sequencing studies of different tissues of P. grandiflorum have been widely conducted. However, studies on transcriptome sequencing and expression patterns of key genes in the saponin synthesis pathway of Tongcheng P. grandiflorum, a high-quality medicinal resource of different years, are relatively limited. Results: This study involved transcriptome sequencing and bioinformatics analysis of the roots from annual, biennial, and triennial P. grandiflorum in the Tongcheng area. After data filtering and assembly, we obtained 111.44 Gb of clean base data, including 742,880616 clean reads. We identified 5,156 differential expression unigenes between at least two sample groups, with differences noted among annual, biennial, and triennial P. grandiflorum plants. GO enrichment analysis annotated 3509, 1819, and 1393 DEGs in comparison TC1vsTC2, TC1vsTC3, and TC2vsTC3, respectively. Furthermore, KEGG enrichment analysis identified 16 genes encoding key enzymes in the terpene skeleton biosynthesis, sesquiterpene and triterpene biosynthesis pathways, including SE, AACT, FPPS, DXR, HMGR, HMGS, and DXS. The results of qRT-PCR experiments showed that most of the genes were most highly expressed in annual P. grandiflorum. Conclusions: The present study provided transcriptomic data from the roots of Tongcheng P. grandiflorum of different years, which provides critical bioinformatics data on the growth and development of P. grandiflorum, laying a foundation for further research on saponins and identifying key enzymes involved in this process across different growth stages. [ABSTRACT FROM AUTHOR]

Terpenes represent a highly diverse group of natural products with wide applications. Terpenoid structures can be derived from different renewable sources and utilized as fuels. Application as fuels requires hydrogenation of the double bonds in the respective molecules to ensure clean combustion. This hydrogenation can be performed either directly with elemental hydrogen or indirectly via transfer hydrogenation with a Liquid Organic Hydrogen Carrier. In this study, the thermochemical fundamentals of these reaction has been evaluated. For this task, for a first time a combination of experimental thermochemistry and quantum-chemical molecular modelling has been applied. The results show the hydrogenation of the respective structures is thermodynamically highly favourable. Correspondingly, dehydrogenation would be comparatively unfavorable. Yet, for a fuel no dehydrogenation is required. As an alternative to conventional hydrogenation, transfer hydrogenation, which is often subject to partial conversions due to limitations by the reaction equilibrium, can be realized with a high degree of conversion. While the entropy of reaction for hydrogen transfer from cyclohexyl-structures to terpene structures is close to zero, the enthalpy of reaction is highly negative. This leads to a Gibbs energy of reaction which is clearly negative and ensures a large thermodynamic driving force for the reaction. As a consequence, downstream processing, which is usually very demanding for transfer hydrogenations, is comparatively easy. These finding underline the great potential of these bio-derived substances for conversion into sustainable fuels. • Hydrogenated terpenes considered as a promising biosynthetic fuels. • Feasibility of direct hydrogenation and transferhydrogenation reactions evaluated. • Experimental thermochemistry was combined with quantum chemistry. • Gibbs energies are negative and ensure large driving forces for reactions. [ABSTRACT FROM AUTHOR]

Inspired by nature's redox management in bioinorganic systems, we developed various Zn-complexes to catalyze a radical-mediated borrowing hydrogen process for producing β-disubstituted ketones. A diverse range of secondary alcohols, including fatty alcohols, terpenoids and steroid analogs, were successfully utilized for the chemoselective functionalization of ketones. Several organometallic and control studies suggest that coordinatively unsaturated radical species operate as active catalysts to promote alcohol activation and initiate the HAT process. [ABSTRACT FROM AUTHOR]

Copyright of Food & Fermentation Industries is the property of Food & Fermentation Industries and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Naturally occurring and structurally diverse alkene-containing substrates, terpenes, provided a platform for establishing chemo-, regio-, and diastereoselective reactivity in tantalum catalysed hydroaminoalkylation. Naturally derived 1,3-butadienes revealed the unique regio- and diastereoselective (Z)-1,4-addition products accessible from isoprene and β-myrcene by hydroaminoalkylation. Selective terpene functionalisation, within an industrially produced turpentine mixture, demonstrates functionalisation specificity of β-pinene and limonene. Lastly, sesquiterpene functionalisation using β-caryophyllene and humulene provide rare examples of trisubstituted alkene reactivity in hydroaminoalkylation, by leveraging strainrelease and stereoelectronic effects to control chemoselectivity. As a result of these reactivity studies using natural substrates, new tools for understanding alkene electronic, strain, and stereoelectronic effects on chemo- and diastereoselectivity outcomes have revealed new mechanistic insights into hydroaminoalkylation. [ABSTRACT FROM AUTHOR]

Volatile organic compounds (VOCs) and essential oils of conifers are widely used in the pharmaceutical industry. This work aimed to analyze the VOCs of 30 conifer species representing the Pinaceae and Cupressaceae families. Samples were collected from arboreta in Hungary, and their chemical composition was determined by gas chromatography (SPME-GC/MS); then, chemometric analyses were performed using multivariate methods to identify characteristic VOCs of conifers. Here, we present results for monoterpene and sesquiterpene profiles of the examined conifer samples. The most abundant compounds detected were α-pinene, bornyl acetate, limonene, β-pinene, β-caryophyllene, β-myrcene, δ-3-carene, and β-phellandrene. The results showed that the following volatiles were characteristic of the conifer groups: sabinene (RRT=6.0) for the cupressoid group (which includes the Cupressaceae species), longifolene (RRT=15.0) and β-pinene (RRT=6.1) were characteristic of the pinoid group (including Picea, Pinus, and Pseudotsuga species), and camphene (RRT=5.5) and bornyl acetate (RRT=12.6) were characteristic of the abietoid group (including Abies, Cedrus, and Tsuga species). Our results on VOCs in the Pinaceae and Cupressaceae families contribute to the elucidation of biodiversity patterns of conifer species and, in addition, may support the industrial application of terpenes. [ABSTRACT FROM AUTHOR]

Douchi is a highly appreciated product due to its unique flavor, high nutritional value, and health benefits. Douchi from different regions exhibits distinct characteristics. The objective of this study was to investigate the volatile profiles in douchi produced from different geographical origins using gas chromatography-mass spectrometry (GC-MS) and chemometrics. The volatiles were extracted by headspace solid-phase micro-extraction (HS-SPME) and subsequently determined by GC-MS. A comparative analysis was further conducted to identify the variations in volatile compounds among the samples. The correlation between the samples was investigated by employing cluster analysis (CA) and principal component analysis (PCA). An orthogonal partial least squares-discriminant analysis (OPLS-DA) model was established to discriminate samples from different regions and identify key differential compounds. A total of 46 volatile compounds were detected, among which terpenes, alcohols were the main compounds. Furthermore, 14 key differentiating compounds were screened out based on the OPLS-DA modle. The application of GC-MS combined with chemometrics offers a theoretical framework for douchi quality control and classification. [ABSTRACT FROM AUTHOR]

Dryopteris fragrans (L.) Schott has anti-inflammatory and antioxidant properties, and terpenoids are important components of its active constituents. The methyl-D-erythritol 4-phosphate (MEP) pathway is one of the major pathways for the synthesis of terpene precursors in plants, and 1-deoxy-D-xylulose-5-phosphate synthase (DXS) is the first rate-limiting enzyme in this pathway. DXS has been shown to be associated with increased stress tolerance in plants. In this experiment, two DXS genes were extracted from the D. fragrans transcriptome and named DfDXS1 and DfDXS2. Based on phylogenetic tree and conserved motif analyses, DXS was shown to be highly conserved evolutionarily and its localization to chloroplasts was determined by subcellular localization. Prokaryotic expression results showed that the number and growth status of recombinant colonies were better than the control under 400 mM NaCl salt stress and 800 mM mannitol-simulated drought stress. In addition, the DfDXS1 and DfDXS2 transgenic tobacco plants showed improved resistance to drought and salt stress. DfDXS1 and DfDXS2 responded strongly to methyl jasmonate (MeJA) and PEG-mimicked drought stress following exogenous hormone and abiotic stress treatments of D. fragrans. The transcriptional active sites were investigated by dual luciferase and GUS staining assays, and the results showed that the STRE element (AGGGG), the ABRE element (ACGTGGC), and the MYC element (CATTTG) were the important transcriptional active sites in the promoters of the two DXS genes, which were closely associated with hormone response and abiotic stress. These results suggest that the DfDXS gene of D. fragrans plays an important role in hormone signaling and response to stress. This study provides a reference for analyzing the molecular mechanisms of stress tolerance in D. fragrans. [ABSTRACT FROM AUTHOR]

SUMMARY The Lamiaceae (mint family) is the largest known source of furanoclerodanes, a subset of clerodane diterpenoids with broad bioactivities including insect antifeedant properties. The Ajugoideae subfamily, in particular, accumulates significant numbers of structurally related furanoclerodanes. The biosynthetic capacity for formation of these diterpenoids is retained across most Lamiaceae subfamilies, including the early‐diverging Callicarpoideae which forms a sister clade to the rest of Lamiaceae. VacCYP76BK1, a cytochrome P450 monooxygenase from Vitex agnus‐castus, was previously found to catalyze the formation of the proposed precursor to furan and lactone‐containing labdane diterpenoids. Through transcriptome‐guided pathway exploration, we identified orthologs of VacCYP76BK1 in Ajuga reptans and Callicarpa americana. Functional characterization demonstrated that both could catalyze the oxidative cyclization of clerodane backbones to yield a furan ring. Subsequent investigation revealed a total of 10 CYP76BK1 orthologs across six Lamiaceae subfamilies. Through analysis of available chromosome‐scale genomes, we identified four CYP76BK1 members as syntelogs within a conserved syntenic block across divergent subfamilies. This suggests an evolutionary lineage that predates the speciation of the Lamiaceae. Functional characterization of the CYP76BK1 orthologs affirmed conservation of function, as all catalyzed furan ring formation. Additionally, some orthologs yielded two novel lactone ring moieties. The presence of the CYP76BK1 orthologs across Lamiaceae subfamilies closely overlaps with the distribution of reported furanoclerodanes. Together, the activities and distribution of the CYP76BK1 orthologs identified here support their central role in furanoclerodane biosynthesis within the Lamiaceae family. Our findings lay the groundwork for biotechnological applications to harness the economic potential of this promising class of compounds. [ABSTRACT FROM AUTHOR]

This article discusses the genome assembly and characterization of Chlorogloeopsis sp. ULAP02, a cyanobacterium from the Philippines, and the identification of biosynthetic gene clusters (BGCs) responsible for producing bioactive compounds. The study reveals the organism's genome and the potential therapeutic applications of its compounds. Another article explores the genome of Chlorogloeopsis sp. ULAP02 and identifies various BGCs associated with antimicrobial properties. Additionally, a document provides a list of references for scientific articles on microbiology and biochemistry, covering topics such as microorganism classification, protein engineering, and natural product biosynthesis. These resources offer valuable information for researchers in these fields. [Extracted from the article]

Introduction: Triple-negative breast cancer (TNBC) represents a significant global health crisis due to its resistance to conventional therapies and lack of specific molecular targets. This study explored the potential of Eriocephalus racemosus (E. racemosus) as an alternative treatment for TNBC. The cytotoxic properties and high-resolution respirometry mitochondrial activities of E. racemosus against the MDA-MB 231 TNBC cell line were evaluated. Methods: Hexane solvent and bioactive fraction extractions of E. racemosus were performed, while mass spectrometry-based metabolite profiling was used to identify the phytochemical constituents of the extracts. The extracts were further tested against MDA-MB 231 TNBC cells to determine their cytotoxicity. The mode of cell death was determined using flow cytometry. The activities of caspases 3, 8, and 9 were assessed using a multiplex activity assay kit. Glycolytic activity and High-resolution respirometry measurements of mitochondrial function in the MDA-MB 231 cell line were conducted using the Seahorse XFp and Oroboros O2K. Results: Metabolite profiling of E. racemosus plant crude extracts identified the presence of coumarins, flavonoids, sesquiterpenoids, triterpenoids, and unknown compounds. The extracts demonstrated promising cytotoxic activities, with a half maximal inhibitory concentration (IC50) of 12.84 µg/mL for the crude hexane extract and 15.49 µg/mL for the bioactive fraction. Further, the crude hexane and bioactive fraction extracts induced apoptosis in the MDA-MB-231 TNBC cells, like the reference drug cisplatin (17.44%, 17.26% and 20.25%, respectively) compared to untreated cells. Caspase 3 activities confirmed the induction of apoptosis in both cisplatin and the plant crude extracts, while caspase 8 and 9 activities confirmed the activation of both the intrinsic and extrinsic apoptosis pathways. Increased levels of glycolytic activity were observed in the hexane crude extract. High-resolution respiratory measurements showed elevated mitochondrial activities in all mitochondrial states except for complex-IV activity. Conclusion: These findings support further exploration of E. racemosus as a potential therapeutic agent for TNBC, offering a promising avenue for the development of targeted treatments with minimal adverse effects. [ABSTRACT FROM AUTHOR]

Terpene synthases (TPSs) play pivotal roles in generating diverse terpenoids through complex cyclization pathways. Protein engineering of TPSs offers a crucial approach to expanding terpene diversity. However, significant potential remains untapped due to limited understanding of the structure‐function relationships of TPSs. In this investigation, using a joint approach of molecular dynamics simulations‐assisted engineering and site‐directed mutagenesis, we manipulated the aromatic residue cluster (ARC) of a bifunctional terpene synthase (BFTPS), Pestalotiopsis fici nigtetraene synthase (PfNS). This led to the discovery of previously unreported catalytic functions yielding different cyclization patterns of sesterterpenes. Specifically, a quadruple variant (F89A/Y113F/W193L/T194W) completely altered PfNS′s function, converting it from producing the bicyclic sesterterpene nigtetraene to the tricyclic ophiobolin F. Additionally, analysis of catalytic profiles by double, triple, and quadruple variants demonstrated that the ARC functions as a switch, unprecedently redirecting the production of 5/11 bicyclic (Type B) sesterterpenes to 5/15 bicyclic (Type A) ones. Molecular dynamics simulations and theozyme calculations further elucidated that, in addition to cation‐π interactions, C−H⋅⋅⋅π interactions also play a key role in the cyclization patterns. This study offers a feasible strategy in protein engineering of TPSs for various industrial applications. [ABSTRACT FROM AUTHOR]

The biosynthesis of six recently reported non‐canonical C16 sesquiterpenoids named after ancient Greek philosophers, archimedene, aristotelene, eratosthenene, pythagorene, α‐democritene and anaximandrene, was investigated through density functional theory (DFT) calculations and isotopic labeling experiments. The results revealed for all compounds except archimedene a unique fragmentation‐recombination mechanism as previously demonstrated for sodorifen biosynthesis, in addition to a remarkable "dancing" mechanism for anaximandrene biosynthesis. [ABSTRACT FROM AUTHOR]

Background: Metabolic engineering enables the sustainable and cost-efficient production of complex chemicals. Efficient production of terpenes in Saccharomyces cerevisiae can be achieved by recruiting an intermediate of the mevalonate pathway. The present study aimed to evaluate the engineering strategies of S. cerevisiae for the production of taxadiene, a precursor of taxol, an antineoplastic drug. Result: SCIGS22a, a previously engineered strain with modifications in the mevalonate pathway (MVA), was used as a background strain. This strain was engineered to enable a high flux towards farnesyl diphosphate (FPP) and the availability of NADPH. The strain MVA was generated from SCIGS22a by overexpressing all mevalonate pathway genes. Combining the background strains with 16 different episomal plasmids, which included the combination of 4 genes: tHMGR (3-hydroxy-3-methylglutaryl-CoA reductase), ERG20 (farnesyl pyrophosphate synthase), GGPPS (geranyl diphosphate synthase) and TS (taxadiene synthase) resulted in the highest taxadiene production in S. cerevisiae of 528 mg/L. Conclusion: Our study highlights the critical role of pathway balance in metabolic engineering, mainly when dealing with toxic molecules like taxadiene. We achieved significant improvements in taxadiene production by employing a combinatorial approach and focusing on balancing the downstream and upstream pathways. These findings emphasize the importance of minor gene expression modification levels to achieve a well-balanced pathway, ultimately leading to enhanced taxadiene accumulation. [ABSTRACT FROM AUTHOR]

Background: Due to the complex pathophysiological mechanisms involved in cancer progression and metastasis, current therapeutic approaches lack efficacy and have significant adverse effects. Therefore, it is essential to establish novel strategies for combating cancer. Phytochemicals, which possess multiple biological activities, such as antioxidant, anti-inflammatory, antimutagenic, immunomodulatory, antiproliferative, anti-angiogenesis, and antimetastatic properties, can regulate cancer progression and interfere in various stages of cancer development by suppressing various signaling pathways. Methods: The current systematic and comprehensive review was conducted based on Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) criteria, using electronic databases, including PubMed, Scopus, and Science Direct, until the end of December 2023. After excluding unrelated articles, 111 related articles were included in this systematic review. Results: In this current review, the major signaling pathways of cancer metabolism are highlighted with the promising anticancer role of phytochemicals. This was through their ability to regulate the AMP-activated protein kinase (AMPK)/peroxisome proliferator-activated receptor-gamma coactivator-1α (PGC-1α) signaling pathway. The AMPK/PGC-1α signaling pathway plays a crucial role in cancer cell metabolism via targeting energy homeostasis and mitochondria biogenesis, glucose oxidation, and fatty acid oxidation, thereby generating ATP for cell growth. As a result, targeting this signaling pathway may represent a novel approach to cancer treatment. Accordingly, alkaloids, phenolic compounds, terpene/terpenoids, and miscellaneous phytochemicals have been introduced as promising anticancer agents by regulating the AMPK/PGC-1α signaling pathway. Novel delivery systems of phytochemicals targeting the AMPK/PGC-1α pathway in combating cancer are also highlighted in this review. [ABSTRACT FROM AUTHOR]

Natural products are molecules that fulfil a range of important ecological functions. Many natural products have been exploited for pharmaceutical and agricultural applications. In contrast to many other specialised metabolites, the products of modular nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) systems can often (partially) be predicted from the DNA sequence of the biosynthetic gene clusters. This is because the biosynthetic pathways of NRPS and PKS systems adhere to consistent rulesets. These universal biosynthetic rules can be leveraged to generate biosynthetic models of biosynthetic pathways. While these principles have been largely deciphered, software that leverages these rules to automatically generate visualisations of biosynthetic models has not yet been developed. To enable high-quality automated visualisations of natural product biosynthetic pathways, we developed RAIChU (Reaction Analysis through Illustrating Chemical Units), which produces depictions of biosynthetic transformations of PKS, NRPS, and hybrid PKS/NRPS systems from predicted or experimentally verified module architectures and domain substrate specificities. RAIChU also boasts a library of functions to perform and visualise reactions and pathways whose specifics (e.g., regioselectivity, stereoselectivity) are still difficult to predict, including terpenes, ribosomally synthesised and posttranslationally modified peptides and alkaloids. Additionally, RAIChU includes 34 prevalent tailoring reactions to enable the visualisation of biosynthetic pathways of fully maturated natural products. RAIChU can be integrated into Python pipelines, allowing users to upload and edit results from antiSMASH, a widely used BGC detection and annotation tool, or to build biosynthetic PKS/NRPS systems from scratch. RAIChU's cluster drawing correctness (100%) and drawing readability (97.66%) were validated on 5000 randomly generated PKS/NRPS systems, and on the MIBiG database. The automated visualisation of these pathways accelerates the generation of biosynthetic models, facilitates the analysis of large (meta-) genomic datasets and reduces human error. RAIChU is available at https://github.com/BTheDragonMaster/RAIChU and https://pypi.org/project/raichu. Scientific contribution RAIChU is the first software package capable of automating high-quality visualisations of natural product biosynthetic pathways. By leveraging universal biosynthetic rules, RAIChU enables the depiction of complex biosynthetic transformations for PKS, NRPS, ribosomally synthesised and posttranslationally modified peptide (RiPP), terpene and alkaloid systems, enhancing predictive and analytical capabilities. This innovation not only streamlines the creation of biosynthetic models, making the analysis of large genomic datasets more efficient and accurate, but also bridges a crucial gap in predicting and visualising the complexities of natural product biosynthesis. [ABSTRACT FROM AUTHOR]

Leukemia is potentially a fatal disease and is a major public health concern, which is reported to be 13th leading cause of cancer worldwide. Terpenes have been reported to play an important role in food, medicine, cosmetics, hormones, vitamins, and also been found to play a promising role in the field of medicine and have various biological activities, including leukemia, in recent years. This article deals with the publications that were collected from various databases namely PubMed, Scopus, Science Direct, Sci-Finder, and Google Scholar, etc. while using key words "terpenes and leukemia." A number of terpenes have shown their effects against leukemia including thymol, D-limonene, ascaridole, thymoquinone, elephantopus Mollis 23, artesunate, glycyrrhizic acid, ursolic acid, nomilin and oleanolic acid showed to induce apoptosis in human leukemia cell lines. Moreover, terpenes for the treatment of leukemia affecting and regulates different signaling cascades. Based on the reported data, it can be assumed that terpenes may be a promising target in combating leukemia, therefore further detail mechanistic and clinical studies could lead to the discovery of more effective therapeutic agents. [ABSTRACT FROM AUTHOR]

This article discusses the chemical composition of compounds found in the rhizomes of Hedychium convexum, a plant species commonly found in tropical Asia. The researchers collected the plant from China and conducted extractions and chromatographic separations to isolate and identify four compounds. The structures of these compounds were determined using spectroscopic methods. The document also provides information on other compounds isolated from H. convexum, including their chemical formula, physical properties, and spectroscopic data. The research was supported by the Key Laboratory and Science and Technology Innovation Team of Higher Education in Yunnan, China. [Extracted from the article]

This study included one type of forest insect in the Nineveh of northern Iraq, which is plant sap suckers that infect a group of forest trees, including Populus Euphratica and P.deltoides. The results showed a variation in the killing rate resulting from treating poplar leaf nymph aphids with phenols of the study tree species according to the type of tree, concentration, and insect phase. The phenols of the Euphratica poplar leaves excelled on average, with the killing rate of the American type being 62.01 and 56.49% at a concentration of 10%, respectively. For Alkaloids, it was 47.21 and 43.3% for P.euphratica and P.deltoides, respectively. Meanwhile, terpenes were 43.21 and 37.69%. The average percentage of expulsion reached 36.89% in the nymph phase of P. euphratica at a concentration of 10%. The study showed significant superiority of the Alkaloids of Euphratica poplar and the average expulsion percentage over the Alkaloids of the other types. The average percentage of expulsion was 32.69% in the nymph phase at a concentration of 10%. The Euphratica poplar Terpenes outperformed the average kill rate over the Terpenes of the other type, with an average expulsion ratio of 29.92% in the nymph phase at a concentration of 10%. [ABSTRACT FROM AUTHOR]

Reactive oxygen species causes harm to cell membranes and biomolecules, wherefore chronic diseases develop. Antioxidants scavenge such free radicals combating oxidative stress. This research aimed to determine the antioxidant potential of the aqueous stem bark, root and leaf extracts of Rhaphiolepis bibas against standards. DPPH radical scavenging activity was high from th stem bark extract at 72.33% with root extract at 65.85% and leaf extract at 55.91%, while ascorbic acid scavenged 89.53% of DPPH radicals. The leaf extract had the highest H2O2 scavenging activity of 91.92% with stem bark at 91.17% and the root extracts at 89.12%. The aqueous root extract of R. bibas had a significantly higher FRAP capacity in comparison to the leaf extracts and the stem bark. The abilities to chelate iron by the leaf extract were statistically higher compared to the root and stem bark extracts. Stem bark extracts had the highest phenol content of about 149.44 followed by the root extract at 141.14 and the least amount of phenol was found in the aqueous leaf extract having 73.012 Gallic acid equivalent/g. The root extracts had the highest total flavonoid 377.66-milligram quercetin equivalent/gram dry weight followed by stem bark extract at 255.72 and the least amount was found in aqueous leaf extract having 164.52 mgQE/g of sample dry weight. The existence of secondary metabolites linked to antioxidant action was shown by the qualitative phytochemical screening. [ABSTRACT FROM AUTHOR]