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Angewandte Chemie (International Ed. in... Nov 2023Monoterpene indole alkaloids (MIAs) are endowed with high structural and spatial complexity and characterized by diverse biological activities. Given this...
Monoterpene indole alkaloids (MIAs) are endowed with high structural and spatial complexity and characterized by diverse biological activities. Given this complexity-activity combination in MIAs, rapid and efficient access to chemical matter related to and with complexity similar to these alkaloids would be highly desirable, since such compound classes might display novel bioactivity. We describe the design and synthesis of a pseudo-natural product (pseudo-NP) collection obtained by the unprecedented combination of MIA fragments through complexity-generating transformations, resulting in arrangements not currently accessible by biosynthetic pathways. Cheminformatic analyses revealed that both the pseudo-NPs and the MIAs reside in a unique and common area of chemical space with high spatial complexity-density that is only sparsely populated by other natural products and drugs. Investigation of bioactivity guided by morphological profiling identified pseudo-NPs that inhibit DNA synthesis and modulate tubulin. These results demonstrate that the pseudo-NP collection occupies similar biologically relevant chemical space that Nature has endowed MIAs with.
Topics: Monoterpenes; Indole Alkaloids; Alkaloids
PubMed: 37818743
DOI: 10.1002/anie.202310222 -
Food Research International (Ottawa,... Dec 2023Low temperature is the commonly used technique for maintaining the quality of table grapes during postharvest storage. However, this technique could strongly affect the...
Low temperature is the commonly used technique for maintaining the quality of table grapes during postharvest storage. However, this technique could strongly affect the aromatic flavor of fruit. Monoterpenes are the key compounds contributing to the Muscat aromas of grapes. The detailed information and molecular mechanisms underlying the changes in monoterpenes during postharvest low temperature storage have not been thoroughly characterized. In this study, the effects of low temperature storage on the free and bound monoterpene profiles in four cultivars of table grape were determined at both the transcriptomic and metabolomic levels. A total of 27 compounds in both free and bound forms were identified in the four cultivars and showed quantitative differences between the cultivars. Hierarchical cluster and principal component analysis indicated that the free and bound monoterpene profiles were remarkably affected by the low temperature storage. The monoterpenes in the same biosynthesis pathway were clustered together and showed similar evolution trends during low temperature storage. And the content of most of free monoterpenes underwent a rapid decline during low-temperature storage at a certain stage, but the time was different in 4 grape cultivars. Transcriptomic analysis revealed that the expression of DXS, HDR, GPPS and TPS genes involved in the monoterpene synthesis pathway were consistent with the changes in the accumulation of monoterpene compounds. While the expression of HMGS, HMGR genes in MVA pathway and branch genes GGPPS and FPPS were negatively correlated with the accumulation of monoterpenes. The findings provide new insights into the underlying mechanisms of the berry aroma flavor change during low temperature storage.
Topics: Monoterpenes; Vitis; Transcriptome; Temperature; Odorants
PubMed: 37986463
DOI: 10.1016/j.foodres.2023.113601 -
Molecules (Basel, Switzerland) Nov 2023L. herb and flowers have high biological activity; hence, they are used in medicine and cosmetics. The aim of this study was to perform morpho-anatomical analyses of...
L. herb and flowers have high biological activity; hence, they are used in medicine and cosmetics. The aim of this study was to perform morpho-anatomical analyses of the raw material, including secretory tissues, histochemical assays of the location of lipophilic compounds, and quantitative and qualitative analysis of essential oil (EO). Light and scanning electron microscopy techniques were used to analyse plant structures. The qualitative analyses of EO were carried out using gas chromatography-mass spectrometry (GC/MS). The results of this study showed the presence of exogenous secretory structures in the raw material, i.e., conical cells (papillae) on the adaxial surface of petal teeth and biseriate glandular trichomes on the surface flowers, bracts, stems, and leaves. Canal-shaped endogenous secretory tissue was observed in the stems and leaves. The histochemical assays revealed the presence of total, acidic, and neutral lipids as well as EO in the glandular trichome cells. Additionally, papillae located at the petal teeth contained neutral lipids. Sesquiterpenes were detected in the glandular trichomes and petal epidermis cells. The secretory canals in the stems were found to contain total and neutral lipids. The phytochemical assays demonstrated that the subsp. flowers contained over 2.5-fold higher amounts of EO (6.1 mL/kg) than the herb (2.4 mL/kg). The EO extracted from the flowers and herb had a similar dominant compounds: β-pinene, bornyl acetate, (E)-nerolidol, 1,8-cineole, borneol, sabinene, camphor, and α-pinene. Both EO samples had greater amounts of monoterpenes than sesquiterpenes. Higher amounts of oxygenated monoterpenes and oxygenated sesquiterpenoids were detected in the EO from the herb than from the flowers.
Topics: Oils, Volatile; Achillea; Flowers; Plant Leaves; Sesquiterpenes; Monoterpenes
PubMed: 38067521
DOI: 10.3390/molecules28237791 -
Plant Physiology Jun 2024Hydroxylated monoterpenes (HMTPs) are differentially emitted by tomato (Solanum lycopersicum) plants resisting bacterial infection. We have studied the defensive role of...
Hydroxylated monoterpenes (HMTPs) are differentially emitted by tomato (Solanum lycopersicum) plants resisting bacterial infection. We have studied the defensive role of these volatiles in the tomato response to bacteria, whose main entrance is through stomatal apertures. Treatments with some HMTPs resulted in stomatal closure and pathogenesis-related protein 1 (PR1) induction. Particularly, α-terpineol induced stomatal closure in a salicylic acid (SA) and abscisic acid-independent manner and conferred resistance to bacteria. Interestingly, transgenic tomato plants overexpressing or silencing the monoterpene synthase MTS1, which displayed alterations in the emission of HMTPs, exhibited changes in the stomatal aperture but not in plant resistance. Measures of both 2-C-methyl-D-erythritol-2,4-cyclopyrophosphate (MEcPP) and SA levels revealed competition for MEcPP by the methylerythritol phosphate (MEP) pathway and SA biosynthesis activation, thus explaining the absence of resistance in transgenic plants. These results were confirmed by chemical inhibition of the MEP pathway, which alters MEcPP levels. Treatments with benzothiadiazole (BTH), a SA functional analog, conferred enhanced resistance to transgenic tomato plants overexpressing MTS1. Additionally, these MTS1 overexpressors induced PR1 gene expression and stomatal closure in neighboring plants. Our results confirm the role of HMTPs in both intra- and interplant immune signaling and reveal a metabolic crosstalk between the MEP and SA pathways in tomato plants.
Topics: Solanum lycopersicum; Salicylic Acid; Monoterpenes; Plants, Genetically Modified; Plant Diseases; Plant Stomata; Hydroxylation; Thiadiazoles; Gene Expression Regulation, Plant; Sugar Phosphates; Plant Proteins; Pseudomonas syringae; Erythritol; Disease Resistance
PubMed: 38478585
DOI: 10.1093/plphys/kiae148 -
Veterinary Parasitology Sep 2023This study aimed to assess the effect of combining amitraz with essential oils (EOs) from Thymus vulgaris and Lippia sidoides, as well as the monoterpenes thymol and...
Combinations of amitraz with essential oils from Lippia sidoides and Thymus vulgaris, thymol and thymol acetate for Rhipicephalus microplus control: studies under laboratory and field conditions.
This study aimed to assess the effect of combining amitraz with essential oils (EOs) from Thymus vulgaris and Lippia sidoides, as well as the monoterpenes thymol and thymol acetate, on Rhipicephalus microplus in laboratory conditions, and to select the most effective combination for testing in field conditions. The chemical analysis showed that EOs were mainly composed of monoterpenes, with thymol and p-cymene as the major compounds. In larval (LIT) and adult (AIT) immersion tests using different concentrations of the oils and terpenes mixed with amitraz, the results showed that both EOs and thymol improved the efficacy of amitraz against larvae and engorged females of R. microplus, whereas thymol acetate only enhanced activity against larvae. The most favorable outcome was obtained with the EO of L. sidoides combined with amitraz, resulting in 99 % and 100 % efficacy against larvae and engorged females, respectively. Furthermore, the combination of amitraz with thymol showed presented an efficacy of 94 % and 91 % against larvae and engorged females, respectively. Thus, for the other tests, the combination of thymol + amitraz was chosen due to the ease of working with pure thymol in bioassays, and easier standardization. The immersion test (thymol + amitraz) with semi-engorged females showed 100 % efficacy for the combination of thymol + amitraz, while in tests with different solvents (thymol + amitraz), ethanol being the most effective solvent among those tested (ethanol, Triton, and Tween), resulting in 95 % efficacy on engorged females. In the field test, in treatments with amitraz and thymol + amitraz, efficacy of 54 % and 74 % was observed on day + 3 and 33 % and 43 % on day + 7, respectively. Assessing the reproductive biology of females recovered from animals treated with amitraz or amitraz + thymol, in day + 7, efficacies of 33 % and 52 %, respectively, were observed. EOs from T. vulgaris and L. sidoides and thymol improved the acaricidal activity of amitraz on larvae and engorged females of R. microplus under laboratory conditions, while thymol acetate only enhanced activity against larvae. Thymol increased the efficacy of amitraz under field conditions, however for the development of a commercially available acaricide to R. microplus control, additional studies are needed to increase the efficacy. Further research is needed (by changing concentrations, adding other compounds and/or developing formulations) to increase acaricidal efficacy and develop new effective products to combat R. microplus infestations in cattle.
Topics: Female; Animals; Cattle; Oils, Volatile; Thymol; Lippia; Thymus Plant; Rhipicephalus; Monoterpenes; Larva; Acaricides
PubMed: 37562084
DOI: 10.1016/j.vetpar.2023.109997 -
The Science of the Total Environment Oct 2023Biogenic volatile organic compound (BVOC) (such as isoprene (ISO) and monoterpenes (MTs)) emissions from plants play a great role in the atmospheric chemistry. Now...
Biogenic volatile organic compound (BVOC) (such as isoprene (ISO) and monoterpenes (MTs)) emissions from plants play a great role in the atmospheric chemistry. Now frequency of dramatic changes of weather such as transient temperature changing increases, most current studies focus on the effects of simulating climate change (long-term) on BVOC emissions. While studies of transient effects on that are less reported. This study aimed to identify the ISO and MT emissions and the related physiological processes in the short-term scale at different temperature (T) and light intensity (PAR), in seeding stage of Schima superba and Phoebe bournei belonging to typical subtropical tree species. The results showed that the ISO and MT emissions were significantly affected by T and PAR, either independently or interactively. With the increase of T and PAR, the ISO and MT emissions increased, with the maximum rates of ISO and MTs of 39.39 and 1042.35 pmol m s for S. superba under 40 °C × 500 μmol m s condition, while the maximum rates reached 18.73 and 6737.41 pmol m s at 30 °C × 1500 μmol m s for P. bournei. The increase of ISO and MT emissions with T and PAR increasing that was related to the promotion of Pn and g in plants. Regarding MT components, the proportion of α-pinene decreased with T and PAR increasing, with the lowest ratios of 4.91 % and 21.16 % for S. superba and P. bournei under 40 °C × 1500 μmol m s condition. However, the proportion of β-pinene significantly increased, with the highest ratios of 67.42 % and 57.93 % for S. superba and P. bournei under 30 °C × 1500 μmol m s condition, which is attributed to differences in light tolerance between the two plants. Our study provides basis for evaluating the transient changes of environmental factors on BVOC emissions and optimizing regional BVOC emission models.
Topics: Monoterpenes; Temperature; Hemiterpenes; Trees; Plants; Volatile Organic Compounds
PubMed: 37355121
DOI: 10.1016/j.scitotenv.2023.165082 -
Molecules (Basel, Switzerland) Dec 2023Lily is one of the most important cut flowers in the world, with a rich floral fragrance. To further explore the fragrance emission mechanisms of lily cultivars,...
Lily is one of the most important cut flowers in the world, with a rich floral fragrance. To further explore the fragrance emission mechanisms of lily cultivars, headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) and organic solvent extraction-gas chromatography-mass spectrometry (OSE-GC-MS) were used to unveil the volatile organic compounds (VOCs) and endogenous extracts of seven lily cultivars. Furthermore, real-time quantitative PCR (qRT-PCR) was used to determine the expression levels of two key genes ( and ) related to the biosynthesis of monoterpenoids and methyl benzoate. The results show that forty-five VOCs were detected in the petals of seven lily cultivars, and the main compounds were monoterpenoids and phenylpropanoids/benzenoids. Dichloromethane was the best solvent for extracting the endogenous extracts of 'Viviana' petals and eighteen endogenous extracts were detected using dichloromethane to extract the petals of seven lily cultivars. Each compound's emission ratio (natural logarithm of the ratio of VOC content to endogenous extract content) was calculated, and linear regression analyses between emission ratios and boiling points were conducted. Significant linear negative correlations existed between the emission ratios and boiling points of compounds, and the regression equations' coefficients of determination () were all greater than 0.7. was expressed highly in 'Viviana', 'Pink News', and 'Palazzo', and was expressed highly in 'Pink News' and 'Palazzo'. Correlation analyses between the gene expression levels and the monoterpenoids and methyl benzoate contents found that the expression levels have strong positive correlations with monoterpenoids content, while no correlations were found between the expression levels of and the contents of methyl benzoate. This study lays the foundation for research on the release patterns of VOCs in the flowers of , and the breeding of lilies for their floral fragrance.
Topics: Lilium; Volatile Organic Compounds; Methylene Chloride; Plant Breeding; Flowers; Solid Phase Microextraction; Solvents; Monoterpenes
PubMed: 38138428
DOI: 10.3390/molecules28247938 -
Marine Drugs Sep 2023The chemical investigation of a red alga enabled the identification of three new halogenated monoterpenes (-) along with two previously identified metabolites ( and )....
The chemical investigation of a red alga enabled the identification of three new halogenated monoterpenes (-) along with two previously identified metabolites ( and ). Their structures were determined by spectroscopic analysis and also by utilizing single-crystal diffraction analysis and quantum chemical calculation, as well as by comparison with literature data. Further corrections for dichloro and dibromo carbons using the sorted training set (STS) method were established in this study to significantly improve the accuracy in GIAO C NMR calculation of compounds -. To discover the potential bioactive metabolites from , the anti-inflammatory activities of all compounds were examined. Compounds and - showed significant anti-inflammatory activity to inhibit the production of pro-inflammatory cytokines in the LPS-stimulated mature dendritic cells.
Topics: Anti-Inflammatory Agents; Carbon; Cell Movement; Monoterpenes; Rhodophyta
PubMed: 37755106
DOI: 10.3390/md21090493 -
PloS One 2024Monoterpenes are a large class of naturally occurring fragrant molecules. These chemicals are commonly used in olfactory studies to survey neural activity and probe the...
Monoterpenes are a large class of naturally occurring fragrant molecules. These chemicals are commonly used in olfactory studies to survey neural activity and probe the behavioral limits of odor discrimination. Monoterpenes (typically in the form of essential oils) have been used for centuries for therapeutic purposes and have pivotal roles in various biological and medical applications. Despite their importance for multiple lines of research using rodent models and the role of the olfactory system in detecting these volatile chemicals, the murine sensitivity to monoterpenes remains mostly unexplored. We assayed the ability of C57BL/6J mice to detect nine different monoterpenes (the acyclic monoterpenes: geraniol, citral, and linalool; the monocyclic monoterpenes: r-limonene, s-limonene, and γ-terpinene; and the bicyclic monoterpenes: eucalyptol, α-pinene, and β-pinene) using a head-fixed Go / No-Go operant conditioning assay. We found that mice can reliably detect monoterpene concentrations in the low parts per billion (ppb) range. Specifically, mice were most sensitive to geraniol (threshold: 0.7 ppb) and least sensitive to γ-terpinene (threshold: 18.1 ppb). These estimations of sensitivity serve to set the lower limit of relevant monoterpene concentrations for functional experiments in mice. To define an upper limit, we estimated the maximum concentrations that a mouse may experience in nature by collating published headspace analyses of monoterpene concentrations emitted from natural sources. We found that natural monoterpenes concentrations typically ranged from ~1 to 1000 ppb. It is our hope that this dataset will help researchers use appropriate monoterpene concentrations for functional studies and provide context for the vapor-phase delivery of these chemicals in studies investigating their biological activity in mice.
Topics: Mice; Animals; Limonene; Mice, Inbred C57BL; Monoterpenes; Bicyclic Monoterpenes; Acyclic Monoterpenes; Cyclohexane Monoterpenes
PubMed: 38394306
DOI: 10.1371/journal.pone.0298448 -
Molecular Nutrition & Food Research Apr 2024The excretion of dietary odorants into urine and milk is evaluated and the impact of possible influencing factors determined. Furthermore, the metabolic relevance of...
SCOPE
The excretion of dietary odorants into urine and milk is evaluated and the impact of possible influencing factors determined. Furthermore, the metabolic relevance of conjugates for the excretion into milk is investigated.
METHODS AND RESULTS
Lactating mothers (n = 20) are given a standardized curry dish and donated one milk and urine sample each before and 1, 2, 3, 4.5, 6, and 8 h after the intervention. The concentrations of nine target odorants in these samples are determined. A significant transition is observed for linalool into milk, as well as for linalool, cuminaldehyde, cinnamaldehyde, and eugenol into urine. Maximum concentrations are reached within 1 h after the intervention in the case of milk and within 2-3 h in the case of urine. In addition, the impact of glucuronidase treatment on odorant concentrations is evaluated in a sample subset of twelve mothers. Linalool, eugenol, and vanillin concentrations increased 3-77-fold in milk samples after treatment with β-glucuronidase.
CONCLUSION
The transfer profiles of odorants into milk and urine differ qualitatively, quantitatively, and in temporal aspects. More substances are transferred into urine and the transfer needs a longer period compared with milk. Phase II metabolites are transferred into urine and milk.
Topics: Humans; Milk, Human; Female; Odorants; Eugenol; Adult; Benzaldehydes; Acyclic Monoterpenes; Glucuronidase; Lactation; Acrolein; Monoterpenes
PubMed: 38602198
DOI: 10.1002/mnfr.202300831