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Langmuir : the ACS Journal of Surfaces... Oct 2015Monoterpenes are abundant in essential oils extracted from plants. These relatively small and hydrophobic molecules have shown important biological functions, including...
Monoterpenes are abundant in essential oils extracted from plants. These relatively small and hydrophobic molecules have shown important biological functions, including antimicrobial activity and membrane penetration enhancement. The interaction between the monoterpenes and lipid bilayers is considered important to the understanding of the biological functions of monoterpenes. In this study, we investigated the effect of cyclic and linear monoterpenes on the structure and dynamics of lipids in model membranes. We have studied the ternary system 1,2-dimyristoyl-sn-glycero-3-phosphocholine-monoterpene-water as a model with a focus on dehydrated conditions. By combining complementary techniques, including differential scanning calorimetry, solid-state nuclear magnetic resonance, and small- and wide-angle X-ray scattering, bilayer structure, phase transitions, and lipid molecular dynamics were investigated at different water contents. Monoterpenes cause pronounced melting point depression and phase segregation in lipid bilayers, and the extent of these effects depends on the hydration conditions. The addition of a small amount of thymol to the fluid bilayer (volume fraction of 0.03 in the bilayer) leads to an increased order in the acyl chain close to the bilayer interface. The findings are discussed in relation to biological systems and lipid formulations.
Topics: Calorimetry, Differential Scanning; Dimyristoylphosphatidylcholine; Lipid Bilayers; Magnetic Resonance Spectroscopy; Molecular Dynamics Simulation; Monoterpenes; Scattering, Radiation
PubMed: 26375869
DOI: 10.1021/acs.langmuir.5b00856 -
Medicinal Chemistry (Shariqah (United... 2021Citral is one of the main components of lemongrass oil present at a concentration of 65-85% approximately and is generally separated by steam refining. It is an... (Review)
Review
BACKGROUND
Citral is one of the main components of lemongrass oil present at a concentration of 65-85% approximately and is generally separated by steam refining. It is an important component in the manufacturing of scents, citrus chemicals, cosmetics, food and pharmaceutical products.
OBJECTIVES
This article aims at reviewing the published literature to highlight the metabolism, extraction strategies and therapeutic significance of citral for improving the scope of its application in the food and pharma industry.
DISCUSSIONS
Apart from steam refining, there are other techniques like solvent extraction, supercritical fluid extraction and ultrasonication by which citral can be extracted and the method of extraction defines its quality. It is an unstable molecule and undergoes rapid deterioration on exposure to air. Citral is biosynthesized by the plants through the 5 carbon precursor isopentenyl diphosphate (IPP) units utilizing two diverse biochemical pathways, acetate- mevalonate (acetate- MVA) pathway or 2C-methylerythritol-4-phosphate (MEP). Orally Citral was absolutely digested in the gastrointestinal tract and its metabolism leads to the discharge of metabolites which include a number of acids and a biliary glucuronide. There is no scientific evidence about the long term bioavailability of citral in the body and it has no adverse effect on tissue related to its accumulation and delayed excretion. Citral exhibits various important therapeutic properties like antimicrobial, antioxidant, anticancer, anti-diabetic and anti-inflammatory.
CONCLUSION
Citral is a potent biomolecule with various important biological activities and therapeutic implications. Strategies are required to increase the stability of citral which could increase its applications.
Topics: Acyclic Monoterpenes; Animals; Cymbopogon; Humans
PubMed: 31880247
DOI: 10.2174/1573406416666191227111106 -
Chemistry & Biodiversity Aug 2022Secondary plant metabolites are chemical compounds produced by plants through a variety of metabolic pathways. It is known that these compounds, among others,...
Secondary plant metabolites are chemical compounds produced by plants through a variety of metabolic pathways. It is known that these compounds, among others, monoterpenes, are characterized by holding valuable pro-health activities when consumed or applied. Taking into account the development of civilizational diseases, eating foods enriched with compounds such as the monoterpenes is highly recommended. Good sources of such health-promoting food items include common fruits and vegetables, seed sources and plant parts used to enhance flavour such as spices. It is known that monoterpene compounds instigate or contribute to a variety of biological activities. It is known that the compounds can scavenge free radicals, reduce Fe(III) and inhibit AChE which are considered as possible anti-neurodegenerative activities. The aim of the presented study was to determinate another activity of selected monoterpenes, namely towards reducing and chelating Cu(II) and Fe(II), respectively. The assays were based on colorimetric CUPRAC and ferrozine-based methods. Study results explicitly indicated chelation and reduction activities of the selected monoterpenes. These properties considerably support the benefits of consuming plants rich in these compounds.
Topics: Copper; Ferrozine; Ions; Iron; Monoterpenes
PubMed: 35773202
DOI: 10.1002/cbdv.202200461 -
Current Pharmaceutical Design Dec 2018Carvacrol has a high therapeutic potential, with in vitro studies showing promising results in different cellular models using a variety of methodological designs.... (Review)
Review
Carvacrol has a high therapeutic potential, with in vitro studies showing promising results in different cellular models using a variety of methodological designs. Therefore, the objective of this study was to conduct a systematic review to analyze the pharmacological effects of carvacrol in in vitro studies. A comprehensive search of the literature was made using four databases: Science Direct, Scopus, MEDLINE-PubMed, and Web of Science using different combinations of the following keywords: carvacrol, drug therapy, therapeutic uses, in vitro study. The search of the databases was for studies conducted in the period up to and including September 2016. A total of 3,269 studies were initially identified, with only 31 meeting the inclusion criteria. The included studies contained a variety of in vitro models able to determine the properties of Carvacrol. The following properties of Carvacrol were identified: antimicrobial (7 studies), bactericidal (4), bactericidal and antifungal (1), antiinflammatory (4), anticancer (4), mutagenic (4), antioxidant (3), antifungal (3), antidepressant (1), as a modulator of nerve impulses (1) and an immunological modulator (1). The In vitro studies with Carvacrol included in this review showed a diversity of models and confirmed the therapeutic potential of this product in relation to several diseases.
Topics: Animals; Anti-Infective Agents; Anti-Inflammatory Agents; Antineoplastic Agents; Antioxidants; Cymenes; Drug Design; Humans; Monoterpenes
PubMed: 30280662
DOI: 10.2174/1381612824666181003123400 -
Nature Sep 2022Monoterpenes (CH) are emitted in large quantities by vegetation to the atmosphere (>100 TgC year), where they readily react with hydroxyl radicals and ozone to form...
Monoterpenes (CH) are emitted in large quantities by vegetation to the atmosphere (>100 TgC year), where they readily react with hydroxyl radicals and ozone to form new particles and, hence, clouds, affecting the Earth's radiative budget and, thereby, climate change. Although most monoterpenes exist in two chiral mirror-image forms termed enantiomers, these (+) and (-) forms are rarely distinguished in measurement or modelling studies. Therefore, the individual formation pathways of monoterpene enantiomers in plants and their ecological functions are poorly understood. Here we present enantiomerically separated atmospheric monoterpene and isoprene data from an enclosed tropical rainforest ecosystem in the absence of ultraviolet light and atmospheric oxidation chemistry, during a four-month controlled drought and rewetting experiment. Surprisingly, the emitted enantiomers showed distinct diel emission peaks, which responded differently to progressive drying. Isotopic labelling established that vegetation emitted mainly de novo-synthesized (-)-α-pinene, whereas (+)-α-pinene was emitted from storage pools. As drought progressed, the source of (-)-α-pinene emissions shifted to storage pools, favouring cloud formation. Pre-drought mixing ratios of both α-pinene enantiomers correlated better with other monoterpenes than with each other, indicating different enzymatic controls. These results show that enantiomeric distribution is key to understanding the underlying processes driving monoterpene emissions from forest ecosystems and predicting atmospheric feedbacks in response to climate change.
Topics: Atmosphere; Climate Change; Droughts; Forests; Monoterpenes; Trees
PubMed: 36071188
DOI: 10.1038/s41586-022-05020-5 -
Environmental Science & Technology Dec 2022The formation of secondary organic aerosol (SOA) from the structurally similar monoterpenes, α-pinene and Δ-carene, differs substantially. The aerosol phase is already...
The formation of secondary organic aerosol (SOA) from the structurally similar monoterpenes, α-pinene and Δ-carene, differs substantially. The aerosol phase is already complex for a single precursor, and when mixtures are oxidized, products, e.g., dimers, may form between different volatile organic compounds (VOCs). This work investigates whether differences in SOA formation and properties from the oxidation of individual monoterpenes persist when a mixture of the monoterpenes is oxidized. Ozonolysis of α-pinene, Δ-carene, and a 1:1 mixture of them was performed in the Aarhus University Research on Aerosol (AURA) atmospheric simulation chamber. Here, ∼100 ppb of monoterpene was oxidized by 200 ppb O under dark conditions at 20 °C. The particle number concentration and particle mass concentration for ozonolysis of α-pinene exceed those from ozonolysis of Δ-carene alone, while their mixture results in concentrations similar to α-pinene ozonolysis. Detailed offline analysis reveals evidence of VOC-cross-product dimers in SOA from ozonolysis of the monoterpene mixture: a VOC-cross-product dimer likely composed of the monomeric units -caric acid and 10-hydroxy-pinonic acid and a VOC-cross-product dimer ester likely from the monomeric units caronaldehyde and terpenylic acid were tentatively identified by liquid chromatography-mass spectrometry. To improve the understanding of chemical mechanisms determining SOA, it is relevant to identify VOC-cross-products.
Topics: Humans; Volatile Organic Compounds; Air Pollutants; Aerosols; Monoterpenes; Ozone
PubMed: 36355568
DOI: 10.1021/acs.est.2c04786 -
Plant, Cell & Environment Jan 2022Tree stems have been identified as sources of volatile organic compounds (VOCs) that play important roles in tree defence and atmospheric chemistry. Yet, we lack...
Tree stems have been identified as sources of volatile organic compounds (VOCs) that play important roles in tree defence and atmospheric chemistry. Yet, we lack understanding on the magnitude and environmental drivers of stem VOC emissions in various forest ecosystems. Due to the increasing importance of extreme drought, we studied drought effects on the VOC emissions from mature Scots pine (Pinus sylvestris L.) stems. We measured monoterpenes, acetone, acetaldehyde and methanol emissions with custom-made stem chambers, online PTR-MS and adsorbent sampling in a drought-prone forest over the hot-dry summer of 2018 and compared the emission rates and dynamics between trees in naturally dry conditions and under long-term irrigation (drought release). The pine stems were significant monoterpene sources. The stem monoterpene emissions potentially originated from resin, based on their similar monoterpene spectra. The emission dynamics of all VOCs followed temperature at a daily scale, but monoterpene and acetaldehyde emission rates decreased nonlinearly with drought over the summer. Despite the dry conditions, large peaks of monoterpene, acetaldehyde and acetone emissions occurred in late summer potentially due to abiotic or biotic stressors. Our results highlight the potential importance of stem emissions in the ecosystem VOC budget, encouraging further studies in diverse environments.
Topics: Droughts; Mass Spectrometry; Methanol; Monoterpenes; Pinus sylvestris; Plant Stems; Resins, Plant; Sesquiterpenes; Soil; Switzerland; Temperature; Volatile Organic Compounds
PubMed: 34723383
DOI: 10.1111/pce.14219 -
Phytochemistry Nov 2022Plant monoterpenes are challenging compounds, since they often act as solvents, and thus have both phytotoxic and antimicrobial properties. In this study an approach is...
Plant monoterpenes are challenging compounds, since they often act as solvents, and thus have both phytotoxic and antimicrobial properties. In this study an approach is developed to identify and characterize enzymes that can detoxify monoterpenoids, and thus would protect both plants and microbial production systems from these compounds. Plants respond to the presence of monoterpenes by expressing glycosyltransferases (UGTs), which conjugate the monoterpenoids into glycosides. By identifying these enzymes in a transcriptomics approach using Mentha × piperita, a family of UGTs was identified which is active on cyclic monoterpenoids such as menthol, and on acyclic monoterpenoids such as geranic acid. Other members of this family, from tomato, were also shown to be active on these monoterpenoids. In vitro and in vivo activity of different UGTs were tested with different substrates. We found that some glycosyltransferases significantly affect the toxicity of selected monoterpenoids in Escherichia coli, suggesting that glycosyltransferases can protect cells from monoterpenoid toxicity.
Topics: Glycosides; Glycosyltransferases; Mentha piperita; Menthol; Monoterpenes; Solvents
PubMed: 36037906
DOI: 10.1016/j.phytochem.2022.113371 -
Natural Product Reports Oct 2021Covering: since early reports up to the end of 2020This review presents a complete coverage of the mavacuranes alkaloids since early reports till date. Mavacuranes... (Review)
Review
Covering: since early reports up to the end of 2020This review presents a complete coverage of the mavacuranes alkaloids since early reports till date. Mavacuranes alkaloids are a restrictive sub-group of monoterpene indole alkaloids (MIAs), which are represented by their two emblematic congeners, namely, -mavacurine and pleiocarpamine. Their skeleton is defined by a bond between the indolic N1 nitrogen and the C16 carbon of the tetracyclic scaffold of the corynanthe group in MIA. A limited number of congeners is known as this skeleton can be considered as a cul-de-sac in main MIA biosynthetic routes. Thanks to the enhanced enamine-type reactivity, mavacuranes are frequently involved in the formation of multimeric MIA scaffolds. This review covers isolation aspects and synthetic approaches towards the mavacurane core and bisindole assemblies. To access the mavacurane core, only a few strategies are reported and the main synthetic difficulties usually originate from the important rigidity of the pentacyclic system. For the bisindole assemblies, biomimetic routes are privileged and deliver complex structures using smooth conditions.
Topics: Biosynthetic Pathways; Indole Alkaloids; Monoterpenes
PubMed: 33666614
DOI: 10.1039/d0np00088d -
Phytomedicine : International Journal... May 2024Genus Paeonia, which is the main source of Traditional Chinese Medicine (TCM) Paeoniae Radix Rubra (Chishao in Chinese), Paeoniae Radix Alba (Baishao in Chinese) and... (Review)
Review
BACKGROUND
Genus Paeonia, which is the main source of Traditional Chinese Medicine (TCM) Paeoniae Radix Rubra (Chishao in Chinese), Paeoniae Radix Alba (Baishao in Chinese) and Moutan Cortex (Mudanpi in Chinese), is rich in active pharmaceutical ingredient such as monoterpenoid glycosides (MPGs). MPGs from Paeonia have extensive pharmacological effects, but the pharmacological effects and molecular mechanisms of MPGs has not been comprehensively reviewed.
PURPOSE
MPGs compounds are one of the main chemical components of the genus Paeonia, with a wide variety of compounds and strong pharmacological activities, and the structure of the mother nucleus-pinane skeleton is similar to that of a cage. The purpose of this review is to summarize the pharmacological activity and mechanism of action of MPGs from 2012 to 2023, providing reference direction for the development and utilization of Paeonia resources and preclinical research.
METHODS
Keywords and phrases are widely used in database searches, such as PubMed, Web of Science, Google Scholar and X-Mol to search for citations related to the new compounds, extensive pharmacological research and molecular mechanisms of MPGs compounds of genus Paeonia.
RESULTS
Modern research confirms that MPGs are the main compounds in Paeonia that exert pharmacological effects. MPGs with extensive pharmacological characteristics are mainly concentrated in two categories: paeoniflorin derivatives and albiflflorin derivatives among MPGs, which contains 32 compounds. Among them, 5 components including paeoniflorin, albiflorin, oxypaeoniflorin, 6'-O-galloylpaeoniflorin and paeoniflorigenone have been extensively studied, while the other 28 components have only been confirmed to have a certain degree of anti-inflammatory and anticomplementary effects. Studies of pharmacological effects are widely involved in nervous system, endocrine system, digestive system, immune system, etc., and some studies have identified clear mechanisms. MPGs exert pharmacological activity through multilateral mechanisms, including anti-inflammatory, antioxidant, inhibition of cell apoptosis, regulation of brain gut axis, regulation of gut microbiota and downregulation of mitochondrial apoptosis, etc. CONCLUSION: This systematic review delved into the pharmacological effects and related molecular mechanisms of MPGs. However, there are still some compounds in MPGs whose pharmacological effects and pharmacological mechanisms have not been clarified. In addition, extensive clinical randomized trials are needed to verify the efficacy and dosage of MPGs.
Topics: Glycosides; Paeonia; Drugs, Chinese Herbal; Monoterpenes; Anti-Inflammatory Agents; Glucosides
PubMed: 38432036
DOI: 10.1016/j.phymed.2024.155483