betadex and linalool

The thermal degradation of linalool-chemotype

Topics: Acyclic Monoterpenes; beta-Cyclodextrins; Capsules; Cinnamomum; Drug Stability; Hot Temperature; Oils, Volatile; Plant Leaves; Plant Oils

Free essential oils and their active components have a low physiochemical stability and low aqueous solubility which limit their applications as food preservatives and in packaging industry. The aim of this study was to characterize the physicochemical properties, antioxidant activities and antimicrobial activity of randomly methylated β cyclodextrin (RAMEB) encapsulated thyme oil, lemon balm oil, lavender oil, peppermint oil and their active components that include thymol, citral, linalool, menthol and borneol. Inclusion complex formation of essential oils (EOs) and RAMEB were evaluated by several methods. Antioxidant capacities of RAMEB-EOs/components were reported to be more stable than free EOs/components (P < 0.05). Rapid SYBR green I/propidium iodide live/dead microbial cellular discrimination assay for Schizosaccharomyces pombe, Escherichia coli and Staphylococcus aureus showed similar results when compared with flow cytometry analysis (P < 0.01) suggesting that our novel microplate fluorescence method could be applied for the fast live/dead microbial discrimination in antimicrobial assays.

Topics: Acyclic Monoterpenes; Anti-Infective Agents; Antioxidants; beta-Cyclodextrins; Escherichia coli; Food Microbiology; Food Preservatives; Lavandula; Mentha piperita; Methylation; Microbial Sensitivity Tests; Monoterpenes; Oils, Volatile; Plant Oils; Schizosaccharomyces; Staphylococcus aureus; Thymol

Supercritical fluid technology (SFT) offers many advantages as a potential complexation method compared to the conventional kneading technique. Its applicability to processess in which solvents are not required is a significant benefit. The main aim of this study was to evaluate, experimentally and computationally, the applicability of SFT in the preparation of β-cyclodextrin complexes with two selected essential oils, namely, carvacrol and linalool. Preparation of the complexes was performed using kneading and SFT method. Several methods were used in the solid-state characterization. These include thermal analysis, powder X-ray diffraction, Fourier transform infrared spectroscopy, and solid-state nuclear magnetic resonance. Besides, molecular dynamics simulations of all studied systems were conducted in order to have a deeper and a detailed insight, at the atomic level, of the nature of the two used techniques. Despite all the advantages of SFT, better results of guest molecule entrapment inside β-cyclodextrin were obtained with the kneading method. The percentages of oil content for linalool samples were 70 ± 14 and 84 ± 9% for SFT and kneading method, respectively, while the drug content values for carvacrol samples were 67 ± 15 and 81 ± 13% for SFT and kneading method, respectively. Interestingly, simulation results were in perfect agreement with the experimental ones and, moreover, they provided a plausible explanation for the obtained results. In conclusion, our results showed that the SFT was unsuccessful in enhancing the stability of the studied complexes contrary to that of the conventational kneading method, and in both cases, molecular dynamics simulations correctly predicted the expected outcomes.

Topics: Acyclic Monoterpenes; beta-Cyclodextrins; Cymenes; Molecular Dynamics Simulation; Monoterpenes; Nuclear Magnetic Resonance, Biomolecular; Oils, Volatile; Solvents; Spectroscopy, Fourier Transform Infrared; Technology, Pharmaceutical; X-Ray Diffraction

Beta-cyclodextrin (β-CD) inclusion complexes with naturally derived antimicrobial (AM) agents: thymol, carvacrol and linalool were prepared using a co-precipitation technique. Conditions including solvent composition, temperature, reaction time and total solvent volume were investigated to optimise the inclusion efficiency (IE) and yield. Electrospray ionisation mass spectrometry was used to confirm the formation of the thymol/β-CD complex and gas chromatography was used to quantify the amount AM agent that was encapsulated, absorbed onto the surface, or remaining in the filtered solvent. The systematic optimisation of the conditions improved both the yield of the complex and the IE of the AM agents compared to previously reported methods that have been applied to other agents. Using a 1:1 mole ratio of the AM agent to β-CD, the optimised parameters resulted in maximum yields of 87, 84 and 86% (w/w) for thymol, carvacrol and linalool, respectively, with IE's close to 100% (w/w) for each agent.

Topics: Acyclic Monoterpenes; Anti-Infective Agents; beta-Cyclodextrins; Cymenes; Monoterpenes; Thymol

Carvacrol and linalool are natural compounds extracted from plants and are known for their insecticidal and repellent activities, respectively. However, their low aqueous solubility, high photosensitivity, and high volatility restrict their application in the control of agricultural pests. The encapsulation of volatile compounds can be an effective way of overcoming such problems. Inclusion complexes between beta-cyclodextrin (β-CD) and carvacrol (CVC) or linalool (LNL) were investigated. Inclusion complexes were prepared by the kneading method. Both complexes presented 1:1 host:guest stoichiometry and the highest affinity constants were observed at 20 °C for both molecules. The nanoparticles containing carvacrol and linalool had mean diameters of 175.2 and 245.8 nm, respectively and high encapsulation efficiencies (<90%) were achieved for both compounds. Biological assays with mites (Tetranychus urticae) showed that the nanoparticles possessed repellency, acaricidal, and oviposition activities against this organism. Nanoencapsulated carvacrol and linalool were significantly more effective in terms of acaricidal and oviposition activities, while the unencapsulated compounds showed better repellency activity. The nanoformulations prepared in this study are good candidates for the sustainable and effective use of botanical compounds in agriculture, contributing to the reduction of environmental contamination, as well as promoting the effective control of pests in agriculture.

Topics: Acyclic Monoterpenes; Animals; beta-Cyclodextrins; Chitosan; Cymenes; Insecticides; Mites; Monoterpenes; Nanoparticles

Linalool (LIN) is a monoterpene alcohol present in some aromatic medicinal plants with biological activities that can impact cardiovascular diseases. This chemical class is highly volatile and β-cyclodextrin (β-CD) has been employed to improve the pharmacological properties of monoterpenes. Thus, the aim of this study was to evaluate the cardiovascular effects of LIN free focusing on the antihypertensive properties of this monoterpene and to study whether LIN, complexed in β-cyclodextrin (LIN-βCD) is able to improve the pharmacological activity of LIN. Spontaneously hypertensive rats (SHR) were randomly divided into 5 groups, each treated daily for 21 days, in the following manner: group 1 (vehicle solution); group 2 (captopril; 30 mg/kg/day); group 3 (LIN; 100 mg/kg/day); group 4 (LIN; 50 mg/kg/day) and group 5 (LIN/β-CD; 50 mg/kg/day). Daily body weight measurements were conducted and mean arterial pressure and heart rate were measured every 5 days. The mesenteric artery from treated animals was tested for phenylephrine and sodium nitroprusside (SNP) sensitivity. The SHR treated with vehicle demonstrated progressive increase in mean arterial pressure and captopril, a positive control, induced a significant decrease. After 21 days of treatment, the blood pressure of the SHR treated by (-)-LIN (100 mg/kg) was significantly reduced. In addition, various important cardiovascular parameters improved, including: the treatment with LIN prevented the development of cardiac hypertrophy, increased levels of the anti-inflammatory cytokine (IL-10), increased vasodilator responsiveness and reduced sensitivity to the sympathetic agonist. Furthermore, the inclusion complex containing LIN in β-CD produced a higher antihypertensive profile when compared with uncomplexed form. Taking together, our results suggested that LIN shown a potential antihypertensive effect and β-CD may be an important tool to improve the cardiovascular activity of LIN and other water-insoluble compounds.

Topics: Acyclic Monoterpenes; Animals; Antihypertensive Agents; beta-Cyclodextrins; Blood Pressure; Dose-Response Relationship, Drug; Drug Carriers; Hypertension; Monoterpenes; Rats, Inbred SHR; Vasodilation

Pesticides are the main tactics for pest control because they reduce the pest population very fast and their efficiency does not depend on abiotic factors. However, the indiscriminate use of these substances can speed up the development of resistant populations and causing environmental contamination. Therefore, alternative methods of pest control are sought, such as the use of botanical compounds. Nanoencapsulation of volatile compounds has been shown to be an important tool that can be used to overcome the lack of stability of these compounds. In this work, we describe the preparation and characterization of chitosan nanoparticles functionalized with β-cyclodextrin containing carvacrol and linalool. The toxicity and biological activity were evaluated. Decreases of toxicity were observed when the compounds were nanoencapsulated. The nanoparticles presented insecticidal activity against the species Helicoverpa armigera (corn earworm) and Tetranychus urticae (spider mite). In addition, repellent activity and reduction in oviposition were observed for the mites.

Topics: Acyclic Monoterpenes; Animals; beta-Cyclodextrins; Biological Control Agents; Cell Survival; Chitosan; Cymenes; Insecticides; Monoterpenes; Moths; Nanoparticles; Pest Control, Biological; Tetranychidae

The volatility and limited water solubility of linalool is a critical issue to be solved. Here, we demonstrated the electrospinning of polymer-free nanofibrous webs of cyclodextrin/linalool-inclusion complex (CD/linalool-IC-NFs). Three types of modified cyclodextrin (HPβCD, MβCD, and HPγCD) were used to electrospin CD/linalool-IC-NFs. Free-standing CD/linalool-IC-NFs facilitate maximum loading of linalool up to 12% (w/w). A significant amount of linalool (45-89%) was preserved in CD/linalool-IC-NFs, due to enhancement in the thermal stability of linalool by cyclodextrin inclusion complexation. Remarkably, CD/linalool-IC-NFs have shown fast-dissolving characteristics in which these nanofibrous webs dissolved in water within two seconds. Furthermore, linalool release from CD/linalool-IC-NFs inhibited growth of model Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria to a great extent. Briefly, characteristics of liquid linalool have been preserved in a solid nanofiber form and designed CD/linalool-IC-NFs confer high loading capacity, enhanced shelf life and strong antibacterial activity of linalool.

Topics: Acyclic Monoterpenes; Anti-Bacterial Agents; beta-Cyclodextrins; Cyclodextrins; Escherichia coli; Monoterpenes; Nanofibers; Staphylococcus aureus

(-)-Linalool is a monoterpene constituent of many essential oils. This particular monoterpene has both anti-inflammatory and antimicrobial activity. Moreover, this compound has been shown to be antinociceptive. However, the poor chemical stability and short half-life prevents the clinical application of (-)-linalool and many other essential oils. Important to the topic of this study, β-cyclodextrin (β-CD) has been used to increase the solubility, stability, and pharmacological effects of numerous lipophilic compounds in vivo. In this study, the gastroprotective activities of (-)-linalool (LIN) and linalool incorporated into inclusion complex containing β-cyclodextrin (LIN-βCD) were evaluated using models of acute and chronic gastric ulcers in rodents. LIN and LIN-βCD showed strong gastroprotective activity (p < 0.001). The LIN-βCD complex revealed that the gastroprotective effect was significantly improved compared with LIN uncomplexed, suggesting that this improvement is related to increased solubility and stability. Taking together the potentiation of the antioxidant profile of this monoterpene, our results suggest that β-CD may represent an important tool for improved gastroprotective activity of (-)-linalool and other water-insoluble compounds.

Topics: Acetic Acid; Acyclic Monoterpenes; Animals; Anti-Ulcer Agents; Antioxidants; beta-Cyclodextrins; Cytoprotection; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Stability; Drug Therapy, Combination; Ethanol; Female; Gastric Mucosa; Lipid Peroxidation; Magnoliopsida; Male; Mice; Monoterpenes; Oils, Volatile; Peroxidase; Phytotherapy; Plant Oils; Plants, Medicinal; Rats, Wistar; Solubility; Stomach; Stomach Ulcer; Sulfhydryl Compounds

The analgesic activity of (-)-linalool (LIN), a monoterpene present in essential oils of Lamiaceae species, has been previously demonstrated in rodents. However, its possible use in the treatment of fibromyalgia (FM) was never demonstrated. Additionally, as a short half-life is a limitation for the LIN medicinal application, the employment of drug delivery systems has been used to improve pharmaceutical properties of this compound. We investigated the anti-nociceptive effect of LIN, isolated or in β-cyclodextrin complex (LIN-CD), in an animal model of chronic non-inflammatory muscle pain (a FM animal model), as well as its effect on the central nervous system (CNS). Male Swiss mice were subjected to two injections of acidic saline (pH 4; 20 μL/gastrocnemius) and were treated on alternate days, with LIN-CD (25 mg/kg, p.o.), LIN (25 mg/kg, p.o.), tramadol (TRM 4 mg/kg, i.p.), or vehicle (neutral saline). After 60 min, they were screened for mechanical hyperalgesia (von Frey), motor coordination (rotarod), and muscle strength (grip strength meter) for 27 days. The CNS areas involved in the anti-hyperalgesic activity were evaluated by immunofluorescence. LIN or LIN-CD produced a significant reduction (p < 0.001) of mechanical hyperalgesia on chronic non-inflammatory muscle pain model, which remained for 24 h only in LIN-CD, and these compounds significantly (p < 0.05) activated neurons of the locus coeruleus, nucleus raphe magnus, and periaqueductal gray areas. So, our results suggest that LIN-CD improved analgesic profile of LIN, with a probable involvement of descending pain pathways and the anti-nociceptive effect of linalool in an animal model of chronic non-inflammatory muscle pain. So far, only the investigations in animal models of inflammatory pain and supraspinatus were published.

Topics: Acyclic Monoterpenes; Animals; beta-Cyclodextrins; Disease Models, Animal; Drug Therapy, Combination; Fibromyalgia; Gene Expression Regulation; Hyperalgesia; Male; Mice; Monoterpenes; Pain Measurement; Proto-Oncogene Proteins c-fos

Many plants produce (-)-linalool, a plant-derived monoterpene alcohol, including members of the Lamiaceae (mints) and Lauraceae family (laurels, cinnamon, rosewood). The anti-inflammatory and analgesic effects of (-)-linalool have been widely suggested for various studies. Poor chemical stability and short half-life restrain the clinical applications of some essential oil and monoterpenes, including (-)-linalool. However, β-cyclodextrin (β-CD) has been used to increase solubility and stability of lipophilic compounds and also to improve the pharmacological effects. In this study, the antinociceptive effect of (-)-linalool and (-)-linalool/β-CD was examined using the acetic acid writhing reflex, formalin and hotplate tests in rodents. (-)-Linalool and (-)-linalool/β-CD demonstrated strong antinociceptive activity in all the chemical- and heat-induced mice models (p < 0.01 or p < 0.001). These findings imply the involvement of both peripheral and central antinociceptive mechanisms. In peritonitis induced by carrageenan, isolated monoterpene or β-CD complex also reduced total leucocyte migration and TNF-α levels in peritoneal fluid. The inclusion complexes, (-)-linalool/β-CD, revealed that the antinociceptive effect was significantly (p < 0.01) improved when compared with (-)-linalool alone. Such results were unlikely to be provoked by any motor abnormality. Together, our results suggest that β-CD might represent an important tool for improvement of analgesic and anti-inflammatory profiles of (-)-linalool and other water-insoluble compounds, such as lipophilic monoterpenes or essential oils.

Topics: Acyclic Monoterpenes; Analgesics; Animals; beta-Cyclodextrins; Disease Models, Animal; Drug Carriers; Humans; Male; Mice; Monoterpenes; Pain; Tumor Necrosis Factor-alpha

The aim of this study was to increase the stability and water solubility of fragrance materials, to provide controlled release of these compounds, and to convert these substances from liquid to powder form by preparing their inclusion complexes with cyclodextrins (CDs). For this purpose, linalool and benzyl acetate were chosen as the fragrance materials. The use of beta-cyclodextrin (beta CD) and 2-hydroxypropyl-beta-cyclodextrin (2-HP beta CD) for increasing the solubility of these 2 fragrance materials was studied. Linalool and benzyl acetate gave a B-type diagram with beta CD, whereas they gave an A(L)-type diagram with 2-HP beta CD. Therefore, complexes of fragrance materials with 2-HP beta CD at 1:1 and 1:2 molar ratios (guest:host) were prepared. The formation of inclusion complexes was confirmed using proton nuclear magnetic resonance ((1)H-NMR) spectroscopy and circular dichroism spectroscopy. The results of the solubility studies showed that preparing the inclusion complex with 2-HP beta CD at a 1:1 molar ratio increased the solubility of linalool 5.9-fold and that of benzyl acetate 4.2-fold, whereas the complexes at a 1:2 molar ratio increased the solubility 6.4- and 4.5-fold for linalool and benzyl acetate, respectively. The stability and in vitro release studies were performed on the gel formulations prepared using uncomplexed fragrance materials or inclusion complexes of fragrance materials at a 1:1 molar ratio. It was observed that the volatility of both fragrance materials was decreased by preparing the inclusion complexes with 2-HP beta CD. Also, in vitro release data indicated that controlled release of fragrances could be possible if inclusion complexes were prepared.

Topics: 2-Hydroxypropyl-beta-cyclodextrin; Acyclic Monoterpenes; Benzyl Compounds; beta-Cyclodextrins; Chromatography, High Pressure Liquid; Circular Dichroism; Cosmetics; Magnetic Resonance Spectroscopy; Monoterpenes; Perfume; Powders; Reproducibility of Results; Solubility; Solutions; Solvents; Time Factors; Volatilization; Water