(+)-Menthone

Natural peppermint-flavored cheese.[Pubmed:30927754]

Acta Sci Pol Technol Aliment. 2019 Jan-Mar;18(1):75-85.

BACKGROUND: The essential oils of edible and medicinal plants, herbs and spices are natural biologically ac- tive agents. Peppermint has a special position in Egyptian culture and is used as fresh or dried leaves. One of the main aims of the food industry is to manufacture products with good sensory acceptance. The present study aims to produce a novel attractive cheese with a low concentration of natural peppermint (Mentha piperita) essential oil (PEO). Moreover, PEO volatile composition, total phenolic content (TPC) and antioxidant activity extracted by the hydro-distillation of peppermint fresh leaves were investigated. METHODS: Volatile components of PEO were identified using a GC-MS instrument. Total phenolic content and antioxidant activity were determined using the DPPH radical scavenging method for PEO. Moreover, PEO-flavored cheeses at a level of 20, 40, 60, 80 and 100 ppm compared to plain cheese were analyzed for sensorial, chemical and rheological properties during storage at 5°C. RESULTS: Identification of PEO’s volatile compounds using GC-MS with a flame ionization detector analy- sis showed that the main components were menthol (37.62%), menthone (20.98%), carvone (11.76%), dihydro carveol acetate (11.23%), cineol (5.89%), β-caryophyllene (2.94), limonene (2.78%) and iso-menthone (2.39). Moreover, the antioxidant activity of PEO was 56.03 (%) with a TPC of 0.299 (mg/ml). Sensory evaluation of cheese showed the flavor and body and texture of PEO-flavored cheeses were higher than plain cheese during the storage period. There were no significant (p ≤ 0.05) differences in the cheese’s appearance nor in the chemical composition of plain and PEO-flavored cheeses. However, the TVFA and SN of plain cheese was significantly (p ≤ 0.05) lower than PEO cheeses at the level of 60, 80 and 100 ppm during the storage period. CONCLUSIONS: Hydro-distillation of Egyptian peppermint leaves revealed a lot of volatile compounds and antioxidant activity for the resulting essential oil; Moreover, the presence of PEO in cheese leading to enhanced TVFA and SN nitrogen contents compared to plain cheese may offer a novel flavored cheese with desirable multifunctional health effects in humans. Peppermint-flavored cheese was more accepted than plain cheese and survived without any defects until the end of the cheese storage period.

Controlled Release of Peppermint Oil from Paraffin-Coated Activated Carbon Contained in Sachets to Inhibit Mold Growth During Long Term Storage of Brown Rice.[Pubmed:30912858]

J Food Sci. 2019 Apr;84(4):832-841.

The aim of the study was to control the release of peppermint oil (700 microL/L) by coating activated carbon (AC) contained in sachets with different solutions (tapioca starch, corn starch, gelatine, carnauba, paraffin, and mixed carnauba-paraffin) for inhibiting the growth of Aspergillus flavus on brown rice (BR). Paraffin-coated AC with adsorbed peppermint oil was then applied to extend the shelf life of BR during long-term storage (60 days) at 30 +/- 2 degrees C. The mechanism of peppermint oil vapor release in this system was also studied using GC-MS. The result revealed that paraffin-coated AC with adsorbed peppermint oil present in sachets showed the highest antifungal activity against A. flavus growing on the surface of BR. In addition, paraffin-coated AC with adsorbed peppermint oil could prolong the shelf life of BR from 10 days (control) to at least 60 days under tropical climatic conditions. Moreover, storage of BR in the presence of sachets containing paraffin-coated AC with adsorbed peppermint oil at a concentration of 700 microL/L revealed no significant effects on major rice quality-related factors, such as moisture content, color, water uptake percentage, and gelatinization temperature. Peppermint oil component analysis by GC-MS indicated that paraffin could trap some minor components of peppermint oil and allow the major components such as menthone, menthol, and alpha-pinene, which are compounds that play an important role in mold growth inhibition, to be exposed to air. Thus, this research demonstrated the potential of paraffin-coated AC containing adsorbed peppermint oil for controlling the growth of molds during prolonged rice storage. PRACTICAL APPLICATION: Paraffin-coated activated carbon with adsorbed peppermint oil has the potential to be commercially applied to brown rice grains for facilitating long-term storage. This technique is beneficial for avoiding the occurrence of negative sensorial factors when peppermint oil vapors are used. This process is interesting and easy to apply during large-scale implementation of a rice storage system.

Chemical Composition and in vivo Efficacy of the Essential Oil of Mentha piperita L. in the Suppression of Crown Gall Disease on Tomato Plants.[Pubmed:30867394]

J Oleo Sci. 2019 Mar 13.

This study was undertaken to determine the antibacterial efficacy of the essential oil (EO) of peppermint (Mentha piperita L.), in vitro and in vivo, against the phytopathogenic bacteria Agrobacterium tumefaciens (A. tumefaciens). The EO composition of M. piperita L. was investigated by Gas chromatography-mass spectrometry (GC/MS) with 26 identified volatile constituents. The major constituents were menthol (33.59%) and iso-menthone (33.00%). This EO exerted a bactericidal activity against multiple strains of Agrobacterium species with minimum inhibitory concentration (MIC) values ranged from 0.01 to 12.50 mg/mL. In planta experiments, M. piperita EO, tested at concentration of 200 mg/mL, completely inhibited the formation of tumors on tomato plants inoculated with pathogenic strain A. tumefaciens ATCC 23308(T). These results suggest that M. piperita EO could be used to control plant bacterial disease caused by A. tumefaciens.

The effects of vitamin C and menthone on acyclovir induced DNA damage in rat spermatozoa: An experimental study.[Pubmed:30775686]

Int J Reprod Biomed (Yazd). 2018 Nov;16(11):703-710.

Background: Acyclovir (ACV) is known to be toxic to gonads, inducing apoptosis in the reproductive system. The beneficial effects of vitamin C (Vit C) and menthone, both as antioxidant agents on various organs has been reported. Objective: This study evaluated the potential role of the Vit C and menthone on the DNA damage in rat spermatozoa induced by the ACV. Materials and Methods: In this experimental study, adult male albino Wistar rats with average weight of 250+/-10 gr, were divided into six groups (n=18/each), as: ACV (15 mg/kg/day), ACV+Vit C (20 mg/kg/day), ACV+ menthone (100 microl/d), ACV+ menthone (250 microl/d), ACV+ menthone (400 microl/day) and control group without any treatment. At the end of experiment, the animals were sacrificed and sperm samples were collected and isolated in phosphate-buffered saline and examined by TUNEL staining process. The percentage of TUNEL positive spermatozoa was evaluated by fluorescence microscopy. Each experiment was performed in three repeats. Results: Male rats exposed to ACV had significant increase in DNA damages in comparison to other groups. The percentage of TUNEL positive sperm cells was 90.83 (p<0.001) in ACV group. The protective role of both antioxidants used in high dose, compensate the adverse effects of the ACV. The results showed that the percentage of apoptotic sperm in the ACV+Vit C group was 16.38 (p<0.001) and in the ACV+ menthone (400 microl/d) group was 16.05 (p<0.001). Conclusion: The present results showed that Vit C and menthone at higher dose have a good compensatory effect with significant reduction in DNA damages in sperm cells by reversing the adverse effect of ACV on the reproductive system in male rat.

Chemical Composition of the Essential Oil of the Endemic Species Micromeria frivaldszkyana (Degen) Velen.[Pubmed:30691126]

Molecules. 2019 Jan 26;24(3). pii: molecules24030440.

Micromeria frivaldszkyana is an endemic species found only in Bulgaria. Its essential oil (EO) composition is unknown. This study assessed the EO yield and composition of M. frivaldszkyana as a function of the location and of drying prior to the EO extraction. M. frivaldszkyana was sampled from two natural habitats, Uzana and Shipka in the Balkan Mountains; the EO was extracted via hydrodistillation and analyzed on GC/MS. The plants from the two locations had distinct EO composition. The EO content (in dried material) was 0.18% (Uzana) and 0.26% (Shipka). Monoterpene ketones were the major group of the EO constituents. Also, hydrocarbons predominated in the EO from Shipka, and alcohols predominated in the EO from Uzana. The EO from Uzana had a greater concentration of menthone (56% vs. 17% from Shipka) and neomenthol (7.8% vs. 2.4%). Conversely, the EO from Shipka had greater concentrations of pulegone (50% vs. 20% from Uzana), limonene (10.1% vs. 2.6%), and germacrene D (3.4% vs. 1.1%). Drying prior to the EO extraction altered the concentration of some constituents. This is the first report of M. frivaldszkyana EO yield and composition. The EO showed some similarities with the chemical profile of other Micromeria species, but overall, it has an unique chemical profile and may have distinctive applications.

Influence of six essential oils on invasive Solidago canadensis L. seed germination.[Pubmed:30689411]

Nat Prod Res. 2019 Jan 28:1-3.

Solidago canadensis L. (SC) (Canadian goldenrod) is a dangerous plant invader in Europe, which suppress the indigenous flora. Essential oils (EOs) are considered biological control agents. GC-MS analysis for identification of main components was conducted and the potential phytotoxicity of six EOs were also evaluated. Limonene and beta-thujone were dominant components in Salvia officinalis L., menthone and menthol in Mentha x piperita L., carvacrol in Origanum vulgare L., estragole/anisole and anethole in Foeniculum vulgare Mill., limonene and carvone in Anethum graveolens L., and anethole in Pimpinella anisum L. Along with EOs, anethole, anisole, camphor, carvone, estragole, limonene, menthol, menthone, thujone and thymol were used independently to evaluate phytotoxic effect against Canadian goldenrod seed germination. A significant inhibitory effect was registered for origanum (1.250 microg.ml(-1)). The influence of single components was significant. The highest phytotoxic activity was registered with anethole and estragole. Phenolic compounds were the inhibitoriest, followed by oxygenated and hydrocarbon monoterpenes.

Synthesis of nitrogen-containing monoterpenoids with antibacterial activity.[Pubmed:30663357]

Nat Prod Res. 2019 Jan 19:1-6.

Incorporation of the Beckmann rearrangement into the presented research resulted in the formation of nitrogen-containing terpenoid derivatives originating from naturally occurring compounds. Both starting monoterpenes and obtained derivatives were subjected to estimation of their antibacterial potential. In the presented study, Staphylococcus aureus was the most sensitive to examined compounds. The Minimal Inhibitory Concentration (MIC) experiments performed on S. aureus demonstrated that the (-)-menthone oxime (-)-8 and (+)-pulegone oxime (+)-13 had the best antibacterial activity among the tested derivatives and starting compounds. Their MIC90 value was 100 microg/mL. The obtained derivatives were also evaluated for their inhibitory activity against bacterial urease. Among the tested compounds, three active inhibitors were found - oxime 14 and lactams (-)-15 and 16 limited the activity of Sporosarcina pasteurii urease with Ki values of 174.3 microM, 43.0 microM and 4.6 microM, respectively. To our knowledge, derivative 16 is the most active antiureolytic lactam described to date.

Insecticidal potential and repellent and biochemical effects of phenylpropenes and monoterpenes on the red flour beetle, Tribolium castaneum Herbst.[Pubmed:30635879]

Environ Sci Pollut Res Int. 2019 Mar;26(7):6801-6810.

The main objectives of the present study are to introduce new, ecologically safe, and natural compounds for controlling red flour beetle, Tribolium castaneum, and to understand the possible mode of action of these compounds. Therefore, the insecticidal and repellent activities of two phenylpropenes and six monoterpenes have been evaluated against the adults of T. castaneum. The inhibitory effects of these compounds on the activity of adenosine triphosphatases (ATPases) and acetylcholinesterase (AChE) were also tested. In fumigant toxicity assay, (-)-terpinen-4-ol (LC50 = 20.47 mul/l air) and alpha-terpinene (LC50 = 23.70 mul/l air) exhibited the highest toxicity without significant differences between them. Moreover, (-)-menthone and p-cymene showed strong toxicity, while (-)-citronellal, trans-cinnamaldehde, and eugenol were not active. In contact toxicity assay, the two phenylpropenes, trans-cinnamaldehde and eugenol, had the highest toxicity with same LC50 value of 0.02 mg/cm(2). The monoterpenes and phenylpropenes showed pronounced repellent effect on the adults of T. castaneum at 0.001 mg/cm(2) with (-)-menthone, trans-cinnamaldehyde, and alpha-terpinene being the most effective after 2 h of exposure. Repellent activity depended on compound, exposure time, and concentration. On the other hand, the tested compounds exhibited strong inhibition of ATPases form the larvae of T. castaneum as their IC50 values ranged between 1.74 and 19.99 mM. In addition, (-)-citronellal (IC50 = 9.82 mM) and trans-cinnamaldehde (IC50 = 23.93 mM) caused the highest inhibitory effect on AChE, while alpha-pinene (IC50 = 53.86) and p-cymene (IC50 = 68.97 mM) showed the weakest inhibitory effect. The results indicated that the tested phenylpropenes and monoterpenes had the potential to be developed as natural insecticides and repellents for controlling T. castaneum.

Seasonal Variation in Essential Oils Composition and the Biological and Pharmaceutical Protective Effects of Mentha longifolia Leaves Grown in Tunisia.[Pubmed:30627570]

Biomed Res Int. 2018 Dec 9;2018:7856517.

This research assessed the seasonal variation of the chemical composition and antibacterial and anticholinesterase activities of essential oils extracted from M. longifolia leaves. The leaves organic fractions were also investigated for their biological activities and pharmacological functions. The essential oil highest yield was recorded in the spring season. Pulegone (26.92%), 1.8 cineole (21.3 %), and L-menthone (10.66 %) were determined as its major compounds in the winter season. In the spring oil, the main components were pulegone (38.2 %) and oleic and palmitic acids (23.79 % and 15. 26 %, respectively). Oxygenated monoterpenes were predominant in the two analyzed samples. The tested oils and organic extracts exhibited promising antibacterial effects against all of the tested bacterial strains. Thanks to its richness in phenolic and flavonoid compounds, the ethyl acetate fraction (Ml EtOAcF) displayed the most active DPPH scavenging ability (IC50 =12.64 mug/ml) and an interesting beta-carotene bleaching inhibition (IC50 =34.75 mug/ml) making it a potential candidate for anti-inflammatory evaluation on rats. This evaluation evidenced that M. longifolia pretreated rats showed a marked decrease in paw oedema and inflammatory cells. Additionally, a remarkable acetylcholinesterase inhibitory activity of the Ml EtOAcF (IC50 = 12.3mug/ml) and essential oils were also observed suggesting their neuroprotective property against Alzheimer's disease. Moreover, it was found that its activity level was season dependent. Our investigation, therefore, clearly revealed the medicinal characteristics of M. longifolia leave indicating their potential uses for natural remedies.

[Changes of ion absorption, distribution and essential oil components of flowering Schizonepeta tenuifolia under salt stress].[Pubmed:30593232]

Zhongguo Zhong Yao Za Zhi. 2018 Nov;43(22):4410-4418.

In this paper, a pot experiment using quartz sands was conducted to study the effects of different concentrations of NaCl (0, 25, 50, 75, 100 mmol.L(-)(1)) on the ion absorption, distribution and essential oil components of flowering Schizonepeta tenuifolia. The results showed that as NaCl concentration increased, Na(+) content of root, stem, leaf and flower increased significantly, and that of the aerial parts was in a higher level than in the root. Regarding the K(+) content, it decreased in the root but increased in stem, leaf and flower. Some changes were detected in the Ca(2)(+) content, but not significant on the whole. The value of K(+)/Na(+) and Ca(2)(+)/Na(+) reduced as a result of increasing NaCl concentrations. The content of essential oil increased under medium salt treatment (50 mmol.L(-)(1) NaCl). However, the synthesis and accumulation of essential oil was inhibited by the serious salt treatment (100 mmol.L(-)(1) NaCl). Over 98% of the essential oil components were terpenes, in which pulegone and menthone were the most two abundant compounds. Varieties of essential oil components did not change significantly under salt stress but their relative proportions did. The transformation of pulegone to menthone was enhanced and the value of pulegone/menthone based on their relative contents decreased with NaCl concentration increasing. Consequently, menthone ranked the most abundant compound by replacing pulegone. Relative content of D-limonene increased under medium and serious salt stress, and that of beta-caryophyllene only increased under mild treatments. So our research could provide references for the standard cultivation on saline soil of S. tenuifolia.

Radiation-mediated molecular weight reduction and structural modification in carrageenan potentiates improved photosynthesis and secondary metabolism in peppermint (Mentha piperita L.).[Pubmed:30521890]

Int J Biol Macromol. 2019 Mar 1;124:1069-1079.

In an attempt to gain insights into the possible relationship between the irradiation-mediated molecular weight reduction and structural modification and the growth-promotion activity, characterization of the polysaccharide before and after irradiation was carried out through Fourier Transform Infrared (FT-IR), Ultraviolet-visible (UV-vis) and Nuclear Magnetic Resonance (NMR) spectroscopic studies. Moreover, graded concentrations of irradiated carrageenan (IC) were applied through foliage to assess the performance of peppermint (Mentha piperita L.). Among the various concentrations of IC [0 (control), un-irradiated carrageenan (UC), 40, 80, 120, 160 and 200mgL(-1)], the effect of 80mgL(-1) IC established to be most favorable for most of the parameters studied. Rubisco and phenylalanine ammonia lyase activities were maximally enhanced by 65.9% and 35.6% by the application of 80mgL(-1) IC, respectively; as compared to the control and UC. A maximum enrichment in the content (32.8%) and yield (88.3%) of essential oil was noted by the application of 80mgL(-1) IC, respectively. Results of the gas chromatography revealed that the contents of menthol and 1, 8-cineole were increased; however, menthone and menthyl-acetate contents were decreased by the application of IC over the control and UC.

External Reversal of Chirality Transfer in Photoswitches.[Pubmed:30513134]

Angew Chem Int Ed Engl. 2019 Feb 11;58(7):1945-1949.

The transfer of stereoinformation is at the heart of asymmetric reactions. By incorporating the natural monoterpene l-menthone into the backbone of a diarylethene, we achieved efficient chirality transfer upon photocyclization, resulting in the preferred formation of one major closed isomer in a diastereomeric ratio (d.r.) of 85:15. More significantly, we were able to completely reverse the diastereomeric outcome of the ring closure simply by altering the chemical environment or the irradiation conditions. As a result, we could selectively accumulate the less favored minor closed isomer, with remarkable d.r. values of >99:1 and 74:26, respectively. Computations revealed that a stability inversion after photocyclization is the basis for the observed unprecedented control over diastereoselectivity.

Volatile Flavor Components of Blended Tea with Fermented Tea and Herbs.[Pubmed:30386753]

Prev Nutr Food Sci. 2018 Sep;23(3):245-253.

This study was conducted to characterize the volatile components of Korean fermented tea and blended tea with Korean fermented tea and several herbs. A total of 161 volatile components in 4 samples of FT (fermented tea), BT (blended tea) 1, BT2, and BT3 were analyzed in this study. A total of 61 volatile compounds were identified in the FT sample, which contained the most abundant hydrocarbons. The major compounds were 3-methyldecane (10.48%), 2,2,4, 6,6-pentamethylheptane (10.00%), and 2,3,6-trimethyloctane (7.90%). A total of 75 volatile compounds were identified in the BT1 sample, which consisted of fermented tea, orange cosmos, lemon grass, chamomile, and peppermint. L-(-)-menthol (36.79%), menthone (24.92%), and isomenthone (8.70%) were the highest compounds. A total of 76 volatile compounds were identified in the BT2 sample, which was composed of fermented tea, rose hip, lemongrass, lavender, and peppermint. Alcohols were identified as the most abundant, and linalool (26.32%), linalyl acetate (18.45%), and L-(-)-menthol (11.99%) were the major components. A total of 85 volatile compounds were identified in the BT3 sample composed of fermented tea, citrus peel, chamomile, hibiscus, and beet. Sesquiterpenes were identified as the most abundant including L-limonene (74.45%), beta-myrcene (3.06%), and gamma-terpinene (7.47%).

Phytotoxicity of Essential Oils on Selected Weeds: Potential Hazard on Food Crops.[Pubmed:30248993]

Plants (Basel). 2018 Sep 22;7(4). pii: plants7040079.

The chemical composition of winter savory, peppermint, and anise essential oils, and in vitro and in vivo phytotoxic activity against weeds (Portulaca oleracea, Lolium multiflorum, and Echinochloa crus-galli) and food crops (maize, rice, and tomato), have been studied. Sixty-four compounds accounting for between 97.67(-)99.66% of the total essential oils were identified by Gas Chromatography-Mass Spectrometry analysis. Winter savory with carvacrol (43.34%) and thymol (23.20%) as the main compounds produced a total inhibitory effect against the seed germination of tested weed. Menthol (48.23%), menthone (23.33%), and iso-menthone (16.33%) from peppermint only showed total seed germination inhibition on L. multiflorum, whereas no significant effects were observed with trans-anethole (99.46%) from anise at all concentrations (0.125(-)1 microL/mL). Low doses of peppermint essential oil could be used as a sustainable alternative to synthetic agrochemicals to control L. multiflorum. The results corroborate that in vivo assays with a commercial emulsifiable concentrate need higher doses of the essential oils to reproduce previous in vitro trials. The higher in vivo phytotoxicity of winter savory essential oil constitutes an eco-friendly and less pernicious alternative to weed control. It is possible to achieve a greater in vivo phytotoxicity if less active essential oil like peppermint is included with other active excipients.