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Background There is always an increasing demand for natural remedies from natural sources which can substitute the synthetic therapeutic drugs and lessen their side effects. The present study aims to investigate the antioxidant, anti-inflammatory, antimicrobial properties and in silico docking study of Citrus macroptera leaf (CML) extract in both in vivo and in vitro aspect. Material and methods The antioxidant and anti-inflammatory potential of crude extract was investigated in vitro and in vivo on Wistar albino rat. The antioxidant potentiality also investigated on HepG2 cell line. Antimicrobial activity was evaluated against Staphylococcus sp. and Klebsiella sp. Chemical compounds of the crude extract were identified by GC-MS analysis. In silico docking was also done against NF-ҡB protein. Results At 200 μg/ml concentration, CML significantly scavenges reactive oxygen species (ROS) which was generated on HepG2 cell line. CML showed 71% anti-inflammatory activity (p ≤ 0.001) against carrageenan-induced paw edema in albino Wistar rats. CML extract is very effective against staphylococcus sp. than Klebsiella sp. In the docking analysis, the proximadiol and menthone had − 5.6 kcal/mol and − 5.7 kcal/mol binding affinity with the protein NF-ҡB. Conclusion In the present work, CML provided notable antioxidant, anti-inflammatory, and antimicrobial activity. This activity was confirmed by both in vitro and in vivo followed by in silico docking technique. Overall, the experimental results presented in this study suggest that crude extract of CML could be used as a promising antioxidant and anti-inflammatory candidate with potential benefits.

Vulvovaginal candidiasis is a common health problem affecting about 75% of women at reproductive age. Teratogenicity and fetal toxicity resulting from antifungal therapy during pregnancy necessitates formulation of novel therapeutic agents. Disk diffusion method was performed to evaluate the antifungal activity of Mentha longifolia extracts against different candidal strains. Moreover, the anticancer activity of different M. longifolia extracts against MCF7 breast cancer cell line was evaluated by MTT assay. The M. longifolia n-hexane extract exhibited the highest antifungal activity, while the methanolic extract showed no antimicrobial activity against the tested Candida strains. Minimum inhibitory concentration (MIC) of n-hexane extract was 250 µg/disk against C. tropicalis while it was 500 µg/disk against C. albicans and C. glabrata. Minimum fungicidal concentration (MFC) was 0.5 mg/disk against C. albicans and C. tropicalis, and 1 mg/disk against C. glabrata. GC–MS analysis of the n-hexane extract was performed to detect the active phytochemical components. Menthone (18.37%) was the main phytochemical active component of n-hexane extract followed by butyloctanol (16.13%), 1,5-(1-Bromo-1-methylethyl)-2-methyl-2-cyclohexen-1-one (14.89%), α-tocopherol (13.13%), eugenol (12.21%), α-resorcylamide (11.56%), citronellal (3.71%), butylated hydroxytoluene (3.21%), isocaryophyllene (2.81%), 2-hexyldecanol (2.12%) and tau-cadinol (1.87%). The methanolic extract exhibited the highest anticancer activity against MCF7 breast cancer cell line while diethyl ether extract exhibited the lowest activity with IC50 of 91.67 and 244.70 µg/ml respectively. M. longifolia extracts could be used as a potential source of novel anticandidal and anti-carcinogenic therapeutic agents. Keywords: Vulvovaginal candidiasis, Mentha longifolia, Anti-candida, Minimum inhibitory concentration, Cytotoxicity, Phytochemicals

Platinum nanoparticles supported on MgO, Al2O3, ZrO2, TiO2 were utilized for monoterpenoid oximes hydrogenation. Monocyclic menthone and carvone oximes synthesized from bio-derived monoterpenoids with a different structure were used to explore the effect of substrate structure on the reaction regularities. The oximes hydrogenation was carried out under hydrogen atmosphere at 100 °C using methanol as a solvent. Platinum catalysts were prepared by the impregnation methods. The catalysts were characterized by transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray fluorescence spectroscopy, nitrogen physisorption. Hydrogenation of carvone oxime containing a conjugated oxime group and several reducible functional groups resulted in both hydrogenation and deoximation giving 5-isopropyl-2-methylcyclohexanamine and carvomenthone over Pt/Al2O3 and Pt/ZrO2 catalysts. Menthone oxime hydrogenation over Pt/Al2O3 catalysts with an average particle size of 0.8 nm provided the desired menthylamine formation with the selectivity of 90% at complete oxime conversion. Platinum catalysts based on MgO, ZrO2 and TiO2 enhanced menthone oxime deoximation to menthone.

The aim of the present work is to evaluate the protective ability of newly menthone derivatives 7-isopropyl-4-methyl-4,5,6,7-tetrahydro-1H-indazole (HMP) and 7-isopropyl-4-methyl-1-phenyl-4,5,6,7-tetrahydro-1H-indazole (PMP) as mild steel corrosion inhibitors in 1M HCl, which may get applications as eco-friendly corrosion inhibitors in acidizing processes in the industry. The corrosion attitude of mild steel at various concentrations of the inhibitors was examined in the range from 298 to 328 K. An increase in the inhibitory effectiveness in acidic solution at higher concentration and temperature follow the existence of inhibitors. The aspect of adsorption mixed type of inhibitors was highlighted by the Polarization curves. The adsorption of HMP and PMP is in line with the Langmuir isotherm model. Theoretical indices study of both inhibitors (HMP and PMP) via CDFT (the conceptual density functional theory) has been studied. To search for the best spatial configuration of steel/inhibitor a Monte Carlo simulation studies were applied.

Cera pepper ( Capsicum pubescens ) is an exotic fruit considered as a rich source of nutraceuticals with known benefits for human health and also an economic resource for local producers in Mexico. The present investigation reports on the in vitro and in situ antifungal activity of the essential oil from Mentha piperita and its two major volatiles (menthol and menthone) against Fusarium sambucinum , which is a causal agent of soft rot in cera pepper. The application of these components in pepper fruits previously infected with F. sambucinum caused a significant delay (p < 0.05) in the emergence of soft rot symptoms. This effect was reflected in the maintenance of pH and fruit firmness during a period of 10 days. The nutrimental content of the fruits (protein, fiber, fat and other proximate parameters) was conserved in the same period of time. The nutraceutical content of these fruits was estimated by the quantification of seven carotenoids (violaxanthin, cis-violaxanthin, luteoxanthin, antheraxanthin, lutein, zeaxanthin and beta-carotene), ascorbic acid and capsaicinoids (capsaicin and dihydrocapsaicin). According to our results, the essential oil from M. piperita and its major volatiles exerted a preservative effect on these metabolites. Our findings demonstrated that the essential oil of M. Piperita and its major volatiles represent an ecological alternative for the control of fusariosis caused by F. sambucinum in cera peppers under postharvest conditions.

A series of novel menthone derivatives bearing pyrimidine and urea moieties was designed and synthesized to explore more potent natural product-derived antitumor agents. The structures of the target compounds were confirmed by FTIR, NMR, and HRMS. The in vitro antitumor activity was tested by standard methyl thiazolytetrazolium assay and showed that 4i, 4g, 4s, and 4m are the best compounds with IC50 values of 6.04 ± 0.62µM, 3.21 ± 0.67µM, 19.09 ± 0.49µM, and 18.68 ± 1.53µM, against Hela, MGC-803, MCF-7, and A549, respectively. The results of the preliminary action mechanism studies showed that compound 4i, the representative compound, could induce cell apoptosis in Hela cells in a dose-dependent manner and might arrest the cell cycle in the G2/M phase. Furthermore, the results of network pharmacology prediction and Western blot experiments indicated that compound 4i might inhibit Hela cells through inhibit PI3K/Akt/mTOR signaling pathway. The binding modes and the binding sites interactions between compound 4i and the target proteins were predicted preliminarily by the molecular docking method.

Monoterpenoids are the main components of plant essential oils and the active components of some traditional Chinese medicinal herbs like Mentha haplocalyx Briq., Nepeta tenuifolia Briq., Perilla frutescens (L.) Britt and Pogostemin cablin (Blanco) Benth. Pulegone reductase is the key enzyme in the biosynthesis of menthol and is required for the stereoselective reduction of the Δ2,8 double bond of pulegone to produce the major intermediate menthone, thus determining the stereochemistry of menthol. However, the structural basis and mechanism underlying the stereoselectivity of pulegone reductase remain poorly understood. In this study, we characterized a novel (−)-pulegone reductase from Nepeta tenuifolia (NtPR), which can catalyze (−)-pulegone to (+)-menthone and (−)-isomenthone through our RNA-seq, bioinformatic analysis in combination with in vitro enzyme activity assay, and determined the structure of (+)-pulegone reductase from M. piperita (MpPR) by using X-ray crystallography, molecular modeling and docking, site-directed mutagenesis, molecular dynamics simulations, and biochemical analysis. We identified and validated the critical residues in the crystal structure of MpPR involved in the binding of the substrate pulegone. We also further identified that residues Leu56, Val282, and Val284 determine the stereoselectivity of the substrate pulegone, and mainly contributes to the product stereoselectivity. This work not only provides a starting point for the understanding of stereoselectivity of pulegone reductases, but also offers a basis for the engineering of menthone/menthol biosynthetic enzymes to achieve high-titer, industrial-scale production of enantiomerically pure products.

In this work, we studied in vitro propagation of three cultivars of Mentha × piperita L. Murashige and Skoog medium (MS) supplemented with 0.5 mg·L−1 BAP was the most optimal medium for micropropagation of the cultivars studied. The ability of peppermint plants field-acclimated after in vitro micropropagation to produce essential oils (EOs) was investigated. EO was obtained by hydrodistillation from dried leaves and flowering shoots from control (field grown) plants and plants acclimated in field conditions after in vitro propagation. The samples were collected at the first and second year of vegetation, and their chemical composition was investigated using gas chromatography-mass spectrometry (GC-MS). Differences were observed in the yield, as well as in the quantitative and qualitative composition of the EOs extracted from the control plants and field-acclimated plants after in vitro propagation. Menthol was the main component of the EO in control plants, while pulegone and menthone were dominant in the EO pattern in field-acclimated in vitro regenerants in the first year of the growing season. However, in the second year of vegetation, the content of the main EO components in field-acclimated peppermint plants was approximately the same as in control plants. The antioxidant activity of EOs extracted from field-acclimated after in vitro micropropagation plants was found to be the same as in control field-grown M. × piperita plants.

Peppermint (Mentha x piperita L.) and Japanese catnip (Schizonepeta tenuifolia (Benth.) Briq.) accumulate p-menthane monoterpenoids with identical functionalization patterns but opposite stereochemistry. In the present study, we investigate the enantioselectivity of multiple enzymes involved in monoterpenoid biosynthesis in these species. Based on kinetic assays, mint limonene synthase, limonene 3-hydroxylase, isopiperitenol dehydrogenase, isopiperitenone reductase, and menthone reductase exhibited significant enantioselectivity toward intermediates of the pathway that proceeds through (-)-4S-limonene. Limonene synthase, isopiperitenol dehydrogenase and isopiperitenone reductase of Japanese catnip preferred intermediates of the pathway that involves (+)-4R-limonene, whereas limonene 3-hydroxylase was not enantioselective, and the activities of pulegone reductase and menthone reductase were too low to acquire meaningful kinetic data. Molecular modeling studies with docked ligands generally supported the experimental data obtained with peppermint enzymes, indicating that the preferred enantiomer was aligned well with the requisite cofactor and amino acid residues implicated in catalysis. A striking example for enantioselectivity was peppermint (-)-menthone reductase, which binds (-)-menthone with exquisite affinity but was predicted to bind (+)-menthone in a non-productive orientation that positions its carbonyl functional group at considerable distance to the NADPH cofactor. The work presented here lays the groundwork for structure-function studies aimed at unraveling how enantioselectivity evolved in closely related species of the Lamiaceae and beyond.

Several economically important crops, fruits and vegetables are susceptible to infection by pathogenic fungi and/or bacteria postharvest or in field. Recently, plant essential oils (EOs) extracted from different medicinal and officinal plants have had promising antimicrobial effects against phytopathogens. In the present study, the potential microbicide activity of Mentha × piperita cv. ‘Kristinka’ (peppermint) EO and its main constituents have been evaluated against some common phytopathogens. In addition, the cell membrane permeability of the tested fungi and the minimum fungicidal concentrations were measured. The antifungal activity was tested against the following postharvest fungi: Botrytis cinerea, Monilinia fructicola, Penicillium expansum and Aspergillus niger, whereas antibacterial activity was evaluated against Clavibacter michiganensis, Xanthomonas campestris, Pseudomonas savastanoi and P. syringae pv. phaseolicola. The chemical analysis has been carried out using GC-MS and the main components were identified as menthol (70.08%) and menthone (14.49%) followed by limonene (4.32%), menthyl acetate (3.76%) and β-caryophyllene (2.96%). The results show that the tested EO has promising antifungal activity against all tested fungi, whereas they demonstrated only a moderate antibacterial effect against some of the tested bacteria.

A comparative study of volatile constituents, antioxidant activity, and molecular docking was conducted between essential oils from Mentha longifolia L., Mentha spicata L., and Origanum majorana L., widely cultivated in Madinah. The investigation of volatile oils extracted by hydrodistillation was performed using Gas Chromatography-Mass Spectrometry (GC-MS). A total number of 29, 42, and 29 components were identified in M. longifolia, M. spicata, and O. majorana representing, respectively, 95.91, 94.62, and 98.42, of the total oils. Pulegone (38.42%), 1,8-cineole (15.60%), menthone (13.20%), and isopulegone (9.81%) were the dominant compounds in M. longifolia oil, carvone (35.14%), limonene (27.11%), germacrene D (4.73%), and β-caryophyllene (3.02%) were dominant in M. spicata oil, terpin-4-ol (42.47%), trans-sabinene hydrate (8.52%), γ-terpinene (7.90%), α-terpineol (7.38%), linalool (6.35%), α-terpinene (5.42%), and cis-sabinene hydrate (3.14%) were dominant in O. majorana oil. The antioxidant activity, assessed using DPPH free radical–scavenging and ABTS assays, was found to be the highest in O. majorana volatile oil, followed by M. spicata and M. longifolia, which is consistent with the differences in total phenolic content and volatile constituents identified in investigated oils. In the same context, molecular docking of the main identified volatiles on NADPH oxidase showed a higher binding affinity for cis-verbenyl acetate, followed by β-elemene and linalool, compared to the control (dextromethorphan). These results prove significant antioxidant abilities of the investigated oils, which may be considered for further analyses concerning the control of oxidative stress, as well as for their use as possible antioxidant agents in the pharmaceutical industry.

—The Meerwein–Ponndorf–Verley–Oppenauer non-catalytic reaction of cyclic monoterpenic ketones and alcohols (menthone, camphor, menthol, and borneol) was studied under supercritical conditions. It has been showed that the ketones can be reduced in supercritical isopropanol with high selectivity (89–98%) without any catalyst or base. At the same time, the conversion of menthone was 63% at 350°C, and that of camphor was 11% at 300°C for 5 h reaction. The conversions of menthol and borneol in the reverse dehydrogenation reaction in supercritical acetone were 34 and 22%, respectively, and the selectivities were 95 and 88%. Thermal dehydration is a main side reaction for all the reactions.

Rose-scented geranium, Pelargonium graveolens L'Herit. (Geraniaceae), is an economically important plant. GC-MS analysis of the essential oil, prepared by hydro-distillation from this plant species, showed the presence of iso-menthone (15.71%), epi-α-cadinol (15.49%), iso-menthol (6.46%), geranyl formate (6.22%), geraniol (6.16%) and citronellol (5.53%). The composition of the absolute prepared by solvent extraction was compared to that of the essential oil. Change in citronellol to geraniol ratio in the absolute was monitored during leaf development. Estimation of the ratio of the two compounds was carried out using 1H NMR spectroscopy. Geraniol content was highest in young leaves and citronellol content increased with increase in leaf age. Meta-analysis of the essential oil constituents reported from different countries was carried out. Menthone and isomenthone as well as citronellol and geraniol were negatively correlated. A significantly positive correlation was found between geraniol and linalool.

Background: Nitrogen is the most important nutrient requirement for plants. Nitrogen supplying affected the leaf area, carbon fixation, glandular trichomes formation, ATP and NADPH content which resulted to the terpenoids biosynthesis enhancement and essential oils accumulation. Objective: This study was aimed to evaluate changes of essential oil content and components by use different levels of Urea fertilizer and its relation with the antioxidant status of peppermint. Method: The two field experiments were conducted on randomized complete block design at 2013 and 2014. The treatments consisted of three levels of nitrogen fertilizer (urea) (0, 75, and 150 kg ha-1). The evaluated traits were included antioxidant enzymes, essential oil percentage and essential oil components. Results: The urea fertilizer had a significant effect (P≤0.01) on the soluble protein amount and antioxidant enzymes activity. Urea consumption in the both years increased the peppermint essential oil content. The interaction of nitrogen fertilizer and year had a significant effect on most of the essential oil components excepted to β-pinene, myrcene, Limonene, 1,8- Cineole, Z-β- Ocimene, and α- Terpineol. Conclusion: Using nitrogen fertilizer increased the peppermint essential oil content. Also, nitrogen deficiency reduced the soluble proteins and essential oil content and in contrast, it increased antioxidant enzymes activity and pulegone content. Therefore, consumption of 75 kg urea per hectare is recommended due to increasing essential oil content, decreasing pulegone rate, and no significant effect on menthol, menthone, and menthofuran contents.

Salep mucilage was extracted from salep tubers and used to produce edible films containing pennyroyal extracts (PER) (0, 0.5, 1, and 1.5% v/v) as a new antibacterial/antioxidant edible film, and their physical, mechanical, permeability, thermal, microstructural and antibacterial properties were measured. Results showed that pulegone (20.8%) and menthone (34.7%) were the most representative components of PER. Water vapor permeability (WVP) was determined in the range of 2.26–2.81 × 10−11 g−1s−1Pa−1. Oxygen permeability (O2P) was found between 30.53 and 35.64 cm3μmm−2d−1 kPa−1. As expected, the PER concentration from 0% to 1.5% (w/w) increased the elongation at break (EAB) but decreased tensile strength (TS) and Young's modulus (YM). The 2, 2-diphenyl-1-picrylhydrazyl (DPPH), ferric reducing antioxidant power (FRAP) and 2, 2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) methods were used to evaluate the antioxidant activity. Based on the results of the agar disc diffusion test, the antibacterial properties significantly increased with the incorporation of PER. Salep mucilage based (SBM) edible films containing PER showed a powerful antibacterial activity against Yersinia enterocolitica, Staphylococcus aureus, and Shewanella putrefaciens among bacteria tested.

Many phytochemicals have medicinal properties including anti-inflammatory, antioxidant and cytotoxic activities. The current study aims to estimate and identify the chemical composition of Calamintha fenzlii Vis. leaves volatile oil and to evaluate its cytotoxic, anti-inflammatory and antioxidant properties. The volatile oil (VO) of C. fenzlii leaves was separated using microwave ultrasonic method and the chemical composition was characterized using Gas Chromatography–Mass Spectroscopy method. The anti-inflammatory, antioxidant and cytotoxic activities were determined using a COX inhibitor screening, the DPPH-free radical scavenging and MTS (3-(4,5-dimethylthiazol-2-yl)-5-(3-cyrboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt) cell viability colorimetric assays, respectively. The chemical constituents of C. fenzlii VO were dominated by oxygenated monoterpenoid (96.91%). The major chemical components of C. fenzlii VO were represented by menthone 68.93% and pulegone 23.1%. The cytotoxicity test results revealed that the 23.22, 11.6, 5.8 and 2.9 mg/ml of C. fenzlii VO treatments induced cell death significantly (p ≤ 0.0001) by 70%, while 1.4 and 0.7 mg/ml induced cell cytotoxicity significantly (p ≤ 0.0001) by approximately 50% and 40%, respectively. The VO showed moderate antioxidant activity with an IC50 value of 15.38 ± 0.81 µg/ml. The COX-1 IC50 value was 0.215 µg/ml, while COX-2 IC50 was 0.241 µg/ml. Our data demonstrate for the first time that the VO of the Palestinian C. fenzlii plant possesses cytotoxic, anti-inflammatory and antioxidants effects. It is a good source of therapeutic active compounds that could have potential applications in the nutraceutical and pharmaceutical industries.

Background: The present study aimed to determine the chemical composition and in-vitro antibacterial activity of Ziziphora clinopodioides essential oil (ZCEO). Methods: The chemical composition of ZCEO was determined using gas chromatography-mass spectrometry (GC-MS) analysis. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were calculated using the microwell dilution assay to assess the antibacterial effects of ZCEO emulsion and nano-emulsion on E. coli O157:H7. Results: A yield of 1% (w/w) was identified for ZCEO isolation and pulegone (58.78%), menthone (1.15%), and isomenthone (9.91%) as the key components of ZCEO phytochemicals. The MIC values of the ZCEO emulsion and nano-emulsion were 0.8 and 0.025 mg/ml, respectively, and the MBC values were estimated at 1.6 and 0.05, respectively. Conclusion: It is recommended that the nano-emulsion of ZCEO be applied as a potential source of natural preservatives in food industries.

Interest in the use of the nanoparticles as plant growth elicitors mushroomed within the last decade and the field is quite intriguing to meet the growing needs of the burgeoning population. Peppermint is a plant of considerable importance to the traditional as well as modern medical world primarily because of its essential oil (EO). In view of the beneficial effects of silicon (Si) in plants and the substantial pharmaceutical importance of peppermint, the present study was designed to investigate the influence of silicon nanoparticles (SiNPs) on some of the photosynthetic and yield parameters of the plant as the nanoparticles are edged over the normal elemental forms due to some unique physico-chemical characteristics. A simple randomized experiment was designed and the treatments included: foliar spray of de-ionized water only (control), and foliar spray of SiNPs with 50, 100, 150, and 200 mg L−1. Lower concentrations of SiNPs (50 and 100 mg L−1) proved significant (P ≤ 0.05) for most of the parameters studied and increased the peltate glandular trichome density and diameter significantly. An increase of 11.5% was reported in chlorophyll content while chlorophyll fluorescence increased by 6.8%, net photosynthetic rate by 21.1% and total phenol content by 11.9% at 150 days after plantation (DAP). EO content exhibited an increase of 26.5%. While menthol content was increased by 8.85%, menthone and menthyl-acetate contents were decreased by 2.2% and 10%, respectively at 150 DAP.

Water stress is a worldwide agricultural challenge that limits crop growth and quality. Chemical compounds that promote tolerance to water stress, such as omeprazole showed recently promising results. The present study investigates the effect of weekly drenching applications of 0, 10, 50, 100, or 200 μM omeprazole on Mentha piperita (peppermint) subjected to water stress by watering at 100%, 70%, and 50% of container substrate capacity for 7 weeks in an experiment that spanned two seasons. Peppermint that received higher doses of omeprazole showed increased plant height, leaf number, leaf area, and dry weight under normal and water stress conditions. The amounts of chlorophyll and proline in the leaves as well as gas exchange increased in omeprazole-treated plants relative to the control plants. Omeprazole treatment also resulted in increased activity of the enzymes catalase and ascorbate peroxidase, reduced accumulation of the reactive oxygen species hydrogen peroxide, increase in the essential oil ratio, and improvement in essential oil composition. Omeprazole-treated plants showed higher ratios of menthol and menthone composition relative to the control plants. The changes in essential oil composition were associated with increased expression of genes associated with the menthol biosynthesis pathway. These findings indicate that omeprazole can ameliorate water stress in peppermint by increasing vegetative and root growth; increasing chlorophyll amount, photosynthetic rate, and gas exchange; reducing water loss by boosting leaf water potential and relative water content; increasing proline content; and modulating the gene expression of secondary metabolites.

The steam distillation method was used to obtain samples of essential oil of some species of genus Agastache L. introduced in Belarus. More than 20 components have been identified and determined in the essential oils of Agastache pallidiflora ssp.neomexicana L., Agastache aurantiaca L., Agastache mexicana L., Agastache foeniculum L. by gas liquid chromatography.The quantitative composition of the samples of essential oils depends on the type of plant material. The main its components are limonene, 1.8-cineol, mentone, isomentone, methyl chavicol, methyeugenol. The main component of essential oils Agastache pallidiflora ssp. neomexicana L. и Agastache aurantiaca L is mentone (40–65 %). Essential oil Agastache foeniculum L. is enriched with pulegone and isomentone. Methyl chavicol and methyleugenol dominate in Agastache mexicana essential oil. Distribution of the enantiomers of limonene, menthone and pulegone are shown. Regardless of the plant species, the samples are optically pure in the (+)-pulegone. The nature of the distribution of the enantiomers of limonene and menthone is an individual characteristic of the studied Agastache L. essential oils.

The essential oils of chamomile; Chamomilla recutita L., rosemary; Rosmarinus officinalis L. and peppermint; Mentha piperita L. were tested under laboratory conditions for their ovicidal and biochemical activity against the eggs of greater wax moth, Galleria mellonella L.The incubation periods, hatching periods and hatching percentages of the eggs treated by the three oils using spraying technique were significantly retarded at the four concentrations 1%,2%,4% and 8%. Generally, the maximum ovicidal activity was recorded at 8% concentrations and the peppermint oil showed marked activity against the eggs of greater wax moth. The longest incubation period (15 days), the longest hatching period (6.67days) and the highest inhibition of hatchability (5.07%) achieved with peppermint oil treatment, followed by rosemary oil (13.67 days, 5.33 days and 18.25%) then chamomile oil (9 days, 5.67 days and 32.45%), respectively. The chemical constituents of the three essentials oils were analysed using gas chromatography (GC). Bisabolol oxide a (43.76 %) and bisabolol oxide b (16.11%) were the major components of chamomile oil whereas, camphor (23.56 %), 1,8-cineole (17.86 %) were for rosemary oil and menthol (47.38 %), menthone (29.99 %) for peppermint oil. Present study demonstrated disturbance in total soluble protein, total lipid contents and inhibition the activity of acid phosphatase and phenoloxidase.

The efficiency of chemically characterized Mentha piperita L. essential oil (EO), a plant based insecticide was tested for acetylcholinesterase activity (AChE) and antioxidant enzyme system (SOD, CAT, GSH and GSSH) in Sitophilus oryzae (L.) and Tribolium castaneum (Herbst.). GC–MS results evidenced for menthone and menthol as the major compounds of EO. As a fumigant, EO and its major component showed 100% mortality at 75.0 μL/L air and 100.0 μL/L air against S. oryzae and T. castaneum at 24 h of exposure. Antifeedant activity exhibited 100% lethal activity against pests in comparison to sub lethal doses. In vivo percent inhibition of AChE activity ranged between S. oryzae (29.68%, 18.81% and 14.34%) and T. castaneum (20.67%, 13.73% and 9.19%). Significant changes in antioxidant defense system studied for SOD, CAT, GSH and GSSH were noticed. Results revealed the toxicity of EO associations with the inhibition of AChE activity accompanied by oxidative imbalance. Therefore, M. piperita EO has a noteworthy role in insecticidal properties and could be recommended as an eco-friendly alternative to synthetic insecticides.

Mints are perennial herbs that are cultivated for medicinal and aromatic purposes. They are highly polymorphic and their taxonomy is difficult. Sixty mint accessions, representing seven Mentha species (M. aquatica L., M. longifolia L., M. piperita L., M. pulegium., M. rotundifolia L., M. spicata L. and M. spicata var. crispa 'moroccan'), were collected at full flowering from 51 Tunisian localities. Essential oil yields were found to vary from 0.45 to 2.5%, (w/w). Analyses of these oils by GC/FID and GC/MS and their subsequent classification by statistical analysis resulted in six clusters with significant variations in their terpenoid compositions: i) pulegone/isomenthone/menthone; ii) isomenthone/pulegone; iii) menthone/pulegone ; iv) piperitenone oxide; v) linalool/linalyl acetate/1,8 cineol/myrcene; and vi) carvone/limonene/1.8 cineol. M. pulegium accessions grouped two chemotypes: one rich in pulegone and the second rich in isomenthone. M. longifolia grouped one chemotype rich in pulegone and a second rich in menthone. M. spicata grouped one chemotypes characterized by a moderate to high carvone content and the second pulegone-rich. M. rotoundifolia accessions were piperitone oxide-rich. M. aquatica and M. piperita have linalool and linalyl acetate as major compounds. These results clearly indicate that there were a large biochemical diversity among the investigated Tunisian Mentha spp. accessions. Genetic and ecological diversities may explain this chemical diversity.

The side effects of skin disease antibiotics and lengthy periods of therapy are major shortcomings of both old and newly developed ranges of antifungals. Hence, there is a need to develop an effective, cheap and readily available antifungal of a natural origin to combat skin diseases. The aim of this study was to investigate the effect of Agathosma betulina and Coleonema album essential oil (EO) on the growth and morphology of two fungal strains (Trichophyton rubrum and T. mentagrophytes) responsible for ringworm, and analyse the components of the EO of both plants. There was inhibition/reduction of fungal growth in all plates exposed to EO volatiles. However, the rates of inhibition varied among the fungal species, EO and different volumes tested. The volatiles from A. betulina EO showed a remarkable inhibitory effect with the highest inhibition recorded at 40 μl. The best inhibition was recorded in T. rubrum exposed to volatiles at 40 μl of A. betulina EO with a fungal growth index of 2.3%, indicating its ability of strong fungicidal effects. The mode of action of the EO volatiles was elucidated using electron microscopy. The volatiles inhibited fungal growth by inhibiting the production of spores. Agathosma betulina EO (40 μl) resulted in the destruction of hyphae and spores of T. rubrum. The major components of the EO of A. betulina were limonene (29.8%), menthone (21.6%), and isomenthone (14.7%), while of C. album were pinene (27.4%), and myrcene (14.5%).

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 5dC. Results Identification of PEOrs 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%), b-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 l 0.05) differences in the cheesers appearance nor in the chemical composition of plain and PEO-flavored cheeses. However, the TVFA and SN of plain cheese was significantly (p l 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.

In the current study, the active packaging films based on poly lactic acid (PLA) containing 1.5% w/w zinc oxide (ZnO) nanoparticles and varying concentrations (0.5, 1, 1.5% w/w) of Zataria multiflora Boiss. essential oil (ZEO) and Menthe piperita L. essential oil (MEO) were produced. The efficacies of the resulted active films on shelf life extension of Otolithes ruber fish during 16 days of refrigerated storage (4 ± 1 °C) were evaluated. The antibacterial activity of the films was tested against five common food-borne pathogens (Escherichia coli, Salmonella enterica, Pseudomonas aeruginosa, Bacillus cereus and Staphylococcus aureus) by disc diffusion method. The fillet samples were analyzed periodically for microbiological (aerobic count, Enterobacteriaceae count, Pseudomonas spp., Lactic acid bacteria (LAB) count and H2S-producing bacteria) and chemical (TBARS and TVB-N). PLA/ZnO/ZEO and PLA/ZnO/MEO films showed enhanced antibacterial (691 and 513.33 mm2, repectively, against S. aureus) and antioxidant (69.14 and 49.08%, repectively) activity than control. Based on the microbial count, the active films significantly increased the shelf life of fillets from 8 to 16 days. The lowest TBARS (0.8 mg MA/kg muscle) and TVB-N (21.23 mg/100 g muccle) values were obtained in fillets wrapped with PLA/ZnO containing 1.5% ZEO. Carvacrol and menthone were found to be the main compounds of ZEO and MEO following GC analysis, respectively. Atomic absorption spectrophotometer showed transfer only a minuscule amount of Zn2+ ions to the meat. Overally, the PLA/ZnO films containing the essential oils could be deemed as a potential alternative to the current common technologies for extending the shelf-life of meat products like ‘Otolithes ruber fillets.

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 200 mg L−1], the effect of 80 mg L−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 80 mg L−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 80 mg L−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.

The base-free transfer hydrogenation (THR) of menthone with six aliphatic alcohols as hydrogen source has been developed under sub- and supercritical conditions. Under sc conditions (at 350 °C and 78–210 atm) without any catalyst, all alcohols demonstrated the similar H-donor activity, which was high enough. The menthone conversion was about 64 ± 5% for 5 h of the reaction, whereas the selectivity on menthol reached 92–99% for all alcohols except MeOH (73%). The non-catalytic THR at 250 °C was very slow and the conversion in the most active 2-PrOH was only 7.0–7.5% for 9 h of the reaction. Under subcritical conditions at 150 °C, the non-catalytic menthone reduction was negligible in all alcohols. But in secondary 2-PrOH and 2-BuOH, the base-free THR catalyzed by Raney® nickel results in excellent conversion and selectivity of menthol at 150 °C, whereas no conversion of menthone was observed in primary alcohols under the same reaction conditions. A quasi-equilibrium of isomeric menthone/isomenthone mixture reached via enolization was evaluated under sub- and supercritical conditions and the Gibbs energies of the isomerization in each alcohol were calculated.

Radiolytic degradation of natural polysaccharides like chitosan into small oligomers and application of these as aqueous solutions to plants is a novel and recent approach towards increasing the yield of plants. Plant growth regulators, known for their growth stimulating and terpenoid biosynthetic activities also constitute a good choice for increasing the content of economically important by-products in these plants. Keeping in view the above, a pot experiment was devised with the aim to study whether foliar application of gibberellic acid (GA3) and irradiated chitosan (IC) could enhance essential oil (EO) content and composition, growth and biochemical attributes of Peppermint. The treatments included: a water sprayed absolute control (de-ionised water), Acetic-acid control (0.03% acetic acid), (10 mg L−1) GA3, (90 mg L−1) irradiated chitosan and combination of both i.e, GA3 + IC. Compared to control, the combined treatment enhanced most of the parameters significantly. It increased essential oil (EO) content by 27.9%, EO yield by 61.29%, menthol content by 15.4% and menthone content by 5.85%. However, the menthyl acetate content was reduced by 1.46%.

12 Pág. Departamento de Reproducción Animal​, This work has demonstrated the ixodicidal and insect antifeedant effects of essential oils from 14 experimentally cultivated aromatic plants. The strong ixodicidal and antifeedant oils corresponded to Thymus zygis, Thymus vulgaris, Satureja montana, Oreganum virens, and Mentha suaveolens. The moderately active oils were from Lavandula angustifolia, Mentha piperita, Mentha spicata, Artemisa herba-alba, and Rosmarinus officinalis. The most effective larvicidal and antifeedant compounds were piperitenone oxide, carvacrol, piperitenone, and thymol, explaining the effects of the most active essential oils. The rest of the tested compounds were not ixodicidal or antifeedant. Therefore, the activity of moderately active oils cannot be explained by their main components (linalyl acetate, linalool, menthone, menthol, limonene, camphor, 1,8-cineole, p-cymene, α-pìnene, and carvone), suggesting synergistic effects. Considering the ixodicidal and antifeedant effects of these extracts, the plants have been ranked in relation to Thymus vulgare, a commercial biopesticide ingredient, for their potential as botanical pesticides. T. zygis, S. montana, and M. suaveolens ranked over T. vulgaris as ixodicidal agents and S. montana as insecticidal. Therefore, we propose the plant populations of S. montana, T. zygis, and M. suaveolens tested here for further development as biopesticide ingredients., This work has been supported by grants from ERASMUS+ no. 2018-1-FR01-KA202-047892, Biocontrol E Training (BET), and ERASMUS+ 600873-EPP-1-2018-1-ES-EPPKA2. European Hub on New Challenges in the Field of Essential Oils (EOHUB), PID2019-106222RB-C31, MCI, Spain, RTA 2014-00080-00-00, Spain, and the R+D contracts CSIC-Villamagna Estudio Biodirigido de Extractos Ixodicidas and UCM-Villamagna SL Investigación en torno al control de las garrapatas y al estado sanitario de la fauna silvestre.

A two-year field experiment was conducted at the Islamic Azad University, Iran, in 2018 and 2019 growing season to examine the influence of foliar application of zinc and salicylic acid on chlorophyll, phenolic and flavonoid content, essential oil percentage, oil yield, total dry matter and oil composition of peppermint (Mentha piperita L) under drought stressed conditions. Irrigation regimes (no stress, moderate, and severe drought stress), zinc (0, 2 and 4 mg L−1), and salicylic acid (0 and 1 mM) foliar application were included in the treatment group. Drought stress reduced the chlorophyll content and oil percentage of peppermint, but moderate drought stress increased oil percentage. The application of zinc increased total phenolic compound content. Total phenolic and flavonoid contents increased with increasing stress levels. Comparisons of the drought and zinc treatments showed that the highest DPPH (2,2-diphenyl-1-picrylhydrazyl) was in severe drought stress plus 2 mg L−1 zinc treatment. Drought stress and salicylic acid comparisons showed that the highest oil yield was observed in well-watered plants and salicylic acid. The application of zinc + salicylic acid resulted in higher oil percentage and oil yield compared with the non-treated control. Menthol and menthone concentrations increased significantly in response to moderate drought but were reduced under severe drought. Moderate drought stress increased synthesis of oil compounds while foliar applications of zinc and salicylic acid alleviated its effect.