Search

Acne is a highly prevalent skin disease with a great psychological impact on patients as self-perception, self-confidence, and depression. This work aimed to develop an anti-acne preparation from active anti-bacterial medicinal plants to circumvent the severe side effects and drug resistance commonly reported with topical erythromycin anti-acne preparations. Essential oils: Salvia officinalis L. (sage), Rosmarinus officinalis L. (rosemary), Commiphora myrrha Nees Engl. (myrrh), Origanum majorana L. (marjoram), Pelargonium zonale L. L'Hér. ex Aiton (geranium) and Chrysanthemum morifolium Ramat. (chrysanthemum) were extracted by hydrodistillation and analyzed using gas chromatography/mass spectrometry (GC/MS). The anti-acne activities of the oils against Cutibacterium acnes ATCC 6919 were evaluated by microdilution methods to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The most active essential oils were loaded in a film-forming nanogel prepared with chitosan, pluronic F127 and glycerol in the ratio of 3:1:1, prior to investigation in a murine acne in vivo model. Marjoram and chrysanthemum oils showed the highest antimicrobial activity against C. acnes (MIC = 0.156% v/v and 0.125% v/v, respectively). GC/MS of the actives showed that gamma-terpinene (26.46%) and terpinen-4-ol (22.24%) were the predominant constituents in marjoram, whereas chrysanthenone (32.79%) was the main component in chrysanthemum. The formulated essential oil-loaded film-forming nanogels of both oils exhibited significant anti-acne activity in mice via reducing the bacterial loads, activating the antioxidant nuclear factor erythroid 2–related factor 2 (Nrf2) pathway and inhibiting the inflammatory tumor necrosis factor-alpha (TNF-α) pathway. Further studies should be designed to evaluate the clinical evidence for the use of marjoram and chrysanthemum oil products in acne treatment. [ABSTRACT FROM AUTHOR]

Many researches have been conducted to introduce ultrasound as an auxiliary factor to increase the efficiency of extraction of essential oils from medicinal plants. However, few researchers have studied the role of ultrasound waves in stimulating chemical reactions of the essential compounds of plants. This research was conducted with the aim of investigating the effect of ultrasound on the main components of essential oil of Thymus vulgaris L. after extracting the essential oil and without the presence of plant tissue. For this purpose, the aerial parts of the plant were harvested at the flowering stage from the south of Tehran in June 2021 . The essential oil of the plant was extracted using a distillation apparatus (Clevenger) and its compounds were determined and measured by GC and GC/MS. Subsequently, ultrasonic waves were applied to the extracted essential oil by a titanium probe (400 w) with three variable factors of temperature, time, and the ratio of essential oil/ water at three levels. Finally, 27 treated essential oil samples were prepared and their chemical compounds were quantified by GC. The primary essential oil contained 44.37% of thymol, 29.80% of p-cymene and 21.24% of γ-terpinene. The results showed that the application of ultrasound to the essential oil increased the amount of thymol and decreased the amounts of γ-terpinene and p-cymene. By optimizing the conditions (1:0 ratio of thyme essential oil and water, 20˚C and 10 min), the active ingredient thymol was reduced from 44.37% to 70.18%. Ultrasonic waves in the presence of water and oxygen caused the production of hydroproxyl radical (HOO˙) and then showed oxidation reactions to produce thymol from γ-terpinene and p-cymene. The results showed that in addition to helping to increase the efficiency of extraction, ultrasound can cause a change in the chemistry and the ratio of phytochemical compounds in the essential oil by stimulating radical reactions. [ABSTRACT FROM AUTHOR]

Thyme oil (TO) is derived from the flowers of various plants belonging to the genus Thymus. It has been used as a therapeutic agent since ancient times. Thymus comprises numerous molecular species exhibiting diverse therapeutic properties that are dependent on their biologically active concentrations in the extracted oil. It is therefore not surprising that oils extracted from different thyme plants present different therapeutic properties. Furthermore, the phenophase of the same plant species has been shown to yield different anti-inflammatory properties. Given the proven efficacy of TO and the diversity of its constituents, a better understanding of the interactions of the various components is warranted. The aim of this review is to gather the latest research findings regarding TO and its components with respect to their immunomodulatory properties. An optimization of the various components has the potential to yield more effective thyme formulations with increased potency. [ABSTRACT FROM AUTHOR]

This review highlights the progress made in recent years in harnessing the peculiar chemistry of the hydroperoxyl, or perhydroxyl, radical (HOO•) during lipid peroxidation, particularly with regard to its interaction with antioxidants. The HOO• radical, the protonated form of superoxide, plays an important role in the propagation and termination of lipid peroxidation in nonaqueous systems. However, differently from alkylperoxyl (ROO•) radicals that have only oxidizing ability, HOO• has a two-faced oxidizing and reducing activity. The HOO• radical can reduce the radical of the antioxidant (phenols and aromatic amines) by H-atom transfer (A• + HOO• ⟶ AH + O2) thus increasing the length of the inhibition period and the effectiveness of the antioxidant. The simultaneous presence of HOO• and ROO• radicals triggers the catalytic antioxidant activity of quinones and nitroxides and explains the antioxidant activity of melanin-like polymers. The HOO• radical can be formed by fragmentation of ROO• radicals deriving from amines, alcohols, substituted alkenes and may be present at low concentrations in many oxidizing systems. Pro-aromatic compounds, like the natural essential oil component γ-terpinene, are the most effective sources of HOO• and behave as co-antioxidants in the presence of nitroxides or quinones. The future developments and applications of HOO• chemistry in the context of the inhibition of autoxidation are also discussed. [ABSTRACT FROM AUTHOR]

Lung cancer is the second most commonly diagnosed cancer and has the highest mortality rate worldwide despite the remarkable advances in its treatment. Origanum majorana Essential Oil (OMEO) has been shown to be effective against non-small cell lung cancer (NSCLC) cells, decreasing their viability and colony growth in vitro, as well as inhibiting tumor growth in chick embryo chorioallantoic membranes (CAM) and nude mice in vivo. OMEO is mainly composed of four monoterpenes, namely terpinen-4-ol, sabinene hydrate, α-terpinene, and γ-terpinene. In this study, we aimed to investigate the potential anticancer effects of these monoterpenes, either alone or in combination, on NSCLC. Our findings indicate that these four monoterpenes significantly decreased NSCLC cell viability in a concentration-dependent manner, reduced their colony growth in vitro, and also downregulated survivin expression in these cells. Moreover, different combined mixtures of these monoterpenes further enhanced their anticancer effects on cellular viability, with a terpinen-4-ol and sabinene hydrate combination being the most potent. We also found that terpinen-4-ol, in combination with sabinene hydrate, markedly enhanced the anticancer effect of the individual monoterpenes on NSCLC viability within a shorter treatment duration through, at least in part, survivin downregulation. Furthermore, this combination enhanced the inhibition of colony growth in vitro and the tumor growth of NSCLC cells xenografted onto chick embryo CAM in vivo. Altogether, our study highlights the potential of these monoterpenes for use in further pre-clinical investigations against various cancer hallmarks.

Highlights The chemical composition of M. alternifolia EO was identified by GC–MS. The EO of M. alternifolia and its components, terpinen-4-ol and γ-terpinene, had potent bioactivity against S. littoralis. M. alternifolia EO and their components, terpinen-4-ol and γ-terpinene have great potential as a biopesticide in integrated pest management programs.

A wild population of Thymus piperella L. was monitored for two years in order to correlate phenological stages and meteorological data with yield and, essential oil (EO) composition. The plant material was extracted by hydrodistillation and the EO was submitted to GC-MS and GC-FID analysis. To achieve reliable quantification, relative response factors were applied. The results showed a progressive increase in the proportion of carvacrol according to the sunlight duration and temperature increase, until reaching a maximum at the beginning of flowering stage (52.9 % and 41.0 % in 2018 and 2019, respectively). A simultaneous decrease was found in the amount of p-cymene (8.2 % and 12.8 % respectively) in the same stage, whereas γ -terpinene showed a similar evolution to that observed for carvacrol but with lower values (3.3 % - 14.6 %). From statistical analysis, significant changes in the relative proportions of carvacrol and its metabolic precursors: γ-terpinene and p-cymene were found. They have been explained based on the proposed metabolic pathways in the literature. On the other hand, when relating the changes in the EO profiles with rainfall data, a strong influence of the water supply on the evolution of the chemical composition was observed. [ABSTRACT FROM AUTHOR]

Coriander (Coriandrum sativum L.), one of the oldest spice plants globally, has wide usage, mainly owing to its essential oil content. This study investigated the effects of rhizobacteria, mycorrhizae, and their combination on the yield and essential oil profile of coriander. The treatments resulted in statistically higher yield properties and essential oil values than the control. The effects of the microorganism treatments on the yield characteristics were not statistically different. However, the treatments significantly affected the essential oil content and yield. While the arbuscular mycorrhizal fungi and combined application of the microorganisms were statistically equal, arbuscular mycorrhizal fungi had a higher value in essential oil content and yield by 0.75% and 11.8 L ha−1, respectively. The combined application resulted in higher values of linalool (9.47%) and γ -terpinene (6.75%), the components with the highest rate in the essential oil composition. The principal component analysis highlighted the importance of the combined application on the crucial components. In the light of the results, beneficial microorganism treatments were considered significant for yield and essential oil enhancement. Therefore, the wide use of these treatments will highly contribute to coriander cultivation. • AMF, PGPR, and their combination significantly enhanced yield traits. • AMF provided the highest improvement on essential oil production. • AMF and PGPR had significant effects on some of the crucial essential oil compounds. • Combine treatment (AMF + PGPR) resulted in higher values of linalool and γ-terpinene. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the variations in yield of essential oil, chemical constituents, antimicrobial and antioxidant potential of Monarda didyma L. (aerial parts) at three different phenophases, namely vegetative stage, full blooming and maturity (seed setting) stages. The essential oil content ranged from 0.62-0.75% in whole aerial parts, with the highest yield in the full flowering (0.75 ± 0.042%), followed by pre flowering (0.70 ± 0.033%) and seed setting (0.62 ± 0.052%) stages. Linalool was found as the major compound followed by γ-terpinene, thymol methyl ether, p-cymene and thymol in the oils during different phenophases of plant. Linalool was maximum in vegetative (pre flowering) stage (60.15 ± 1.56%) as compared to full blooming (44.32 ± 2.55%) and seed setting (46.49 ± 1.63%) stages respectively. γ-Terpinene, the second major constituent was found to be maximum in full blooming stage (21.06 ± 3.06%) as compared to the other stages, and showed cogent variations in percent composition of γ-terpinene during different phenological stages. In thymol methyl ether content, significant variation was observed during all three phenophases of plant. The antioxidant (DPPH assay) activity showed that M. didyma oil has maximum activity at seed setting stage. The maximum antimicrobial activities in oil was active at vegetative phase of plant against bacteria and yeast i.e., Bacillus sp., E. coli, L. monocytogens, P. aeruginosa, S. aureus, C. albicans and revealed favourable values of MIC (0.5% to1% v/v) and MBC/MFC (0.5 to 2% v/v) against bacterial and yeast cultures. [ABSTRACT FROM AUTHOR]

The present study aims to evaluate the antifungal activity of Thymus vulgaris essential oil and its CMC-based coating against Fusarium cf. oxysporum, the most pathogenic fungus in tomato fruits in Tehran markets. The effect of the coating on the physicochemical properties of tomato fruits was evaluated. The phytochemicals of the essential oil were also determined and qualified by GC and GC–MS methods. Based on the results, thymol (42.98%), p-cymene (28.58%), and γ-terpinene (22.78%) were identified as major components of the oil. Thyme essential oil inhibited spore germination of F. oxysporum with an IC50 value of 0.079 µg/mL, more potent than kresoxim-methyl (0.106 µg/mL), as a standard antifungal agent. Also, the essential oil exhibited a high mycelial growth inhibitory activity and showed fungicidal activities at low volumes. In addition, the formulated coating (0.5% essential oil) prevented the growth of fungal infection with 85.31% inhibition in inoculated tomatoes after 9 days. After different storage periods (11- and 17-days), lower mass loss, higher titratable acidity, lower total soluble solid content, and lower lycopene content of coated fruits were observed in comparison with uncoated ones. This proved that the coating can increase the shelf life of the fruits, by providing a semi-permeable film around them. The results suggest that by using this product as an edible coating, the fungal infections and ripening process can be controlled and the storage life of tomatoes can be extended effectively. [ABSTRACT FROM AUTHOR]

Thyme oil (TO) is derived from the flowers of various plants belonging to the genus Thymus. It has been used as a therapeutic agent since ancient times. Thymus comprises numerous molecular species exhibiting diverse therapeutic properties that are dependent on their biologically active concentrations in the extracted oil. It is therefore not surprising that oils extracted from different thyme plants present different therapeutic properties. Furthermore, the phenophase of the same plant species has been shown to yield different anti-inflammatory properties. Given the proven efficacy of TO and the diversity of its constituents, a better understanding of the interactions of the various components is warranted. The aim of this review is to gather the latest research findings regarding TO and its components with respect to their immunomodulatory properties. An optimization of the various components has the potential to yield more effective thyme formulations with increased potency.

Background: Spodoptera littoralis is mostly controlled by the use of synthetic insecticides. Nonetheless, the use of these insecticides causes a slew of issues. On this pest, the antifeedant activity of Melaleuca alternifolia essential oil (EO) and its two principal components was investigated. Results: The gas chromatography–mass spectrometry (GC/MS) analysis revealed that the M. alternifolia EO was composed of eleven compounds. Terpinen-4-ol (40.1%) and γ-terpinene (21.9%) were chosen as the major constituents. In terms of antifeedant efficacy, treatment with M. alternifolia EO and these components reduced leaf consumption and the efficiency of food conversion in larvae in a concentration-dependent manner. When compared to untreated larvae, weight, growth, and pupation percentage were all significantly lower. Conclusions: The findings show that M. alternifolia EO and its components, terpinen-4-ol and γ-terpinene can be effectively combined for cotton leafworm management. Highlights: The chemical composition of M. alternifolia EO was identified by GC–MS. The EO of M. alternifolia and its components, terpinen-4-ol and γ-terpinene, had potent bioactivity against S. littoralis. M. alternifolia EO and their components, terpinen-4-ol and γ-terpinene have great potential as a biopesticide in integrated pest management programs. [ABSTRACT FROM AUTHOR]

Citrus peel essential oil (PEO) is utilized in the food and juice processing, pharmaceuticals, and aroma industries due to various nutritional, pharmaceutical and cosmaceutical properties. In this study, the PEO of five wild Citrus species (Citrus medica , C. indica , C. latipes , C. hystrix , and C. cavaleriei) from northeast India, has been extracted using the hydro-distillation method. The oil yield varied from 0.02% to 0.32% (w/w). Gas Chromatography-Mass Spectrometry (GC-MS) analysis of citrus PEO showed the presence of 36 compounds in the range of 84.63–95.9%. Limonene was the major compound in the PEO, with the highest percentage in C. cavaleriei (80.86%), followed by C. hystrix (75.7%), medica (66.9%), C. indica (63.03%), and C. latipes (23.95%). Other compounds present in a considerable percentage were γ -terpinene (C. latipes , 16.86%; C. indica , 14.72%; C. medica , 6.73%), myrcene (C. indica , 5.34%), β -pinene (C. latipes , 9.49%), 3-carene (C. medica , 6.38%), (E)- β -caryophyllene (C. latipes , 6.07%), and neryl acetate (C. latipes , 6.10%). Anti-inflammatory assay of PEO in the five Citrus species revealed the highest anti-inflammatory activity in C. indica. The study suggests that wild citrus fruits can be an important source of limonene and other bioactive compounds with potential pharmaceutical and industrial applications. • The Essential oil and anti-inflammatory activity of five wild Citrus were studied. • Essential oil composition was estimated for the first time in Citrus indica. • Limonene was the major compound in the PEO of all the wild Citrus species. • PEO of Citrus indica showed the highest anti-inflammatory effect. [ABSTRACT FROM AUTHOR]

Essential oils (EOs) isolated from aerial parts (leaves, buds and twigs) of Eucalyptus tereticornis Sm. and Eucalyptus camaldulensis Dehnh were analysed for yield, specific gravity (SG), refractive index (RI) and chemical composition. Chemical composition analysis of the EOs was carried out by GC/MS technique. The transverse section (TS) of the leaf was subjected to oil glands measurement by Stereoscopic Zoom Microscope. EOs yield from aerial parts of E. tereticornis varies from 1.0-2.0 % (10-20 g kg−1 leaves biomass), 0.7-1.5 % (7-15 g kg−1 buds biomass) and 0.3-0.5 % (3-5 g kg−1 twigs biomass), while in E. camaldulensis 0.8-1.4 % (8-14 g kg−1 leaves biomass), 1.0-1.4 % (10-14 g kg−1 buds biomass) and 0.4-0.7 % (4-7g kg−1 twigs biomass). RI and SG values for EOs from E. tereticornis were observed in the ranges of 1.442-1.479 and 0.883-0.913 respectively. Similarly, RI and SG values for EOs from E. camaldulensis were observed in the ranges of 1.44-1.462 and 0.889-0.993 respectively. Chemical composition analysis confirms that E. tereticornis oil was a cineole type (1,8-cineole: 21.31-29.15 %) whereas E. camaldulensis terpinene type (γ-terpinene: 22.33-26.91 %). Average oil gland density in leaf of E. tereticornis and E. camaldulensis was observed as 2.7×107 n/m2 and 2.5×107 n/m2 respectively. Cluster analysis differentiates both the eucalyptus species in terms of EO composition. In addition, four and five principal components can be extracted for E. tereticornis and E. camaldulensis respectively and which explains 96.26 % and 97.87 % of the accumulated variation of the data analysed. [ABSTRACT FROM AUTHOR]

The chemical profile of Thymus proximus essential oil (EO) and its allelopathic, phytotoxic, and insecticidal activity was evaluated. Carvacrol, p-cymene, and γ-terpinene were detected as the major components of the EO, representing 85.9% of the total oil. About 50 g fresh plant material of T. proximus in a 1.5-L air tight container completely inhibited the seed germination of Amaranthus retroflexus and Poa anuua. Meanwhile, the EO exhibited potent phytotoxic activity, which resulted in 100% germination failure of both the test species when 2 mg/ml (for A. retroflexus) and 5 mg/ml (for Poa annua) oil was applied. The EO also triggered a significant insecticidal activity on Aphis gossypii with a LC50 value of 6.34 ppm. Carvacrol was identified as the main active compound responsible for both the plant suppressing effect and the insecticidal activity of the EO. Our study is the first on the allelopathic, phytotoxic, and insecticidal activity of T. proximus EO, and the determination of the responsible compound, which indicated their potential of being further explored as environment friendly biopesticides.

The chemical profile of Thymus proximus essential oil (EO) and its allelopathic, phytotoxic, and insecticidal activity was evaluated. Carvacrol, p-cymene, and γ-terpinene were detected as the major components of the EO, representing 85.9% of the total oil. About 50 g fresh plant material of T. proximus in a 1.5-L air tight container completely inhibited the seed germination of Amaranthus retroflexus and Poa anuua. Meanwhile, the EO exhibited potent phytotoxic activity, which resulted in 100% germination failure of both the test species when 2 mg/ml (for A. retroflexus) and 5 mg/ml (for Poa annua) oil was applied. The EO also triggered a significant insecticidal activity on Aphis gossypii with a LC50 value of 6.34 ppm. Carvacrol was identified as the main active compound responsible for both the plant suppressing effect and the insecticidal activity of the EO. Our study is the first on the allelopathic, phytotoxic, and insecticidal activity of T. proximus EO, and the determination of the responsible compound, which indicated their potential of being further explored as environment friendly biopesticides. [ABSTRACT FROM AUTHOR]

In this study, the composition of the essential oil of tea tree (Melaleuca alternifolia) leaves and the antifungal effects of the essential oil on food-borne molds isolated from meat products were investigated. The α-pinene (21.64 %), γ-terpinene (21.09 %), terpinen-4-ol (17.31 %), limonene (9.37 %), and o-cymene (6.54 %) were found to be the major components of M. alternifolia essential oil. The essential oil showed the highest antifungal activity on Aspergillus niger (25.82 mm zone diameter), followed by Aspergillus fumigatus (22.27 mm), Aspergillus flavus (21.092 mm), and Penicillium notatum (20.30 mm) (p<0.05), respectively. The minimum inhibitory concentration (MIC) values of M. alternifolia essential oil on the mold species used in the study varied between 0.032 and 0.376 mg/L, and the value of minimum fungicidal concentration (MFC) values ranged from 0.021 to 0.341 mg/L (p<0.05). The MIC/MFC ratio of M. alternifolia essential oil on 10 different mold species varies between 1.05 and 1.68 mg/L. According to the MIC/MFC ratio, the M. alternifolia essential oil showed a lethal effect on all of the mold species studied in this research. [ABSTRACT FROM AUTHOR]

Qualitative and quantitative variations in the essential oil of wild growing Origanum vulgare L. ssp. gracile plants were studied in response to different phenological stages (pre, full and post-flowering). The essential oil of air-dried leaves was isolated by water distillation using a Clevenger-type apparatus and was analyzed by Gas Chromatography (GC) and Gas Chromatography-Mass Spectrometry (GC/MS). The highest (1.87%) and the lowest (1.01%) essential oil content were obtained from post-flowering and preflowering stages, respectively. In total, 24 components were identified and quantified in three phenological stages representing 96.75, 97.63, and 98.59% of the oil, respectively. Carvacrol (46.62, 46.5 and 27.6%), ρ-cymene (7.76, 13.54 and 37.08%) and γ-terpinene (21.54, 13.91 and 6.82%) were the main constituents of essential oils in pre, full, and postflowering stages, respectively. Oxygenated monoterpenes (43.35-61.32%) and monoterpene hydrocarbons (30.81-48.02%) were the main classes of identified compounds in three essential oils. According to the findings of this research, the postflowering stage can be considered as the most appropriate time for obtaining the highest essential oil content, but to achieve the highest rate of phenolic compounds, the preflowering and full-flowering stages can be recommended. [ABSTRACT FROM AUTHOR]

In this study, the variability of essential oil composition in different parts of summer savory was investigated. Extraction of essential oils from air-dried leaves and healthy seeds was done using water-distillation in Clevenger-type apparatus for 4 h. In total, 23 and 24 components were identified in the leaves and seeds of summer savory, respectively. Carvacrol (46.023%), Estragole (Methyl Chavicol) (6.257%), Caryophyllene (4.753%), and E-Caryophyllene (4.753%) were the major constituents in the seeds and Carvacrol (56.537%), γ-Terpinene (21.377%), and p-Cymene (8.587%) were the major constituents in the leaves. Among all constituents, Carvacrol, Caryophyllene, E-Caryophyllene, ß-Bisabolene, cis-a-Bisabolene, Caryophyllene oxide, Z-Citral, E-Citral, γ-Terpinene, and d-3-Carene were present in both of leaves and seeds. Significant positive and negative correlations were detected between constituents for the investigated parts of summer savory. In addition, the correlation analysis of same volatile constituents in seeds and leaves indicated that some constituents in one part of summer savory have a significant correlation with another part. Also, γ-Terpinene in leaves has a negative significant correlation with γ-Terpinene in the seeds. [ABSTRACT FROM AUTHOR]

This work investigates the influence of ascorbic acid (ASA) on the essential oil (EO) isolated from leaves and peels of two Citrus species {Citrus deliciosa (Ten.) and Citrus tangerine (Hort. ex Tanaka)}. Experiments were carried out in sandy soil at the Experimental Farm, National Research Centre (NRC), Egypt. Citrus trees were treated with different levels of ASA (0, 0.2, and 0.4 g/L). Essential oils of both Citrus species were isolated by hydrodistillation (HD) and then, analyzed by Gas chromatography and Gas chromatography-Mass spectrometry. The EO compositions were influenced by ASA treatments. For both species, EO (%) and the main constituents of leaves (linalool and thymol) or peels (limonene and γ-terpinene) EO increased. Various chemical groups (MCH, MCHO, SCH, SCHO, or DCHO) changed. ASA at 0.2 g/L resulted in the highest yield of EO percentages and major constituents for both species. [ABSTRACT FROM AUTHOR]

The effect of foliar application of Salcylic acid (SA) on grain and oil yield of Cuminum cyminum L. in field condition were investigated in the region of Fasa (Fars province, Iran). Treatments comprised 0.1, 0.4, 0.7 and 1.1 mM SA applied to plants. Results indicated that the highest values of oil content (5.03 % v/w) and 1000 grain weight (3.20 g) were obtained from the application of 1.1 mM SA, however, no significant differences were found between SA levels on grain yield. The results of EO analysis showed that the amounts of β-pinene (2.36-3.48 %), ρ-cymene (7.55-9.19 %), γ-terpinene (9.61-12.37 %), γ-terpinene-7-al (24.47-31.96 %) and cumin aldehyde (24.60-29.19 %) as major oil components increased gradually with increasing SA levels, however, the amounts of cis-sabinene hydrate (0.04-0.06 %), trans-sabinene hydrate (0.12-0.17 %), terpinene-4-ol (0.16-0.28 %) and γ-terpinene-7-al (24.47-31.96 %) decreased with increasing SA levels. [ABSTRACT FROM AUTHOR]

One of the main factors affecting historical art crafts material is the biodeterioration performed by bacteria and fungi, in archives, museums or private collections. Several microorganisms cause degradation to the natural organic material such as fibers, woods, and dyes as well as to stone objects. These alterations produce deterioration of physical, chemical, mechanical and esthetic properties. Consequently, in this publication, we report the high antibacterial and antifungal activities of wild thyme essential oil, oil that can be used as an alternative natural tool in the fight against microorganisms affecting historical art crafts. Essential oil of the Thymus capitatus growing wild in northern Sicily has been extracted by hydrodistillation from aerial parts collected at different growth times. The constituents of the essential oil have been characterized by gas chromatography (GC) and GC–mass spectrometry. Fifty-five compounds have been identified. Essential oils were characterized by a high content of carvacrol (81.2–14.2%), γ-terpinene (34.4–2.6%) and p -cymene (22.8–5.0%) of the total oil content. Essential oil yield and composition vary throughout the vegetation time of the plant. The best time to harvest this species of thyme, for phenol content, is during or immediately before the full bloom. The related oils (Tc2 and Tc3) showed a good antibacterial activity against Bacillus subtilis and Staphylococcus epidermidis and excellent antifungal properties against Fusarium oxysporum and Aspergillus niger. [ABSTRACT FROM AUTHOR]

Lung cancer is the second most commonly diagnosed cancer and has the highest mortality rate worldwide despite the remarkable advances in its treatment. Origanum majorana Essential Oil (OMEO) has been shown to be effective against non-small cell lung cancer (NSCLC) cells, decreasing their viability and colony growth in vitro, as well as inhibiting tumor growth in chick embryo chorioallantoic membranes (CAM) and nude mice in vivo. OMEO is mainly composed of four monoterpenes, namely terpinen-4-ol, sabinene hydrate, α-terpinene, and γ -terpinene. In this study, we aimed to investigate the potential anticancer effects of these monoterpenes, either alone or in combination, on NSCLC. Our findings indicate that these four monoterpenes significantly decreased NSCLC cell viability in a concentration-dependent manner, reduced their colony growth in vitro, and also downregulated survivin expression in these cells. Moreover, different combined mixtures of these monoterpenes further enhanced their anticancer effects on cellular viability, with a terpinen-4-ol and sabinene hydrate combination being the most potent. We also found that terpinen-4-ol, in combination with sabinene hydrate, markedly enhanced the anticancer effect of the individual monoterpenes on NSCLC viability within a shorter treatment duration through, at least in part, survivin downregulation. Furthermore, this combination enhanced the inhibition of colony growth in vitro and the tumor growth of NSCLC cells xenografted onto chick embryo CAM in vivo. Altogether, our study highlights the potential of these monoterpenes for use in further pre-clinical investigations against various cancer hallmarks.

The genus Nepeta L. (Lamiaceae) comprises about 300 species as annual or perennial herbs or small shrubs, spread in central and southern Europe, the Near East, central and southern Asia, and some areas of Africa. Several species have been used in the traditional medicine. In the present study, the chemical composition of the essential oils from aerial parts of two populations of Nepeta apuleji Ucria collected in Sicily, a rare species, growing also in South Spain and NW Africa, were analysed by GC-MS. No one has been previously worked and published on the essential oil of this species. Main constituents of the two oils of the two populations were the monoterpenes β -pinene (11.6-6.3%) and γ -terpinene (9.4-5.0%), and the sesquiterpenes β -caryophyllene (11.9-9.8%) and germacrene D (1.8-13.0%). The chemical profile of the two essential oils presented herein and they compared with previously investigated Nepeta taxa oils, reported in the article.

Medicinal plants play a crucial role in the search for components that are capable of neutralizing the multiple mechanisms of fungal resistance. Psidium salutare (Kunth) O. Berg is a plant native to Brazil used as both food and traditional medicine to treat diseases and symptoms such as stomach ache and diarrhea, whose symptoms could be related to fungal infections from the genus Candida. The objective of this study was to investigate the influence of seasonal variability on the chemical composition of the Psidium salutare essential oil, its antifungal potential and its effect on the Candida albicans morphogenesis. The essential oils were collected in three different seasonal collection periods and isolated by the hydrodistillation process in a modified Clevenger apparatus with identification of the chemical composition determined by gas chromatography coupled to mass spectrometry (GC/MS). The antifungal assays were performed against Candida strains through the broth microdilution method to determine the minimum fungicidal concentration (MFC). Fungal growth was assessed by optical density reading and the Candida albicans dimorphic effect was evaluated by optical microscopy in microculture chambers. The chemical profile of the essential oils identified 40 substances in the different collection periods with γ-terpinene being the predominant constituent. The antifungal activity revealed an action against the C. albicans, C. krusei and C. tropicalis strains with an IC50 ranging from 345.5 to 2,754.2 µg/mL and a MFC higher than 1,024 µg/mL. When combined with essential oils at sub-inhibitory concentrations (MIC/16), fluconazole had its potentiated effect, i.e. a synergistic effect was observed in the combination of fluconazole with P.salutare oil against all Candida strains; however, for C. albicans, its effect was reinforced by the natural product in all the collection periods. The results show that the Psidium salutare oil affected the dimorphic transition capacity, significantly reducing the formation of hyphae and pseudohyphae in increasing concentrations. The results show that P. salutare oil exhibits a significant antifungal activity against three Candida species and that it can act in synergy with fluconazole. These results support the notion that this plant may have a potential use in pharmaceutical and preservative products.

Most of the essential oils (EO) known for mosquitocidal activity contain terpenes as part of their chemical constituents. In this study, four monoterpenes namely γ‐terpinene (T), R‐(+)‐limonene (L), carvacrol (C), and trans‐anethole (A) were screened against late third instar Aedes aegypti Linn. larvae singly and in combination to find out the synergistic interaction. The monoterpenes γ‐terpinene, R‐(+)‐limonene, trans‐anethole, and carvacrol showed larvicidal activity with LC50 values of 9.76, 11.88, 50.19, 48.57 ppm and LC90 values of 16.99, 17.78, 65.21, 75.02 ppm, respectively for Ae. aegypti when tested individually. Prepared binary combinations at LC20 values and studied the synergistic interactions based on cotoxicity factor (CTF) and found that all the binary combinations showed synergistic interactions (CTF > 20). Further, the binary (1:1), ternary (1:1:1), and quaternary (1:1:1:1) terpene combinations on equal weight basis were prepared, evaluated against Ae. aegypti larvae and synergistic interactions were studied by Wadley's method. Among the eight combinations two combinations viz. LC (LC5010.42 ppm) and LA (LC5011.86 ppm) were showing synergistic interactions (R > 1.5) and others were exhibiting additive effect (1.5 ≥ R > 0.5) and none of the combinations showed antagonism (R < 0.5). Among the two methods used the Wadley's method found suitable when combinations were made on an equal weight basis. The two binary combinations found in this study are promising synergistic mixtures which has scope in designing mosquito larvicidal EOs by enriching the EOs with terpenes or by producing EO combinations with these terpenes as chemical constituents in the correct proportions. [ABSTRACT FROM AUTHOR]

Effect of vermicompost treatments on essential oil content and composition of Satureja hortensis L. were studied under drought stress conditions. A factorial experiment based on completely randomized design with three replications were conducted in greenhouse condition at University of Mohaghegh Ardabili, Iran. In this experiment three levels of drought stress (Full irrigation, water cut in 50 % of flowering, and water cut in early stages of flowering) and vermicompost (volume ratios of 0, 10, 20 and 30 % v/v of pots) was analyzed. The results indicated that, the highest essential oil contents (1.43 and 1.4 %) was produced in 30 % v/ v of pots vermicompost and followed by the highest level of stress respectivley. The lowest essential oil content (1.06 %) was produced in plants grown in medium without any vermicompost. The major compounds of essential oil were carvacrol (50.8 - 59 %), γ-Terpinene (21 - 25.5 %), α-Terpinene (2.6 - 5.7 %), p-Cymene (2.2 - 4 %), α-thujene (1.3 - 2.6 %), β-Myrcene (0.82 - 2 %) and α-Pinene (1.06 - 1.8 %). Results suggested that irrigation based on water cut in early stages of flowering, with application of 30 % v/v vermicompost can improve essential oil content in Satureja hortensis cultivation. [ABSTRACT FROM AUTHOR]

A greenhouse experiment was conducted to study the effects of irrigation interval (4, 8, 12 and 16 days) and harvest (2, 4, 6, 8, 10 and 12 months after transplanting) on biomass, essential oil (EO) content and composition of Thymus vulgaris. As irrigation interval increased, herb fresh and EO yield decreased, but EO content increased, suggesting water stress stimulates EO content. While fresh weight peaked at 4 months, EO content and yield peaked at 6 months; then they declined and reached the bottom at 12 months. Thymol, p-cymene and γ-terpinene were the major compounds in T. vulgaris. The highest γ-terpinene and p-cymene were obtained when harvested at 12 months. The highest thymol was obtained when harvested at 2 months and irrigated every 4 days. This study showed biomass, EO content, yield and the accumulation of EO constituents of T. vulgaris are influenced by irrigation interval and harvest in different ways. [ABSTRACT FROM AUTHOR]

The steam volatile constituents from the aerial parts and roots of Selinum vaginatum C. B. Clarke (Apiaceae) growing wild in the central Himalayan region of Uttarakhand, India were isolated by steam distillation and analyzed by capillary gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). A total of thirty-one and forty-six constituents, representing 97.7 % and 96.7 % of the total oil composition were identified from the aerial parts and roots of S. vaginatum, respectively. The aerial parts oil consisted mainly of monoterpene hydrocarbons (48.7 %), with 2E,6E-farnesol (36.0 %), γ-terpinene (24.3 %) and β-pinene (16.3 %) as a major constituents while the roots oil mainly contains oxygenated sesquiterpenes (72.8 %), with maximum content of 2E,6Z-farnesol (60.0 %) and elemol (5.0 %). The oil samples showed significant antibacterial activity against Gram-positive Staphylococcus aureus, Enterococcus faecalis, Bacillus subtilis and Gram-negative Klebsiella pneumoniae. Minimum inhibitory concentration value (31.25 μL/mL) of the essential oil from the aerial parts was observed against Bacillus subtilis, Xanthomonas phaseoli, Klebsiella pneumoniae and Pasteurella multocida whereas from roots it was observed against Bacillus subtilis, Enterococcus faecalis, Erwinia chrysanthemi, Klebsiella pneumoniae and Salmonella enterica enterica. Both the oil samples showed bactericidal effect against B. subtilis, S. enterica enterica and E. faecalis at 62.5, 125 and 250 μl/mL, respectively. [ABSTRACT FROM AUTHOR]

Small hive beetle (Aethina tumida Murray), indigenous to Africa, has spread to other parts of the world where has become a threat to the honeybee industry. In the present study, insecticidal properties (contact, fumigant, and repellent toxicities) of three main constituents derived from Trachyspermum ammi (L.) Sprague ex Turrill fruits essential oil were evaluated against adult small hive beetles under laboratory conditions. The Hydrodistillation of T. ammi fruits, grown in Ethiopia, yielded a pale yellow essential oil (3.5% v/w) with a strong aromatic odor. Analyses by gas chromatography-mass spectrometry identified twenty-two compounds that accounted for 98.68% of the total essential oil. The essential oil was dominated by monoterpenoids, comprising γ-terpinene (32.72%), p-cymene (27.92%), and thymol (24.36%). The essential oil showed strong contact and fumigation toxicities against the small hive beetle adults, with a LD50 value of 66.64 µg/adult and a LC50 value of 89.03 mg/L air, respectively. Among the main constituents, thymol was the most toxic component found in both contact (LD50 = 41.79 µg/adult) and fumigation (LC50 = 52.66 mg/L air) toxicities. The other two components, γ-terpinene and p-cymene, were less effective in both contact and fumigant toxicities testing. The results showed that T. ammi essential oil and thymol could serve as potential alternatives to synthetic insecticides for the control of small hive beetle adults.

The intent of this study was to utilize distillation timeframes (DT) of nutmeg (Myristica fragrans) essential oil (EO) to generate fractions with differential chemical compositions and bioactivity. Ten fractions were captured at the following distillation timeframes: 0.0−0.5, 0.5−1.0, 1.0−2.5, 2.5−5.0, 5.0−10, 10−30, 30−60, 60−90, 90−120, and 120−240 min. In addition, a control EO was collected from a straight 0−240 min non-stop distillation. ANOVA and advanced regression modeling revealed that the produced EO fractions possess substantial variation in the concentration of potentially desired compounds. The concentrations (%) of α-phellandrene, 3-carene, p-cymene, limonene, α-thujene, α-pinene, camphene, sabinene, β-pinene, and myrcene decreased, while the concentrations (%) of α-terpinene, γ-terpinene, terpinolene, and myristicin increased in later DT fractions. Nutmeg EO showed some antimalarial activity against Plasmodium falciparum D6, but did not exhibit significant antifungal activity. In general, nutmeg seed oil yields increased with an increase of DT. These results may be utilized by industries using nutmeg EO.

The administration of antibiotics in aquaculture has raised concern about the impact of their overuse in marine ecosystems, seafood safety and consumers’ health. This “green consumerism” has forced researchers to find new alternatives against fish pathogens. The present study focused on 12 Mediterranean medicinal-aromatic plants as potential antimicrobials and antioxidant agents that could be used in fish aquaculture. In vitro assays showed that the essential oils (EOs) from all studied plants had anti-bacterial and antioxidant properties, with their efficacy being dependent on their chemical composition. More specifically, EOs rich in carvacrol, p-cymene and γ-terpinene exhibited not only the strongest inhibitory activity against the growth of bacterial pathogens (inhibitory concentration: 26−88 μg mL−1), but also the greatest total antioxidant capacity (ABTS: 2591−5879 μmole mL−1; CUPRAC: 931−2733 μmole mL−1). These compounds were mainly found in the EOs from Greek oregano (Origanum vulgare subsp. hirtum), Spanish oregano (Thymbra capitata) and savoury (Satureja thymbra) collected from cultivations in Greece. The specific EOs stand out as promising candidates for the treatment of bacterial diseases and oxidative stress in farmed fish. Further in vivo experiments are needed to fully understand the effects of EO dietary supplementation on fish farming processes.

Ajowan ( Trachyspermum ammi L.) is a highly valued medicinally important seed spice from Apiaceae family, which contains essential oil, exhibiting a chemical composition that can be strongly altered with developmental stages of the inflorescence. In order to investigate the changes of metabolite profile of Ajowan, the inflorescence harvested in ten developmental stages. The oil of each inflorescence stage collected by hydrodistillation and analysed by GC/MS. The essential oil concentrations were in a range of 3.71% (stage 1)–5.08% (stage 8). In this study, fourteen components were identified, which thymol, γ-terpinene, and ρ-cymene comprised between 94% and 96% of the essential oil. The results showed that during the anthesis stages, the thymol percentage in the essential oil of Ajowan was decreased, but the γ-terpinene percentage was increased. Hence, during the fruit ripening stages, the thymol and ρ-cymene percentages were increased but the γ-terpinene percentage was decreased. There was a negative correlation of γ-terpinene, ρ-cymene, and thymol. The results suggested that different harvest stages of Ajowan inflorescence have a significant effect on the essential oil concentration and composition. Furthermore, the anthesis stage was an important turning point of the main component percentage of the volatile oil composition of Ajowan inflorescence. [ABSTRACT FROM AUTHOR]

The fruits of eight populations of B. persicum were collected from different regions in northeast of Iran. Essential oil of B. persicum was extracted by hydrodistillation and analysed by GC-FID and GC/MS. The oils yields of dried fruits were found to be between 3.1 and 7.9% (v/w). In total, 19 compounds were identified that representing about 95.4-98.9% of the oil compositions. The major compounds (>5%) were γ-terpinene (29.2-40.1%), cuminic alcohol (16.4-28.4%), cumin aldehyde (9.1-18.9%), p-cymene (9.4-15.6%), safranal (3.4-7.9%) and limonene (3.7-6.4%). Monoterpene hydrocarbons were the main constituents in all populations. A hierarchical cluster analysis was done to put the chemical compositions of the essential oils from B. persicum fruit into perspective. The cluster analysis revealed at least five different groups and between these populations. The results of this experiment showed differences among the amount of oil yield, main and minor compounds in studied B. persicum populations. [ABSTRACT FROM AUTHOR]

Bioactivity of essential oils (EOs) from Monarda species has never been investigated on phytoparasitic nematodes. In this study, the EOs from two Italian ecotypes of Monarda didyma and M. fistulosa and their main compounds, carvacrol, γ-terpinene, o-cymene, and thymol, were evaluated for their in vitro activity on the infective stages of phytoparasitic nematodes Meloidogyne incognita and Pratylenchus vulnus, as well as on M. incognita egg hatch. Soil treatments with the two EOs were also investigated for their suppressiveness on M. incognita on tomato. Both EOs were strongly active on M. incognita juveniles, as a only 1.0 μL mL−1 LC50 value was evaluated after a 24-h exposure to both EOs, whereas a lower activity was recorded on P. vulnus (15.7 and 12.5 μL mL−1 LC50 values for M. didyma and M. fistulosa EOs, respectively). Among the EOs’ main compounds, carvacrol was highly active also at a short exposure in low concentrations, whereas γ-terpinene and thymol were much less active on both nematode species and o-cymene showed a discrete activity on P. vulnus only at the highest concentration. Hatch percent of M. incognita eggs treated with M. didyma and M. fistulosa EOs was always significantly lower than in water or in Tween 20 and Oxamyl solutions. In the experiment in soil, the multiplication of M. incognita and gall formation on tomato roots was significantly reduced by soil treatments with both EOs. The strong nematicidal activity of both Monarda EOs may suggest them as potential sources of new sustainable nematicidal products. [ABSTRACT FROM AUTHOR]

The tick Rhipicephalus microplus affects cattle health, with production loss in tropical and subtropical regions. Moreover, the use of commercial acaricides has been reduced due to the resistance of this parasite. Although alternatives such as plant bioactive molecules have been sought, essential oils present variations in their chemical constituents due to environmental factors, which can interfere with their acaricidal activity. The objective of the present study was to evaluate the seasonal influence of the essential oil of Ocimum gratissimum and its major constituents on acaricidal activity against R. microplus larvae. A high-yield essential oil of O. gratissimum and its major constituents were used, and a plant with a thymol-type oil was selected for seasonal analysis and acaricidal activity against R. microplus. Gas chromatography (GC) and GC-mass spectrometry (MS) were employed to identify 31 oil constituents (average yield of 6.26%). The main compounds were found to be thymol (33.4 to 47.9%), γ-terpinene (26.2 to 36.8%), and p-cymene (4.3 to 17.0%). Concerning acaricidal activity, the December (LC 0.84 mg/mL) and September (LC 1.58 mg/mL) oils obtained in the dry season were the most active, and assays performed with commercial standards revealed LC values of p-cymene, thymol, and γ-terpinene of 1.41, 1.81, and 3.08 mg/mL, respectively. Overall, lower acaricidal activities were found for oils produced from plants harvested in the rainy season. The results showed that seasonal variation in the chemical composition of the O. gratissimum essential oil influences its acaricidal activity. The seasonal variations in the thymol-type essential oil of O. gratissimum can represent an important strategy for the control of R. microplus. [ABSTRACT FROM AUTHOR]

The candidiasis caused by C. albicans is a public health problem. The abuse of antifungals has contributed to the development of resistance. B. morelensis has demonstrated antibacterial and antifungal activities. In this work the activity of the essential oil of B. morelensis was evaluated and for its two pure compounds with analysis of the different mechanisms of pathogenesis important for C. albicans. The essential oil was obtained by the hydro-distillation method and analyzed using GC-MS. The anti-Candida activity was compared between to essential oil, α-Pinene and -Terpinene. GC-MS of the essential oil demonstrated the presence of 13 compounds. The essential oil showed antifungal activity against four C. albicans strains. The most sensitive strain was C. albicans 14065 (MFC 2.0 mg/mL and MIC50 0.125 mg/mL) with α-Pinene and -Terpinene having MFCs of 4.0 and 16.0 mg/mL respectively. The essential oil inhibited the growth of the germ tube in 87.94% (8.0 mg/mL). Furthermore, it was observed that the essential oil diminishes the transcription of the gene INT1. This work provides evidence that confirms the anti-Candida activity of the B. morelensis essential oil and its effect on the growth of the germ tube and transcription of the gene INT1. [ABSTRACT FROM AUTHOR]

Summer savory essential oil is used as a flavour in food industries, treat various diseases and it has different biological activities. Essential oil production from aromatic plants is one way to utilize arid lands. Ascorbic acid plays an important role in essential oil production under arid lands. Plants subjected to various doses of ascorbic acid control (0.0), 100, 200 and 300 mg L-1. The greatest essential oil contents (0.5 - 0.6%; 79.2 - 100.8 ml Plot-1) were reported under 200 mg L-1 ascorbic acid rate. Twenty three constituents were detected in essential oil isolated under each treatment. Carvacrol and γ-terpinene were identified as major components which increased under ascorbic acid rates. 200 mg L-1 rate resulted in the highest values of major compounds {Carvacrol (46.5%) and γ-terpinene (32.4%)}. 300 mg L-1 rate produced the highest amounts of monoterpene hydrocarbons (MCH, 41.4%) and oxygenated sesquiterpenes (SCHO, 1.4%). Control rate reported the highest value of oxygenated monoterpene (MCHO, 55.9%) while the highest value of sesquiterpene hydrocarbons (SCH, 4.8%) was recorded under the rates of 200 or 300 mg L-1. [ABSTRACT FROM AUTHOR]

The essential oil obtained from Citrus wilsonii Tanaka leaves with hydrodistillation was investigated by GC and GC-MS. The main components of the essential oil were identified to be citronellol (16.94%), nerol acetate (10.35%), γ-terpinen (9.85%), citronellal (9.36%) and β-pinene (6.72%). Among them, the four active constituents, predicted with a bioactivity-test, were isolated and identified as citronellol, γ-terpinene, nerol (neryl) acetate and β-pinene. It was found that the essential oil of C. wilsonii leaves and isolated compounds possessed fumigant and contact toxicity against Tribolium castaneum adults. The essential oil and γ-terpinen showed strong fumigant toxicity against T. castaneum (LC50 = 8.18 and 4.09 mg L-1). Repellency of the crude oil and active compounds was also determined. Citronellol, neryl acetate and β-pinene were strongly repellent (100%, 86% and 92%, respectively, at 78.63 nL cm-2, after 2 h treatment) against T. castaneum. The essential oil and citronellol exhibited the same level of repellency compared with the positive control, DEET. The results indicate that the essential oil of C. wilsonii leaves and its active compounds had the potential to be developed as natural fumigants, insecticides and repellents for control of T. castaneum.

Finger citron (Citrus medica var. sarcodactylis) is a popular ornamental tree and an important source of essential oils rich in terpenoids, but the mechanisms behind volatile formation are poorly understood. We investigated gene expression changes combined with volatile profiling of ten samples from three developing organs: flower, leaf, and fruit. A total of 62 volatiles were identified with limonene and γ-terpinene being the most abundant ones. Six volatiles were identified using partial least squares discriminant analysis (PLS-DA) that could be used as markers for distinguishing finger citron from other citrus species. RNA-Seq revealed 1,611,966,118 high quality clean reads that were assembled into 32,579 unigenes. From these a total of 58 terpene synthase (TPS) gene family members were identified and the spatial and temporal distribution of their transcripts was measured in developing organs. Transcript levels of transcription factor genes AP2/ERF (251), bHLH (169), bZIP (76), MYB (155), NAC (184), and WRKY (66) during finger citron development were also analyzed. From extracted subnetworks of three modules constructed by weighted gene co-expression network analysis (WGCNA), thirteen TPS genes and fifteen transcription factors were suggested to be related to volatile terpenoid formation. These results provide a framework for future investigations into the identification and regulatory network of terpenoids in finger citron.

The isomerization of limonene over the Ti-SBA-15 catalyst, which was prepared by the hydrothermal method, was studied. The main products of limonene isomerization were terpinolene, α-terpinene, γ-terpinene, and p-cymene--products with numerous applications. The amount of these products depended on reaction time, temperature, and catalyst content. These parameters changed in the following range: reaction time 30-1380 min, temperature 140-160 °C, and catalyst content 5-15 wt %. Finally, the most favorable conditions for the limonene isomerization process were established: a reaction time of 180 min, temperature of 160 °C, and amount of the catalyst 15 wt %. In order to obtain p-cymene (dehydroaromatization product), the most favorable conditions are similar but the reaction time should be 1380 min. The application of such conditions allowed us to obtain the highest amounts of the desired products in the shortest time. [ABSTRACT FROM AUTHOR]

The objective of this research work was to investigate the chemical composition and the insecticidal activity of Tranchyspermum ammi (Carom oil) against grain bugs originated in stored grains. In this study, essential oil of Tranchyspermum ammi is obtained by hydrodistillation using Clevenger apparatus. Thymol is a major chemical constituent isolated from Carom oil. Presence of thymol in Carom oil was determined and confirmed by GC, GC-MS and FT-IR analysis. Organoleptic and Physio-chemical properties of Carom oil were also analyzed. Apart from thymol, other compounds present in Carom oil were pcymene, γ-terpinene and β-pinene. 67.73% of thymol was quantified in Carom oil. [ABSTRACT FROM AUTHOR]

Leaves (500g) of Ocimum gratissimum harvested at interval of three hours (7:00 am-7:00 pm) in a day were separately hydrodistilled for three hours. Oil yields from the leaves ranged from 0.33 - 0.94%. GC and GC-MS analyses revealed abundance of hydrocarbon monoterpenoids in the oils (47.6-67.9%). Principal constituents of the oils were; ã-terpinene (17.6 - 26.9), m-cymene (18.1-26.0%), thymol (18.3-32.6%), á-thujene (3.6-5.0%), â-myrcene (3.7-4.7%), â-selinene (2.7-8.2%) and â-caryophyllene (1.7-3.6). Fumigant toxicity and repellence bioassays of the oils revealed that the oils exhibited insecticidal properties against Callosobruchus maculatus. The oil from 10:00 am harvest demonstrated stronger efficacy than other oils. The LT50 {1.78 h} of the oil against C. maculatus was significantly lower than the oils from other harvests. Percentage mortality (83.33%) observed in the oil was significantly greater than the oil from other harvests. Percentage repellency (90.00%) observed in the oil was significantly greater than the PR of the oils from other harvests. With the insecticidal properties, the oils can be used as alternative to synthetic insecticide against Callosobruchus maculatus. [ABSTRACT FROM AUTHOR]

Cumin ( Cuminum cyminum L.) is a commercial plant that used for various purposes in medicinal, cosmetic and food industries. Agro-morphological and chemical diversities of 20 accessions of Iranian cumin were evaluated. The samples were phenotypically diverse, which plant height, lateral branches number per plant, flower umbels number per plant, seeds (fruit) number per plant, 1000-seed weight and fruit yield were characteristics with the significant variation among studied accessions. The average content of fruit yield, essential oil content and essential oil yield of different cumin accessions were 400.2 kg ha −1 , 2.1% (w/w), and 8.3 kg ha −1 , respectively. In total, 23 components were identified in the essential oils, that γ-terpinene (26.53–37.81%), cumin aldehyde (9.45–20.66%), cumin alcohol (1.63–15.22%) and β-pinene (8.32–13.84%) were the major components of all samples, however, a significant variation among the accessions was observed for the quantity and quality of majority constituents. Among accessions, the Yazd accession (accession 17) showed the highest contents of essential oil, essential oil yield and cumin aldehyde. Number of flower umbels, seeds and lateral branches per plant significantly correlated with fruit yield. Cumin aldehyde showed the negative correlations with γ-terpinene and β-pinene. Morphological characters did not have significant correlations with essential oil content and its chemical components. In this study, it was obvious that the dendrogram based on morphological traits was mostly differed from the one based on phytochemical variables that showed a high potential of studied accessions for breeding programs. [ABSTRACT FROM AUTHOR]

Ajowan ( Trachyspermum ammi ) is an industrial medicinal plant with different food and pharmaceutical applications. Essential oil yield and composition of 24 ajowan populations in different locations of Iran was investigated. The essential oil content of populations ranged from 1.68% in Yazshah to 5.55% in Yazd. According to GC–MS analysis, thymol (48.84–61.44%), γ-terpinene (26.96–19.46%) and p-cymene (15.09–20.32%) were the major components. According to hierarchical cluster and principal component analyses, two chemotypes were determined for Iranian ajowan populations, including high thymol, and high γ-terpinene and p-cymene groups. The highest correlation coefficient was between β-pinene and α-pinene (+0.709), while the highest negative correlation was between γ-terpinene and thymol (−0.896). In the present study, the climatic and soil orders of studied populations were determined. Canonical correspondence analysis (CCA) was also applied to assess the impact of geographic variation and environmental conditions on chemical variability of ajowan. Finally, it can be suggested that high essential oil and thymol content (phenolic chemotype) can be obtained in poor, undeveloped, relatively stony and shallow soil orders in arid and semi-arid conditions, while none phenolic ones needs higher humidity and soil depth that the first group. [ABSTRACT FROM AUTHOR]

Black cumin orNigella sativaL. essential oil and seeds are used in folk medicine, as a bread or cheese flavoring and as a spice in various kinds of meals.Nigella sativaL. plants subjected to different levels of kinetin, control (0.0 mg L-1), 25, 50, and 75 mg L-1. The highest essential oil contents [0.4% and yield (2.7 ml 100 Plants-1)] were recorded at 75 mg L-1kinetin treatment. Sixteen components were identified in the essential oil of each treatment; p-cymene, α-thujene and γ-terpinene were detected as the major components which changed under different kinetin levels. Monoterpene and sesquiterpene hydrocarbons increased with various treatments of kinetin compared with control treatment. Oxygenated monoterpenes increased towards 50 mg L-1kinetin treatment, and then decreased with 75 mg L-1kinetin treatments. Oxygenated sesquiterpenes increased with 50 mg L-1kinetin treatments while it was decreased with 25 and 75 mg L-1kinetin treatments. [ABSTRACT FROM AUTHOR]