Southern French thyme oils: chromatographic study of chemotypes

Oils obtained from seven chemotypes (thymol, linalool, geraniol, borneol, (E)‐sabinene hydrate/terpinene‐4‐ol, p‐cymene and carvacrol) of Thymus vulgaris (thyme) that exist in the South of France were analysed by gas chromatography/mass spectrometry (GC/MS) and characterised. Wild thyme growing in three departments (Bouches du Rhone, Var and Vaucluse) of Provence and in a fourth neighbouring department (Gard) was also studied. This is often the result of a mixture of three chemotypes: thymol, carvacrol and p‐cymene. Linalool and (E)‐sabinene hydrate/terpinene‐4‐ol were observed as minor chemotypes. GC/MS was also used to monitor seasonal variations in the composition of the oil obtained from thyme harvested at the same location (Gemenos, near Marseille, Bouches du Rhone) during the plant vegetative and life cycles (19 samples). Four components were determined: the phenols thymol and carvacrol and the monoterpene hydrocarbon precursors p‐cymene and γ‐terpinene. Results showed maximum oil (34.1 mL kg⁻¹ dry matter) and phenolic terpenoid (95.4 mmol kg⁻¹ dry matter) contents occurring in May, the period of flowering and harvesting. In contrast, in December the oil displayed a higher level of phenolic precursors (p‐cymene and γ‐terpinene, 72.8 mmol kg⁻¹ dry matter) than phenolic terpenoids. Depending on the harvesting date, the oils isolated from southern French thyme (T. vulgaris) could have different potential biological activities. Copyright © 2005 Society of Chemical Industry     

Antioxidant activity of essential oil of oregano species from Argentina in relation to their chemical composition

The purpose of this work was to determine chemical composition and antioxidant activity of essential oil of different oregano species from Argentina: ‘Cordobes’, ‘Criollo’, ‘Mendocino’ and ‘Compacto’. The essential oil composition was determined by gas–liquid chromatography and mass spectrometry. Scavenging activity was analysed by DPPH test. The antioxidant activity of the essential oils was determined by an accelerated oxidation test in canola oil. Thirty‐nine compounds were identified in the oregano essential oils. The oregano species showed differences in their chemical composition, radical scavenging activity and antioxidant activity. The main compounds in the studied oregano species were thymol and trans‐sabinene hydrate followed by γ‐terpinene, terpinen‐4‐ol and α‐terpinene. The oregano, ‘Criollo’, was rich in γ‐terpinene and had lower thymol and trans‐sabinene hydrate and higher α‐terpinene and carvacrol contents than the other oregano species. ‘Mendocino’ had higher trans‐sabinene hydrate and limonene than the other oregano species. ‘Cordobes’ and ‘Compacto’ had higher thymol content, radical scavenging activity and antioxidant activity in canola oil.     

Essential oil composition of sea fennel (Crithmum maritimum) form Turkey.

Constituents of essential oils of sea fennel (Crithmum maritimum L.) collected in different localities of Turkey in 1997 and 1998 have been identified by GC/MS. The effects of collection time and locality on the oil content and composition have been studied. The samples were classified into groups according to the main components: sabinene, gamma-terpiene, methyl thymol and terpinen-4-ol; gamma-terpinene, dill apiol and sabinene; gamma-terpiene, methyl thymol and limonene; p-cymene, methyl thymol and gamma-terpinen. (Z)-beta-ocimene and spathulenol were found with high percentage values in some samples. cis-p-Menth-4-en-1,2-diol was identified in only one oil. Early collected plants yielded oil rich in p-cymene. Effect of freezing plant did not have any important effect in oil composition.     

Chemical composition and antimicrobial activity of Anzer tea essential oil

Anzer tea (Thymus praecox, subsp. caucasicus var. caucasicus) naturally grows in the eastern Black Sea region of Turkey. Anzer tea, a creeping plant with crimson‐pink flowers, is important for honey production in the region. In the present study, content, composition and antimicrobial properties of Anzer tea's essential oil were investigated. Essential oil content of dried aerial plant parts varied between 1.53% and 2.05%. Essential oil composition was studied by means of gas chromatography–mass spectrometry, and 26 components were identified. The major components were thymol (47.45%), γ‐terpinene (8.73%), p‐cymene (8.30%), terpinyl acetate (4.88%) and carvacrol (4.66%). Essential oil was also screened for its antibacterial activity. In a screen for antibacterial activity, Anzer tea essential oil had significant activity against Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Candida albicans. Copyright © 2007 Society of Chemical Industry     

The influence of harvest time on essential oil composition,phenolic constituents and antioxidant properties of Turkish oregano (Origanum onites L.)

BACKGROUND: The aim of this research was to determine essential oil composition, phenolic constituents and antioxidant properties of Turkish oregano (Origanum onites L.) leaves harvested during the months of June to September. RESULT: The maximum essential oil yield in the leaves appeared in the middle of July. The main components of oregano oil were carvacrol, thymol, γ‐terpinene, p‐cymene, α‐terpinene and α‐pinene. Carvacrol was highest in the July harvest. The maximum extract yield was found in September. Oil distilled from early‐season (June) harvested leaves had the highest antioxidant ability, expressed as low concentration providing 50% inhibition of free radical scavenging activity and high levels of reducing/antioxidant capacity. Twelve phenolic compounds of oregano extract were identified and the main components were found to be rosmarinic acid and acecetin. The maximum rosmarinic acid and acecetin were found in harvests of July and June, respectively. Total phenolic contents, free radical scavenging activities and reducing/antioxidant capacities were found to be highest in the July harvest. DISCUSSION: All yields, chemical compositions, free radical scavenging activities and reducing/antioxidant capacities of extracts and essential oils of Turkish oregano changed importantly depending on vegetative periods of growing season. Copyright © 2009 Society of Chemical Industry     

In vitro degradation of 10 mono‐ and sesquiterpenes of plant origin by caprine rumen micro‐organisms

The extent of disappearance of 10 mono‐ and sesquiterpenes in presence of mixed rumen micro‐organisms has been measured in 24‐h batch cultures. The molecules that were tested are frequently found in the plants consumed by ruminants in highland pastures (limonene, β‐myrcene, β‐ocimene, α‐pinene, sabinene, γ‐terpinene and thymol) or are potential markers of the diet (camphene, β‐caryophyllene and α‐copaene). All terpenes were tested at 2 µL mL^?1, except α‐copaene and thymol, which were tested at 0.9 µL mL^?1 and 2 mg mL^?1, respectively. Camphene and thymol were not degraded to a significant extent. The disappearance of part of β‐caryophyllene, (?)‐limonene and γ‐terpinene could not be attributed to the direct action of rumen micro‐organisms but rather than to an effect of the extracellular medium. In contrast, a third group of one sesquiterpene (α‐copaene) and four monoterpenes (myrcene, β‐ocimene, α‐pinene and sabinene) was extensively degraded by rumen micro‐organisms, at rates of 1.6, 4.5, 3.5, 4.8 and 5.4 µmol mL^?1 inoculum day^?1, respectively. The preliminary exposure of rumen micro‐organisms to a specific blend of essential oils compounds, containing mainly thymol, guajacol and limonene, increased the extent of disappearance of γ‐terpinene only. Copyright © 2007 Society of Chemical Industry     

Chemical composition,antioxidant activity and anti‐lipase activity of Origanum vulgare and Lippia turbinata essential oils

This study reported the chemical composition, phenolic content, antioxidant and anti‐lipase activity of oregano and Lippia essential oils. The major compounds found in oregano essential oil were γ‐terpinene (32.10%), α‐terpinene (15.10%), p‐cymene (8.00%) and thymol (8.00%). In Lippia essential oil, α‐limonene (76.80%) and 1,8‐cineole (4.95%) represented the major compounds. Oregano essential oil had higher phenolic content (12.47 mg gallic acid mL^?1) and DPPH scavenging activity (IC₅₀ 0.357 μg mL^?1) than Lippia essential oil (7.94 mg gallic acid mL^?1 and IC₅₀ 0.400 μg mL^?1, respectively). Both essential oils had similar antioxidant indexes (about 1.2) determined by Rancimat. Moreover, oregano essential oil had also higher anti‐lipase activity (IC₅₀ 5.09 and 7.26 μg mL^?1). Higher phenolic content in the essential oils was related with higher scavenging and anti‐lipase activities. Oregano and Lippia essential oils could be used as natural antioxidants on food products.     

Antibacterial activities of essential oils and extracts of Turkish Achillea,Satureja and Thymus species against plant pathogenic bacteria

BACKGROUND: The aims of this study were to examine the chemical composition of the essential oils and hexane extracts of the aerial parts of Satureja spicigera (C. Koch) Boiss., Thymus fallax Fisch. & CA Mey, Achillea biebersteinii Afan, and Achillea millefolium L. by GC and GC–MS, and to test antibacterial efficacy of essential oils and n‐hexane, chloroform, acetone and methanol extracts as an antibacterial and seed disinfectant against 25 agricultural plant pathogens. RESULTS: Thymol, carvacrol, p‐cymene, thymol methyl ether and γ‐terpinene were the main constituents of S. spicigera and T. fallax oils and hexane extracts. The main components of the oil of Achillea millefolium were 1,8‐cineole, δ‐cadinol and caryophyllene oxide, whereas the hexane extract of this species contained mainly n‐hexacosane, n‐tricosane and n‐heneicosane. The oils and hexane extracts of S. spicigera and T. fallax exhibited potent antibacterial activity over a broad spectrum against 25 phytopathogenic bacterial strains. Carvacrol and thymol, the major constituents of S. spicigera and T. fallax oils, also showed potent antibacterial effect against the bacteria tested. The oils of Achillea species showed weak antibacterial activity. Our results also revealed that the essential oil of S. spicigera, thymol and carvacrol could be used as potential disinfection agents against seed‐borne bacteria. CONCLUSION: Our results demonstrate that S. spicigera, T. fallax oils, carvacrol and thymol could become potentials for controlling certain important agricultural plant pathogenic bacteria and seed disinfectant. Copyright © 2009 Society of Chemical Industry     

Essential oils of Origanum vulgare L. subsp. glandulosum (Desf.) Ietswaart from Tunisia: chemical composition and antioxidant activity

BACKGROUND: Characterisation of the essential oils from O. glandulosum collected in three locations of Tunisia, chemical composition and the evaluation of their antioxidant activities were carried out. RESULTS: The essential oils from Origanum vulgare L. subsp. glandulosum (Desf.) Ietswaart collected from three localities of north Tunisia—Krib, Bargou and Nefza—were obtained in yields of 2.5, 3.0 and 4.6% (v/w), respectively. The essential oils were analysed by GC and GC/MS and assayed for their total phenolics content, by the Folin–Ciocalteu method, and antioxidant effectiveness, using the 2,2‐diphenyl‐1‐picrylhydrazil (DPPH) radical scavenging assay. The main components of these essential oils, from Nefza, Bargou and Krib, were p‐cymene (36%, 40% and 46%), thymol (32%, 39% and 18%), γ‐terpinene (24%, 12% and 16%) and carvacrol (2%, 2% and 15%), respectively). The ability to scavenge the DPPH radicals, expressed by IC₅₀, ranged from 59 to 80 mg L^?1. The total phenolic content, expressed in gallic acid equivalent (GAE) g kg^?1 dry weight, varied from 9.37 to 17.70 g kg^?1 dw. CONCLUSIONS: A correlation was identified between the total phenolic content of the essential oils and DPPH radical scavenger capacity. The occurrence of a p‐cymene chemotype of O. glandulosum in the northern region of Tunisia is demonstrated. Copyright © 2010 Society of Chemical Industry     

Chemical composition and insecticidal properties of Origanum glandulosum (Desf.) essential oil from Algeria

BACKGROUND: To find natural compounds with insecticidal properties which could be an alternative to synthetic insecticides, oregano essential oil was tested against the insect Rhizopertha dominica devastating stored cereals. RESULTS: Oregano oils were isolated by steam distillation, analysed by gas chromatography and gas chromatography–mass spectrometry and investigated for their insecticidal activities against Rhizopertha dominica. Contact and fumigant toxicities of global oil and three of its fractions recovered respectively after 2 h and after 0–2.5, 2.5–5 and 5–10 min of extraction were tested using the filter paper method. Eighteen components, representing 92.6% of the oil, were identified. The major components were thymol (38.8%), carvacrol (32.9%), p‐cymene (7.9%) and γ‐terpinene (5.1%). Toxicity tests showed that insect mortality increases with the concentration used (0.39%, 0.78%, 1.56%, 3.12% and 6.24%V). For all concentrations, the contact effect of global oil and fraction F₂ was better than the fumigant effect. Whereas fractions F₁ and F₃ were more toxic by fumigation for concentrations lower or equal to 1.56%, their contact effect was more significant for concentrations higher than 1.56%. CONCLUSION: These results suggest that oregano oil has important insecticidal properties and may be useful as a natural grain protectant against Rhizopertha dominica to replace synthetic insecticides. Copyright © 2008 Society of Chemical Industry     

Chemical composition and in vitro antimicrobial activity of the essential oil of Origanum minutiflorum O Schwarz & PH Davis

The essential oil obtained by hydrodistillation from the aerial parts of Origanum minutiflorum O Schwarz & PH Davis, an endemic species in Turkey, was analysed for its antimicrobial activity in vitro. Gas chromatography/mass spectrometry analysis of the essential oil resulted in the identification of 34 constituents accounting for 961.5 mL L^?1 of the oil, the major compounds present being carvacrol (793.4 mL L^?1), p‐cymene (32.6 mL L^?1) and γ‐terpinene (21.4 mL L^?1). The in vitro antimicrobial activity of the essential oil was investigated in order to evaluate its efficacy against 16 bacteria and two yeasts, using disc diffusion and minimum inhibitory concentration methods. The essential oil showed strong antimicrobial activity against all test micro‐organisms except Pseudomonas aeruginosa. Its main components carvacrol and p‐cymene were also assayed for their antimicrobial activities. Carvacrol exhibited comparable activity to the crude oil, proving it to be the main component responsible for the biological activity observed. This study demonstrates the in vitro antimicrobial activity of the essential oil of this endemic remedy against a wide spectrum of clinically important micro‐organisms, including pathogenic yeasts, being the first report on the anticandidal properties of the essential oil of O. minutiflorum. Copyright © 2006 Society of Chemical Industry     

Composition, quality control and antimicrobial activity of the essential oil of cumin (Cuminum cyminum L.) seeds from Bulgaria that had been stored for up to 36 years

The essential oil of seeds of cumin (Cuminum cyminum L.) from Bulgaria stored for more than 35 years was analyzed by physicochemical methods, GC, GC‐MS and olfactometry and its antimicrobial activity tested using different strains of microorganisms. More than sixty constituents of this cumin oil could be identified as essential volatiles, responsible for the pleasant fresh, clean, spicy (typical cumin‐like) odour of a high quality product. Cumin aldehyde (36%), β‐pinene (19.3%), p‐cymene (18.4%) and γ‐terpinene (15.3%) were the principal compounds found. Antimicrobial testing showed high activity of the essential C. cyminum oil against the mold Aspergillus niger, the Gram (+) bacteria Bacillus subtilis and Staphylococcus epidermidis as well as the yeast Saccharomyces cerevisiae and Candida albicans.     

In vitro degradation by mixed rumen bacteria of 17 mono‐ and sesquiterpenes typical of winter and spring diets of goats on Basilitica rangelands (southern Italy)

BACKGROUND: Nine monoterpenes (δ‐3‐carene, p‐cymene, limonene, β‐myrcene, (E)‐ and (Z)‐β‐ocimene, α‐phellandrene, α‐terpinene, γ‐terpinene), seven oxygenated monoterpenes (1,8‐cineole, linalool, (E)‐ and (Z)‐linalool oxide, 4‐terpinenol, α‐terpineol, α‐terpinolene) and one sesquiterpene (β‐cedrene) were investigated for their degradability in the rumen microbial ecosystem. These molecules were identified as dominant terpenes in the winter and spring diets of milking goats in Basilicata (southern Italy). RESULTS: All terpenes were tested at 3.33 µL L^?1 for 24 h using in vitro incubation with mixed rumen bacteria from dairy goats. Oxygen‐containing compounds were those recovered at the highest levels (89% of (E)‐linalool oxide, 93% of (Z)‐linalool oxide, 91% of 1,8‐cineole, 82% of terpineol and 72% of 4‐terpinenol), except linalool. The linear alkenes β‐myrcene and β‐ocimene almost completely disappeared. Results were more variable among cyclic alkenes, with recovery rates ranging from 50% in the case of limonene to less than 1% for α‐phellandrene. 17% of the only sesquiterpene of the group, β‐cedrene, was recovered. CONCLUSION: Recovery rates differed markedly among terpenes, partly in relation to the presence of oxygen and rings in the molecules. These observations should contribute to a better understanding of the changes in composition between the diet and milk terpenes. Copyright © 2008 Society of Chemical Industry     

Essential oils and fatty acids composition of Tunisian and Indian cumin (Cuminum cyminum L.) seeds: a comparative study

BACKGROUND: Cumin (Cuminum cyminum L.) seeds of two geographic origins, Tunisia (TCS) and India (ICS), were studied regarding their fatty acid and essential oil composition. RESULTS: Oil yields were 17.77 and 15.40% for TCS and ICS respectively. Petroselinic acid (C18:1n‐12) was the major fatty acid in both varieties, with a higher proportion being found in TCS (55.90% of total fatty acids (TFA)) than in ICS (41.42% TFA). Moreover, the most predominant fatty acids were palmitic, petroselenic and linoleic acids, accounting for more than 91% TFA in both varieties. The unsaturated fatty acid content was high: 70.95% TFA in TCS and 62.17% TFA in ICS. Essential oil yields differed significantly (P < 0.05) between the two varieties: 1.21 and 1.62% for ICS and TCS respectively. A total of 40 compounds were identified, 34 of which were present in both essential oils. The two varieties displayed different chemotypes: γ‐terpinene/1‐phenyl‐1,2‐ethanediol for TCS and cuminaldheyde/γ‐terpinene for ICS. CONCLUSION: The study revealed that the biochemical composition of cumin seeds is origin‐dependent and that cumin seeds are rich in an unusual fatty acid, petroselinic acid. Besides, cumin essential oil is a rich source of many compounds, including cuminaldehyde and γ‐terpinene. The overall results suggest the exploitation of cumin seeds as a low‐cost renewable source for industrial processing in the fields of cosmetics, perfumes and pharmaceuticals. Copyright © 2011 Society of Chemical Industry     

Terpene profiles in Cantal and Saint‐Nectaire‐type cheese made from raw or pasteurised milk

Terpene profiles in cheese can be considered a ‘terroir’ fingerprint as the information contained in it should enable the pastures on which the animals were fed to be recognised. Yet a certain elasticity of the signature must be taken into account when determining authentication strategies, since products acknowledged as containing a common signature may have undergone certain procedures, such as cheese making and milk pasteurisation, that could have potentially altered their terpene profiles. In this study, Cantal and Saint‐Nectaire‐type cheeses were made from both raw and pasteurised milk from the same herd of dairy cows that had been grazed on natural grassland. Cheeses from raw and pasteurised milk were made from the same milking on the same days. Cantal and Saint‐Nectaire‐type cheeses were made on 4 different days, alternatively over four weeks. The terpenes in the cheese fat were analysed by dynamic headspace/gas chromatography/mass spectrometry. A great diversity of monoterpenes, sesquiterpenes and oxygen‐containing derivatives were identified. The major terpenes identified in most cheeses were β‐caryophyllene, α‐ and β‐pinene and limonene. Milk pasteurisation did not induce changes in the terpene profile of the cheese. Significant differences (p < 0.001) were observed between Cantal and Saint‐Nectaire cheeses: α‐pinene, β‐myrcene and β‐phellandrene were, respectively, three, five and five times more abundant in Cantal cheese, while tricyclene, α‐phellandrene and geraniol were found exclusively in Cantal cheese. In contrast, unidentified sesquiterpenes with retention indices (KI) = 1342 and 1511, α‐cubebene, longifolene and γ‐elemene were more abundant or exclusively found in Saint‐Nectaire cheese. A significant relationship with the date of milking (p < 0.01) was observed for α‐pinene and tricyclene in Cantal, for β‐myrcene, δ‐3‐carene, p‐cymene and α‐terpinene in Saint‐Nectaire cheese. Copyright © 2005 Society of Chemical Industry     

Evaluation of Antioxidant and Antimicrobial Activities of Essential Oils from Carum copticum Seed and Ferula assafoetida Latex

Carum copticum and Ferula assafoetida have several medicinal properties including antispasmodic, carminative, sedative, analgesic, and antiseptic. Reactive oxygen species (ROS), reactive nitrogen species (RNS), hydrogen peroxide (H₂O₂), and thiobarbituric acid reactive substances (TBARS) scavenging activities of Carum and Ferula oils along with their antibacterial and antifungal activities were examined. Thymol (40.25%), γ‐terpinene (38.7%) and p‐cymene (15.8%) were detected as the main components of Carum oil while, β‐pinene (47.1%), α‐pinene (21.36%), and 1, 2‐dithiolane (18.6%) were the main components of Ferula oil. Inhibitory concentrations (IC50) for total radical scavenging were between 40 and 60 and 130 and 160 μg/mL of Carum and Ferula oil, respectively. Minimal inhibitory concentration (MIC) for Salmonella typhi, Escherichia coli, Staphylococcus aureus, Bacillus subtilis, Aspergillus niger, and Candida albicans were 78 ± 8, 65 ± 7, 14 ± 3, 5 ± 2, 5.6 ± 1.3, and 8.8 ± 2.2 μg/mL of Carum oil, respectively. MIC for S. typhi, E. coli, S. aureus, B. subtilis, A. niger, and C. albicans were >200, >200, 125 ± 17, 80 ± 12, 85 ± 5, and 90 ± 11 μg/mL of Ferula oil, respectively. Accordingly, Carum and Ferula oils could be used as safe and effective natural antioxidants to improve the oxidative stability of fatty foods during storage and to preserve foods against food burn pathogens. Practical Application : This study clearly demonstrates the potential of Carum and Ferula oil especially Carum oil as natural antioxidant and antimicrobial agent. The chemical composition of essential oils was identified. Thus, identification of such compounds also helps to discover of new antioxidant, antibacterial and antifungal agents for potential applications in food safety and food preservation.     

Electrospun nanofibers from cyclodextrin inclusion complexes with cineole and p‐cymene: enhanced water solubility and thermal stability

The electrospinning of self‐standing nanofibrous webs from inclusion complexes (IC) of cineole and p‐cymene with two modified cyclodextrins (HPβCD, HPγCD) was achieved without using carrier polymeric matrix. Although they are highly volatile, certain amount of cineole and p‐cymene was protected in cyclodextrin inclusion complexes nanofibers (CD‐IC‐NF). That is, 68.4%, 78.1%, 54.5% and 44.0% (w/w) of active agent were preserved in cineole/HPβCD‐IC‐NF, cineole/HPγCD‐IC‐NF, p‐cymene/HPβCD‐IC‐NF and p‐cymene/HPγCD‐IC‐NF, respectively. Remarkable, high thermal stability for cineole (~150 °C – 270 °C) and p‐cymene (~150 °C – 275 °C) was achieved for CD‐IC‐NF samples due to CD‐IC formation. The water solubility of cineole and p‐cymene was significantly improved by inclusion complexation where CD‐IC‐NF samples become readily dissolved in water. In brief, essential oils and flavours such as cineole and p‐cymene could be applicable in food and oral care applications owing to their fast‐dissolving behaviour along with high water solubility, enhanced thermal stability and free‐standing feature of CD‐IC‐NF webs.     

Oregano: chemical analysis and evaluation of its antimalarial, antioxidant, and cytotoxic activities

Abstract: GC‐FID and GC‐MS analysis of essential oil from oregano leaves (Origanum compactum) resulted in the identification of 46 compounds, representing more than 98% of the total composition. Carvacrol was the predominant compound (36.46%), followed by thymol (29.74%) and p‐cymene (24.31%). Serial extractions with petroleum ether, ethyl acetate, ethanol, and water were performed on aerials parts of Origanum compactum. In these extracts, different chemical families were characterized: polyphenols (gallic acid equivalent 21.2 to 858.3 g/kg), tannins (catechin equivalent 12.4 to 510.3 g/kg), anthocyanins (cyanidin equivalent 0.38 to 5.63 mg/kg), and flavonoids (quercetin equivalent 14.5 to 54.7 g/kg). The samples (essential oil and extracts) were subjected to a screening for antioxidant (DPPH and ABTS assays) and antimalarial activities and against human breast cancer cells. The essential oil showed a higher antioxidant activity with an IC₅₀= 2 ± 0.1 mg/L. Among the extracts, the aqueous extract had the highest antioxidant activity with an IC₅₀= 4.8 ± 0.2 mg/L (DPPH assay). Concerning antimalarial activity, Origanum compactum essential oil and ethyl acetate extract showed the best results with an IC₅₀ of 34 and 33 mg/mL, respectively. In addition, ethyl acetate extract (30 mg/L) and ethanol extract (56 mg/L) showed activity against human breast cancer cells (MCF7). The oregano essential oil was considered to be nontoxic.     

Influence of CMC‐ and guar gum‐based silver nanoparticle coatings combined with low temperature on major aroma volatile components and the sensory quality of kinnow (Citrus reticulata)

Aroma profile and organoleptic quality of CMC‐ and guar gum‐based silver nanoparticle‐coated kinnow (Citrus reticulata cv. Blanco) was evaluated for 120 days at 4 °C and 10 °C, 85–95% relative humidity. Loss in three major aroma‐active volatile compounds (limonene, linalool and γ‐terpinene) was determined after every 15 days by GC‐MS. Sensory quality of coated and uncoated fruit stored at 10 °C was declined during storage. Twenty five volatile aroma compounds were identified in fresh kinnow juice. Guar gum‐Ag coatings and 4 °C storage has significantly reduced losses of limonene, linalool and γ‐terpinene contents from 91 to 23%, 99 to 10% and 97 to 29% respectively as compared to uncoated fruit stored at 10 °C. Study suggests that CMC‐ and guar gum‐based silver nanoparticle‐coated kinnow stored at 4 °C has preserved the fruit aroma and sensory quality for 120 days.