Quantitative analysis of α-pinene and β-myrcene in mastic gum oil using FT-Raman spectroscopy

Analytical Method for Quantifying Monoterpenoids (p-Cymene and Myrcene) in Nanoemulsions Using High-Performance Liquid Chromatography

BACKGROUND

Myrcene and cymene, aromatic monoterpenes found in plants and essential oils, possess distinctive aromatic qualities. However, their volatility and limited solubility pose challenges in precise handling and formulation. Meanwhile, nanoemulsions emerge as promising drug delivery systems, improving the bioavailability and stability of these active ingredients.

OBJECTIVE

This article aimed to develop an HPLC method for the quantification of two monoterpenoids, p-cymene and myrcene, in nanoemulsions.

METHOD

The method used a Phenomenex® Synergi™ Fusion-RP column (150 mm × 4.6 mm id, 4 μm particle size) on an HPLC system with isocratic elution. The mobile phase was composed of acetonitrile and water (60:40, v/v) and was validated in terms of specificity, linearity, accuracy, precision, robustness, and selectivity.

RESULTS

The method provided accurate and precise results with a correlation coefficient of 0.999 and RSD values of less than 2%. The method can be used for quality control of nanoemulsions containing these monoterpenoids and as a reference for future studies on their efficacy and stability.

CONCLUSIONS

The study demonstrates the feasibility of using HPLC for the quantification of monoterpenoids in nanoemulsions and its potential as a quality control tool for nanoemulsion-based drug delivery systems.

HIGHLIGHTS

The method's accuracy, precision, and reliability, as evidenced by high correlation coefficients and low RSD values, underscore its suitability for ensuring the consistent formulation of these monoterpenoid-containing nanoemulsions, while also serving as a reference point for future research endeavors in this field.

Ultraviolet spectrophotometry as method to determine the concentration of β-myrcene released from chitosan in aqueous medium

Myrcene (β-myrcene), found in essential oils from plant species such as hops and cannabis, has many advantageous properties, but its use is limited due to volatility and low solubility in water. One way to circumvent these limitations is to encapsulate the essential oils in a polymer matrix. However, these hydrophobic molecules are difficult to quantify when dispersed in water. Seeking to study the release of this terpene in drug release tests from polymeric matrices, this work aimed to develop an easy and cheap UV spectrophotometric method for the quantification of β-myrcene in aqueous medium. To achieves this goal, samples were prepared in 0.05% (w/v) polysorbate 80 solution, with concentrations of β-myrcene ranging from 0.01% to 0.1% (v/v), and were analyzed at 226 nm. Each sample was analyzed in triplicate and repeated on three different days, to evaluate the repeatability of the results. The results were subjected to Q, F and Student's t-tests. The regression parameters obtained for β-myrcene were above 0.99 and through statistical analysis, it was possible to confirm the repeatability for the results. The values of the limits of detection and quantification indicated that the method is not affected by intrinsic factors of the equipment. The results of accuracy, robustness and selectivity showed recovery rates within acceptable limits. This demonstrates that the quantification of β-myrcene in aqueous medium by UV spectrophotometry is feasible.

Sialagogic Effects Through Olfactory Stimulation with Mastic Resin and α-pinene Volatiles in vivo

BACKGROUND

Xerostomia, often associated with decreased saliva quality, poses challenges due to limited treatment efficacy. This study aimed to investigate alternative approaches to enhance saliva secretion through olfactory volatile stimulation with mastic resin and its main compound α-pinene, known for inhibiting acetylcholinesterase in vitro.

METHODS

The inhibitory effects of freshly prepared mastic resin extract oil and α-pinene oil on acetylcholinesterase (AChE) activity were measured in vitro. Eighty healthy participants were recruited and divided into two groups: exposed to mastic resin volatiles (n = 40) or α-pinene volatiles (n = 40). Saliva samples were collected pre, during and post exposure to analyze saliva flow rate, spinnbarkeit, ion composition and MUC5B levels.

RESULTS

Mastic resin extract oil and α-pinene oil inhibited AChE activity by 207 % and 22 %, respectively. Olfactory stimulation with these volatiles significantly increased saliva secretion rate without altering spinnbarkeit and ion composition. Salivary MUC5B concentration rose after exposure to mastic resin volatiles.

CONCLUSIONS

Olfactory stimulation with mastic resin and α-pinene volatiles demonstrated a bona fide in vivo effect on saliva secretion, confirming their sialagogic capability, potentially as a result of local glandular AChE inhibition. These findings highlight the therapeutic potential of both volatile compounds in treating patients with xerostomia and hyposalivation through olfactory exposure.

Chios Mastic Gum: Chemical Profile and Pharmacological Properties in Inflammatory Bowel Disease: From the Past to the Future

Chios mastic gum, the product of the tree Pistacia lentiscus var. Chia, has been used for more than 2500 years in traditional Greek medicine for treating several diseases, thanks to the anti-inflammatory and antioxidant properties of its components. Despite the long-time use of mastic in gastroenterology and in particular in chronic-inflammation-associated diseases, to date, the literature lacks reviews regarding this topic. The aim of the present work is to summarize available data on the effects of P. lentiscus on inflammatory bowel disease. A comprehensive review of this topic could drive researchers to conduct future studies aimed at deeply investigating P. lentiscus effects and hypothesizing a mechanism of action. The present review, indeed, schematizes the possible bioactive components of mastic gum. Particular care is given to P. lentiscus var. Chia medicaments' and supplements' chemical compositions and their pharmacological action in inflammatory bowel disease.

μ-Raman Determination of Essential Oils' Constituents from Distillates and Leaf Glands of Origanum Plants

A novel, inexpensive and simple experimental setup for collecting μ-Raman spectra of volatile liquids in very small quantities was developed. It takes advantage of capillary forces to detain minute volatile liquid volumes. Spectra of volatile and even scattering or absorbing media can be measured more effectively. The method is used to facilitate the collection of intensity-consistent Raman spectra from a series of reference compounds present in Origanum essential oils, in order to quantify their constituents by multiple linear regression. Wild grown Origanum plants, collected from five different regions in Greece and taxonomically identified as O. onites, O. vulgare subsp. hirtum and O. vulgare subsp. vulgare, were appropriately distilled to acquire their essential oils. Comparison of the Raman results with those from headspace gas chromatography-mass spectrometry (HS GC-MS) confirmed the successful relative quantification of the most abundant essential oil constituents, highlighting the similarities and differences of the three Origanum taxa examined. Finally, it is demonstrated that directly measuring the leaf peltate glandular hairs yields exploitable results to identify the main components of the essential oil they contain, underlining the potential of in situ (field or industry) measurements utilizing microscope-equipped portable Raman spectrometers.

Myrcene-What Are the Potential Health Benefits of This Flavouring and Aroma Agent?

Myrcene (β-myrcene) is an abundant monoterpene which occurs as a major constituent in many plant species, including hops and cannabis. It is a popular flavouring and aroma agent (food additive) used in the manufacture of food and beverages. This review aims to report on the occurrence, biological and toxicological profile of β-myrcene. The main reported biological properties of β-myrcene-anxiolytic, antioxidant, anti-ageing, anti-inflammatory, analgesic properties-are discussed, with the mechanisms of activity. Here we also discuss recent data regarding the safety of β-myrcene. Overall, β-myrcene has shown promising health benefits in many animal studies. However, studies conducted in humans is lacking. In the future, there is potential for the formulation and production of non-alcoholic beers, functional foods and drinks, and cannabis extracts (low in THC) rich in β-myrcene.

Chemical Profiling of Pistacia lentiscus var. Chia Resin and Essential Oil: Ageing Markers and Antimicrobial Activity

Chios Mastic Gum (CMG) and Chios Mastic Oil (CMO) are two unique products of the tree Pistacia lentiscus var. Chia, cultivated exclusively on the Greek island of Chios. In the present study, the method proposed by the European Pharmacopoeia for mastic identification was employed using HPTLC together with an in-house method. A GC-MS methodology was also developed for the chemical characterization of CMOs. α-Pinene and β-myrcene were found in abundance in the fresh oils; however, in the oil of the aged collection, oxygenated monoterpenes and benzenoids such as verbenone, pinocarveol, and α-campholenal were found at the highest rates. Additionally, the antimicrobial activity of Chios Mastic Gums (CMGs) with their respective Chios Mastic Oils (CMOs) was evaluated, with growth tests against the fungi Aspergillus nidulans, Aspergillus fumigatus, Candida albicans, Mucor circinelloides, and Rhizopus oryzae, and the bacteria Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis, with the samples exhibiting a moderate activity. To our knowledge, this is the first time that an HPTLC method is proposed for the analysis of mastic and its essential oil and that a standardized methodology is followed for the distillation of CMO with a parallel assessment of the ageing effect on the oil’s composition.

Contact Dermatitis From Gum Mastic (Pistacia lentiscus) and Gum Storax (Liquidambar styraciflua) in Mastisol-Allergic Patients

BACKGROUND

Mastisol Liquid Adhesive is widely used on the skin, especially after surgical procedures. It contains gum mastic, gum storax, methyl salicylate, and ethanol.

OBJECTIVE

The aims of the study were to review our experience patch testing patients allergic to Mastisol and to assess coreacting substances.

METHODS

We identified 18 patients who were allergic to Mastisol. Most of these had a history of postoperative or cardiac electrode dermatitis and underwent patch testing with multiple surgically related substances, including ingredients of Mastisol, compound tincture of benzoin, and fragrance-related ingredients and botanicals.

RESULTS AND CONCLUSIONS

Among Mastisol-allergic patients, 13 (72%) of 18 were allergic to gum mastic, whereas 7 (44%) of 16 were allergic to gum storax. There was frequent coreactivity with various fragrance-related materials, including Majantol, Styrax benzoin, Myroxylon balsamum, Myroxylon pereirae, propolis, and others. Two gum mastic-allergic patients had positive patch tests with hydroperoxides of linalool and several other linalool-containing essential oils. As gum mastic contains linalool, it may explain some gum mastic reactions. Among patients without a history of postoperative contact dermatitis, 1 (0.4%) of 250 was patch test positive for gum mastic. This patient had allergic contact dermatitis from fragrances, so the gum mastic reaction was likely a true-positive relevant reaction.

Traditional uses, phytochemistry and pharmacology of Chios mastic gum (Pistacia lentiscus var. Chia, Anacardiaceae): A review

ETHNOPHARMACOLOGICAL RELEVANCE

Chios mastic gum constitutes a unique Greek product, produced exclusively in the southern part of the island of Chios. References about its use from local populations for the treatment of gastrointestinal disorders or as a cosmetic agent can even be encountered in ancient texts of Galen, Theophrastus and Dioscorides. Nowadays, this versatile resin has been rediscovered, not only as a traditional remedy and aromatic agent, but as a potent phytotherapeutic product with various biological properties.

AIM OF THE STUDY

The aim of this study is to quote the summation of the ethnopharmacology, phytochemical profile and pharmacological properties of the resin of Pistacia lentiscus var. Chia and thus provide the scientific community with a summary of the research conducted so far. Furthermore, perspectives and uses are being discussed and studied so as to broaden the field of its applications.

MATERIALS AND METHODS

A comprehensive review of the literature on Pistacia lentiscus var. Chia was performed using as resources scientific databases such as Scopus, Sciencedirect, Pubmed and Web of science, studies and traditional books provided by the Chios Mastiha Growers Association as well as PhD and Master' s theses.

RESULTS

Chios mastic gum has been used as a traditional medicine over the last 2500 years. More than 120 chemical compounds have been identified in the resin and the major components are a natural polymer, acidic and neutral triterpenes and volatile secondary metabolites. Several plant extracts and compounds have been studied for their antibacterial, anti-inflammatory, antioxidant, anti-ulcer, anti-diabetic, cardioprotective and anti-cancer properties in vitro and in vivo. Clinical interventions and trials have also showed the therapeutic potential of Chios mastic gum. In 2015 Pistacia lentiscus L., resin (mastic) was recognized as a herbal medicinal product with traditional use by the European Medicines Agency (EMA) with two therapeutic indications (mild dyspeptic disorders & skin inflammation/healing of minor wounds). Over the last years, Chios mastic gum is widely involved in medicinal products, food supplements and cosmetics and has become object of study, also in the field of Pharmacotechnology.

CONCLUSIONS

Chios mastic's beneficial properties have been demonstrated in the treatment of gastrointestinal disorders, wound healing, skin inflammations, plasma lipid and blood sugar reduction and oral care. These properties are attributed to triterpenes and volatile compounds. However, because of the resin's chemical complexity and the lack of commercial standards for its main compounds, there is a notable gap in literature concerning the biological evaluation of CMG's isolated components. Therefore, future research should focus on the development of efficient extraction, isolation and analysis techniques in order to unravel CMG's full pharmacological potential.

Chemical Characterization and Biological Activity of the Mastic Gum Essential Oils of Pistacia lentiscus Var. Chia from Turkey

The essential oils (EOs) were isolated by hydrodistillation from wild and cultivated Pistacia lentiscus L. var. chia-mastic gum tree (Anacardiaceae) from two natural habitats, namely from Cesme-Uzunkoy (1) and Mordogan (2), and one cultivated source, Cesme-Germiyan (3), in Izmir, Turkey. This comparative study evaluated the chemical composition and biological activity of mastic gum essential oils (MGEOs). For this purpose, MGEOs 1-3 were analyzed by gas chromatography-flame ionization detection (GC-FID), gas chromatography-mass spectrometry (GC-MS), and chiral GC for α-pinene. Laboratory assays were conducted to assess for potential in vitro cytotoxicity (multiple in vitro cancer cell lines), antimicrobial properties (five bacterial species and yeast), anti-inflammatory activity (inhibition of inducible nitric oxide synthase, iNOS), and the attraction of Ceratitis capitata (Mediterranean fruit fly, medfly), respectively. Chemical analysis indicated that MGEOs 1 and 2 were rich in α-pinene (56.2% and 51.9%), myrcene (20.1% and 18.6%), and β-pinene (2.7% and 3.1%), respectively; whereas MGEO-3 was characterized by a high level of α-pinene (70.8%), followed by β-pinene (5.7%) and myrcene (2.5%). Chiral GC analyses showed that concentration ratios between (-)/(+)-α-pinene and (-)-α-pinene/myrcene allowed for differentiation between wild and cultivated MGEO sources. In biological assays, MGEOs 1-3 did not exhibit significant antimicrobial effects against the pathogens evaluated and were not strong attractants of male medflies; however, all three MGEOs displayed a dose-dependent inhibition of iNOS, and MGEOs 1 and 2 exhibited selective in vitro cytotoxicity against human cancer cells. These results suggest that wild-type mastic gum oils from Cesme and Mordogan (MGEOs 1 and 2) are potential sources of beneficial products and warrant further investigation.

Aroma Investigation of Chios Mastic Gum (Pistacia lentiscus Variety Chia) Using Headspace Gas Chromatography Combined with Olfactory Detection and Chiral Analysis

Chios mastic gum (Pistacia lentiscus var. Chia) exhibits intensely sourish, green, resinous, and woody odor notes with hints of citrus and pine. Despite its attractive flavor, no description of its aroma properties by molecular sensory techniques has been published thus far. A total of 25 odor-active compounds with flavor dilution (FD) factors of 1-512 were identified by gas chromatography-mass spectrometry-olfactometry (GC-MS-O) combined with headspace solid-phase microextraction (HS-SPME) and stir bar sorptive extraction (HS-SBSE). Quantitative analyses performed by multiple HS-SPME and calculation of odor activity values of 10 odorants with high FD factors revealed an essential role of several minor components (e.g., β-myrcene, limonene, β-linalool, and perillene) for the overall aroma of mastic gum, besides the dominating compound α-pinene. The indispensable contribution of the minor odorants to mastic gum was further confirmed by aroma recombination and omission tests. Varying enantiomeric excess values of the key odorants were observed by multidimensional GC-MS.

Dietary mastic oil extracted from Pistacia lentiscus var. chia suppresses tumor growth in experimental colon cancer models

Plant-derived bioactive compounds attract considerable interest as potential chemopreventive anticancer agents. We analyzed the volatile dietary phytochemicals (terpenes) present in mastic oil extracted from the resin of Pistacia lentiscus var. chia and comparatively investigated their effects on colon carcinoma proliferation, a) in vitro against colon cancer cell lines and b) in vivo on tumor growth in mice following oral administration. Mastic oil inhibited - more effectively than its major constituents- proliferation of colon cancer cells in vitro, attenuated migration and downregulated transcriptional expression of survivin (BIRC5a). When administered orally, mastic oil inhibited the growth of colon carcinoma tumors in mice. A reduced expression of Ki-67 and survivin in tumor tissues accompanied the observed effects. Notably, only mastic oil -which is comprised of 67.7% α-pinene and 18.8% myrcene- induced a statistically significant anti-tumor effect in mice but not α-pinene, myrcene or a combination thereof. Thus, mastic oil, as a combination of terpenes, exerts growth inhibitory effects against colon carcinoma, suggesting a nutraceutical potential in the fight against colon cancer. To our knowledge, this is the first report showing that orally administered mastic oil induces tumor-suppressing effects against experimental colon cancer.

Study on the synthesis of bio-based epoxy curing agent derived from myrcene and castor oil and the properties of the cured products

Two biobased curing agents derived from castor oil and myrcene were prepared and were used to cure epoxy E-51.

Quality profile determination of Chios mastic gum essential oil and detection of adulteration in mastic oil products with the application of chiral and non-chiral GC-MS analysis

The determination of mastic oil profile, with emphasis on its chiral characteristics, could serve as a method for detecting adulteration in products found in the market with a claim of mastic oil content aiming towards protecting it from counterfeiting. Furthermore the evaluation of the raw material is crucial, as the profile is potentially affected by factors as mastic origin and storage time. Thus 45 authentic mastic oil samples were analyzed by GC-MS employing a chiral column and content limits for all major constituents were determined. The chiral GC-MS analysis proved that selected concentration ratios between these constituents, namely those of (-)/(+)-α-pinene (≤1:100) and (-)-α-pinene/myrcene (1.9:100-11:100) could serve as markers for the determination of mastic oil authenticity. Employing this methodology, the analysis of 25 mastic oils contained in cosmetic and dietary products, as well as an artificial mastic oil sample, exhibited several differentiations that could indicate adulteration either with artificial essential oils or volatile compounds, or the use of aged mastic oil.

Quantitative analysis of essential oils of Thymus daenensis using laser-induced fluorescence and Raman spectroscopy

Laser-induced fluorescence and Raman spectroscopy are used for the investigation of different genotypes of Thymus daenensis native to the Ilam province of Iran. Different genotypes of T. daenensis essential oils, labeled T1 through T7, possess slight differences with regard to the composition of the thymol. The gas chromatography-mass spectrometry (GC-MS) method is performed to determine the concentration of each constituent as a reference method. The Raman spectra of different concentrations of pure thymol dissolved in hexane as standard samples are obtained via a laboratory prototype Raman spectroscopy setup for the calculation of the calibration curve. The regression coefficient and limit of detection are calculated. The possibility of the differentiation of different genotypes of T. daenensis is also examined by laser-induced fluorescence spectroscopy, although we do not know the exact amounts of their components. All the fluorescence spectral information is used jointly by cluster analysis to differentiate between 7 genotypes. Our results demonstrate the acceptable precision of Raman spectroscopy with GC-MS and corroborate the capacity of Raman spectroscopy in applications in the quantitative analysis field. Furthermore, the cluster analysis results show that laser-induced fluorescence spectroscopy is an acceptable technique for the rapid classification of different genotypes of T. daenensis without having any previous information of their exact amount of constituents. So, the ability to rapidly and nondestructively differentiate between genotypes makes it possible to efficiently select high-quality herbs from many samples.

Genotoxic and Antigenotoxic Assessment of Chios Mastic Oil by the In Vitro Micronucleus Test on Human Lymphocytes and the In Vivo Wing Somatic Test on Drosophila

Chios mastic oil (CMO), the essential oil derived from Pistacia lentiscus (L.) var. chia (Duham), has generated considerable interest because of its antimicrobial, anticancer, antioxidant and other beneficial properties. In the present study, the potential genotoxic activity of CMO as well as its antigenotoxic properties against the mutagenic agent mitomycin-C (MMC) were evaluated by employing the in vitro Cytokinesis Block MicroNucleus (CBMN) assay and the in vivo Somatic Mutation And Recombination Test (SMART). In the in vitro experiments, lymphocytes were treated with 0.01, 0.05 and 0.10% (v/v) of CMO with or without 0.05 μg/ml MMC, while in the in vivo assay Drosophila larvae were fed with 0.05, 0.10, 0.50 and 1.00% (v/v) of CMO with or without 2.50 μg/ml MMC. CMO did not significantly increase the frequency of micronuclei (MN) or total wing spots, indicating lack of mutagenic or recombinogenic activity. However, the in vitro analysis suggested cytotoxic activity of CMO. The simultaneous administration of MMC with CMO did not alter considerably the frequencies of MMC-induced MN and wing spots showing that CMO doesn’t exert antigenotoxic or antirecombinogenic action. Therefore, CMO could be considered as a safe product in terms of genotoxic potential. Even though it could not afford any protection against DNA damage, at least under our experimental conditions, its cytotoxic potential could be of interest.

Bioassay-guided evaluation of anti-inflammatory and antinociceptive activities of pistachio, Pistacia vera L

The ethanolic and aqueous extracts prepared from different parts of Pistacia vera L. (Anacardiaceae) as well as its oleoresin were evaluated for their in vivo anti-inflammatory and antinociceptive activities. Among the extracts screened, only the oleoresin was shown to possess a marked anti-inflammatory activity against carrageenan-induced hind paw edema model in mice without inducing any gastric damage at both 250 and 500 mg/kg doses whereas the rest of the extracts were totally inactive. While the oleoresin was found to display significant antinociceptive activity at 500 mg/kg dose, the ethanolic and aqueous extracts belonging to fruit, leaf, branch and peduncle of Pistacia vera did not exhibit any noticeable antinociception in p-benzoquinone-induced abdominal contractions in mice. Fractionation of the oleoresin indicated the n-hexane fraction to be active, which further led to recognition of some monoterpenes, mainly alpha-pinene (77.5%) by capillary gas chromatography-mass spectrometry (GC-MS) as well as the oleoresin itself. alpha-Pinene was also assessed for its antinociceptive and anti-inflammatory activities in the same manner and exerted a moderate anti-inflammatory effect at 500 mg/kg dose.

Chemical composition and antibacterial activity of the essential oil and the gum of Pistacia lentiscus Var. chia

The essential oil and gum of Pistacia lentiscus var. chia, commonly known as the mastic tree, are natural antimicrobial agents that have found extensive uses in medicine in recent years. In this work, the chemical composition of mastic oil and gum was studied by GC-MS, and the majority of their components was identified. alpha-Pinene, beta-myrcene, beta-pinene, limonene, and beta-caryophyllene were found to be the major components. The antibacterial activity of 12 components of mastic oil and the oil itself was evaluated using the disk diffusion method. Furthermore, attempts were made to separate the essential oil into different fractions in order to have a better picture of the components responsible for its antibacterial activity. Several trace components that appear to contribute significantly to the antibacterial activity of mastic oil have been identified: verbenone, alpha-terpineol, and linalool. The sensitivity to these compounds was different for different bacteria tested (Escherichia coli, Staphylococcus aureus, and Bacillus subtilis), which suggests that the antibacterial efficacy of mastic oil is due to a number of its components working synergistically. The establishment of a correlation between the antibacterial activity of mastic oil and its components was the main purpose of this research. Mastic gum was also examined, but it proved to be more difficult to handle compared to the essential oil.

Chemical discrimination of arabica and robusta coffees by Fourier transform Raman spectroscopy

This article deals with the potential of Fourier transform (FT) Raman spectroscopy in discrimination of botanical species of green and roasted coffees. There are two species of commercial importance: Coffea arabica (arabica) and Coffea canephora (robusta). It is recognized that they differ in their lipid fraction, especially in the content of the diterpene kahweol, which is present at 0.1-0.3% dry matter basis in arabica beans and only in traces (<0.01%) in robusta. The visual examination of the Raman spectra of the lipid fraction extracted from arabica, robusta and liberica samples shows differences in the mid-wavenumbers region: arabica spectra have two characteristic scattering bands at 1567 and 1478 cm(-1). The spectrum of the pure kahweol shows the same bands. Principal component analysis is applied to the spectra and reveals clustering according to the coffee species. The first principal component (PC1) explains 93% of the spectral variation and corresponds to the kahweol concentration. Using the PC1 score plot, two groups of arabica can be distinguished as follows: one group with high kahweol content and another group with low kahweol content. The first group includes samples coming from Kenya and Jamaica; the second group includes samples from Australia. The main difference between these coffees is that those from Kenya and Jamaica are well-known for growing at a high altitude whereas those ones from Australia are grown at a low altitude. To our knowledge, the application of Raman spectroscopy has never been used in coffee analysis.

Rapid method for simultaneous quantitative determination of four major essential oil components from oregano (Oreganumsp.) and thyme (Thymus sp.) using FT-Raman spectroscopy

A simple and rapid method for the quantitative determination of four major components found in oregano and thyme essential oils is presented. The method correlates the Raman peak intensity in the spectral region from 1800 to 600 cm(-1) and the concentration percentage of each particular constituent in the sample. To achieve accurate quantification results and avoid the risk of overlapping peaks of unknown Raman-active substances in natural essential oils, the peaks must be analyzed. For this purpose, PEAKSOLVE software (Ver. 1.0.5) was used. Unknown samples were measured with the FT-Raman method, and the results were compared to those of the gas chromatographic (GC) analysis. The comparison was made at a confidence level of 99%, and the two methods scored equally in terms of repeatability and accuracy even at the edge of the method specifications. The new method can provide accurate results in very short times once the setup is complete and could be utilized in areas where vast amounts of samples must be analyzed.

Chemical composition and antimicrobial activity of the essential oils from the gum of Turkish pistachio (Pistacia vera L.)

The essential oil from the gum of Pistachio (Pistacia vera L. (Anacardiaceae)) grown in Turkey was obtained by the hydro-distillation method, and its chemical composition was analyzed by GC and GC-MS. Moreover, the antimicrobial activities of the oil against the growth of 13 bacteria and 3 pathogenic yeasts were evaluated using the agar-disk diffusion and minimum inhibitory concentration (MIC) methods. The results showed that the essential oil contained about 89.67% monoterpenes, 8.1% oxygenated monoterpenes and 1.2% diterpenes. alpha-Pinene (75.6%), beta-pinene (9.5%), trans-verbenol (3.0%), camphene (1.4%), trans-pinocarveol (about 1.20%), and limonene (1.0%) were the major components. The antimicrobial results showed that the oil inhibited nine bacteria and all the yeasts studied, and the activities were considerably dependent upon concentration and its bioactive compounds such as carvacrol, camphene, and limonene. Moreover, the essential oil of the gum was found to be more effective yeastcide than Nystatin, synthetic yeastcide. Furthermore, the antibacterial activities of the oil were lower than those of standard antibiotics, ampicillin sodium, and streptomycine sulfate under the conditions studied.