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The rate of evaporation of volatile oils from oil-in-water emulsions can be strongly retarded by using a polymeric emulsion stabiliser instead of a low molar mass surfactant.
A surway is presented on the authors' work in the field of volatile oil research. The gas chromatographic method previously used for analysis of essential oils was transformed to capillary gas chromatographic conditions. The method is also suitable for separation of compound-pairs frequently occurring in essential oils (peppermint, rosemary, lavender, sage, clary sage, thyme oils). Beside the gas chromatographic analysis of essential oils, which was necessary for their standardization and qualification, the influence of different extraction methods and some biological facts e.g. the ontogenesis on the change of essential oil composition are also discussed. It has been established that the water steam distillation from acidic medium can be more advantageous than the traditional one, if the volatile terpene derivatives were bound in form of glycosides or dimeric quajazolide lactons were present in plant (oregano, Sideritis, wormwood oils). Comparing the composition of essential oil obtained by water steam distillation and supercritical fluid extraction (SFE) it was found that the SFE fractions are richer in ester constituents because the possibility of hydrolysis is reduced, and the oils are more valuable than the classic oils. On the other hand, when the transformation processes are important (chamomile), the distillation is the better method. The change of essential oil composition of Ocimum basilicum L. and Anthriscus cerefolium L. was also studied during the vegetation period. It has been established that in budding and early flowering stages the basil oil was rich in monoterpenes; the quantity of sesquiterpenes and phenylpropane derivatives increased only in later stadiums. Finally the extraction and analytical processes are discussed which are used for standardization of complex plant preparations which contained essential oil as active agent and represented various medicinal forms.
OBJECTIVE: To study the inclusion action of beta-cyclodextrin (beta-CD) with limonene. METHOD: Orthogonal design. RESULT: The optimum preparing condition was a proportion of 1:9 (ml:g) for oil to beta-CD inclusion, temperature at 40 degrees C and stirred for 2 h. CONCLUSION: The condition was optimum for preparation of the inclusion compound of beta-CD with the volatile oil of limonene.
OBJECTIVE: To study the optimum extraction parameters and components on ant oil from Polyrhachis vicina. METHOD: The optimum condifious for supercritical CO2 fluid extraction (SFE-CO2), were investigated with orthogonal design, GC-MS was applied for analyzing. The components and their contents in the ant oil were analyzed by GC-MS, and the contents of lead, zinc and manganese in the oil were determined by ICP-AES. RESULT: The optimum extraction parameters were achieved, temperature of 50 degrees C, pressure of 30 MPa and time of 2 hours. The extracting yield of the ant volatile oil was 11.4% - 14.3%. 51 Constituents were identified including 9-octadecenoic acid, ethyl oleate, cholesterol, n- Hexadecanoic acid, etc, and the content of various constituents was determined by orea normalization. The oil contained unsaturated fatty acid of 64.6%, lead of 0.80 microg x g(-1), zinc of 0.54 microg x g(-1) and manganese of 0.15 microg x g(-1). CONCLUSION: The method showes advantages including faster and efficient of extraction, good quality and no solvent residues in the oil.
The variations of the essential oils in Acorus calamus and their major compositions with seasons and producing areas were investigated by steam distillation and internal standard method. The result has shown that June is the best season for A. calamus cropping and that the major components of the volatile oil in the same part of the plant from different producing areas have the same chemical structure type.
In this work, for the first time, microwave distillation (MD) coupled with simultaneous headspace single-drop microextraction (HS-SDME) was developed for the determination of the volatile components in the Chinese herb, Artemisia capillaris Thunb. The volatile components were rapidly isolated by MD, and simultaneously extracted and concentrated by using a dodecane microdrop. The volatile oil extracted in the microdrop solvent was analyzed by gas chromatography-mass spectrometry (GC-MS). The experimental parameters of solvent selection, microdrop volume, microwave power, irradiation time and sample amount were investigated, and the method precision was also studied. The optimal parameters were extraction solvent of dodecane, solvent volume of 2.0 microL, microwave power of 400 W, irradiation time of 4 min, and sample amount of 2.0 g. Thirty-five volatile compounds present in Artemisia capillaris Thunb. were identified by using the proposed method, which were identical with those obtained by the conventional steam distillation method. The experimental results showed that MD-HS-SDME is a simple, rapid, reliable, and solvent-free technique for the determination of volatile compounds in Chinese herbs.
The essential oils of Ocimum basilicum L., Origanum vulgare L., and Thymus vulgaris L. were analyzed by means of gas chromatography-mass spectrometry and assayed for their antioxidant and antimicrobial activities. The antioxidant activity was evaluated as a free radical scavenging capacity (RSC), together with effects on lipid peroxidation (LP). RSC was assessed measuring the scavenging activity of the essential oils on 2,2-diphenyl-1-picrylhydrazil (DPPH(*)) and OH(*) radicals. Effects on LP were evaluated following the activities of essential oils in Fe(2+)/ascorbate and Fe(2+)/H(2)O(2) systems of induction. Essential oils exhibited very strong RSCs, reducing the DPPH radical formation (IC(50)) in the range from 0.17 (oregano) to 0.39 microg/mL (basil). The essential oil of T. vulgaris exhibited the highest OH radical scavenging activity, although none of the examined essential oils reached 50% of neutralization (IC(50)). All of the tested essential oils strongly inhibited LP, induced either by Fe(2+)/ascorbate or by Fe(2+)/H(2)O(2). The antimicrobial activity was tested against 13 bacterial strains and six fungi. The most effective antibacterial activity was expressed by the essential oil of oregano, even on multiresistant strains of Pseudomonas aeruginosa and Escherichia coli. A significant rate of antifungal activity of all of the examined essential oils was also exhibited.
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Volatile oil from the rhizomes of Zingiber nimmonii (J. Graham) Dalzell was isolated, characterized by analytical gas chromatography and gas chromatography-mass spectroscopy. Sixty-five constituents accounting for 97.5% of the oil were identified. Z. nimmonii rhizome oil is a unique caryophyllene-rich natural source with isomeric caryophyllenes, beta-caryophyllene (42.2%) and alpha-humulene (alpha-caryophyllene, 27.7%), as its major constituents along with traces of isocaryophyllene. The rhizome oil contained 71.2% sesquiterpenes, 14.2% oxygenated sesquiterpenes, 8.9% monoterpenes, 1.9% oxygenated monoterpenes and 1.3% non-terpenoid constituents. The antimicrobial activity of the oil was tested against human and plant pathogenic bacteria and fungi. The oil showed significant inhibitory activity against the fungi, Candida glabrata, C. albicans and Aspergillus niger and the bacteria Bacillus subtilis and Pseudomonas aeruginosa. No activity was observed against the fungus Fusarium oxysporum.
Static headspace (SHS), headspace solid phase microextraction (HS-SPME), headspace sorptive extraction (HSSE), and direct thermal desorption (DTD) were applied to the analysis of four French virgin olive oils from Corsica. More than 60 compounds were isolated and characterized by GC-RI and GC-MS. SHS was not suited to the characterization of olive oil volatile compounds because of low sensitivity. The SPME and HSSE techniques were successfully applied to olive oil headspace analysis. Both methods allow the characterization of volatile compounds (mainly C(6) aldehydes and alcohols), which contribute significantly to the "green" flavor note of virgin olive oils. The PDMS stir bar showed a higher concentration capacity than a DVB/CAR/PDMS SPME fiber due to the higher volume of polymeric coating. DTD was a very good tool for extracting volatile and especially semivolatile compounds, such as sesquiterpenes, but requires a significant investment like that for HSSE. Finally, SPME may be a more appropriate technique for routine quality control due to its operational simplicity, repeatability, and low cost.
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Although poppy seed oil is an expensive article of trade, no literature about identification methods for adulteration with cheaper vegetable oils, like sunflower oil, has been published. This kind of adulteration is a challenge for routine analytical methods, such as the determination of fatty acid composition, because of almost similar fatty acid ratios. The detection of adulteration of poppy seed oils with sunflower oils at different levels (5-40%, w/w) by using SPME-GC-MS and MALDI-ToF-MS is the subject of our investigation. With the mentioned SPME-GC-MS method, it was possible to detect an admixture of sunflower oils in all relevant (5-40%) amounts by using alpha-pinene as a marker compound. Admixture of sunflower oil with high levels of triolein (high-oleic acid type) could be undoubtedly detected by MALDI-MS down to the 5-10% level. In contrast, adulteration of pure poppy seed oil by "standard" sunflower oils remained indistinguishable using this MALDI-MS.
Chemical analysis on Curcuma zedoaria rhizome volatile oil, using gas chromatography-mass spectrometer techniques, demonstrated the presence of beta-tumerone (19.88%), 1,8-cineole (8.93%), and 7-zingiberene (7.84%) as major constituents. Larvicidal efficacy against Aedes aegypti mosquitoes of zedoary oil and its formulated preparation, zedoary oil-impregnated sand granules, were investigated and compared with that of Abate(R)sand (temephos). Zedoary oil exhibited pronounced potential against the fourth instar larvae of A. aegypti with an LC(50) and LC(99) of 33.45 and 83.39 ppm, respectively. Application of zedoary oil at a dosage yielding ten times that of LC(99) offered complete larval mortality (100% mortality) for a period of 3 days, and the larval mortality subsequently decreased to lower than 50% after application for more than 5 days. Zedoary oil-impregnated sand granules provided remarkably longer activity, with a larval mortality of 100% for a period of 9 days; and mortality below 50% was obtained in week 3 of application. The complete larval mortality that resulted from applying temephos at dosages of 0.1 and 1 ppm persisted for a period of 6 days and 4 weeks, respectively, and the larval mortality below 50% was reported on day 18 and week 11, respectively. Testing A. aegypti species against stored samples of zedoary oil-impregnated sand granules demonstrated that the product stored at 4 degrees C showed the longest larvicidal activity, followed by those kept at ambient temperature and 45 degrees C, yielding a complete larval mortality for 9, 8, and 6 days, respectively. Most samples of zedoary oil-impregnated sand granules stored at each temperature for 1 month showed slightly higher efficacy than those kept for 2 months. The larvicidal efficacy of samples stored at 4 degrees C seemed to be comparable to that of the fresh sample. The efficacy in killing A. aegypti larvae and good biological stability of zedoary oil-impregnated sand granules make this product promising as an alternative to essential oil in the development of new botanical natural larvicide for use in mosquito control programs.
Myrtus communis L. (Myrtaceae) leaves as well as the volatile oil (Myrtii Oleum; MO) obtained from the leaves are used to lower the blood glucose level in type-2 diabetic patients in Turkish folk medicine. However, little attention has been paid to the therapeutic use of this plant. The present study was designed to investigate the oral hypoglycaemic activity of single and multiple doses of MO in normal and alloxan-diabetic rabbits. MO did not show any effect in normoglycaemic rabbits either in single or multiple dose administrations, but a good hypoglycaemic activity was observed 4 h after the administration to diabetic animals at 50 mg/kg. To investigate the effect of MO on repeated administration in both normal and diabetic rabbits, it was administered in 50 and 100 mg/kg doses once a day for one week. MO significantly lowered blood glucose by 51% in alloxan-diabetic rabbits on the fourth hour and the following days at a dose of 50 mg/kg (P < 0.001). The hypoglycaemic dose (50 mg/kg) was also determined by performing the oral glucose tolerance test (OGTT) in normal rabbits. The hypoglycaemic effect of the MO was 21% higher in rabbits, which received the glucose load orally, when compared with control group. However, MO did not affect serum insulin concentrations in normal and alloxan-diabetic rabbits but reduced the serum triglyceride concentrations by 14% in alloxan-diabetic rabbits. The above observations show that MO exerts hypoglycaemic as well as mild hypotriglyceridemic activity in diabetic animals. The reduction in blood glucose level may be due to the reversible inhibition of alpha-glucosidases present in the brush-border of the small intestinal mucosa, higher rate of glycolysis as envisaged by the higher activity of glucokinase, as one of the key enzymes of glycolysis, and enhanced rate of glycogenesis as evidenced by the higher amount of liver glycogen present after MO administration.