Extraction of essential oils of leaves and flowers ofAchillea monocephala by superheated water

A comprehensive LC-MS/MS method validation for the quantitative investigation of 37 fingerprint phytochemicals in Achillea species: A detailed examination of A. coarctata and A. monocephala

The current study aims to optimize and validate a comprehensive LC-MS/MS method for the quantification of 37 phytochemicals (15 phenolic acids, 17 flavonoids, 3 non-phenolic organic acids, 1 phenolic aldehyde and 1 benzopyrene) in Achillea species. Though Achillea species were chosen as real life samples, the current method is applicable to a wide range of plant species. The developed method was fully validated in terms of linearity, accuracy (recovery), inter-day and intra-day precision (repeatability), limits of detection and quantification (LOD/LOQ) and relative standard uncertainty (U% at 95% confidence level (k = 2)). Reversed-phase ultrahigh performance liquid chromatography was optimized to achive optimum separation for 37 phytochemical compounds and to overcome the suppression effects. MS detection was performed using a triple quadrupole mass spectrometer and negative or positive ionization modes were optimized for each analyte. Multiple reaction monitoring (MRM) was used to quantify the analytes, related molecular ions and transition ions were optimized. Phytochemical screening of ethanol and methanol-chloroform extracts of root and aerial parts of A. coarctata and A. monocephala were performed by using the developed and validated LC-MS/MS method. Root and aerial parts of both species have considerable amounts of certain phenolic-nonphenolic acids (quinic, malic, fumaric, chlorogenic and vanillic acids) and flavonoids (rutin, hesperidin, isoquercitrin, apigetrin, luteolin, apigenin). Additionally, total phenolic and flavonoid amounts, antioxidant (DPPH free radical scavenging assay, ABTS radical cation decolorization assay, β-carotene lipid peroxidation test system and CUPRAC cupper reduction capacity methods), anticholinesterase, tyrosinase, urease inhibition and cytotoxic activities (on HeLa (Human Cervical Carcinoma Cell Line) of A. coarctata and A. monocephala were also investigated. It has been determined that the studied Achillea species, that are rich in total phenolic-flavonoid and chlorogenic acid contents, have high antioxidant and cytotoxic potential at the same time. According to the results of LC-MS/MS, antioxidant and cytotoxic activity studies, after detailed chemical investigation and toxicity studies on these species, A. coarctata and A. monocephala may be promoted as promising sources of natural agents and used for the development of nutraceuticals or functional food ingredients in future.

Methyl eugenol: its occurrence, distribution, and role in nature, especially in relation to insect behavior and pollination

This review discusses the occurrence and distribution (within a plant) of methyl eugenol in different plant species (> 450) from 80 families spanning many plant orders, as well as various roles this chemical plays in nature, especially in the interactions between tephritid fruit flies and plants.

Superheated water extraction and phase transfer methylation of phenoxy acid herbicides from solid matrices

Phase transfer catalytic methylation was applied to directly derivatise chlorophenoxy acid herbicides in superheated water extracts from sand and soil samples. The extractions were carried out at 120 degrees C statically for 5 min and then dynamically for 10 min at 1.0 mL min(-1) using water at pH 11.0 for a sand matrix and a flow rate of 0.5 mL min(-1) at pH 7.0 for soil samples. The methylation was carried out on-line on the extraction solution with ultrasonication at 80 degrees C, using either 0.05 mmol tetrabutylammonium bromide (TBAB) or 0.0125 mmol cetyltrimethylammonium bromide (CTAB) as phase transfer catalysts with 0.20 mmol methyl iodide in 2.0 mL dichloromethane trapping solvent. The former catalyst provided a higher yield but the latter gave fewer interfering peaks. The recoveries of most chlorophenoxy acids using the TBAB catalyst ranged from 67 to 105% for sand and from 82 to 114% for soil sample, except phenoxyacetic acid, 2-(2, 4-dichlorophenoxy)propanoic acid and 1-naphthaleneacetic acid, while those by using CTAB were slightly lower. Detection limits of all the analytes extracted from sand using TBAB catalyst were in a range of 5.3-16 microg g(-1) analysed by using gas chromatography with flame ionization detection (GC-FID).

Use of compressed fluids for sample preparation: Food applications

This review attempts to provide an updated overview (including works published till June 2006) on the latest applications of compressed fluids as sample preparation techniques for food analysis. After a general review of the principles of supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE; also called accelerated solvent extraction, ASE or subcritical water extraction, SWE, when water is employed as extraction solvent), the principal applications of such techniques in the mentioned fields of food and natural products are described, discussing their main advantages and drawbacks.