Chemometric approach for development, optimization, and validation of different chromatographic methods for separation of opium alkaloids.

The excessive and continuously growing interest in the simultaneous determination of poppy alkaloids imposes the development and optimization of convenient high-throughput methods for the assessment of the qualitative and quantitative profile of alkaloids in poppy straw. Systematic optimization of two chromatographic methods (gas chromatography (GC)/flame ionization detector (FID)/mass spectrometry (MS) and reversed-phase (RP)-high-performance liquid chromatography (HPLC)/diode array detector (DAD)) for the separation of alkaloids from Papaver somniferum L. (Papaveraceae) was carried out. The effects of various conditions on the predefined chromatographic descriptors were investigated using chemometrics. A full factorial linear design of experiments for determining the relationship between chromatographic conditions and the retention behavior of the analytes was used. Central composite circumscribed design was utilized for the final method optimization. By conducting the optimization of the methods in very rational manner, a great deal of excessive and unproductive laboratory research work was avoided. The developed chromatographic methods were validated and compared in line with the resolving power, sensitivity, accuracy, speed, cost, ecological aspects, and compatibility with the poppy straw extraction procedure. The separation of the opium alkaloids using the GC/FID/MS method was achieved within 10 min, avoiding any derivatization step. This method has a stronger resolving power, shorter analysis time, better cost/effectiveness factor than the RP-HPLC/DAD method and is in line with the "green trend" of the analysis. The RP-HPLC/DAD method on the other hand displayed better sensitivity for all tested alkaloids. The proposed methods provide both fast screening and an accurate content assessment of the six alkaloids in the poppy samples obtained from the selection program of Papaver strains.

The essential oil composition of Thymus tosevii and Thymus macedonicus from Bulgaria.

Essential oils composition of Thymus tosevii Velen. and Thymus macedonicus (Deg. et Ur.) Ronn. from Bulgaria were examined by analytical GC and GC-MS techniques. 39 components were separated in the oil of T. tosevii and 22 of them were identified, representing 94.37% of the oil. The most abundant constituents were: terpinyl acetate (43.59%), thymol (11.43%) and nerol (11.72%). More than 70 components were separated in the essential oil of T. macedonicus, 35 were identified, representing 96.03% of the oil. The major components were geranyl acetate (30.00%) and terpinyl acetate (17.30%), followed by lower amounts of nerol (14.25%), linalool (12.94%) and thymol (4.14%). Both examined taxa contained essential oils composed mainly from monoterpene oxygenate compounds while the fractions of monoterpene hydrocarbons as well as sesquiterpene components were very low.

Investigation of antimicrobial activity of essential oils of several Macedonian Thymus L. species (Lamiaceae).

Antimicrobial activity of twenty specimens of essential oils of eleven Thymus species, naturally occurring in the Macedonian flora, was investigated by agar diffusion and broth dilution methods. Inhibition of growth and microbicidal action was examined on three Gram positive bacteria (Staphylococcus aureus, Streptococcus pyogenes and Streptococcus pneumoniae). In spite of wide variability in essential oil composition, ranging from traces of thymol to the amount of about 50% thymol in oils, all examined samples of Thymus essential oil possessed strong antibacterial activity. Zones of inhibition of growth (for 25% dilution of oils) was from 10-54 mm in diameters. MICs ranging from 0.012-0.1% while MMCs were from 0.025-0.4% for essential oils that contained large amounts of phenols and 0.2-1.6% for those which contained traces of phenols and large amounts of geraniol, linalool and (Z + E)-citral.

Polyphenolic characterization and chromatographic methods for fast assessment of culinary Salvia species from South East Europe.

Although the knowledge and use of several Salvia species (Salvia officinalis, Salvia fruticosa, and Salvia pomifera) can be dated back to Greek Era and have a long history of culinary and effective medicinal use, still there is a remarkable interest concerning their chemistry and especially the polyphenolic composition. Despite the demand in the food and pharmaceutical industry for methods for fast quality assessment of the herbs and spices, even now there are no official requirements for the minimum content of polyphenols in sage covered by current regulations neither the European Pharmacopoeia monographs nor the ISO 11165 standard. In this work a rapid analytical method for extraction, characterization and quantification of the major polyphenolic constituents in Sage was developed. Various extractions (infusion - IE; ultrasound-assisted extraction - USE and microwave-assisted extraction - MWE) were performed and evaluated for their effectiveness. Along with the optimization of the mass-detector and chromatographic parameters, the applicability of three different reverse C18 stationary phases (extra-density bonded, core-shell technology and monolith column) for polyphenolics characterization was evaluated. A comprehensive overview of the very variable polyphenolic composition of 118 different plant samples of 68 populations of wild growing culinary Salvia species (S. officinalis: 101; S. fruticosa: 15; S. pomifera: 2) collected from South East Europe (SEE) was performed using HPLC-DAD-ESI-MS(n) and more than 50 different compounds were identified and quantified. With this work the knowledge about polyphenols of culinary Sage was expanded thus the possibility for gaining an insight into the chemodiversity of culinary Salvia species in South East Europe was unlocked.

Composition of the essential oil from Thymus moesiacus from Macedonia.

Composition of the essential oil of Thymus moesiacus Velen. from Macedonia was examined by GC and GC-MS methods. The main constituents of the oil were geraniol, linalool, geranyl acetate, and terpenyl acetate.

Infrared analysis of Macedonian mushroom dietary fibre.

The existing confusion in the terminology and composition of the mushroom dietary fibre literature data induced us to analyze simultaneously the chemical constitution of various dietary fibre isolates obtained from numerous mushroom samples. For that purpose, in 53 kinds of edible Macedonian mushrooms total dietary fibre was isolated by two parallel methods intended for material of plant and animal origin. With the aid of infrared spectroscopy the chemical constitution of the both isolated components was also investigated. The infrared spectra of the total dietary fibre isolates, obtained according to both applied methods, were similar and close to chitin. In all spectra cellulose is missing.