Investigation of Euphrasia rostkoviana Hayne Using GC–MS and LC–MS

Gas and liquid chromatography coupled with mass spectrometry was applied to solve difficulties and reinvestigate the serious matrix problems affecting analysis of the active compounds in Euphrasia rostkoviana Hayne. The main groups of compounds were obtained by extracting the herb stepwise with n-hexane, chloroform, ethyl acetate and methanol. Polyamide column chromatography facilitated further separation. Phenolic/flavonoid- and terpenoid-type molecules were studied by GC–MS, HPLC and LC–MS–MS. The β-sitosterol content of the herb was determined by gas chromatography with flame ionisation detection (GC-FID). Caffeic acid, chlorogenic acid, coumaric acid and flavonoid glycosides of apigenin, luteolin, rhamnetine (hexoside), kaempferol (both hexoside and rutinoside) and quercetin (rutinoside) were identified in the fractions of the methanolic extract.     

Monitoring Volatile and Non-Volatile Salicylates in Filipendula ulmaria by Different Chromatographic Techniques

The use of salicylate containing herbs as analgesic and antirheumatic remedies can be traced back to ancient times. While salicaceen contains only derivatives of salicylalcohol, Filipendula ulmaria is characteristic for various forms of volatile and non-volatile salicylates. The main pharmacological effect of Filipendula ulmaria is due to its salicylic acid component, which is released via oxidation from various aglycones (e.g. salicylaldehyde, methylsalicylate) developed from glycosides through hydrolysis in the digestive system. Our current study is focussed on the determination of volatile and non-volatile salicylates in various parts and extracts of the plant, using different chromatographic techniques.     

LC–MS Qualitative Analysis and Simultaneous Determination of Six Filipendula Salicylates with Two Standards

Salicylate containing herbs, such as Salix alba (white willow) and Filipendula ulmaria (meadowsweet) are commonly used, because of their antipyretic, analgesic and antirheumatic effect. In this work six salicylates were identified and/or structurally characterized in the methanolic extract of F. ulmaria and were simultaneously determined using salicylic acid and salicin as external standards. Analysis occured by an LC-DAD-MS–MS triple quadrupole system, determination was accomplished in SIM mode. Linearity, inter- and intra-day precision (highest RSD % 9.85), accuracy and recovery were all within acceptable ranges, except recovery for salicin standard (51.76%). LLOQ for salicylic acid was 150 ng mL⁻¹, for salicin 24 ng mL⁻¹. Estimative contents of salicylates were calculated with both standard calibrations, results and their error were compared. This is the first study to provide detailed quantitative data on Filipendula salicylates.

     

Synthesis of novel ceramide-like penetration enhancers

Ceramide-like penetration enhancers have been synthesized by isosteric replacements of the 1-hydroxymethyl and amide moieties of natural ceramides. Metabolically more stable oxime and five-membered heterocyclic (1,2,4-oxadiazole, 1,2,4-triazole, tetrazole) analogues are more polar and possess H-bond acceptor properties, which make them potentially useful in optimizing key intermolecular features in interactions between the modified ceramide structures and the lipid layers of stratum corneum.     

Evaluation of Sempervivum tectorum L. Flavonoids by LC and LC–MS

A reversed-phase high-performance liquid chromatography method with UV detection was developed for determination of [(N-morpholine)methylene]daunorubicin hydrochloride (DD-M) during studies of its stability. In this LC method the following were used: an RP-column, the mobile phase—acetonitrile:methanol:solution A (9:1:10 v/v/v) [solution A contains 2.88 g of sodium laurilsulfate and 1.6 mL of phosphoric acid(V)] with a flow rate of 1.4 mol L⁻¹ and quinine hydrochloride as an internal standard. The detection wavelength was 254 nm. The method was validated with regard to linearity, limit of detection, limit of quantitation, selectivity and precision. Hydrolysis of the DD-M catalyzed by hydrogen ions in hydrochloric acid and a spontaneous reaction of the DD-M degradation under the influence of the water in sodium hydroxide took place. The thermodynamic parameters of these reactions—energy, enthalpy and entropy of activation—were calculated. It was observed that a positive salt effect occurred in hydrochloric acid.