Variation of free phenolic acids in medicinal plants belonging to the Lamiaceae family.

Ten species belonging to the family Lamiaceae and representing the most popular medicinal plants used in Polish phytotherapy were examined for the content of free phenolic acids (PhAs). Two depsides, rosmarinic and chlorogenic acids, as well as eight simple PhAs, protocatechuic, gentisic, p-hydroxybenzoic, caffeic, vanillic, syringic, p-coumaric and ferulic acids, in different qualitative and quantitative proportions depending on the plant examined were determined by the rapid, selective and accurate method combining solid-phase extraction and high-performance liquid chromatography.

Application of conventional UV, photodiode array (PDA) and fluorescence (FL) detection to analysis of phenolic acids in plant material and pharmaceutical preparations.

Free phenolic acids (PhAs) contained in methanolic extracts of Eleutherococcus senticosus roots and pharmaceutical preparations, deriving from this plant, were isolated by solid-phase extraction (SPE) and identified by reversed-phase high-performance liquid chromatography (RP-HPLC). To obtain precise, accurate and validated results of qualitative and quantitative analysis, ultraviolet (at lambda=254 nm), photodiode array (at lambda=254 and 280 nm) and fluorescence (at lambda(Ex)=230 or 265 nm and lambda(Em)=350 nm) detection was used. Additionally, the HPLC separation of PhAs on two different octadecyl sorbents: Hypersil (Shandon, UK) and Symmetry (Waters, USA) was performed. Eight PhAs: chlorogenic, protocatechuic, p-hydroxybenzoic, caffeic, vanillic, syringic, p-coumaric and ferulic, in different quantitative proportions, were identified, both in the roots of E. senticosus and pharmaceutical formulations examined.

Qualitative and quantitative analysis of phenolic acids in Asclepias syriaca L.

TLC and HPLC was applied to qualitative and quantitative determination of phenolic acids free and liberated by acid and alkaline hydrolysis in common milkweed. The presence of phenolic acids, namely p-hydroxybenzoic, p-coumaric, protocatechuic and caffeic acids, was confirmed in the leaves and flowers. Moreover, the flowers contained gallic acid, and the leaves contained alpha-resorcylic, vanilic and chlorogenic acids. Conjugated forms of phenolic acids predominate in the plant. They hydrolyse mainly to coffeic, p-coumaric, ferulic and p-hydroxybenzoic acids.

Determination of furanochromones and pyranocoumarins in drugs and Ammi visnaga fruits by combined solid-phase extraction-high-performance liquid chromatography and thin-layer chromatography-high-performance liquid chromatography.

A new, simple and rapid solid-phase extraction method for the determination of furanochromones and pyranocoumarins in Ammi visnaga L. fruits and pharmaceuticals by reversed-phase high-performance liquid chromatography (RP-HPLC) was developed. The isolation of compounds examined was carried out on octadecyl BakerBond SPE columns using various concentrations of methanol, acetonitrile and tetrahydrofuran in water. High and reproducible recoveries were obtained. To compare the results of quantitative analysis a preparative TLC procedure was also elaborated and carried out.

Sample preparation for taxol and cephalomannine determination in various organs of Taxus sp.

Solid-phase extraction and preparative thin-layer chromatography were applied as sample preparation techniques for the purification of crude extracts from twigs and needles of various Taxus species as well as for the isolation of taxol and cephalomannine for further reversed phase high performance liquid chromatography analysis. Significant differences in the contents of taxanes examined were found. The preparative chromatographic methods used were compared and evaluated as routine and reproducible procedures for the rapid isolation and determination of taxol and cephalomannine in plant extracts.