Search

An HPLC-ESI-MS method in a positive mode is proposed to qualitatively analyse the saponin fractions from dietary supplements of Tribulus terrestris L. This method allows for theseparation of structural isomers, as highlighted for some terrestrosines. The MS fragmentation pattern resulted diagnostic to collect structural information and the characteristic loss of water from some furostanolic saponins was highlighted for the first time. Due to the wide number of glycosidic furostanolic and spirostanolic saponins extracted from tribulus, a complete reference “molecular weight map” was created. Finally, a seml-quantitative evaluation of the total saponin content was carried cut by HPLC-MS using protodioscin as external standard. [ABSTRACT FROM AUTHOR]

The aim of this investigation was to obtain qualitative and quantitative profiles of the flavonoid and biflavonoid composition of six cypress species— Cupressus funebris L., Cupressus sempervirens L., Cupressus glabra L., Cupressus arizonica L., Cupressus goveniana L., and Cupressus lusitanica L. HPLC-diode-array detection (DAD), HPLC-MS, and HPTLC were used to identify the individual compounds. A chromatographic method was optimized for identification and quantification of the main flavonoid glycosides and biflavonoids. The flavonoids identified and calibrated were: rutin, quercetin glucoside, quercetin rhamnoside, and kaempferol 3- O-rhamnoside. The biflavonoids identified and calibrated were: cupressuflavone, amentoflavone, robustaflavone, hinokiflavone, methylrobustaflavone, methylamentoflavone, and dimethylcupressuflavone. [ABSTRACT FROM AUTHOR]

The aim of this work was to contribute to the phytochemical characterization of Cichorium intybus L. var. silvestre, chicory. Semi-preparative HPLC analysis was applied to an extract of fresh wild chicory leaves to separate and collect the main polyphenolic compounds. HPLC-diode-array detection (DAD), HPLC-MS, and NMR were used for the complete chemical characterization of all the compounds isolated. The molecules characterized were monocaffeoyl tartaric acid, chicoric acid, monocaffeoly p-hydroxycinnamoyl tartaric acid, caffeoyl feruloyl tartaric acid, chlorogenic acid, quercetin-3- O-glucuronide, luteolin-7- O-glucuronide, and quercetin-3- O-glucoside. The chromatographic behaviour of the main components of the extract of the leaves has been compared on three different stationary phases-LiChrosorb RP18, Luna C18, and Luna Phenyl-Hexyl. [ABSTRACT FROM AUTHOR]

Matricaria recutita L. is a spontaneous herbaceous perennial plant and its drug is largely used, as an infusion, for its anti-inflammatory properties, especially for respiratory and gastroenteric tracts. Granular soluble extracts of this drug are also used in children’s diets. The purpose of this work was to investigate the polyphenolic content of different parts of chamomile flowers. Methanolic extracts were compared and directly analysed by HPLC-DAD and HPLC-MS. The comparison between UV-Vis and MS spectra, carried out in positive and negative ionisation mode, allows identification of all the main polyphenolic compounds present in different parts of the flowers. The findings reported herein both confirm the presence of several flavonoids, described previously, and evidence large amounts of caffeic and ferulic acid derivatives. No other evidence of the presence of these compounds in chamomile flowers has been previously reported. Quantitative comparison of the flavonoid and phenolic acid derivatives present in receptacles, ligulate, tubular and total flowers was also performed. [ABSTRACT FROM AUTHOR]

Flavonol glycosides of Sedum telephium L. were analysed by MEKC. Baseline separation was achieved within 14 min using a fused silica capillary and a borate/phosphate buffer solution (35 mM, pH 5.8) containing 35 mM SDS and 4% MeOH. The applied voltage was 25 kV and the thermostating temperature was kept constant at 40°C. Injection was performed via the pressure mode for 3 s, the detection wavelength was 205 nm. The optimized MEKC method was used for the quantitative determination of flavonol glycosides in extracts of S. telephium leaves. Analysis was also performed by HPLC-MS using an electrospray ionization (ESI) interface. The good agreement between the quantitative CE results and those obtained by LC clearly demonstrated the applicability of the methods presented. [ABSTRACT FROM AUTHOR]

Hypericum perforatum L. is a spontaneous perennial herbaceous plant, widely distributed in Europe, Asia, Northern Africa, and North America. The dried flowers or dried aerial parts are used to prepare the drug Hyperici Herba or St. John's Wort. Nowadays this drug is largely used as a natural antidepressant; hypericin and hypericin-like substances are considered the main active ingredients. In this work the hypericin and pseudohypericin content of hydroalcoholic extracts both of Hyperici Herba and of Hypericum perforatum L. dried flowers were measured by two techniques, TLC-densitometry with fluorescence detection and reversed-phase HPLC-DAD (diode-array detection). The quantitative data obtained by applying these techniques were compared and the identification of the main flavonoid constituents was performed by HPLC-DAD for characterization of the extracts. The quantitative data obtained by use of the two techniques were in good agreement and statistical analysis of the findings was indicative of the equivalence of the techniques. [ABSTRACT FROM AUTHOR]

A liquid-solid extraction and purification procedure (LSE) was developed to identify and quantify polyphenols in the leaf tissue of Myrtus communis L. Identification and quantitation of individual compounds was performed using HPTLC, HPLC-DAD and HPLC-MS analysis. Leaves of Myrtus communis L. contain small amounts of phenolic acids (caffeic, ellagic and gallic acids) and quercetin derivatives (quercetin 3-O-galactoside and quercetin 3-O-rhamnoside), whereas catechin derivatives (epigallocatechin, epigallocatechin 3-O-gallate, epicatechin 3-O-gallate) and myricetin derivatives (myricetin 3-O-galactoside, myricetin 3-O-rhamnoside) are present in large amounts. This is the first report on the occurrence of galloyl-derivatives of catechin and gallo-catechin in Myrtus communis L. leaves. [ABSTRACT FROM AUTHOR]