Twelve biologically active compounds, ten triterpenoids (?-amyrin, ß-amyrin, ?-amyrin, lupeol, lupenon, lupeol acetate, cycloartenol, cycloartenol acetate, ursolic acid and oleanolic acid) and two sterols (stigmasterol and ß-sitosterol) were separated and identified combining TLC and HPLC-UV-MS for the first time. Moreover, resolution of four isomeric triterpenols (?-amyrin, ß-amyrin, cycloartenol and lupeol) without pre-chromatographic derivatization was achieved by TLC for the first time as well.
COBISS.SI-ID: 4217626
The development of a new isocratic HPLC method enables simultaneous separation and identification of nine structurally highly resembling shikonin derivatives (even positional and geometric isomers) for the first time: shikonin, acetylshikonin, propionylshikonin, isobutyrylshikonin, tigloylshikonin, 3,3-dimethylacrylshikonin, angelylshikonin, 2-methyl-n-butyrylshikonin and isovalerylshikonin. These biologically active compunds were identified for the first time in Echium italicum L. by this newly developed HPLC method, NMR and MS spectra.
COBISS.SI-ID: 4134682
Catechins are important bioactive compounds in the plant kingdom. Consumption of food (green tea, red grapes, cocoa etc.) rich with catechins is associated by prevention of chronic diseases. Until now, for TLC detection of catechins aromatic aldehyde vanillin has mainly been used. The main drawback of vanillin reagent is rapid discoloration of chromatographic bands. Therefore, instead of vanillin we used 4-dimetylaminocinnamaldehyde. The reagent containing this aldehyde gives more stable bands also less aldehyde and acid are needed for the preparation of this reagent.
COBISS.SI-ID: 4134938
The anion adducts formed in the spray process contribute significantly to the signal intensity of an ionized inclusion complexes. The relative intensities of anion adducts in mass spectra depend on the concentration ratio of the anion and the CD in spray droplets, while the relative intensity of the ionized inclusion complex depends on CD and CA concentrations in solutions and the value of K. Alternatively, in the gas phase the anion-adduct complex is fragmented or transformed into the inclusion complex conformation.
COBISS.SI-ID: 4058650
The complexes of coenzyme Q10 with ß- and ?-cyclodextrin in aqueous solutions were prepared in a special and innovative method. The formation of complexes was evaluated using IR spectrometry, X-ray diffractometry and TGA/DSC analysis. Complex formation resulted in an increase in water solubility at room temperature and pH 6.5. The solubility of coenzyme Q10 in the presence of cyclodextrins linearly increases with temperature and pH. The UV light (?=254 nm) and temperature together have a great effect on coenzyme Q10 stability.
COBISS.SI-ID: 4345882