Giorgio Pintore | PubMed Health

PubMed2006

Induction of hypericins in Hypericum perforatum in response to chromium.

Seedlings of Hypericum perforatum were grown with 0.01 and 0.1 mM of chromium added to the nutrient media. A treatment with 0.01 mM Cr(VI) for seven days resulted in an increased production of protopseudohypericin (+135%), hypericin (+38%) and pseudohypericin (+5%). Treatment with 0.1 mM Cr(VI) for two days also caused an increase of protopseudohypericin (+167%), hypericin (25%) and pseudohypericin (+5%). The greatest effect of chromium treatment was observed at a concentration of 0.1 mM for seven days: protopseudohypericin increased +404% and pseudohypericin to +379%. Hypericin was not affected by this treatment.

Analysis of Variance↗

PubMed2003

Comparative enantioseparations with native beta-cyclodextrin, randomly acetylated beta-cyclodextrin and heptakis-(2,3-di-O-acetyl)-beta-cyclodextrin in capillary electrophoresis.

Comparative enantioseparations were performed with three neutral cyclodextrins (CDs) in capillary electrophoresis (CE). In particular, native beta-CD was compared with single component heptakis(2,3-di-O-acetyl)-beta-CD (HDA-beta-CD) and randomly acetylated beta-CD (Ac-beta-CD) with the emphasis on the enantiomer migration order. The opposite affinity of the enantiomers of several chiral analytes was observed towards native beta-CD and its acetylated derivatives. The enantiomer affinity pattern of some chiral analytes was also opposite towards the two acetylated derivatives of beta-CD. In the case of the chiral drug clenbuterol (CL) an attempt was made to evaluate the possible structural reasons of the affinity reversal using one- and two-dimensional as well as transverse rotating frame nuclear Overhauser effect spectroscopy (ROESY). Significant differences were observed between the structure of the CL complexes with beta-CD and HDA-beta-CD.

Acetylation↗