[Show abstract][Hide abstract] ABSTRACT: Two new benzophenones were isolated from the leaves of Hypericum carinatum. Their structures were established on the basis of 2D NMR spectroscopic analyses and mass spectrometry as cariphenone A (6-benzoyl-5,7-dihydroxy-2,2,8-trimethyl-2H-chromene) (1) and cariphenone B (8-benzoyl-5,7-dihydroxy-2,2,6-trimethyl-2H-chromene) (2). Five known compounds, the phloroglucinol derivative uliginosin B (3), 1-eicosanol, sitosterol, stigmasterol, and campesterol, were also characterized. Compounds 1-3 were evaluated for their total antioxidant capacity through a total radical-trapping parameter assay. Only compound 1 showed moderate antioxidant activity, exhibiting inhibition of chemiluminescence similar to that of quercetin at the same concentration.
[Show abstract][Hide abstract] ABSTRACT: Crude methanolic extracts and fractions from the aerial parts of seven species of Hypericum (H. caprifoliatum Cham. and Schltdl., H. carinatum Griseb., H. connatum Lam., H. ternum A. St.-Hil., H. myrianthum Cham. and Schltdl., H. piriai Arechav. and H. polyanthemum Klotzsch ex Reichardt) growing in southern Brazil were analyzed for their in vitro antifungal activity against a panel of standardized and clinical opportunistic pathogenic yeasts and filamentous fungi, including dermatophytes, by the agar dilution method. Chloroform and hexane extracts of H. ternum showed the greatest activity among extracts tested.
[Show abstract][Hide abstract] ABSTRACT: Recently the crude methanol extracts of six Hypericum species were analysed against a panel of microorganisms and it was found that H. caprifoliatum Cham. & Schlecht., H. myrianthum Cham. & Schlecht. and H. polyanthemum Klotzsch ex Reichardt were the most active. This paper reports the activity of the hexane, chloroform and methanol fractions of these plants as well as the activity of some isolated compounds against Staphylococcus aureus determined by bioautographic procedures. Copyright (c) 2005 John Wiley & Sons, Ltd.
Phytotherapy Research 04/2005; 19(4):291-3. DOI:10.1002/ptr.1546 · 2.66 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The air dried and powdered plant material, aerial parts, was extracted in a Soxhlet
apparatus with petroleum ether for 12 h and then the extract was evaporated to
dryness under reduced pressure. The petroleum ether extract was analyzed by TLC
on silica gel. The main products were isolated by column chromatography on silica
gel using a n-hexane/EtOAc gradient system followed by preparative TLC on silica
gel with chloroform: hexane (3:1), to afford uliginosin B, from both H.carinatum
and H.polyan themum and hiperbrasilol B, from both H.caprifol iatum and H.connatum.
The products were identified by 1H NMR and 13C NMR spectroscopy.