calceolarioside-a and acteoside

A general strategy for the synthesis of phenylethanoid glycosides (PhG) including echinacoside 1, acteoside 2, calceolarioside-A 3 and calceolarioside-B 4 is reported. The strategy features the application of low substrate concentration glycosylation and N-formyl morpholine modulated glycosylation methods for the construction of 1,2-trans β- and α-glycosidic bonds. The reported strategy does not invoke the use of the participatory acyl protecting function, which is incompatible with the ester function present in target PhG compounds. A preliminary study of the anti-proliferation properties of the PhG compounds 1–4 was performed; the acteoside 2 exhibited the best inhibition on the prostatic cancer cell proliferation.

Topics: Caffeic Acids; Cell Line, Tumor; Cell Proliferation; Chemistry, Organic; Glucosides; Glycosides; Humans; Male; Phenols; Phenylethyl Alcohol; Prostatic Neoplasms

By means of HIV gp41 binding affinity directed chromatographic fractionation, three phenylethanoid glycosides; calceolarioside A ( 1), calceolarioside B ( 2) and acteoside ( 3), along with four hydroxycoumarins; esculin ( 4), fraxin ( 5), fraxetin ( 6) and esculetin ( 7), and one lignan, (-)-olivil ( 8) were isolated from the n-butyl alcohol fraction of Fraxinus sieboldiana var. angustata. Among the isolated compounds, calceolarioside B ( 2) and esculetin ( 7) showed moderate binding affinity on HIV gp41 with IC 50 values of 0.1 mg/ml and 0.5 mg/ml, respectively. Calceolarioside A ( 1), calceolarioside B ( 2), acteoside ( 3), and (-)-olivil ( 8) were isolated for the first time from this plant.

Topics: Binding, Competitive; Caffeic Acids; Coumarins; Esculin; Fraxinus; Glucosides; Glycosides; HIV Envelope Protein gp41; HIV-1; Humans; Phenols; Phytotherapy; Plant Bark; Plant Extracts; Umbelliferones