Isoflavonoids from Ficus benjamina and their inhibitory activity on BACE1.

Examination of an active extract of the fruit of Ficus benjamina var. nuda (Miq.) Barrett has led to the isolation of six new isoflavones and two coumarano-chroman-4-ones, along with fifteen known compounds. The structures of the eight new compounds were elucidated on the basis of extensive NMR experiments and mass spectrometric measurements. The inhibitory activity of the compounds on the proteolytic cleavage of amyloid precursor protein by the aspartic protease BACE1 was evaluated. Both coumarano-chroma-4-ones and some isoflavones showed moderate activity in this assay.

Metabolites from the fungus Phoma sp. 7210, associated with Aizoon canariense.

A new metabolite, 3,16-diketoaphidicolan (1), was isolated together with four known compounds: aphidicolin (2), 17-acetyl-aphidicolin (3), (+)-eupenoxide (4), and phomoxanthone A (5) from the endophytic fungus Phoma sp. The structure of the new compound 1 was determined by spectroscopic methods (mainly extensive 1D and 2D NMR experiments and by mass spectral measurements) and confirmed by X-ray crystallography. Its absolute configuration was assigned by means of the solid-state CD/TDDFT approach comparing the solid-state CD spectrum with the TDDFT-calculated one on the X-ray geometry.

allo-aromadendrane- and picrotoxane-type sesquiterpenes from Dendrobium moniliforme.

Eight sesquiterpenes, four stilbene derivatives along with two lignans have been isolated from lipophilic fraction of stems of Dendrobium moniliforme (Orchidaceae). Among the eight sesquiterpenes, one allo-aromadendrane-type and four picrotoxane-type sesquiterpenes were identified to be new compounds, and alpha-dihydropicrotoxinin was isolated as a new natural product. Their structures were established on the basis of spectroscopic analysis.

Identification and determination of ecdysones and flavonoids in Serratula strangulata by micellar electrokinetic capillary chromatography.

The simultaneous determination of 20-hydroxyecdysone ( 1), 25-deoxy-11,20-dihydroxyecdysone ( 2), kaempferol 4',7-dimethyl ether ( 3) and biochanin A ( 4) in the fruit, leaf and root of Serratula strangulata Iljin has been investigated by micellar electrokinetic capillary chromatography for the first time. With an electrolyte containing 15 mmol/L borate, 60 mmol/L SDS, 20 % (v/v) methanol, at pH 9.08 and 20 kV applied voltage, the four analytes were completely separated within 22.7 min. The effects of concentration of borate, electrolyte pH, the concentrations of SDS and organic modifier and the applied voltage on electrophoretic behavior and separation were studied. Regression equations revealed linear relationships (correlation coefficients: 0.9986 - 0.9997) between the peak areas of the analytes and the corresponding concentrations. The levels of analytes in the different parts of S. strangulata were easily determined with recoveries ranging from 95.3 % to 104.0 %.

Two new components from Serratula strangulata Iljin.

From the alcoholic extract of the whole plants of Serratula strangulata, two new compounds have been isolated and their structures established by spetroscopic methods as strangusin-A (1) and strangusin-B (2).