Hydroxypropyl-ß-Cyclodextrin Complexes of Styryllactones Enhance the Anti-Tumor Effect in SW1116 Cell Line.

Styryllactones, a class of compounds obtained from the genus Goniothalamus (Annonaceae), have demonstrated in vitro antitumor activity. However, the aqueous solubility of these compounds is poor. In this study, we identified the absolute configurations of the previously isolated compounds, which were first isolated in our laboratory, by single-crystal X-ray diffraction analysis using Cu Kα radiation. Subsequently, the antitumor activities of the compounds were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide staining in four tumor cell lines. The induced apoptosis activity of leiocarpin E-7'-Monoacetate was studied by an annexin V fluorescein isothiocyanate/propidium iodide double-staining experiment, and the caspase activity was tested in the SW1116 cell line. The results demonstrated that the antitumor activities of cheliensisin A and goniodiol-7-monoacetate were limited by their poor water solubility. To address this issue, hydroxypropyl-ß-cyclodextrin (HP-ß-CD) complexes of the compounds were synthesized by the saturated aqueous method. The complexes were then analyzed using a differential scanning calorimeter. The IC50 of cheliensisin A was reduced by 45% and 58% against SW1116 and SMMC-7721 cell lines, respectively. Similarly, the IC50 of goniodiol-7-monoacetate was reduced by 55% and 34% against the two tumor cell lines, respectively. To further evaluate whether the styryllactones and complexes possessed selectivity against cancer cell lines and normal cell lines, toxicity against human normal cell line (HEK293T) was evaluated. The results demonstrated that the HP-ß-CD complexes displayed more cytotoxicity than the respective pristine compounds against the HEK293T cell line. However, there existed a therapeutic window when the complexes were applied against cancer cell lines. In summary, the synthesis of several styryllactone compounds complexed with HP-ß-CD was reported for the first time. These complexes could significantly enhance the cytotoxic effects of styryllactone compounds.

TLC-bioautography directed isolation of antibacterial compounds from active fractionation of Ferula ferulioides.

A novel optimised isolation method, TLC-bioautography, was evaluated and utilised in this research. Antibacterial compounds which were isolated from the dichloromethane extract of Ferula ferulioides (Steud.) Korovin were detected by means of the method. Their structures were elucidated by extensive spectral and chemical methods. Their antibacterial activities against drug-resistant Staphylococcus aureus (S. aureus) strains were evaluated with broth microdilution method, and the results proved that TLC-bioautography was an effective and highly efficient way to screen natural compounds from plant extracts against drug-resistant strains.

Lewis Acid Catalyzed Tandem Polycyclization of Internal Alkynols and Vinyl Azides.

A novel Lewis acid catalyzed tandem cyclization reaction of internal alkynols and vinyl azides has been achieved to afford a series of products containing a pyran-based indeno[1,2-c]isochromene scaffold in moderate to high yields. This tandem polycyclization protocol provides a straightforward entry to construct the complex polycyclic skeleton through cycloisomerization, formal [4 + 2] cycloaddition, and an elimination process.

A copper(II) perchlorate-promoted tandem reaction of internal alkynol and salicyl N-tosylhydrazone: direct access to isochromeno[3,4-b]chromene.

A copper(ii) perchlorate-promoted tandem reaction of internal alkynol and salicyl N-tosylhydrazone provides a novel, concise method for constructing isochromeno[3,4-b]chromene in 35-94% yields. The tandem reaction involves cycloisomerization, formal [4+2] cycloaddition and an elimination process.