Polyprenylated acylphloroglucinols from Hypericum sampsonii with cytotoxicity against pancreatic carcinomas.

Chemical investigation on the 80% EtOH extract of the air dried aerial parts of Hypericum sampsonii resulted in the isolation of two new polycyclic polyprenylated derivatives, hypersampines A and B (1 and 2). The structures of the new compounds were elucidated by spectroscopic data (NMR, IR, and UV) and high resolution mass analysis. The two isolated polyprenylated acylphloroglucinols were tested in vitro for cytotoxic activities against 6 pancreatic cell lines. As a result, compounds 1 and 2 possessed modest cytotoxic activities against all the tested tumor cell lines with IC50 values less than 40 µM.

Effects of clarithromycin on the pharmacokinetics of tacrolimus and expression of CYP3A4 and P-glycoprotein in rats.

The objective of this study was to investigate the effect of clarithromycin on the pharmacokinetics of tacrolimus in rats and better understand its mechanism. In the control group (n = 6), rats received a single oral dose of 1 mg tacrolimus on day 6. In the experimental group (n = 6), rats received 0.25 g of clarithromycin daily for five consecutive days and then a single oral dose of 1 mg tacrolimus on day 6. Orbital venous blood (250 µL) was collected at 0, 0.25, 0.50, 0.75, 1, 2, 4, 8, 12, and 24 h before and after tacrolimus administration. Blood drug concentrations were detected via mass spectrometry. Small intestine and liver tissue samples were collected after rats were euthanized via dislocation, and CYP3A4 and P-glycoprotein (P-gp) protein expression was determined using western blotting. Clarithromycin increased the blood tacrolimus concentration and affected its pharmacokinetic properties in rats. Compared with those in the control group, the AUC0-24 , AUC0-∞ , AUMC(0-t) , and AUMC(0-∞) of tacrolimus in the experimental group were significantly increased, whereas the CLz/F was significantly lower (P < 0.01). Simultaneously, clarithromycin significantly inhibited CYP3A4 and P-gp expression in the liver and intestine. Protein expression of CYP3A4 and P-gp in the liver and the intestinal tract was significantly downregulated in the intervention group compared with that in the control group. Clarithromycin significantly inhibited the protein expression of CYP3A4 and P-gp in the liver and intestine, thereby increasing the mean blood concentration and significantly increasing the AUC of tacrolimus.

Supramolecular chirality of coordination polymers of Ag+ with a chiral thiol ligand that bears a ß-turn structure.

We report coordination polymers forming from Ag+ and a chiral thiol ligand that bears a ß-turn structure, exhibiting supramolecular chirality showing both the majority rules effect (MRE) and the racemate rules effect (RRE).

Selective synthesis of 4-(sulfonyl)-methyl-1H-pyrazoles and (E)-4,5-dihydro-1H-pyrazoles from N-allenic sulfonylhydrazones.

Selective synthesis of 4-(sulfonyl)-methyl-1H-pyrazoles and (E)-4,5-dihydro-1H-pyrazoles from N-allenic sulfonylhydrazones with sulfonyl group migrations has been developed. A key feature of these reactions is that the migrations of the sulfonyl groups to different positions can be controlled by changing the Lewis acids.