Novel oxidative ring opening reaction of H-isotelluro-chromenes to bis(o-formylstyryl) ditellurides.

The oxidation of 1-unsubstituted or 1-phenyl-1H-isotellurochromenes with m-chloroperbenzoic acid (mCPBA) in CHCl3 resulted in a ring opening reaction to produce as the sole products the corresponding o-formyl or benzoyl distyryl ditellurides, which were also produced by the hydrolysis of the 2-benzotelluropyrylium salts readily prepared from the parent isotellurochromene.

[Preparation of PLGA microspheres encapsulating highly concentrated glycyrrhizin and the bile elimination of glycyrrhizin after subcutaneous administration in rats].

The aim of this study was to prepare poly (lactide-co-glycolide) (PLGA) microspheres encapsulating highly concentrated glycyrrhizin (GZ), a hydrophilic drug, and to compare the release characteristics of GZ in in vitro experiments and GZ elimination into bile after subcutaneous administration in rats. The preparation was carried out based on water drying using a (w/o)/w emulsion. The encapsulation rate of GZ in microspheres was 76% when the GZ concentration in the outer water phase was equal to that in the inner water phase for the preparation of (w/o)/w emulsion.

Pharmacokinetics of glycyrrhizin in normal and albumin-deficient rats.

The pharmacokinetics of glycyrrhizin (GZ) was compared in albumin-deficient rats (NAR) and normal rats (SDR) after intravenous administration. The study sought to clarify the relationship between GZ concentration and its elimination rate in serum, liver and bile when the serum protein binding of GZ decreased. Serum protein binding in SDR and NAR, respectively, was 99.

Reactions of 2-benzoselenopyrylium salts with hydrazine: a new easy access to 5H-2,3-benzodiazepines.

While the solvent-free reactions of the 2-benzoselenopyrylium salts (9) with methyl- or phenylhydrazine afforded the 1-hydrazino-1H-isoselenochromenes (11, 12), the treatment of the salts (9) with anhydrous hydrazine in dry acetonitrile resulted in a ring transformation to give the 5H-2,3-benzodiazepines (13) in one-pot under mild conditions in moderate yields.

Studies on tellurium-containing heterocycles. Part 20. Reactions of 2-benzoselenopyrylium salts and 2-benzotelluropyrylium salts with nucleophiles: formation of 1-functionalized 1H-isoselenochromenes and 1H-isotellurochromenes.

The reactions of the 2-benzoselenopyrylium (1A) and 2-benzotelluropyrylium cations (1B) with a variety of nucleophiles have been investigated. LiAlH(4), sodium alkoxide (NaOMe, NaOi-Pr and NaOt-Bu), diethylamine, n-butylamine and acetone reacted with 1 to give the 1H-isochromenes (2) and the corresponding 1-substituted products (4-9) under mild conditions in almost good to high yields. The 1-alkyl(phenyl)isoselenochromenes (10-13) and 1-benzylisochromenes (18A, 18B), which were produced by the reaction of the salts 1 with Grignard reagents, were converted to the corresponding 1,3-disubstituted 2-benzopyrylium salts (14-17, 19) by treatment with triphenylcarbenium tetrafluoroborate (Ph(3)C(+) BF(4)(-)), respectively.