Stereoselective Synthesis of the C1-C16 Fragment of the Purported Structure of Formosalide B.

The first stereoselective synthesis of the C1-C16 fragment possessing stereo-enriched fully substituted tetrahydropyran (THP) along with tetrahydrofuran (THF) rings of the proposed structure of formosalide B is described in 12 longest linear steps with 22% overall yield, starting from two cheap and commercially available 1,5-pentanediol and l-glutamic acid, following a convergent approach. The key steps involve in this synthesis are Horner-Wadsworth-Emmons reaction, Sharpless asymmetric dihydroxylation, and acid-mediated ketalization to assemble the substituted THP ring, one-pot Sharpless dihydroxylation-SN2-type cyclization, and Wittig homologation to construct the THF derivative.

Synthesis and anticancer activity evaluation of novel azacalix[2]arene[2]pyrimidines.

A series of novel azacalix[2]arene[2]pyrimidines were synthesized, and evaluated for their antiproliferative activities against A549, MCF7, SH-SY5Y and CNE human cancer cell lines in vitro by using the CCK-8 assay. A number of compounds showed low micromolar antiproliferative activities against MCF7 cell line. Compound 4j, containing a pyrrolidine moiety, exhibited the strongest inhibitory activity with an IC50 value of 0.58 µM. Furthermore, breast cancer cells were used to explore the inhibition mechanism of these azacalix[2]arene[2]pyrimidines. The results suggested these compounds were involved in inducing cell apoptosis via up-regulation of caspase-3 and caspase-9 protein expression, and the cell cycle was arrested at the S phase. Our reports here represent the first studies on the biological activities of azacalix[2]arene[2]pyrimidines.