Asymmetric Total Synthesis of (-)-Maoecrystal V.

The asymmetric total synthesis of (-)-maoecrystal V, a novel cytotoxic pentacyclic ent-kaurane diterpene, has been accomplished. Key steps of the current strategy involve an early-stage semipinacol rearrangement reaction for the construction of the C10 quaternary stereocenter, a rhodium-catalyzed intramolecular O-H insertion reaction, and a sequential Wessely oxidative dearomatization/intramolecular Diels-Alder reaction to forge the pentacyclic framework of maoecrystal V.

Total synthesis of maoecrystal V.

Maoecrystal V (1) is a novel diterpenoid, which was originally isolated from the leaves of the Chinese medicinal herb Isodon eriocalyx in 2004 by Sun et al.1 It has been found to be selectively cytotoxic towards HeLa cells, with an IC50 value of 20 ng mL(-1) . Significant research efforts have been devoted to the synthesis of maoecrystal V because of its intriguing biological properties, rarity in nature, and complex structural features.

[Changes of gene expression profile in human myeloma cell line induced by thalidomide].

The study was aimed to investigate the anti-myeloma molecular mechanism of thalidomide (TLD) by detecting gene expression profiles of human myeloma cell line RPMI8226 treated with thalidomide. cDNA microarray were used to detect thousands of gene expression in gene chip. Two cDNA probes were prepared through reverse transcription from mRNA of RPMI8226 cells untreated and treated with TLD.