The axially chiral tetra-ortho-substituted biaryl skeleton exists in numerous biologically important natural products, pharmaceutical molecules, chiral catalysts, and ligands. The efficient synthesis of chiral tetra-ortho-substituted biaryl structures remains a challenging but unsolved problem. Among various asymmetric synthetic protocols, enantioselective Suzuki-Miyaura cross-coupling represents one of the most straightforward and versatile approaches. Herein we describe a powerful Suzuki-Miyaura coupling enabled by a P-chiral monophosphorus ligand BaryPhos, providing a broad range of synthetically challenging chiral tetra-ortho-substituted biaryls in excellent enantioselectivities and yields. In addition to the enhanced reactivity for sterically hindered cross-coupling, the rational design of BaryPhos also enabled a new catalysis mode of asymmetric cross-coupling involving noncovalent interactions between the ligand and two coupling partners to effect efficient stereoinduction. This protocol is robust and practical, allowing for a concise enantioselective synthesis of therapeutically valuable male contraceptive and antitumor agent gossypol.

Garmultins A and B (1 and 2), two polycyclic polyprenylated acylphloroglucinols characterized by the coupling of two novel cages, 2,11-dioxatricyclo[4.4.1.0]undecane and tricyclo[4.3.1.0]decane, along with five biogenetically related analogues (3-7), were isolated from Garcinia multiflora. Their structures and absolute configurations were determined by extensive NMR analysis, X-ray crystallography, and electronic circular dichroism calculations. Three compounds were capable of inhibiting oncogene expression and inducing apoptosis in human erythroleukemia cells.

Objective: The aim of this study was to investigate the cellular effects of melittin on the growth and apoptosis of human hepatocellular carcinoma (HCC) cells and to provide the molecular mechanism for potential application of a recombinant adenovirus carrying the melittin gene (Ad-rAFP-Mel) in the treatment of liver cancer. Methods: Human HCC cells (BEL-7402) were infected with Ad-rAFPMel at different times. In vitro cell growth was determined by MTT assay. Cellular apoptosis was evaluated quantitatively and qualitatively by phase-contrast microscopy, transmission electron microscopy, DNA ladder electrophoresis, TUNEL staining and flow cytometry. Results: Ad-rAFP-Mel infection had an inhibitory effect on the proliferation of BEL-7402 cells. The morphological changes of apoptosis were confirmed by microscopy and DNA electrophoresis. The ultrastructural characteristics of apoptotic cells, such as chromatin condensation and nuclear fragmentation, were also observed by electron microscopy in the Ad-rAFP-Mel-infected cells. Ad-rAFPMel infection markedly induced cellular apoptosis, and Fas expression on Bel-7402 cells infected by Ad-rAFPMel was up-regulated. Conclusion: The fact that melittin can induce apoptosis of the HCC cell line BEL-7402 leads us to consider adenovirus-mediated delivery of melittin as a promising approach for the treatment of HCC. However, the underlying mechanism needs to be further investigated.

Three indole alkaloid glycosides, strobilanthosides A-C (1-3), two known indole alkaloid glucosides (4 and 5), and five phenylethanoid glycosides (8-10) were isolated from the aerial parts of Strobilanthes cusia. The structures of the new compounds were elucidated by spectrometric analysis, and the absolute configurations of 1 and 2 were established by ECD spectrocsopy. N'-β-d-Glucopyranosylindirubin (5) showed weak antibacterial activity (MIC 62.5-125 μM) against Staphylococcus aureus.