Orientin regulates the proliferation and migration of hepatocellular carcinoma cells.

Orientin is a flavone isolated from medicinal plants used in traditional Chinese medicine (TCM) that suppresses the growth of cancer cells in vitro. The effects of orientin in hepatoma carcinoma cells remain unknown. The aim of this paper is to investigate the effects of orientin on the viability, proliferation, and migration of hepatocellular carcinoma cells in vitro. In this study, we found that orientin could inhibit the proliferation, migration, and the activation of NF-κB signaling pathway in hepatocellular carcinoma cells. An activator of NF-κB signaling pathway, PMA, could abolish the inhibitory effect of orientin on NF-κB signaling pathway and proliferation and migration of Huh7 cells. These findings raise the possibility that orientin can be used in the treatment of hepatocellular carcinoma.

Ag/Pyridine Co-Mediated Oxidative Arylthiocyanation of Activated Alkenes.

An efficient Ag/pyridine co-mediated oxidative arylthiocyanation of activated alkenes via radical addition/cyclization cascade process was developed. This reaction could be carried out under mild conditions to provide biologically interesting 3-alkylthiocyanato-2-oxindoles in good to excellent yields. Mechanistic studies suggested a unique NCS• radical addition path and clarified the dual roles of catalytic pyridine as base and crucial ligand to accelerate the oxidation of Ag(I) to Ag(II), which is likely oxidant responsible for the formation of NCS• radical. These mechanistic results may impact the design and refinement of other radical based reactions proceeding through catalytic oxidations mediated by Ag(I)-pyridine/persulfate. The chemical versatility of thiocyanate moiety was also highlighted via SCN-tailoring chemistry in post-synthetic transformation for new S-C(sp³/sp²/sp), S-P, and S-S bonds constructions. The protocol provides an easy access to many important bioisosteres in medicinal chemistry and an array of sulfur-containing 2-oxindoles that are difficult to prepare by other approaches.

Isolation, identification, semi-synthesis of aziditaxel derivatives and their biological evaluation.

Two new taxoids (5 and 6) were obtained by isolating impurities in aziditaxel, and their structures were characterized based on data analysis of (1)H NMR, (13)C NMR, HPLC-MS, and through comparison with literature. In order to test their cytotoxicities against human nonsmall lung cancer cell lines (A549), sufficient amounts of compounds 5 and 6 were obtained by semi-synthesis and both of them showed equipotent cytotoxiesty compared with taxol, docetaxel, and aziditaxel.

New ursane-type triterpene with NO production suppressing activity from Nauclea officinalis.

Two new ursane-type triterpenes, named as 3ß, 19α, 23, 24-tetrahydroxyurs-12-en-28-oic acid (1) and 2ß, 3ß, 19α, 24-tetrahydroxyurs-12-en-28-oic acid (2), together with two known triterpenoids, 3-oxo-urs-12-ene-27, 28-dioic acid (3) and quinovic acid-3-ß-rhamnopyranoside (4), were isolated from the stems (with barks) of Nauclea officinalis. The structures of 1 and 2 were determined by the combined use of single-crystal X-ray diffraction and spectroscopic data analysis. The inhibitory activities on nitric oxide (NO) production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells were examined, and compound 1 was found to inhibit NO production, with the IC(50) value of 4.8 µM.

neo-Clerodane diterpenoids from Scutellaria barbata with cytotoxic activities.

Three neo-clerodane diterpenoids, named barbatins A-C (1-3), and the neo-clerodane diterpenoid nicotinyl ester, named scutebarbatine B (4), were isolated from the whole plant of Scutellaria barbata D. Don. Their structures were elucidated by spectroscopic analyses (UV, IR, HRFAB-MS, 1D NMR and 2D NMR). In vitro, compounds 1-4 showed significant cytotoxic activities against three human cancer lines, namely, HONE-1 nasopharyngeal, KB oral epidermoid carcinoma, and HT29 colorectal carcinoma cells, with IC50 values in the range 3.5-8.1 microM.

Molecular characterization of OsRAD21-1, a rice homologue of yeast RAD21 essential for mitotic chromosome cohesion.

Rad21/Rec8 is an important component and key regulator of cohesins. A RAD21-like gene from rice (Oryza sativa L. ssp. japonica) has been cloned and termed OsRAD21-1. OsRAD21-1 is a single-copy gene in the rice genome and is expressed in the entire plant. OsRad21-1 consists of 1055 amino acid residues and is the largest of the Rad21/Rec8 family identified to date. Based on sequence similarity comparison with other members of this family and gene expression patterns, it is concluded that OsRad21 is a rice orthologue of yeast Rad21.