An elegant synthesis of Zetaclausenamide.
Zetaclausenamide, which was isolated as a hepatoprotective agent from the leaves of medicinal plant Clausena lansium, was synthesized for the first time in six steps including Darzen's condensation, photoisomerization, and the final cyclization reactions.
The Fruits of Wampee Inhibit H2O2-Induced Apoptosis in PC12 Cells via the NF-κB Pathway and Regulation of Cellular Redox Status
Wampee (Clausena lansium) fruits (CLS), whose pulp can be used to prepare fruit cups, desserts, jam, or jelly, can be eaten along with the peel. In this study, a PC12 cell model was built to observe the protective effect of CLS against H2O2-induced oxidative stress. We found that pretreatment with CLS increased cell viability and inhibited cytotoxicity, caspase-3 activity and DNA condensation. CLS also attenuated the increase in ROS production and MMP reduction. Moreover, we attempted to determine whether CLS suppressed the expression and phosphorylation of NF-κB. Western blot and immunostaining assay revealed that CLS inhibited H2O2-induced up-regulation of NF-κB p65 and pNF-κB p65. And CLS significantly suppressed the translocation of NF-κB p65 and pNF-κB p65 from cytoplasm to nuclear. Also, seven major compounds including a new flavanoid, luteolin-4'-O-β-d-gluco-pyranoside (3) and six known compounds 1,2, 4–7 were isolated and identified from CLS. Their antioxidative and H2O2-induced PC12 cell apoptosis-reversing activity were determined. These findings suggest that CLS and its major constituents (flavanoids) may be potential antioxidant agents and should encourage further research into their use as a functional food for neurodegenerative diseases.
Catalytic removal of tert-butyldimethylsilyl (TBS) ether by PVP-I
Abstract A mild, efficient and rapid protocol the deprotection of alcoholic TBDMS ethers using PVP-1 as catalyst in methanol, the procedure of deprotection of various TBDMS ethers were found to be very convenient, easy work-up, high yielding.