An Approach to Optically Pure Bridging Chiral p-tert-Butylcalix[4]arenes through a Homologous Anionic Ortho-Fries Rearrangement.

A novel efficient approach to optically pure bridging chiral calix[4]arenes through a homologous anionic ortho-Fries rearrangement of inherently chiral calix[4]arenes was presented for the first time. As a result, two pairs of N,N'-dimethylformamidyl-substituted bridging chiral p-tert-butylcalix[4]arene enantiomers were facilely obtained. Their absolute configurations were determined through ROESY analysis, ECD comparison, and X-ray crystallographic analysis.

Virtual screening for natural product inhibitors of HIV-1 integrase.

Since there is no human homolog of this enzyme, HIV-1 integrase (IN) represents a rational and important target for treating HIV infection and preventing AIDS. The 3D structure of full-length HIV-1 IN, either separately or in complex with its inhibitors, has been lacking. Thus, scarce information about the interactions between the HIV-1 IN and its inhibitors can be referenced.

[Better performance of Western blotting: quick vs slow protein transfer, blotting membranes and the visualization methods].

Objective: To study how the choices of the quick vs slow protein transfer, the blotting membranes and the visualization methods influence the performance of Western blotting.

Methods: The cellular proteins were abstracted from human breast cell line MDA-MB-231 for analysis with Western blotting using quick (2 h) and slow (overnight) protein transfer, different blotting membranes (nitrocellulose, PVDF and nylon membranes) and different visualization methods (ECL and DAB).

Results: In Western blotting with slow and quick protein transfer, the prestained marker presented more distinct bands on nitrocellulose membrane than on the nylon and PVDF membranes, and the latter also showed clear bands on the back of the membrane to very likely cause confusion, which did not occur with nitrocellulose membrane.