Sudershan K. Arora

Synthesis and antitumor activity of goniofufurone analogues

Synthesis and antitumor activity of goniofufurone analogues 15, 16, 17, 33, and 46 is reported. Key step in the synthesis is Pd (II) mediated oxidative cyclisation of vinyl-(hydroxy) furans 18, 19 to the corresponding lactols 32, 43. Cytotoxicities of 15, 16, 17, 33, and 46 tested against six human cancer cell lines are reported. Change of stereochemistry at C-5, C-6 and C-7 position of goniofufurone (1) did not enhance the cytotoxicities significantly.

Fabrication and characterization of high T/sub c/ superconducting magnetic shield

Superconducting magnetic shields of Y-Ba-Cu-O superconductor were fabricated in tubular form with one end closed. These shields were used successfully to reduce the flux noises of a two-hole RF SQUID of Y-Ba-Cu-O superconductor. Hysteretic critical current density and penetrated field amplitude under increasing and decreasing magnetic fields reveal the presence of grain boundary weak links. The flux trapping behavior can be explained by using a modified version of C.P. Beans self-field-limiting model (1962).