A series of N′,N′-disulphonyl and N′-sulphonyl-N′-acetyl derivatives of N-amino-9,10-dihydroanthracene-9,10-endo-α-methyl-α,β-succinimide and N-amino-1,2,3,4-tetrahydro-1,4-etheno/ethano-naphthalene-2,3-exo/endo-dicarboximides with a benzo ring in the cage-moiety were prepared and their NMR spectra were studied. Shielding constants of the substituents provide evidence for the non-eclipsed conformations of the N′-substituents with the ring carbonyls. The preferred conformations of N′-sulphonyl-N′-acetyl derivatives are explained on steric grounds. In N′-tosyl-N′-acetyl derivatives the tosyl group takes up a fixed conformation about N′-SO2 bond in which the aryl part of the tosyl group projects away from the cage-moiety.

Carbonic anhydrase isoforms IX and XII are overexpressed in hypoxic tumor cells regulating various physiological processes such as cell proliferation, invasion, and metastasis, resulting in the onset and spread of cancer. Selective inhibition of these enzymes is a promising strategy for anticancer therapy. Coumarin derivatives were identified as selective and potent inhibitors of these isoforms. This study reports 6‐aminocoumarin sulfonamide and oxime ether derivatives linked through a chloroacetyl moiety tethered to piperazine and piperidone, respectively, showing selective inhibition against human carbonic anhydrase (hCA) IX and XII with Ki ranging from 0.51 to 1.18 µM and 0.89–4.43 µM. While the sulfonamide derivative 8a exhibited submicromolar inhibition against hCA IX and XII with Ki 0.89 and 0.51 µM, the oxime ether derivatives showed lower activity than the sulfonamides, with the compound 5n inhibiting hCA IX and hCA XII with a Ki of 1.055 and 0.70 µM, respectively. The above results demonstrate the potential of these derivatives as selective, potent inhibitors of carbonic anhydrase IX and XII and provide a foundation for further optimization and development as effective anticancer agents. Further, the binding mode of the synthesized derivatives in the active site were examined using molecular docking and dynamic simulation studies.

Anhand NMR‐spektroskopischer Untersuchungen wird der Einfluß der Substituenten am exocyclischen N‐Atom auf die Konformation an der N‐N‐Bindung der Diels‐Alder‐Addukte (I) diskutiert.

Zirconia containing ceramics have exceptionally high fracture toughness compared with other structural ceramics. Application areas vary widely from traditional uses like refractory and glass to the more advanced fields like ballbearing, automobile appliances, turbine blades, grinding media, cutting tools, space shuttles to bio-implantations. It has the potential to toughen and / or strengthen ceramic matrix utilizing the stress-induced tetragonal to monoclinic phase transformation of ZrO2 .In the present work monoclinic zirconia (0.5-10wt %) doped preformed MgAl2O4 Spinel powder was synthesized and characterized. The mean particle size of the spinel powder was 8.54 µm and that of zirconia was 5.67 µm. The bulk density increased gradually from 2.34 gm/cm 3 of Spinel to 2.52, 2.66, 2.86 gm/cm 3 with 10% zirconia added sample at 1350 o C/1h ,1500 o C and 1650 o C for 1 hour respectively. The apparent porosity of spinel also decreased from 33.29% to 32.00, 29.78 & 23.28% at 1350, 1500 & 1650 o C/1h respectively with 10 wt.% zirconia addition. XRD of all the compositions fired at different temperature reveals that with increase in zirconia content and temperature, transformation of monoclinic to tetragonal phase increased up to 1500 o C, but slightly decreased thereafter at 1650 o C. The mechanical strength of the spinel increased gradually with increase in Zirconia content and temperature. The compressive strength increased three fold from 9.39MPa in spinel only to 24.7MPa with 10wt% zirconia at 1350 o C. With increase in temperature to 1650 o C the fracture toughness also exhibited an increase from 40.4MPa to 82.1MPa with 10wt% zirconia.

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