Binding of human low density lipoproteins (LDL) to their specific receptor on cultured cells can be inhibited by treatment with 1,2-cyclohexanedione which blocks a number of functionally significant arginyl residues on the apolipoprotein. We have used this observation to examine the role of the receptor pathway in LDL catabolism in man. The plasma clearance rates of 125I-LDL and 131I-cyclohexan...

A series of 2-(l-alkylamino)vinylidene-l,3-cyclohexanedione was synthesized and assayed as inhibitors of the Hill reaction in isolated chloroplasts. The pls() value of this series was dramatical­ ly changed by modification of the peripheral of its hydrophilic moiety and the maximum p l50 value of this series was almost equal to that of DCMU. The results suggest that this series may be a good pr...

A series of novel 1, 8-dioxo-octahydroxanthene derivatives containing 4-thiazolidinone framework (4a-f) were synthesized through a four-step reaction starting from the reduction of nitro derivatives of 1, 8-dioxo-octahydroxanthenes. The resulting aminoxanthenes converted to thiourea derivatives via their reaction with methyl isothiocyanate. The final products were synthesized through the re...

The reaction of formaldehyde with β-diketones (Hantzsch reaction) has been often employed for derivatizing formaldehyde to the fluorescent compounds.1,2 Among βdiketones, 5,5-dimethyl-1,3-cyclohexanedione (dimedone, Fig. 1) seems to be the most promising because of the strong fluorescence intensity and stability of the formed compound. Recently, we developed a method for concentrating trace hyd...

The density functionals B3LYP, B3PW91, M062X, and CAM-B3LYP with the 6-311+G(d,p) basis set predict the cysteine sulfenic acid O-sulfenylation of the s-cis-ketoenol tautomer of 1,3-cyclohexanedione proceeds through a cyclic 14-membered transition state structure containing three water molecules.

In a heretofore-unreported reaction, 1,2-cyclohexandione reacts with a variety of alcohols under mild acid-catalyzed dehydration conditions to afford not only ethers of 1,2cyclohexanedione but the corresponding aryl ethers as well in moderate to good yield.

Experiments with the 1,4-cyclohexanedione Belousov-Zhabotinsky reaction demonstrate that three-dimensional scroll waves can rotate around filaments that end in the wake of a traveling excitation pulse. The vortex structures nucleate during the collision of three nonrotating excitation pulses. The nucleation process and the wave-termination of filaments are direct consequences of the system's an...