3,9-Diisopropyl-2,4,8,10-tetra­thia­spiro­[5.5]undeca­ne

The mol­ecule of the title compound, C13H24S4, has C2 symmetry and it crystallizes as a racemate. The structure displays two six-membered rings exhibiting chair conformations, with the isopropyl substituents in equatorial positions. In the crystal structure, weak inter­molecular C—H⋯S inter­actions are observed, leading to a channel-like arrangement along the c axis

Nitrones: not only extraordinary spin traps, but also good nitric oxide sources in vivo

Free radicals are involved in the development of reperfusion injuries. Using a spin trap, the intensity of such lesions can be reduced. Nitrones (effective in vivo spin traps) were tried in this work as in vivo nitric oxide donors. Nitrite and nitrate concentration values (rabbit blood) were used as biomarkers of nitric oxide production. Most nitrones did not increase plasma concentrations of nitrite and nitrate; on the contrary, reduced plasma concentrations of these indicators were noted. However, glyoxal isopropyldinitrone, in a dose of 50 mg kg–1, was highly effective in increasing nitric oxide production. In the same time, nitrones do not react with hepatic homogenates, proving that the release of nitric oxide takes place in the tissues and is not related to hepatic metabolism. Before using nitrones in vivo, they were tested in vitro for the ability to release nitric oxide following a reaction with the hydroxyl radical

Effects of low-molecular weight alcohols on bacterial viability

Alcohol based solutions are among the most convenient and wide spread aid in the prevention of nosocomial infections. The current study followed the efficacy of several types and isomers of alcohols on different bacterial species. Seven alcohols (ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl alcohol, and ethylene glycol) were used to evaluate their minimal inhibitory and bactericidal effects by microdilution method on bacteria that express many phenotypical characteristics: different cell-wall structure (Gram positive/negative bacteria), capsule production (Klebsiella pneumoniae), antibiotic resistance (MRSA vs MSSA) or high environmental adaptability (Pseudomonas aeruginosa). Results: The best inhibitory effect was noticed for n-propyl, followed by iso-propyl, n-butyl, and iso-butyl alcohols with equal values. Ethylene glycol was the most inefficient alcohol on all bacteria. In K. pneumoniae and P. aeruginosa, the bactericidal concentrations were higher than the inhibitory one, and to a level similar to that encountered for most of the Gram-positive bacteria. Among Gram-positive cocci, E. faecalis presented the lowest susceptibility to alcohols. Conclusions: All alcohols presented good effect on bacteria, even in low concentrations. Compared to ethanol as standard, there are better alternatives that can be used as antimicrobials, namely longer-chain alcohols such as propyl or butyric alcohols and their iso- isomers. Ethylene glycol should be avoided, due to its toxicity hazard and low antimicrobial efficacy. Bacterial phenotype (highly adaptable bacteria, biofilm formation) and structure (cell wall structure, presence of capsule) may drastically affect the responsiveness to the antimicrobial activity of alcohols, leading to higher bactericidal than inhibitory concentrations

Synthesis and stereochemistry of some new spiro and polyspiro-1,3-dithiane derivatives

International audienc

Nitrones: not only extraordinary spin traps, but also good nitric oxide sources in vivo

Free radicals are involved in the development of reperfusion injuries. Using a spin trap, the intensity of such lesions can be reduced. Nitrones (effective in vivo spin traps) were tried in this work as in vivo nitric oxide donors. Nitrite and nitrate concentration values (rabbit blood) were used as biomarkers of nitric oxide production. Most nitrones did not increase plasma concentrations of nitrite and nitrate; on the contrary, reduced plasma concentrations of these indicators were noted. However, glyoxal isopropyldinitrone, in a dose of 50 mg kg-1, was highly effective in increasing nitric oxide production. At the same time, nitrones do not react with hepatic homogenates, proving that the release of nitric oxide takes place in the tissues and is not related to hepatic metabolism. Before using nitrones in vivo, they were tested in vitro for the ability to release nitric oxide following a reaction with the hydroxyl radical