Enantioselective alkylation of β-keto esters promoted by dimeric Cinchona-derived ammonium salts as recoverable organocatalysts

Dimeric anthracenyldimethyl-derived Cinchona ammonium salts are used as chiral organocatalysts in 5 mol% for the phase-transfer enantioselective alkylation reaction of 2-alkoxycarbonyl-1-indanones with activated bromides. The corresponding adducts bearing a new all-carbon quaternary center are obtained usually in high yield and with moderate and opposite enantioselectivity (up to 55%) when using ammonium salts derived from quinidine and its pseudoenantiomer quinine as organocatalysts. These catalysts can be almost quantitatively recovered by precipitation in ether and reused.

Natural Compounds from Saffron and Bear Bile Prevent Vision Loss and Retinal Degeneration

All retinal disorders, regardless of their aetiology, involve the activation of oxidative stress and apoptosis pathways. The administration of neuroprotective factors is crucial in all phases of the pathology, even when vision has been completely lost. The retina is one of the most susceptible tissues to reactive oxygen species damage. On the other hand, proper development and functioning of the retina requires a precise balance between the processes of proliferation, differentiation and programmed cell death. The life-or-death decision seems to be the result of a complex balance between pro- and anti-apoptotic signals. It has been recently shown the efficacy of natural products to slow retinal degenerative process through different pathways. In this review, we assess the neuroprotective effect of two compounds used in the ancient pharmacopoeia. On one hand, it has been demonstrated that administration of the saffron constituent safranal to P23H rats, an animal model of retinitis pigmentosa, preserves photoreceptor morphology and number, the capillary network and the visual response. On the other hand, it has been shown that systemic administration of tauroursodeoxycholic acid (TUDCA), the major component of bear bile, to P23H rats preserves cone and rod structure and function, together with their contact with postsynaptic neurons. The neuroprotective effects of safranal and TUDCA make these compounds potentially useful for therapeutic applications in retinal degenerative diseases.

Occupational exposure to hydrogen cyanide and cyanide salts (NaCN,KCN,and Ca (CN)2).

Mode of access: Internet.

Molten salts : selected references /

"Included are 205 references to unclassified reports received by the Office of Technical Information Extension since mid-1958"--Page [1].

Molten salts : selected references /

Includes indexes.

Paper electrophoretic studies of radioactive chromium salts in blood /

"Published with the approval of the Director of the University of Tennessee Agricultural Experiment Station."--Page iii.

Observations on the bile and its diseases and on the oeconomy of the liver : read at the Royal College of Physicians as the Gulstonian lecture of the year 1799 /

Mode of access: Internet.

Investigation of salts for use in uranium metal heat-treating baths /

Numerous salts were considered for uranium metal annealing baths. Tests on melting point, solubility, corrosion stability, and hydrogen concentration were conducted on the salts which appeared to be the most feasible for this operation under existing conditions.

Pi︠a︡tidesi︠a︡tili︠e︡tnīĭ i︠u︡bileĭ S.-Peterburgskago prakticheskago tekhnologicheskago instituta, 28-go noi︠a︡bri︠a︡ 1878.

Includes index of graduates for 1837-1878.

Clinical lectures on the gallbladder and bile ducts,

"Radiology of the gallbladder, by Ernest E. Smith": p. 84-104. "Diagnostic and therapeutic duodenal drainage, by Harry M. Eberhard": p. 105-136.

Corrosion of superalloys by selected fused salts

Mode of access: Internet.