a simple and efficient one-pot three-component synthesis of the biologically important spirooxindole-4h-pyrans was carried out by the reaction of isatin, activated methylene reagents, and 4-hydroxycoumarin in aqueous medium. sba-pr-nh2 was found to be an efficient heterogeneous nanoporous solid basic catalyst (pore size of 6 nm) which can be easily handled and removed from the reaction mixture ...

asphaltenes are the n-pentane or n-heptane insoluble fractions of crude oil that remain in solution under reservoir temperature and pressure conditions. they are destabilized and start to precipitate when the pressure, temperature and/or composition changes occur during primary production. the precipitated asphaltene particles will then grow in size and may start to deposit onto the production ...

A simple procedure afforded novel spiroacenaphthylene derivatives in high yields at room temperature from acenaphthenequinone, malononitrile, and phenol derivatives using amino-functionalized silica (SBA-Pr-NH2) as a heterogeneous efficient solid base catalyst. Using SBA-Pr-NH2 in the current procedure presents several advantages, such as a simpler procedure, shorter reaction times, facile synt...

PR-104 is the phosphate ester of a 3,5-dinitrobenzamide nitrogen mustard (PR-104A) that is reduced to active hydroxylamine and amine metabolites by reductases in tumors. In this study, we evaluate the excretion of [(3)H]PR-104 in mice and determine its metabolite profile in mice, rats, dogs, and humans after a single intravenous dose. Total radioactivity was rapidly and quantitatively excreted ...

PR-39 is a proline-arginine-rich (PR) neutrophil antibacterial peptide originally identified and purified from the porcine small intestine. We report on the synthesis of a functional antibacterial domain of PR-39, the first 26 amino acid residues of the NH2 terminus. PR-26 was as potent as or more potent than PR-39 against enteric gram-negative bacteria. This truncated form of PR-39 potentiated...