Soybean cell suspension cultures grew on defined media with ammonium as the sole nitrogen source if Krebs cycle acids were added. Satisfactory growth was obtained with ammonium salts of citrate, malate, fumarate, or succinate, when compared with the regular medium containing nitrate and ammonium. Little or no growth occurred when ammonium salts of shikimate, tartrate, acetate, carbonate, or sul...

This work describes the synthesis of a series of quaternary ammonium salts and the assessment of their in vitro antileishmanial activity and cytotoxicity. A preliminary discussion on a structure-activity relationship of the compounds is also included. Three series of quaternary ammonium salts were prepared: (i) halomethylated quaternary ammonium salts (series I); (ii) non-halogenated quaternary...

Oligoresorcinol oligomers were found to adopt a single-stranded helical conformation in alkaline water through intramolecular hydrogen bonds, of which a helix-sense bias was induced by the addition of water-soluble chiral compounds, such as ammonium salts, amines and alcohols.

While it is well known that ruminants (with the aid of rumen microorganisms) can utilize ammonium salts and urea in lieu of dietary protein,” 2 it has long been held that monogastric animals cannot.’ In view of the findings of Foster, Schoenheimer, and Rittenberg3 that dietary ammonium N15 is rapidly incorporated into rat tissue proteins, it seemed possible that the nitrogen of ammonium salts m...

A systematic approach was used to evaluate the electrospray ionization mass spectral (ESI-MS) analysis of sucrose octasulfate (SOS), an important pharmaceutical agent. SOS represents a model for other suffated carbohydrates, such as heparin and glycosaminoglycan-derived oligosaccharides that also are highly sulfated and pose difficult analytical problems. A survey of ammonium counterions showed...

Alkaloids such as cinchonidine, quinine and N-methylephedrine have been N-alkylated using polymeric benzyl halides or co-polymerized and then N-alkylated, thus affording a series of polymer-supported chiral ammonium salts which have been employed as phase-transfer catalysts in the asymmetric benzylation of an N-(diphenylmethylene)glycine ester. These new polymeric catalysts can be easily recove...

Cinchona alkaloids (quinine, quinidine, cinchonine, cinchonidine) alkylated at N(1) with chloromethyl anthracene can serve as fluorescent sensors for chiral carboxylic acids. These cinchona ammonium salts are shown to bind chiral carboxylic acids while displaying an increase in fluorescence intensity that can be utilized in determination of enantiomeric excess (ee). Sensor arrays composed of fo...

A new, simple method to obtain ultrathin polycationic monolayers on hydroxylated surfaces is described which uses a bifunctional copolymer comprising a reactive part (trimethoxysilane) and positive charges (quaternary ammonium salts) to confer antimicrobial properties.