A-methyl glucamine

These surfactants are produced by preparing A -methyl-glucamine, followed by reaction of the latter with an alkyl (or fatty) methyl ester, using a base catalyst, to form the required glucamide (see Figure 13.15). 

Chemoselective acylation of a secondary amine, A-methyl glucamine with fatty acid using commercially available lipases from Rhizomucor meihei (Lipozyme) and Candida... 

Synthesis of glucamides by transacylation using fatty esters and triglycerides has also been tested [45]. The reaction was completed in a shorter time than for reverse hydrolysis. Initially both an amide and ester of A/-methyl glucamine were produced and subsequently the ester was consumed to give rise to amide-ester. 

Maugard, T., Remaud-Simeon, M., Petre, D. and Monsan, P. (1997) Lipase-catalysed synthesis of biosurfactants by transacylation of A-methyl-glucamine and fatty-acid methyl esters. 

Some of the ionic iodinated substances used in CAT scans include amidotrizoates (salts of diatrizoic acid) and iothalamates (salts of iothalamic acid)J l The typical cations are sodium ion or meglumine (A-methyl-Z)-glucamine) ion (Fig. 10.1.1),... 

A series of attempts to discover optimum reaction conditions was made in view of preventing formation of by-products arising from the reaction of the acyl halogenide with different functional groups within the N-methyl glucamine molecule. Nonetheless, a subsequent purification step was necessary to remove by-products and unreacted starting material. This turned out to be complicated due to similar solubilities of both the... 

Merck has also developed fosaprepitant (21), a phosphate prodrug of aprepitant with improved solubility and the synthesis is detailed in Scheme 8. It is based on phosphorylation with a ben2yl-protected reagent to give 62 followed by debenzylation and formation of the 7V-methyl-/)-glucamine salt.9... 

Stark FR, Coburn JW. Renal failure following methyl-glucamine diatrizoate (Renografin) aortography report of a case with unilateral renal artery stenosis. J Urol 1966 96(6) 848-51. 

However, other studies show that the current-voltage relationships and the electrophysiological properties of the whole-cell current induced by MTX in human skin fibroblasts differ from those described for TRPC channels [54]. Selectivity, experiments point out some differences also, the most remarkable is a substantial permeabihty to the large cation A-methyl-o-glucamine (NMDG), which is not observed with TRPC channels expressed in heterologous systems. 

Crystallise A -methyl-D(-)-glucamine from MeOH. Its solubility in H2O is 10%. [Karrer Herkenrath Helv ChimActa 20 83 1957 also for other N-alkyl derivatives, Beilstein 4 IV 1914.]... 

Figure 7.19 Two-step synthesis of fatty acid glucamides by reductive alkylation of methylamine with glucose using Raney nickel as the hydrogenation catalyst to obtain Al-methyl glucamine, which is acylated by a base-catalyzed reaction with fatty acid methyl ester in a second step.

An interesting new approach for making carboxylic acid amides is shown in Figure 3.9. Monsan and coworkers [18] used lipases from C. antarctica and Rhi-zomucor miehei as catalysts in the direct amidation reaction between free fatty adds and a secondary sugar amine (N-methyl-glucamine) in hexane. Such a reaction would be impossible in water since amide hydrolysis would predominate for thermodynamic reasons. Because free N-methyl-glucamine was insoluble in hexane, it was added as an ionic complex with the free fatty add. The enzymatic... 

It should be noted that a major difficulty in the detection of nitroxyl anion is explained by the impossibility to apply ESR spectroscopy because nitroxyl is not a free radical. Moreover, the use of spin traps such as iron iV-methyl-D-glucamine dithiocarbamate (Fe-MGD) to distinguish NO and NO production by NO synthase failed because both nitrogen species reacted with this spin trap [87]. 

To ensure the specificity of the signal, it will always be very helpful to test a unique feature of the carrier under investigation, such as specific inhibition, dependence on anions/cations/protons or trans-activation by another substrate. Sodium dependency, for example, can be tested by replacement with N-methyl-D-glucamine, whereas choline chloride as substitute of sodium is not recommended, since it may influence the membrane potential. In light of the recent finding that many transport proteins display an overlapping substrate spectrum, such specificity controls should receive adequate appreciation. 

It is possible that the water-filled a-LTX channel, which is relatively wide ( 10A at its narrowest (Krasilnikov and Sabirov 1992 Orlova et al. 2000), can pass small molecules. Indeed, a-LTX channels inserted in the membranes of synaptosomes, NMJ nerve terminals, and receptor-transfected COS7 cells appear to pass fluorescein (Stokes-Einstein radius, Re = 4.5 A) and norepinephrine (Re < 4 A) (Davletov et al. 1998 Rahman et al. 1999 Volynski et al. 2000), shown in Figure 2 for comparison with 8-hydrated calcium ion (Rc = 4.2 A) and the toxin channel. Analysis of impermeant cations commonly used in channel studies reveals that a-LTX channels are poorly permeable (Hurlbut et al. 1994) to glucosamine H+(Re = 4.6 A) and not significantly permeable (Tse and Tse 1999) to N-methyl-D-glucamine (Re = 5.2 A), thus limiting the pore diameter by 10 A. 

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