N-sulfation

Alaunerde,/. alumina, alaunerdehaltig, a. aluminiferous. Alaun-erdesulfat, n. sulfate of alumina (aluminum sulfate), -erz, n. alunite. -fass, n. (L ol/ier) alum vat. -fels, m. alunite. -festig-keit,/. Paper) alum resistance, alaun-ftirmig, a. aluminiform. -gar, a. dressed with aluQi, alumed, tawed. 

Sulfat, n, sulfate, -ablauge, /. sulfate waste liquor, -anlage,/. sulfate plant. 

Sulfat-ierung,/. sulfating sulfatization. -ion, n. sulfate ion, sulfatisieren, v.i. sulfatize. 

Tonerde-hydrat, n. hydrate of alumina (aluminum hydroxide). -kali, n. potassium aluminate. -lack, m. alumina lake. -metaU, n. aluminum, -natron, n. sodium aluminate. -prMparat, n. alumina preparation, tonerderelch, a, rich in alumina, aluminous. Tonerde-galz, n. aluminum salt, -stein, m, alumina brick, -sulfat, n, sulfate of alumina... 

Complete the following table for aqueous solutions of copper(n) sulfate. 

The repeating disaccharide contains glucosamine (GlcN) and either of the two uronic acids (Figure 48-9). Most of the amino groups of the GlcN residues are N-sulfated, but a few are acetylated. The GlcN also carries a Cg sulfate ester. 

This molecule is present on many cell sur ces as a proteoglycan and is extracellular. It contains GlcN with fewer N-sulfates than heparin, and, unhke heparin, its predominant uronic acid is GlcUA. 

The industrial production of Prussian blue is based on the reaction in aqueous solution of sodium hexacyanoferrate(n), Na4Fe(CN)6, with iron(n) sulfate, FeS04-7H20 in the presence of an ammonium salt, which results initially in the formation of the colourless insoluble iron(n) hexa-cyanoferrate(n) (Berlin white). Prussian blue is generated by subsequent oxidation with a dichromate or chlorate. 

It is important to note that the foregoing, biosynthetic-polymer modification is usually incomplete. In fact, only a fraction of the heparin precursor undergoes all of the transformations shown in Scheme 1. However, as the product of each enzymic reaction constitutes the specific substrate for the succeeding enzyme, the biosynthesis of heparin is not a random process. Thus, sulfation occurs preferentially in those regions of the chain where the amino sugar residues have been N-deacetylated and N-sulfated, and where D-glucuronic has been epimerized to L-iduronic acid.20... 

Whereas a major proportion of the 2-acetamido-2-deoxy-D-glucosyl residues is probably nonsulfated at C-6 (C-sulfation is expected to require prior N-sulfation),23 various degrees of C-sulfation have been reported for N-acetylated regions of heparan sulfates,148,149 and a 6-C-sul-fated, N-acetylated disaccharide was isolated from heparanase digests of heparan sulfates.114,115... 

Periodate oxidation was used in early work for obtaining information on the substitution pattern of heparin.1,100 102 In fully N-substituted (N-sulfated or N-acetylated, or both) glycosaminoglycans, the only bond susceptible to splitting by periodate is C-2-C-3 of unsubstituted uronic acid residues. As illustrated in Scheme 4 for heparin, only nonsulfated D-glucuronic acid and L-iduronic acid residues are split by periodate. 

Zinc/copper couple (Zn/Cu), produced by the treatment of zinc with HC1, followed by the addition of copper(n) sulfate, has been known since the seminal work of Simmons and Smith.67 A less reactive form of activated zinc, but one that is sufficiently active for most applications, is produced by the treatment of the metal with 1,2-dibro-moethane, followed by Me3SiCl.68 The most reactive form of activated zinc, the so-called Rieke zinc (Zn ), is finely divided metallic zinc produced by the homogenous reduction of zinc halides in THF.69... 

Copper(n) sulfate, CUSO4, reacts with sodium hydroxide, NaOH, in a double displacement reaction. A precipitate of copper(n) hydroxide, Cu(OH)2, and aqueous sodium sulfate, Na2S04, is produced. 

G. K. Hamer Yes, that peak comes from the N-acetyl function which is substituted for N-sulfate on the glucosamine. 

G. K. Hamer No, it is not. Using the educated eye (once you know its there in the A type) if you look at the B type very closely you see a tiny peak in the same position. If you look at the 220 MHz proton spectrum it is much more obvious. There is a very small amount in the bovine. The main differences between the two sources are a) N-acetyl substitution for N-sulfate and b) the change in uronic acid. 

VD Nadkami, T Toida, CL Van Gorp, TL Schubert, JM Weiler, KP Hanse, EEO Caldwell, RJ Linhardt. Preparation and biological activity of N-sulfated chondroitin sulfate derivatives. Carbohydr Res 290 87—96, 1996. 

A freshman chemist analyzed a sample of copper(n) sulfate pentahydrate for water of hydration by weighing the hydrate, heating it to convert it to anhydrous copper(II) sulfate, and then weighing the anhydrate. The % H2O was determined to be 30.%. The theoretical value is 33%. Which of the following choices is definitely NOT the cause of the error ... 

While the size requirement for SMC antiproliferative activity had been investigated for heparin (cf. Sect. 2.2), a similar study on fractions of highly active heparan sulfate has not been carried out After the discovery of active sulfated tetrasaccharides it seemed possible that relatively small heparan sulfate substructures with the antiproliferative activity of heparin could be identified. Model heparan sulfate oligosaccharides were devised in which the N-sulfate groups were replaced by O-sulfates and the glucuronic acids were replaced by glucoses, formally carboxyl-reduced and sulfated glucuronic acids - in parallel to CRS-heparin (see above). With this approach the heparan sulfate backbone... 

Four enzymatic steps are necessary for removal of N-sulfated or N-acetylated glucosamine residues from heparan sulfate ... 

---