Galactose preparation

Test the purity of the galactose prepared by determining the specific rotation with a polarimeter. An aqueous solution containing one gramme of substance in 10 c.c. should have a rotation of +845° in a decimetre tube. Hence [a] °° = + 81-50. 

The products from the condensation of n-galactose with polyoxymethylene in the presence of phosphorus pentaoxide were reported as being a sirupy diacetal and a crystalline mono-O-methylene acetal, neither of which has been further investigated. A crystalline 6-O-acetyl-di-O-methylene-D-galactose, prepared by the single-stage procedure used for a similar de-... 

For sugars that can be autoclaved (e.g., glucose and galactose), prepare as 2% w/v solutions in the yeast extract broth and transfer 10mL to capped 18 X 150 mm test tubes. Insert a Durham tube open-side down into each tube, loosely replace the cap, and autoclave at 121 C/250 F for 15 min. 

D (+) Galactose is a constituent of numerous polysaccharides It is best obtained by acid hydrolysis of lactose (milk sugar) a disaccharide of d glucose and d galactose L (—) Galactose also occurs naturally and can be prepared by hydrolysis of flaxseed gum and agar The principal source of d (+) mannose is hydrolysis of the polysaccharide of the ivory nut a large nut like seed obtained from a South American palm... 

Deoxy-sugars. Part XVII. An Investigation of the Glycal Method for the Preparation of Derivatives of 2-Deoxy-D-galactose, W. G. Overend, F. Shafizadeh, and M. Stacey, /. Chem. Soc., (1951) 992-993. 

A number of complexes of copper with 1,1-dithiolenes are known they are interesting, inasmuch as they form (1) polynuclear species, e.g., [Cu4(i-mnt)3]2 . Recently, a copper(III) complex of 1,1-dicarboeth-oxy-2-ethylenedithiolate (DED ) was prepared (375) by oxidation of aqueous solutions of K2[Cu(DED)2] with a 10-15% excess of Cu(II) or H202, and of (BzPh3P)2[Cu(DED)2] with I2. The possibility of this system as a model for the Cu "/Cu. system in n-galactose oxidase has been pointed out. Lewis and Miller (113) also prepared M[Cu(S2C CHN02)2] (M = Cu, or Zn) and Cu[Cu S2C C(CN)2 2], and found that they are effective insecticides. 

Deoxy-2-[ F]fluoro-D-galactose can be prepared through an addition reaction to tri-O-acetyl-D-galactal (465), but better through Sn2 reaction (K F-Kryptofix 222 in MeCN) of methyl 3,4-0-isopropylidene-2-0-triflyl-6-0-trityl-y -D-talopyranoside (220 see Section 11,2), according to the cold synthesis. 

SPS could be degraded by the cruder, aaikalus preparation Pectinex Ultra-SP, giving a product consisting mostly of the monomeric sugars xylose, galactose, fucose, arabinose and... 

Figure 1. Effect of 1% (w/v) pectin (pect), 1% galactose (gal), and of the simultaneous presence of 2% glucose (glu) on the production of extracellular polygalacturonase activity. Two-stages cultures were prepared as described under methods. Polygalacturonase was assayed in the culture filtrate as reducing sugar-releasing activity using sodium polypectate as a substrate.

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