Galactose solution preparation

Autoclavable sugars Glucose (dextrose) and galactose are prepared as a 2% (wt/vol) solution in yeast extract broth described above. When fully solubilized, transfer 10 mL to capped test tubes. 

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. 

Lactosone was first prepared by the hydrochloric acid decomposition of the phenylosazone,1 although it had been noted that, in acid solutions, lactose phenylosazone forms an anhydride.197 Since its discovery,17 the benzaldehyde method has usually been employed,6-10-28 because it avoids the risks of osone hydrolysis and of alteration to the osazone. Lactosone is hydrolyzed by hot, dilute, mineral acid to D-glucosone and D-galactose.1-6 It reacts with cyanide to form an analog of iminoascorbic acid which, on acid treatment, is converted into a mixture of D-glucoascorbic acid and D-galactose.10... 

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. 

Bierenstiel and Schlaf [22] were able to prepare and isolate for the first time the less stable 8-D-galactonolactone by oxidation of galactose with the Schvo s catalytic system, which is based on the dimeric ruthenium complex [(C4Pli4CO)(CO)2Ru]2. The transformation led to the 5-galactonolactone in 93% yield, against 7% of the isolated y-lactone isomer. This procedure also allowed the preparation of 5-D-man-nonolactone in a much better yield (94%) than that reported in an early procedure [23] based on crystallization from a solution of calcium mannonate in aqueous oxahc acid. 

Figure 4. Gas chromatogram of TMSi derivatives prepared from an aqueous equilibrium solution of glucose and galactose. The column was 2.5% SE-30, isothermal at 160°. Gal = galactose glu = glucose.

The experiments were repeated under similar conditions with the same and another mannanase fraction of Yamazaki s, with sprucewood holocellulose prepared in a slightly different way (19). After three weeks incubation, about 19% of the mannan was dissolved away, and the loci of hemicellulose removal were revealed by electron microscopy. In these experiments, the bulk of hemicelluloses was obviously removed by the buffer solution. In addition to mannose, glucose and galactose derived from mannan, xylose and glucose were found in the reaction solutions in appreciable amounts. 

That both components were antibodies was established by agar diffusion tests with these preparations and solutions of the glycan performed in the usual manner. The results of the agar diffusion tests are shown in Figure 3, right plate. The two preparations of antibodies have been designated as anti-galactose (anti-gal) antibodies and anti-lactose (anti-lac) antibodies and some of the properties of the two sets of antibodies are described in a later section. 

The method of preparation was modified somewhat by Alexander, Dimler and Mehltretter, a product of higher purity thereby being obtained. For the pyrolytic vacuum distillation, the same apparatus was employed as for the preparation of levoglucosan and l,6-anhydro- 8-D-glucofuranose from starch. The use of an electrically heated jacket instead of a burner for heating the flask resulted in better control of the reaction. In addition, the dextrorotation of a solution of the sirupy distillate was about twice that reported by Hann and Hudson for their product from the same weight of galactose. 

---