Isomaltose preparation

Agar-diffusion tests with the anti-isomaltose, myeloma protein and several dextran preparations showed that the protein does indeed combine with a number of dextrans. Results of gel electrophoresis of the sample showed that the purified myeloma protein consisted of several multimolecular forms.107 This observation is at variance with a report that the W3129 myeloma protein isolated from the same type of serum was homogeneous.168 Additional studies are needed in order to establish whether the anti-isomaltose, myeloma protein is synthesized as a homogeneous protein or in multimolecular form. 

Isolation of the myeloma protein that combines with isomaltose units of dextran was achieved by affinity chromatography, for which the pattern is shown in Fig. 28. The eluate obtained with isomaltose was collected, dialyzed, and then lyophilized. Diffusion in agar, performed by standard methods, showed that the preparation formed a precipitin with dextran (inset of Fig. 28). 

Some commercial, glucoamylase-containing preparations also contain a transglucosylase that catalyzes the formation of isomaltose. The net result is a lower degree of conversion of starch into D-glucose. Removal of the transglucosylase makes higher conversions possible. 

The unusual utility of this adsorbent has been demonstrated by its role in the preliminary isolation of isomaltose,maltotriose, maltotetra-086, = and panose > from the hydrolytic products of starch in the preparation of n-xylo-biose, -trio.se, -tetraose, -pentaose, -hexaose, and -heptaose from a partially hydrolyzed xylan in the resolution of bi-molecular dianhydrides of L-sorbose < and D-fructose < > in an improved procedure for the preparation of stachyose and in the preparation of a series of maltodextrins (as high as maltoheptaose) from the partial, acid... 

Wolfrom and coworkers85-88 prepared /S-isomaltose (40) and /3-gentio-biose octaacetates (6) in 55 and 6% yields, respectively, by the reaction of 3,4,6-tri-0-acetyl-2-0-nitro-/3-D-glucopyranosyl chloride (39)... 

The earlier preparations of isoamylase also hydrolyzed isomaltose and glycogen a-dextrins, but a separation of these activities and the isoamylase activity has been achieved. ... 

---