Frederick W. Parrish

A cross-polarization—magic-angle sample spinning n.m.r. study of several crystal forms of lactose

Abstract Five different crystalline forms of lactose were investigated by cross-polarization—magic-angle sample spinning (CP—MAS) 13 C-n.m.r. spectroscopy. Both the anhydrous β-lactose and the α-lactose monohydrate structures are known, and the CP—MAS n.m.r. data are in agreement with those structures. The structure of the stable, anhydrous α-lactose has not been reported. The CP—MAS n.m.r. results indicate that the crystal must have two or more lactose molecules per unit cell. The chemical shifts measured for two mixed crystals having α:β ratios of 5:3 and 4:1 are a direct observation of the fact that both materials are real mixed crystals rather than glasses or physical mixtures of crystals of pure α- and β-lactose. The chemical shifts also indicate that the lactose molecules in both mixed crystals are in environments similar to the crystalline environment of the stable, anhydrous α-lactose.

Effects of carbohydrate-structure changes on induced shifts in differential isotope-shift 13C-N.M.R.

Abstract Deuterium-induced, 13C-isotope shifts are shown to vary considerably from the initially predicted values calculated for ordinary pyranose and furanose sugars, when minor structural changes are introduced into the carbohydrate ring. Both substitution of C-OH groups or reduction of C-OH to CH2 permitted the evaluation of γ effects of OD without the contribution of β-OD-induced shifting. The observed γ-shift values for these modified structures were twice as large as those previously noted. This difference is most probably due to favored salvation. Substitution of OH at C-6 led to the predicted loss of differential isotope-shift (d.i.s.) at C-6 because of its isolation from all β and γ OD groups. The 31P resonances of d -glucose 6-phosphate show downfield deuterium shifts. Based on d.i.s. values, new 13C-shift assignments are proposed for isomaltose and 2-amino-2-deoxy-α- d -glucose. A study of acidic carbohydrates has demonstrated that isotope shifts are somewhat larger for sp2-hybridized carbon atoms whose OH groups are acidic. Relaxation times for sp2 carbon atoms isolated from dipolar interaction with protons were very long in D2O relative to their relaxation time in the H2O environment.

Treatment of Low-Tannin Sorghum Grain for Broiler Feed

A low-tannin grain sorghum was processed and formulated into 20 diets used in 2 trials to determine nutritional value of the grain. Sixteen hundred and forty newly-hatched broiler chicks were used in the feed study. Processing variables of the grain included the addition of α-amylase, β-glucanase, an enzyme blend (pigase) containing amylases, proteinases and cellulases, the treatment of abraded grain with gibberellic acid (GA3) and reconstituted grain (high-moisture storage). n nFeed consumption for Trial 1 was significantly greater (P 0.05). n nTrial 2 for 21-day-old chicks showed that the pelleted corn diet produced significantly higher body weight and significantly more feed consumed (P < 0.05) than any of the other diets. Feed efficiency was significantly lower (P < 0.05) for the pelleted corn diet. The remaining diets showed no statistically significant differences. After 28 days, the diet containing sorghum grain reconstituted for 21 days produced significantly lower body weights in the chicks. Generally, body weight was higher with the corn diets than with the untreated sorghum diets, and lowest with the reconstituted grain diets. The pelleted grain diets produced higher body weight than the same grain milled. Results show a reduction in tannin levels for the reconstituted low-tannin sorghum comparable to similar results obtained by other workers for high-tannin sorghum.

Hemagglutinins of some Aspergilli

Abstract Hemagglutinins for human red blood cells have been found in hot-water soluble mycelial extracts of a strain of Aspergillus flavus and two mutant strains of A. parasiticus . The agglutinin from one strain of A. parasiticus was specific for blood group A cells while the other two agglutinins were non-specific. With the A. flavus strain, the greatest hemagglutination activity (HA) was found at 10 days for the mycelial extract, and at 12 days for culture fluid preparations. More agglutinin was produced by fungi grown on sucrose than on d -glucose as carbon source. Solubilities in ammonium sulfate solutions and protein and carbohydrate analyses show that the agglutinins from the mycelial extract and culture fluid preparation are different. The mycelial agglutinin was inhibited by a number of different sugars, many of which possess common stereochemical features.