ABSTRACT Barley grain was divided into eight fractions from the surface layer to the center with a machine used to polish brewers' rice. Small‐, medium‐, and large‐granule starches were isolated from classified barley flour, and their physicochemical properties were investigated. The starch granules were oval to round with a median size of 2 μm for small, 10 μm for medium, and 12–19 μm for large granules. From the surface layer to the center, both the median sizes and the ratio of large granules decreased, and the ratio of medium‐ and small‐granules increased. The starches had A‐type X‐ray diffraction patterns typical of cereal starches. The moisture sorption showed a negative correlation to the granule size. The gelatinization temperatures of starch granules in each layer were approximately the same, but the enthalpies decreased in the order of large, medium, and small granules.
The purposes of this research were to separate constituent of kencur (Kaemferia galangal) essential oil and to evaluate their effects on rats by sniffing method. Separation of kencur essential oil by silica gel column chromatography resulted in 11 fractions and one pure compound. Based on GC-MS and NMR data, the pure compound was 2-propenoic acid, 3-(4-methoxyphenyl)-ethyl ester (EPMC) and fraction 2 consisted of δ-3-carene as a major component. Forty male Sprague-Dawley rats were divided into 5 groups, namely: normal group which consumed normal diet, negative control group which consumed high cholesterol diet without treatment, crude oil group, fraction 2 group and EPMC group which consumed high cholesterol diet with sniffing kencur crude oil, fraction 2 and EMPC, respectively. The results showed that the HDL, cholesterol and triglyceride levels in rat’s blood which sniffed the oils for 5 weeks were significantly different for each group (P<0.05). In conclusion, fraction 2 which consisted of δ-3-carene had slimming effect while kencur crude essential oil and EPMC decreased the cholesterol and triglyceride level in rats’ blood.
Differential scanning calorimetry was carried out to elucidate the properties of two metastable forms of chloramphenicol palmitate (δ form and sub-α form) and the occurrence and the role of the sub-α form during manufacturing of chloramphenicol palmitate oral suspension. The δ form, a new form, was obtained when the small amount of melted chloramphenicol palmitate was cooled very rapidly to below 0° and it was converted to the sub-α form at 23° on heating. The X-ray diffraction pattern of the δ form was distinguished from that of any other forms reported. The other form, sub-α, was obtained by warming the δ form or directly from the melt by rapid cooling. It was transformed to the α form while liberating heat from about 40° through about 75°. The X-ray diffraction pattern, infrared absorption spectra, the behavior in the hot stage of the polarizing microscope and the differential scanning calorimetric curves suggested that the sub-α form is composed of the crystallites of the α form. Estimated thermodynamic values at the 95% confidence limit were ; ΔHmelt→sub-α=-9.2±0.2kcal/mole, ΔHmelt→δ=-2.8±0.5 kcal/mole, ΔHδ→sub-a=-2.2±0.7 kcal/mole, and ΔHsub-α→α=-2.0±0.3 (the sub-α form directly form the melt) and -6.1±0.9 kcal/mole (the sub-α form via the δ form). The supercooled dispersion of chloramphenicol palmitate in the emulsifier solution turned into the suspension while stirring. The first solid state of the chloramphenicol palmitate was estimated to be the sub-α form and it was transformed to the α-form gradually.
SUMMARY: Glutathione reductase was purified to homogeneity from the unicellular alga Chlamydomonas reinhardtii. The enzyme was a monomer with a molecular mass of 54-56 kDa as judged by gel filtration and SDS-PAGE. The activity was maximal at pH 8.2 and 49 °C. The enzyme was specific for NADPH, but not for NADH. The reverse reaction with NAD(P)+ and GSH (glutathione, reduced form) was not observed in the pH range 4.8-8.2. K m values for NADPH and GSSG (glutathione, oxidized form) were 10.6 μ;m and 54.1 μ;M, respectively. Thiol inhibitors and metal ions such as Hg2+ and Cu2+ markedly inhibited the enzyme activity. Activity was lost when the apoenzyme was prepared by dialysis, but was restored to 40% of the original activity by the addition of 50 μ;M-FAD. The enzyme reaction proceeded via a branching mechanism. Upon immunoprecipitation, glutathione reductase activity of C. reinhardtii was inhibited 50% and 90% by antibodies generated against spinach and Euglena glutathione reductases, respectively. Both antibodies cross-reacted with C. reinhardtii glutathione reductase in an immunoblot analysis.
Rate constants for alkaline hydrolysis (in 0.1N NaOH) of aromatic amides such as nicotinamide, benzamide, phenylacetamide, cinnamamide, and their corresponding N-alkyl substituted analogs were determined at 25°and 90°in order to investigate the effect of molecular structure on the stability of these amides against hydroxyl ion attack. Stability constants of these aromatic amide complexes with theophylline and 8-methoxycaffeine at 25°were also computed from phase-solubility data. The results have shown that cinnamamides are most stable against hydroxyl ion attack and formed the most stable complexes with the alkylxanthines while phenylacetamides are least stable in alkaline hydrolysis and least associative with alkylxanthines among benzene derivatives. Both hydrolytic behavior and associative tendency of these amides are discussed in relation to the extent of conjugation of the amide group with the rest of the molecule.
