No abstract

FR901459, a novel immunosuppressant, has been isolated from the fermentation broth of Stachybotrys chartarum No. 19392. The molecular formula of FR901459 was determined as C62HuiN11O13. FR901459 was found to be a member of the cyclosporin family. However, it is structurally distinct from any other cyclosporins discovered so far, in that Leu is present at position 5 instead of Val. FR901459was capable of prolonging the survival time of skin allografts in rats with one third the potency of cyclosporin A.

Succinoglycan samples ranging in weight-average molecular weight from 1.0 x 10(5) to 8.7 x 10(6) (in 0.1 M aqueous NaCl at 25 degrees C), prepared by ultrasonication of a native sample (Rheozan), followed by fractionation, were investigated by static light scattering, sedimentation equilibrium, and viscometry in 0.1 M aqueous NaCl at 25 degrees C where the polysaccharide assumes a certain ordered (helical) conformation. The measured radii of gyration and intrinsic viscosities showed the polysaccharide to behave like a semirigid chain in the aqueous salt. Their analysis based on the unperturbed wormlike chain yielded about 1500 nm-1 and 50 nm for the linear mass density and the persistence length, respectively. The former value was almost twice that expected for the single succinoglycan molecule, and thus it was concluded that the predominant molecular species of succinoglycan present in the aqueous salt is a double helix or an aggregate composed of paired single helices.

No abstract

Model food advanced glycation end products (AGEs) were prepared as glycated casein (GC) and glycated soy protein (GS) by the reaction of casein or soy protein with glucose at 50 degrees C, relative humidity 75% for seven days in a powder state. These browned proteins were used as materials for animal experiments. A mixture of 20% glycated proteins (GC:GS = 1:1) diet was fed to streptozotocin (STZ)-diabetic rats for 11 weeks. The results showed that: (1) fructoselysine was observed in the hepatic portal veins, arteries, and femoral veins of rats fed with glycated proteins after 2 h of feeding; (2) blood sugar of glycated protein-fed rats was lower than that of diabetic rats fed with intact protein, while HbA1C in blood and glucose in urine of both groups were similar; (3) lipid peroxidation status in serum, liver, and kidney of both groups was similar; (4) superoxide dismutase (SOD) and glutathione-S-transferase (GST) enzymatic activity in serum and liver of both groups were also similar; (5) there were no differences in degree of cataract formation and concentration of glucose, fructose, sorbitol, and lipid peroxide in the lenses of both groups. From the above results, it can be estimated that food AGEs are not toxic in biological systems, and reactive oxygen species increase in diabetic rats is not caused by glycated proteins but by other pathways.