Three triterpenes and other terpenoids from Catha cassinoides

The investigation of stems and leaves of Catha cassinoides afforded, in addition to sitosterol, β-amyrin, ursolic acid, lup-20(29)-en-3β,30-diol and friedelin, three new pentacyclic triterpenes: 30-hydroxyfriedelan-3-one, 29-hydroxyfriedelan-3-one and 3-oxo-friedelan-29-oic acid. The structures ofthese were determined by spectral studies and correlations, and were confirmed by X-ray analysis of 29-hydroxyfriedelan-3-one acetate.     

Cellulolytic enzymes for the hydrolysis of leached beet cosette

Summary Cellulolytic fungi were isolated from rotting leaves and tested for extra-cellular cellulase activities (CMCase, avicelase, cellobiase and xylanase). The effect of the proportion of the enzyme activities on the rate of degradation of leached beet cosette was observed using a range of supernatant fluids in appropriate combinations. At low cosette concentrations (1.5–3.0 g/l), avicelase and cellobiase were the rate limiting enzymes; avicelase in the initial stages of reaction and cellobiase after 6–8 hours, when cellobiose inhibition becomes important. A ratio of celiobiase to avicelase of approx 2.0 was established as appropriate. At higher substrate concentrations (10 g/l, 40 g/l) the best cellobiase to avicelase ratio was maintained and up to 40% hydrolysis was obtained in the 10 g/l incubation with 10 Uav/l and 20 Ucellob/l. At 100 g/l cosette concentration, substrate inhibition was observed.     

Reactions between diglycolaldehyde dithioacetals and some nucleophiles

The homogeneous, neutral polysaccharide isolated from the crude polysaccharide of the fruit pulp from bael (Aegle marmelos) contains arabinose, galactose, and glucose in the molar ratios of 2:3:14. The linkages among the different monosaccharide residues were established through methylation analysis and Smith-degradation studies of the polysaccharide. The anomeric configurations of the different glycosyl groups were determined by study of the chromium trioxide oxidation of the acetylated polysaccharide. Results of these experiments have been discussed in order to assess the structure of the neutral polysaccharide.     

Effect of experimental diabetes on glycolytic intermediates and regulation of phosphofructokinase in rat lens

The pattern of glycolytic intermediates in the lens of alloxan-diabetic rats was indicative of regulation at phosphofructokinase. The changes in metabolites influencing phosphofructokinase activity in the diabetic, relative to the normal, rat lens were: glucose 6-phosphate, 182%; fructose 6-phosphate, 107%; fructose diphosphate, 57%. There was also a marked decrease in phosphoenolpyruvate, pyruvate, lactate and ATP but no significant change in other triose phosphates or cyclic AMP. The resuts are considered in relation to the early changes in [Ca²⁺] known to occur in lens in diabetes and to the coordinating effect of fructose diphosphate on flux through the glycolytic route.     

Intracellular (Golgi) receptors for insulinlike peptides in rat liver

An insulinlike peptide (ILAs) has been isolated in our laboratory from human serum. The binding of 123I-labeled ILAs was studied in subcellular fractions from rat liver and found to be much greater in microsomes than purified plasmalemma. The high level of microsomal binding was due to a particular enrichment of binding sites in Golgi elements. Binding to Golgi was time and temperature dependent and was augmented by an increase of either subcellular fraction or 125I-labeled ILAs in accordance with a mass action process. Degradation of 125I-labeled ILAs was greatest in the Golgi vesicle fraction and was reduced by incubation at 4 degrees C. Bound 125I-labeled ILAs could be eluted and was found to retain integrity. Binding was pH dependent with a broad optimum at pH 7.7-8.5. Dissociation of bound 125I-labeled ILAs was time and temperature dependent. It was greater at 37 than 4 degrees C, and was uninfluenced by unlabeled ILAs. The ILAs receptor was stable at 4 degrees C but was markedly decreased by preincubation at 37 degrees C. The binding of 125I-labeled ILAs was inhibited by unlabeled ILAs and related insulinlike peptides (the insulinlike growth factors, IGF-1 and IGF-2) in a dose-dependent manner. Insulin and its analogues had only a partially inhibitory effect, and structurally unrelated peptides were without inhibitory efficacy. In contrast ILAs and IGF-1 and IGF-2 inhibited 125I-labeled insulin binding to its receptors in a dose-dependent fashion. These observations identify a receptor for insulinlike peptides in the Golgi elements of rat liver. It is distinct from the insulin receptor previously observed in these elements. The dual interaction of ILAs and other insulinlike peptides with both the insulin receptor and their own unique receptor constitutes the presumed biochemical basis for the two types of action effected by this family of peptides, namely, an effect on metabolism comparable to insulin and an effect on cellular anabolism and growth.     

Babesia bigemina,Babesia argentina, and Anaplasma marginale: Coinfectious immunity in bovines

Forty-eight intact and eight splenectomized cattle were used to evaluate different systems of coinfectious immunization against Babesia bigemina, Babesia argentina, and Anaplasma marginale. Coinfectious immunity was induced by two methods: (1) blood of cattle acutely infected with B. bigemina, B. argentina and A. marginale was used as the source of inoculum and the post vaccination reactions were chemotherapeutically controlled with Imidocarb, Ganaseg, Gloxazone, and Liquamycin, and (2) by artificially inducing babesiosis with the blood of carrier cattle with chronic infections of B. bigemina and B. argentina without chemotherapy. The degree of resistance was determined by bloodborne and tick-borne challenges. Ticks were collected from cattle and identified as Boophilus microplus and Dermacentor nitens. Vaccinated cattle demonstrated a high degree of resistance to babesiosis and anaplasmosis; however, cattle without coinfectious immunity were treated chemotherapeutically to prevent death losses.