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At least 19 recordsLinked to original sources
PubMed1975

Deoxyfluoroketohexoses: 4-deoxy-4-fluoro-D-sorbose and -tagatose and 5-deoxy-5-fluoro-L-sorbose.

4-Deoxy-4-fluoro-alpha-D-sorbose (6) was prepared in crystalline form by the action of potassium hydrogen fluoride on 3,4-anhydro-1,2-O-isopropylidene-beta-D-psicopyranose (3) followed by deacetonation. Under identical conditions, 3,4-anhydro-1,2-O-isopropylidene-beta-D-tagatopyranose (7) underwent epoxide migration to give 4,5-anhydro-1,2-O-isopropylidene-beta-D-fructopyranose (12), which after deacetonation yielded 4-deoxy-4-fluoro-D-tagatose (15) and 5-deoxy-5-fluoro-alpha-L-sorbopyranose (16), the latter as the crystalline, free sugar. The action of glycol-cleavage reagents on the isopropylidene acetals of the deoxyfluoro sugars was consistent with the assigned structures. The structures were established by 13-C n.m.r. studies of the free deoxyfluoro sugars 6 and 16 and of the isopropylidene acetal 13, and by 1-H n.m.r. studies on the acetylated isopropylidene acetals 5 diacetate, 13 diacetate, and 14 diacetate. 5-Deoxy-5-fluoro-L-sorbose (16) was biologically active, producing in mice effects characteristic of deoxyfluorotrioses and of fluoroacetate. 4-Deoxy-4-fluoro-D-tagatose (15) and 4-deoxy-4-fluoro-D-sorbose (6) produced no apparent effects in mice up to a dose of 500mg/kg. The implications of these findings with respect to transport, phosphorylation, and the action of aldolase on ketohexoses are discussed.

Antineoplastic Agents↗
PubMed1977

[Researches to the conversion of sorbit into sorbose by Acetobacter suboxydans (author's transl)].

The production of sorbose by Acetobacter suboxydans (4) is closely related to the concentration of sorbit in the medium. An increasing concentration of sorbit gives rise to the inhibition of cell reproduction; followed by a decrease of sorbose content in the culture medium. The decrease of sorbose yield in concentrations of about 15% sorbit in medium indicates the decreasing metabolism rate of the total population of Acetobacter suboxydans (4) culture and does not refer to the ability of the individual bacterium cell to produce sorbose. Relevant research work showed, that sorbose production for each bacterium cell distinctly increased with the decrease of the number of cells in a population of Acetobacter suboxydans (4) as a consequence of the application of an increased sorbit concentration. An unrestrained reproduction of bacteria could be obtained by exluding all factors involved in the contamination of sorbit and exhibiting toxic effects. Therefore the organisms could be offered a greater concentration of sorbit for conversion into sorbose. Thus sorbose yield would be increased, respectively. The total conversion of the C-source into sorbose could not be obtained with Acetobacter ruboxydans (4).

Acetobacter↗
PubMed1977

[Effects of dimethylsulfoxide and salicine on the delayed adaption on sorbose and dulcitol of Salmonellae (author's transl)].

Among the majority of Salmonella strains splitting sorbose or dulcitol with delay dimethylsulfoxide shortens the latent period preceding acid formation and abolishes the deceleration of sorbose adaption caused by salicine. In other strains, especially S. paratyphi B cultures, DMSO doesn't touch sorbose adaption directly but amplifies the restraing effect of salicine. From the whole of our findings it can be concluded that in the first group of strains sorbose adaption starts with segregation of adaptive sorbose permease positive mutants, followed by the - salicin-sensitive - induction of this permease, the appearance of mutants aditionally metabolizing sorbose constitutively, and, finally, the substrate-promoted particular growth of adapted cells. The latter category of strains, however, apparently possesses a wild type (constitutive or adaptive?) sorbose permease but splits off mutants with adaptive metabolizing enzymes the induction of which is salicine-sensitive. The amplification of the salicine effect by DMSO found in these strains might be refered to an enhancement of salicine uptake caused by DMSO.

Adaptation, Physiological↗
PubMed1976

L-Sorbose metabolism in Agrobacterium tumefaciens.

The pathway of L-sorbose metabolism in Agrobacterium tumefaciens strain B6 was determined to be: L-sorbose leads to D-glucitol (sorbitol) leads to D-fructose leads to D-fructose-6-phosphate leads to D-glucose-6-phosphate. The reduction of L-sorbose and the oxidation of D-glucitol were mediated by NADPH- and NAD+-linked oxidoreductases, respectively. The intermediates, D-glucitol and D-fructose, were isolated from in vitro reaction mixtures by column chromatography on Dowex 1-borate, and identified enzymatically. D-Fructose was identified chemically by its 1H-NMR spectrum and the IR spectrum and the melting point of the fructosazone. D-Glucitol was characterized chemically by the melting point and the IR spectrum of its hexaacetate. A. tumefaciens ICPB TT111, a representative of another genetic race of Agrobacterium, lacked L-sorbose reductase and therefore failed to grow on L-sorbose; it grew normally on D-glucitol.

Alcohol Oxidoreductases↗
PubMed1979

Metabolism of L-sorbose in the rat and the effect of the intestinal microflora on its utilization both in the rat and in the human.

L-[U-14C]-sorbose was administered orally as single doses to 5 normal rats. The recovery of radioactivity was 5.3% in the urine, 46% in the faeces exclusively as L-sorbose 16% as carbon dioxide. Caloric utilization was approximately 25%. A second group of 3 rats that had previously received L-sorbose in their diet showed 14C recoveries of 8.9% in the urine, 6.6% in the faeces and 59% as carbon dioxide. The time course of expired carbon dioxide suggests that a portion of L-sorbose was rapidly absorbed and partially metabolized while the principal pathway involved fermentation by the intestinal microflora to volatile fatty acids which were subsequently absorbed and metabolized. The total caloric utilization of L-sorbose was estimated to be 70%. It was observed that a human intestinal microflora also required an adaptation period in order to ferment this sugar. The efficiency of the fermentation was estimated to be 70%.

Administration, Oral↗
PubMed1975

Lipid-protein interactions at the erythrocyte membrane. Different influence of glucose and sorbose on membrane lipid transition.

When observed over a temperature range, erythrocyte membrane lipids undergo a transition at 18-20 degrees C (Zimmer, G. and Schirmer, H. (1974) biochim. Biophys. Acta 345, 314-320). This observation has prompted an investigation of the effects that substrate binding has on the transition of the red cell membrane. Glucose and sorbose were compared, since transport kinetics of these sugars still pose unresolved questions. In membranes, preloaded with glucose, the break at the transition temperature was intensified, while it was abolished or reversed in membranes preloaded with sorbose. These results were corroborated using different solubilization procedures (sonication, sodium dodecyl sulfate treatment) of the membranes, and also different techniques (viscosimetry, 90 degrees light scattering, 1-anilino-naphthalene-8-sulfonate fluorescence). In extracted membrane lipids, viscosimetry indicated a break at transition temperature after preloading with either glucose or sorbose. Disc electrophoresis revealed a different binding pattern of the two sugars. It is suggested, that the amplification of the discontinuity in red cell membranes by glucose and the abolition or reversal of the break by sorbose are mediated by membrane protein- and/or membrane lipid-protein interaction.

Blood Proteins↗
PubMed1976

[Sorbose in Salmonella diagnosis (author's transl)].

From 1525 Salmonella strains checked for fermentation of sorbose the majority failed to attack this sugar or split it with distinct delay. None of these cultures showed production of acid from sorbose prior to the third day of incubation. In contrast, sorbose was attacked within 24 hours by 74 out of 100 Ballerup-Bethesda strains. As an easy and reliable basis test combination for performing a minimal biochemical Salmonella diagnosis a series consisting of Kligler's medium and media containing urea, lysine, lactose, sucrose, sorbose, and salicin is suggested.

Salmonella↗
PubMed1978

Inhibition of glycolysis by L-sorbose in dog erythrocytes.

We have demonstrated previously that in vitro L-sorbose acts directly on dog erythrocytes to induce hemolysis. Here we report that L-sorbose depresses lactate formation in dog hemolysates from glucose, mannose and fructose but not from glucose-6-phosphate and galactose, suggesting that L-sorbose interacts with glycolysis at the level of the hexokinase.

Animals↗
PubMed1977

Active transport of L-sorbose and 2-deoxy-D-galactose in Saccharomyces fragilis.

Sorbose and 2-deoxy-D-galactose are taken up in Saccharomyces fragilis by an active transport mechanism, as indicated by the energy requirement of the process and the accumulation of free sugar against the concentration gradient. There are no indications for transport-associated phosphorylation as mechanism of energy coupling with these two sugars. The measured sugar-proton cotransport and the influx inhibition by uncouplers suggest a chemiosmotic coupling mechanism. Thus there are at least two different active transport mechanisms operative in Saccharomyces fragilis: transport-associated phosphorylation in the case of 2-deoxy-D-glucose and chemiosmotic coupling in the case of sorbose and 2-deoxy-D-galactose. The differences between the two mechanisms are discussed. Uncouplers do not stimulate downhill sorbose transport in energy-depleted cells and evoke an almost complete inhibition of efflux and of exchange transport. The differences between this sugar-proton cotransport system and similar systems in bacteria and Chlorella are discussed.

Adenosine Triphosphate↗
PubMed1976

Surface tension activity and paramorphogenic effect of sorbose, sodium desoxycholate, and griseofulvin on the growth of colonies of Chaetomium aureum Chivers.

Sorbose at 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, and 1.0% levels, sodium-desoxycholate at 0.025, 0.050, 0.075, 0.1 and 0.125% levels, and griseofulvin at 0.001, 0.002, 0.003, 0.004, 0.005, 0.006, 0.007, 0.008, 0.009, and 0.010% levels restrict the growth of colonies of Chaetomium aureum, both at pH 6.5 and 7.0. Restriction of colonies was most effective with 0.7% sorbose, 0.1% sodium-desoxycholate, and 0.006% griseofulvin in the medium adjusted to pH 6.5. Surface tension activity of sorbose, sodium-desoxycholate, and griseofulvin in different concentrations was determined, following the usual standard method.

Ascomycota↗
PubMed1976

Studies on cyclodextrin glycosyltransferase. IV. Enzymatic synthesis of 3-O-alpha-D-glucopyranosyl-L-sorbose and 4-O-alpha-D-glucopyranosyl-D-xylose using cyclodextrin glycosyltransferase.

The acceptor specificity of the transglycosylation reaction of cyclodextrin glycosyltransferase[EC 2.4.1.19] was investigated using various sugars and sugar alcohols. L-Sorbose, D-xylose, and D-galactose, which contain configurational or structural changes relative to the D-glucopyranose unit at positions other than position 1, were also shown to be efficient acceptors in the transglycosylation reaction of this enzyme. It was shown by chemical and enzymatic methods that this enzyme could transfer glycosyl residues only to the C3-hydroxyl group of L-sorbose and C4-hydroxyl group of D-xylose, producing oligosaccharides terminated by 3-O-alpha-D-glucopyranosyl-L-sorbose and 4-O-alpha-D-glucopyranosyl-D-xylose at the reducing ends, respectively.

Acetates↗
PubMed1978

[The influence of non-metabolizable alpha- and beta-glycosides on the regulation of sorbose fermentation of salmonellae (author's transl)].

Fermentation of sorbose by late positive Salmonella wildtype cultures and by mutant strains splitting this sugar promptly is restrained by the beta-glucoside salicine and likewise by 1-o-methyl-alpha-D-glucopyranoside (MGP), but is not influenced by lactose or sucrose. In growing cultures salicine works more powerful on sorbose utilization than MGP while in dense suspensions of non-multiplying bacteria the relations are reversed. Among the majority of wildtype strains this suppressive effect is diminished or abolished by dimethylsulfoxide (DMSO), but there are strains in which the glucoside effect is enhanced by DMSO. The sorbose fermentation lag in the presence of salicine or MGP is detectable, too, in dense suspensions of promptly splitting Salmonella mutant strains in media poorly supplied with nitrogen and must therefore be attributed to a non-mutative event. From prior work (Stenzel, 1977c) we got some evidence that this event might depend on an inhibition of enzyme induction. Targets and mode of action of the alpha- and beta-glucoside largely seem to be identical, though possibly there might exist minor differences.

Benzyl Alcohols↗
PubMed1975

Stimulation by organic solvents and detergents of conversion of L-sorbose to L-sorbosone by Gluconobacter melanogenus IFO 3293.

Treatment of Gluconobacter melanogenus IFO 3293 cells with benzene, carbon tetrachloride, cyclohexane, deoxycholate, toluene, or xylene stimulated their conversion of L-sorbose to L-sorbosone two- to threefold. The degree of stimulation depended upon the length of exposure time to the agent and the age of the G. melanogenus cells. A rapid decrease in viability of the cells and degradation of cell RNA was noted after treatment with the effective agents. The G. melanogenus cells were unable to absorb L-sorbose actively after toluene treatment.

Age Factors↗
PubMed1978

Hemolysis in vitro by sorbose, sorbitol and xylitol.

L-sorbose, xylitol and sorbitol solutions (56 mM) were not hemolytic when incubated with erythrocytes of 30 healthy volunteers, 14 thalassemic heterozygotes and in 30 horses, 30 cows and 30 Osborne-Mendel rats. Lysis of dog erythrocytes was most pronounced when incubated with L-sorbose but was also significant in xylitol and sorbitol solutions.

Animals↗
PubMed1975

The effect of sorbose on pH of mixed saliva and interproximal plaque.

Stimulated mixed saliva and interproximal plaque were exposed to the ketohexose sorbose. The average pH of an in vitro 1%-sorbose/saliva mixture increased with time when compared with a highly significant pH-decrease of a sucrose/saliva mixture. In contrast to sucrose rinses, the telemetrically recorded pH of interproximal plaque did not drop below pH 5.5 during and subsequent to rinsing with sorbose solutions.

Adult↗
PubMed1977

[Suppression of sorbose fermentation of Salmonellae by salicine (author's transl)].

Fermentation of sorbose by Salmonellae splitting this sugar with delay is restrained to a varying degree in presence of salicine, depending on the concentration of this glycoside. There is no support that salicine might become metabolized in this process. A similar salicine effect on the delayed fermentation of dulcitol has not been seen.

Fermentation↗