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Bioresource Technology Feb 2022Sugar alcohols are widely marketed compounds. They are useful building block chemicals and of particular value as low- or non-calorigenic sweeteners, serving as sugar... (Review)
Review
Sugar alcohols are widely marketed compounds. They are useful building block chemicals and of particular value as low- or non-calorigenic sweeteners, serving as sugar substitutes in the food industry. To date most sugar alcohols are produced by chemical routes using pure sugars, but a transition towards the use of renewable, non-edible feedstocks is anticipated. Several yeasts are naturally able to convert renewable feedstocks, such as lignocellulosic substrates, glycerol and molasses, into sugar alcohols. These bioconversions often face difficulties to obtain sufficiently high yields and productivities necessary for industrialization. This review provides insight into the most recent studies on utilizing yeasts for the conversion of renewable feedstocks to diverse sugar alcohols, including xylitol, erythritol, mannitol and arabitol. Moreover, metabolic approaches are highlighted that specifically target shortcomings of sugar alcohol production by yeasts from these renewable substrates.
Topics: Erythritol; Glycerol; Sugar Alcohols; Xylitol; Yeasts
PubMed: 34798255
DOI: 10.1016/j.biortech.2021.126296 -
Caries Research 2004The most widely used sugar alcohols are: xylitol, sorbitol, mannitol, maltitol, lactitol and the products Lycasin and Palatinit. It is often claimed that xylitol is... (Review)
Review
The most widely used sugar alcohols are: xylitol, sorbitol, mannitol, maltitol, lactitol and the products Lycasin and Palatinit. It is often claimed that xylitol is superior to the other sugar alcohols for caries control. This paper examines clinical studies on the caries-preventive and therapeutic effects of sugar alcohols with emphasis on sorbitol and xylitol. It is concluded that chewing sugar-free gum 3 or more times daily for prolonged periods of time may reduce caries incidence irrespective of the type of sugar alcohol used. It may be sufficient to do this only on school days. Sucking xylitol-containing candies or tablets may have a similar effect as chewing xylitol chewing gum. Clinical trials suggest greater caries reductions from chewing gums sweetened with xylitol than from gums sweetened with sorbitol. However, the superiority of xylitol was not confirmed in 2 out of 4 clinical trials comparing the caries-preventive effect of xylitol- with sorbitol-sweetened gums. The caries-preventive effects of polyol-containing gums and candies seem to be based on stimulation of the salivary flow, although an antimicrobial effect cannot be excluded. There is no evidence for a caries-therapeutic effect of xylitol. These conclusions are in line with those of recent reviews and with the conclusions of the Scientific Committee on Medicinal Products and Medical Devices of the EU Commission.
Topics: Candy; Cariostatic Agents; Chewing Gum; Clinical Trials as Topic; Dental Caries; Dental Plaque; Humans; Streptococcus mutans; Sugar Alcohols; Sweetening Agents; Tooth Remineralization
PubMed: 15153702
DOI: 10.1159/000077768 -
Life (Basel, Switzerland) Aug 2018Carbonaceous meteorites provide the best glimpse into the solar system's earliest physical and chemical processes. These ancient objects, ~4.56 billion years old,... (Review)
Review
Carbonaceous meteorites provide the best glimpse into the solar system's earliest physical and chemical processes. These ancient objects, ~4.56 billion years old, contain evidence of phenomena ranging from solar system formation to the synthesis of organic compounds by aqueous and (likely) low-temperature photolytic reactions. Collectively, chemical reactions resulted in an insoluble kerogen-like carbon phase and a complex mixture of discrete soluble compounds including amino acids, nucleobases, and monosaccharide (or "sugar") derivatives. This review presents the documented search for sugars and their derivatives in carbonaceous meteorites. We examine early papers, published in the early 1960s, and note the analytical methods used for meteorite analysis as well as conclusions on the results. We then present the recent finding of sugar derivatives including sugar alcohols and several sugar acids: The latter compounds were found to possess unusual "d" enantiomeric (mirror-image) excesses. After discussions on the possible roles of interstellar grain chemistry and meteorite parent body aqueous activity in the synthesis of sugar derivatives, we present a scenario that suggests that most of Earth's extraterrestrial sugar alcohols (e.g., glycerol) were synthesized by interstellar irradiation and/or cold grain chemistry and that the early solar disk was the location of the initial enantiomeric excesses in meteoritic sugar derivatives.
PubMed: 30150578
DOI: 10.3390/life8030036 -
Scientific Reports Jul 2019Clinical imaging is widely used to detect, characterize and stage cancers in addition to monitoring the therapeutic progress. Magnetic resonance imaging (MRI) aided by...
Clinical imaging is widely used to detect, characterize and stage cancers in addition to monitoring the therapeutic progress. Magnetic resonance imaging (MRI) aided by contrast agents utilizes the differential relaxivity property of water to distinguish between tumorous and normal tissue. Here, we describe an MRI contrast method for the detection of cancer using a sugar alcohol, maltitol, a common low caloric sugar substitute that exploits the chemical exchange saturation transfer (CEST) property of the labile hydroxyl group protons on maltitol (malCEST). In vitro studies pointed toward concentration and pH-dependent CEST effect peaking at 1 ppm downfield to the water resonance. Studies with control rats showed that intravenously injected maltitol does not cross the intact blood-brain barrier (BBB). In glioma carrying rats, administration of maltitol resulted in the elevation of CEST contrast in the tumor region only owing to permeable BBB. These preliminary results show that this method may lead to the development of maltitol and other sugar alcohol derivatives as MRI contrast agents for a variety of preclinical imaging applications.
Topics: Algorithms; Animals; Blood-Brain Barrier; Brain Neoplasms; Contrast Media; Disease Models, Animal; Female; Glioma; Image Interpretation, Computer-Assisted; Magnetic Resonance Imaging; Maltose; Phantoms, Imaging; Rats; Rats, Inbred F344; Sugar Alcohols
PubMed: 31366892
DOI: 10.1038/s41598-019-47275-5 -
Chemical Reviews Oct 2016Biomass has been long exploited as an anthropogenic energy source; however, the 21st century challenges of energy security and climate change are driving resurgence in... (Review)
Review
Biomass has been long exploited as an anthropogenic energy source; however, the 21st century challenges of energy security and climate change are driving resurgence in its utilization both as a renewable alternative to fossil fuels and as a sustainable carbon feedstock for chemicals production. Deconstruction of cellulose and hemicellulose carbohydrate polymers into their constituent C and C sugars, and subsequent heterogeneously catalyzed transformations, offer the promise of unlocking diverse oxygenates such as furfural, 5-hydroxymethylfurfural, xylitol, sorbitol, mannitol, and gluconic acid as biorefinery platform chemicals. Here, we review recent advances in the design and development of catalysts and processes for C-C sugar reforming into chemical intermediates and products, and highlight the challenges of aqueous phase operation and catalyst evaluation, in addition to process considerations such as solvent and reactor selection.
Topics: Acids; Alkalies; Catalysis; Furaldehyde; Gluconates; Hexoses; Isomerism; Oxidation-Reduction; Pentoses; Sugar Alcohols
PubMed: 27680093
DOI: 10.1021/acs.chemrev.6b00311 -
Magyar Onkologia Dec 2017The present review about the history of anticancer drug research in Hungary intends to call attention to the importance of studies on their mode of action. Several lines... (Review)
Review
The present review about the history of anticancer drug research in Hungary intends to call attention to the importance of studies on their mode of action. Several lines of evidence suggest that clinically usable oncopharmacological properties could be revealed by this way. Among the numerous compounds certain alkylating sugar alcohols and 2'-deoxyuridine derivatives were submitted to detailed investigations concerning their mode of action. Myelobromol with selective action on the myeloid elements of bone marrow has been justified for its application in chronic myeloid leukemia therapy and also in bone marrow ablation before transplantation. Mitolactol is able to cross bloodbrain barrier, consequently could control certain brain tumors. 5-etil-2'-deoxyuridine by reducing dihydropyrimidine dehydrogenase activity is able to increase 5-fluorouracil concentration in the blood, resulting in improved antitumor effect. In contrast, 5-hexil-2'-deoxyuridine, as an inhibitor of glycoconjugate pathway by reducing heparan sulfate production, has the ability to prevent metastasis. Noteworthy, the remarkable effects of vinca alkaloids, antiestrogens, and GNRH analogues were also presented in this review.
Topics: Antineoplastic Agents, Alkylating; Databases, Factual; Drug Design; Forecasting; Humans; Hungary; Mannomustine; Mitobronitol; Mitolactol; Pharmaceutical Research; Pharmacology, Clinical; Quality Improvement; Retrospective Studies
PubMed: 29257158
DOI: No ID Found -
International Journal of Molecular... Jul 2023Drought stress is a major threat to sustainable crop production worldwide. Despite the positive role of calcium (Ca) in improving plant drought tolerance in different...
Drought stress is a major threat to sustainable crop production worldwide. Despite the positive role of calcium (Ca) in improving plant drought tolerance in different crops, little attention has been paid to its role in mitigating drought stress in potatoes. In the present study, we studied the effect of foliar chelated sugar alcohol calcium treatments on two potato cultivars with different drought responses applied 15 and 30 days after limiting soil moisture. The results showed that the foliar application of calcium treatments alleviated the SPAD chlorophyll loss of the drought-sensitive cultivar 'Atlantic' (Atl) and reduced the inhibition of photosynthetic parameters, leaf anatomy deformation, and MDA and HO content of both cultivars under drought stress. The Ca treatments changed the expression of several () genes involved in calcium sensing and signaling and significantly increased antioxidant enzyme activities, average tuber weight per plant, and tuber quality of both cultivars. We conclude that calcium spray treatments improved the drought tolerance of both potato cultivars and were especially effective for the drought-sensitive cultivar. The present work suggests that the foliar application of calcium is a promising strategy to improve commercial potato yields and the economic efficiency of potato production under drought stress conditions.
Topics: Solanum tuberosum; Calcium; Droughts; Sugar Alcohols; Hydrogen Peroxide; Photosynthesis
PubMed: 37569590
DOI: 10.3390/ijms241512216 -
Journal of Nutritional Science and... 2022Allitol is a rare sugar alcohol obtained by reducing d-allulose (d-psicose). However, information on the effects of long-term dietary allitol intake is limited. This...
Allitol is a rare sugar alcohol obtained by reducing d-allulose (d-psicose). However, information on the effects of long-term dietary allitol intake is limited. This study aimed to investigate the effect of allitol supplementation, as a sugar substitute, on body fat accumulation in rats compared with sucrose, rare sugar d-allulose, or erythritol. Thirty-two male Wistar rats (3 wk old) were fed experimental diets including 5% sucrose, allitol, erythritol, or d-allulose for 8 wk ad libitum. Weight gain, food intake, and food efficiency did not differ among the groups. The total body fat mass and percentage, and intra-abdominal adipose tissue weights were significantly lower in rats fed with the allitol diet than in those fed with the sucrose diet. These body fat indicators tended to be lower in rats fed with the erythritol and d-allulose diets than in those fed with the sucrose diet, but there was no significant difference. The serum glucose-lowering effect obtained in rats fed with the d-allulose diet did not appear in rats fed with the allitol diet. These results suggest that the anti-obesity effect of allitol may be equal to or greater than that of d-allulose.
Topics: Adipose Tissue; Animals; Body Weight; Diet; Dietary Fats; Erythritol; Male; Rats; Rats, Wistar; Sucrose; Sugar Alcohols
PubMed: 36047107
DOI: 10.3177/jnsv.68.348 -
Metabolic Engineering Jul 2022Cupriavidus necator H16 is one of the most researched carbon dioxide (CO)-fixing bacteria. It can store carbon in form of the polymer polyhydroxybutyrate and generate...
Cupriavidus necator H16 is one of the most researched carbon dioxide (CO)-fixing bacteria. It can store carbon in form of the polymer polyhydroxybutyrate and generate energy by aerobic hydrogen oxidation under lithoautotrophic conditions, making C. necator an ideal chassis for the biological production of value-added compounds from waste gases. Despite its immense potential, however, the experimental evidence of C. necator utilisation for autotrophic biosynthesis of chemicals is limited. Here, we genetically engineered C. necator for the high-level de novo biosynthesis of the industrially relevant sugar alcohol mannitol directly from Calvin-Benson-Bassham (CBB) cycle intermediates. To identify optimal mannitol production conditions in C. necator, a mannitol-responsive biosensor was applied for screening of mono- and bifunctional mannitol 1-phosphate dehydrogenases (MtlDs) and mannitol 1-phosphate phosphatases (M1Ps). We found that MtlD/M1P from brown alga Ectocarpus siliculosus performed overall the best under heterotrophic growth conditions and was selected to be chromosomally integrated. Consequently, autotrophic fermentation of recombinant C. necator yielded up to 3.9 g/L mannitol, representing a substantial improvement over mannitol biosynthesis using recombinant cyanobacteria. Importantly, we demonstrate that at the onset of stationary growth phase nearly 100% of carbon can be directed from the CBB cycle into mannitol through the glyceraldehyde 3-phosphate and fructose 6-phosphate intermediates. This study highlights for the first time the potential of C. necator to generate sugar alcohols from CO utilising precursors derived from the CBB cycle.
Topics: Biosensing Techniques; Carbon Dioxide; Cupriavidus necator; Mannitol; Phosphates
PubMed: 35149227
DOI: 10.1016/j.ymben.2022.02.003 -
Cancers Feb 2020The major risk factors for hepatocellular carcinoma (HCC) are hepatitis C and B viral infections that proceed to Chronic Liver Disease (CLD). Yet, the early diagnosis...
The major risk factors for hepatocellular carcinoma (HCC) are hepatitis C and B viral infections that proceed to Chronic Liver Disease (CLD). Yet, the early diagnosis and treatment of HCC are challenging because the pathogenesis of HCC is not fully defined. To better understand the onset and development of HCC, untargeted GC-TOF MS metabolomics data were acquired from resected human HCC tissues and their paired non-tumor hepatic tissues ( = 46). Blood samples of the same HCC subjects ( = 23) were compared to CLD ( = 15) and healthy control ( = 15) blood samples. The participants were recruited from the National Liver Institute in Egypt. The GC-TOF MS data yielded 194 structurally annotated compounds. The most strikingly significant alteration was found for the class of sugar alcohols that were up-regulated in blood of HCC patients compared to CLD subjects ( < 2.4 × 10) and CLD compared to healthy controls ( = 4.1 × 10). In HCC tissues, sugar alcohols were the most significant ( < 1 × 10) class differentiating resected HCC tissues from non-malignant hepatic tissues for all HCC patients. Alteration of sugar alcohol levels in liver tissues also defined early-stage HCC from their paired non-malignant hepatic tissues ( = 2.7 × 10). In blood, sugar alcohols differentiated HCC from CLD subjects with an ROC-curve of 0.875 compared to 0.685 for the classic HCC biomarker alpha-fetoprotein. Blood sugar alcohol levels steadily increased from healthy controls to CLD to early stages of HCC and finally, to late-stage HCC patients. The increase in sugar alcohol levels indicates a role of aldo-keto reductases in the pathogenesis of HCC, possibly opening novel diagnostic and therapeutic options after in-depth validation.
PubMed: 32092943
DOI: 10.3390/cancers12020484