87-99-0 Usage
Uses
Used in Food Industry:
Xylitol is used as a sweetener and excipient in various food products, such as chewing gum, throat lozenges, and chocolate, due to its sweetness and cooling effect.
Used in Pharmaceutical Industry:
Xylitol is used as a polyol substrate for xylitol and sorbitol dehydrogenases, which are enzymes involved in the metabolism of these sugars.
Used in Dental Care:
Xylitol is used as an oral and intravenous nutrient, as well as in anticaries preparations, due to its ability to prevent tooth decay and promote oral health.
Used in Cosmetics Industry:
Xylitol is used as a humectant and skin-conditioning agent, acting as a humidifier by drawing moisture from the air for skin absorption. It is also known for its soothing and anti-microbial properties.
Used in Medical Research:
Xylitol is used as a substrate in the study of enzymes and metabolic pathways, contributing to the understanding of sugar metabolism and its role in various biological processes.
History
Xylitol is equally as sweet as sucrose. This property is of advantage to food processors because in reformulating a product from sucrose to xylitol, approximately the same amounts of xylitol can be used. Because xylitol has a negative heat of solution, the substance cools the saliva, producing a perceived sensation of coolness, quite desirable in some food products, notably beverages. Recently, this property has been used in an iced-teaflavored candy distributed in the European market. As of the late 1980s, 28 countries have ruled positively in terms of xylitol for use in commercial products. Xylitol has been found particularly attractive for use in chewing gum, mint and hard candies, and as a coating for pharmaceutical products. Xylitol has the structural formula shown below, with a molecular weight of 152.1. It is a crystalline, white, sweet, odorless powder, soluble in water and slightly soluble in ethanol and methanol. It has no optical activity.
Production Methods
Xylitol is synthesized by reduction of D-xylose catalytically, electrolytically, and by sodium amalgam. D-Xylose is obtained by hydrolysis of xylan [CAS: 9014-63-5] and other hemicellulosic substances obtained from such sources as wood, corn cobs, almond shells, hazelnuts, or olive waste. Isolation of xylose is not necessary; xylitol results from hydrogenation of the solution obtained by acid hydrolysis of cottonseed hulls. Xylitol also is obtained by sodium borohydride reduction of D-xylonic acid γ -lactone and from glucose by a series of transformations through diacetone glucose.
Production Methods
Xylitol occurs naturally in many fruits and berries, although
extraction from such sources is not considered to be commercially
viable. Industrially, xylitol is most commonly derived from various
types of hemicellulose obtained from such sources as wood, corn
cobs, cane pulp, seed hulls, and shells. These materials typically
contain 20–35% xylan, which is readily converted to xylose (wood
sugar) by hydrolysis. This xylose is subsequently converted to
xylitol via hydrogenation (reduction). Following the hydrogenation
step, there are a number of separation and purification steps that
ultimately yield high-purity xylitol crystals. The nature of this
process, and the stringent purification procedures employed, result
in a finished product with a very low impurity content. Potential
impurities that may appear in small quantities are mannitol,
sorbitol, galactitol, or arabitol.
Less commonly employed methods of xylitol manufacture
include the conversion of glucose (dextrose) to xylose followed by
hydrogenation to xylitol, and the microbiological conversion of
xylose to xylitol.
Biotechnological Production
Xylitol is mostly produced by chemical hydrogenation of xylose which is obtained
by hydrolysis of xylans of plants such as birch and beech trees, corn cobs, bagasse,
or straw, but also by fermentation of xylose, for example, using Candida species.
Xylose, especially for hydrogenation, requires a high purity. It may be obtained
from wood extracts or pulp sulfite liquor, a waste product of cellulose production,
by fermentation with a yeast that does not metabolize pentoses. Some strains of
S. cerevisiae, Saccharomyces fragilis, Saccharomyces carlsbergensis, Saccharomyces
pastoanus, and Saccharomyces marxianus are suitable for this purpose.
Hydrolysates of xylan-rich material are often treated with charcoal and ionexchangers
to remove by-products causing problems in hydrogenation or
fermentation.
Many studies of xylitol production by fermentation have been published.
Different organisms, substrates, and conditions were investigated. As the starting
material, xylose or xylose in combination with glucose was used. Fermentation
was carried out in batch reactors as well as continuously.
Among the variations studied was cell recycling in a submerged membrane
bioreactor for C. tropicalis with a high productivity of 12 g/Lh, a conversion rate
of 85 % and a concentration of 180 g/L. Many studies addressed the
immobilization of cells such as S. cerevisiae, C. guilliermondii, or
D. hansenii, especially with calcium alginate.
Flammability and Explosibility
Nonflammable
Pharmaceutical Applications
Xylitol is used as a noncariogenic sweetening agent in a variety of
pharmaceutical dosage forms, including tablets, syrups, and coatings.
It is also widely used as an alternative to sucrose in foods and
as a base for medicated confectionery. Xylitol is finding increasing
application in chewing gum, mouthrinses, and toothpastes
as an agent that decreases dental plaque and tooth decay (dental
caries). Unlike sucrose, xylitol is not fermented into cariogenic acid
end products and it has been shown to reduce dental caries by
inhibiting the growth of cariogenic Streptococcus mutans bacteria. As xylitol has an equal sweetness intensity to sucrose,
combined with a distinct cooling effect upon dissolution of the
crystal, it is highly effective in enhancing the flavor of tablets and
syrups and masking the unpleasant or bitter flavors associated with
some pharmaceutical actives and excipients.
In topical cosmetic and toiletry applications, xylitol is used
primarily for its humectant and emollient properties, although it has
also been reported to enhance product stability through a
combination of potentiation of preservatives and its own bacteriostatic
and bactericidal properties.
Granulates of xylitol are used as diluents in tablet formulations,
where they can provide chewable tablets with a desirable sweet taste
and cooling sensation, without the ‘chalky’ texture experienced
with some other tablet diluents. Xylitol solutions are employed in
tablet-coating applications at concentrations in excess of 65% w/w.Xylitol coatings are stable and provide a sweet-tasting and durable
hard coating.
In liquid preparations, xylitol is used as a sweetening agent and
vehicle for sugar-free formulations. In syrups, it has a reduced
tendency to ‘cap-lock’ by effectively preventing crystallization
around the closures of bottles. Xylitol also has a lower water
activity and a higher osmotic pressure than sucrose, therefore
enhancing product stability and freshness. In addition, xylitol has
also been demonstrated to exert certain specific bacteriostatic and
bactericidal effects, particularly against common spoilage organisms.
Therapeutically, xylitol is additionally utilized as an energy
source for intravenous infusion therapy following trauma.
Biochem/physiol Actions
A sugar alcohol sweetener detectable by humans. Produced from hemicellulose hydrolysate fermentation.
Safety Profile
Very low toxicity by
ingestion. When heated to decomposition it
emits acrid smoke and irritating fumes. A
sugar.
Safety
Xylitol is used in oral pharmaceutical formulations, confectionery,
and food products, and is generally regarded as an essentially
nontoxic, nonallergenic, and nonirritant material.
Xylitol has an extremely low relative glycemic response and is
metabolized independently of insulin. Following ingestion of
xylitol, the blood glucose and serum insulin responses are
significantly lower than following ingestion of glucose or sucrose.
These factors make xylitol a suitable sweetener for use in diabetic or
carbohydrate-controlled diets.
Up to 100 g of xylitol in divided oral doses may be tolerated
daily, although, as with other polyols, large doses may have a
laxative effect. The laxative threshold depends on a number of
factors, including individual sensitivity, mode of ingestion, daily
diet, and previous adaptation to xylitol. Single doses of 20–30 g and
daily doses of 0.5–1.0 g/kg body-weight are usually well tolerated
by most individuals. Approximately 25–50% of the ingested xylitol
is absorbed, with the remaining 50–75% passing to the lower gut,
where it undergoes indirect metabolism via fermentative degradation
by the intestinal flora.
An acceptable daily intake for xylitol of ‘not specified’ has been
set by the WHO since the levels used in foods do not represent a
hazard to health.
LD50 (mouse, IP): 22.1 g/kg
LD50 (mouse, IV): 12 g/kg
LD50 (mouse, oral): 12.5 g/kg
LD50 (rat, oral): 17.3 g/kg
LD50 (rat, IV): 10.8 g/kg
LD50 (rabbit, oral): 16.5 g/kg
LD50 (rabbit, IV): 4 g/kg
storage
Xylitol is stable to heat but is marginally hygroscopic. Caramelization
can occur only if it is heated for several minutes near its boiling
point. Crystalline material is stable for at least 3 years if stored at
less than 65% relative humidity and 25℃. Milled and specialized
granulated grades of xylitol have a tendency to cake and should
therefore be used within 9 to 12 months. Aqueous xylitol solutions
have been reported to be stable, even on prolonged heating and
storage. Since xylitol is not utilized by most microorganisms, products made with xylitol are usually safe from fermentation and
microbial spoilage.
Xylitol should be stored in a well-closed container in a cool, dry
place.
Incompatibilities
Xylitol is incompatible with oxidizing agents.
Regulatory Status
GRAS listed. Approved for use as a food additive in over 70
countries worldwide, including Europe, the USA and Japan.
Included in the FDA Inactive Ingredients Database (oral solution,
chewing gum). Included in nonparenteral medicines licensed in the
UK and USA. Included in the Canadian List of Acceptable Nonmedicinal
Ingredients.
Check Digit Verification of cas no
The CAS Registry Mumber 87-99-0 includes 5 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 2 digits, 8 and 7 respectively; the second part has 2 digits, 9 and 9 respectively.
Calculate Digit Verification of CAS Registry Number 87-99:
(4*8)+(3*7)+(2*9)+(1*9)=80
80 % 10 = 0
So 87-99-0 is a valid CAS Registry Number.
InChI:InChI=1/C5H12O5/c6-1-3(8)5(10)4(9)2-7/h3-10H,1-2H2/t3-,4+,5+
87-99-0Relevant articles and documents
Improved xylitol production from d-arabitol by enhancing the coenzyme regeneration efficiency of the pentose phosphate pathway in Gluconobacter oxydans
Li, Sha,Zhang, Jinliang,Xu, Hong,Feng, Xiaohai
, p. 1144 - 1150 (2016)
Gluconobacter oxydans is used to produce xylitol from d-arabitol. This study aims to improve xylitol production by increasing the coenzyme regeneration efficiency of the pentose phosphate pathway in G. oxydans. Glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6PGDH) were overexpressed in G. oxydans. Real-time PCR and enzyme activity assays revealed that G6PDH/6PGDH activity and coenzyme regeneration efficiency increased in the recombinant G. oxydans strains. Approximately 29.3 g/L xylitol was obtained, with a yield of 73.2%, from 40 g/L d-arabitol in the batch biotransformation with the G. oxydans PZ strain. Moreover, the xylitol productivity (0.62 g/L/h) was 3.26-fold of the wild type strain (0.19 g/L/h). In repetitive batch biotransformation, the G. oxydans PZ cells were used for five cycles without incurring a significant loss in productivity. These results indicate that the recombinant G. oxydans PZ strain is economically feasible for xylitol production in industrial bioconversion.
Synthesis of xylitol by reduction of xylulose with the combination of hydrogenase and xylulose reductase
Hasumi, Fumihiko,Teshima, Chitoku,Okura, Ichiro
, p. 597 - 598 (1996)
Xylitol synthesis by reduction of xylulose was performed by the combination of NADH regeneration system and xylulose reductase. The conversion of xylulose to xylitol was 98% after 34 h and the turnover number of NAD was 1017.
Novel enzymatic method for the production of xylitol from D-arabitol by Gluconobacter oxydans.
Suzuki, Shun-ichi,Sugiyama, Masakazu,Mihara, Yasuhiro,Hashiguchi, Ken-ichi,Yokozeki, Kenzo
, p. 2614 - 2620 (2002)
Microorganisms capable of producing xylitol from D-arabitol were screened for. Of the 420 strains tested, three bacteria, belonging to the genera Acetobacter and Gluconobacter, produced xylitol from D-arabitol when intact cells were used as the enzyme source. Among them, Gluconobacter oxydans ATCC 621 produced 29.2 g/l xylitol from 52.4 g/l D-arabitol after incubation for 27 h. The production of xylitol was increased by the addition of 5% (v/v) ethanol and 5 g/l D-glucose to the reaction mixture. Under these conditions, 51.4 g/l xylitol was obtained from 52.4 g/l D-arabitol, a yield of 98%, after incubation for 27 h. This conversion consisted of two successive reactions, conversion of D-arabitol to D-xylulose by a membrane-bound D-arabitol dehydrogenase, and conversion of D-xylulose to xylitol by a soluble NAD-dependent xylitol dehydrogenase. Use of disruptants of the membrane-bound alcohol dehydrogenase genes suggested that NADH was generated via NAD-dependent soluble alcohol dehydrogenase.
Poly (styrene-co-divinylbenzene) amine functionalized polymer supported ruthenium nanoparticles catalyst active in hydrogenation of xylose
Mishra, Dinesh Kumar,Dabbawala, Aasif Asharaf,Hwang, Jin- Soo
, p. 52 - 55 (2013)
Poly (styrene-co-divinylbenzene) amine functionalized polymer supported ruthenium nanoparticles catalyst is evaluated first time in selective hydrogenation of xylose to xylitol. The catalyst Ru/PSN is characterized by different techniques such as X-ray powder diffraction, transmission electron microscopy and CO chemisorption. To develop our understanding for the activity of catalyst Ru/PSN, xylose hydrogenation experiments were carried out using catalyst of Ru/PSN with different ruthenium loading (from 1.0% to 3.0%), at different temperatures (from 100 to 140 C) and hydrogen pressures (from 30 to 55 bar). For deactivation test, the catalyst of Ru/PSN recovered from the product solution was reused up to the four times.
Catalytic hydrogenation of xylose to xylitol using ruthenium catalyst on NiO modified TiO2 support
Yadav, Mithilesh,Mishra, Dinesh Kumar,Hwang, Jin-Soo
, p. 110 - 116 (2012)
The activity of Ru catalyst on a new class of NiO modified TiO2 support, Ru/(NiO-TiO2), was studied in the liquid phase catalytic hydrogenation of xylose to xylitol. The TiO2 support was modified by simple impregnation method using nickel chloride precursor and subsequent oxidation. Various catalysts with different targeted compositions of Ru (1.0 and 5.0 wt%) and NiO (1.0, 5.0 and 10 wt%) in NiO-TiO2 were prepared. These catalysts were characterized by using energy dispersive X-ray analysis (EDX/EDS), temperature-programmed reduction (TPR), inductively coupled plasma (ICP) mass spectrometry, transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and CO chemisorption. The novel catalysts are evaluated for selective hydrogenation of xylose and the results compared with those obtained from conventional Raney Ni, Ru/C and Ru/TiO2 catalysts carried out under identical reaction conditions. The effect of NiO additive in the catalyst Ru/(NiO-TiO2), clearly found to enhance the conversion, yield and selectivity to xylitol. Furthermore, the order of catalytic activity may be given as Ru (1.0%)/NiO (5.0%)-TiO2 > Ru (1.0%)/TiO2 > Ru (1.0%)/C> Raney Ni. The effects of Ru and NiO loading, xylose concentration (2.5, 15 and 30 wt%) and temperature (100, 120 and 140°C) were studied. Although at higher temp 140 °C, the conversion of xylose was increased to optimum level, xylose to xylitol selectivity decreased due to formation of by-products.
Efficient D-Xylose Hydrogenation to D-Xylitol over a Hydrotalcite-Supported Nickel Phosphide Nanoparticle Catalyst
Yamaguchi, Sho,Mizugaki, Tomoo,Mitsudome, Takato
, p. 3327 - 3331 (2021)
The hydrogenation of D-xylose is an industrially reliable method for preparing D-xylitol, which is a commonly consumed chemical. Herein, we report the highly efficient and selective hydrogenation of D-xylose to D-xylitol in water over a hydrotalcite (HT: Mg6Al2CO3(OH)16 ? 4(H2O))-supported nickel phosphide nanoparticle catalyst (nano-Ni2P/HT). The HT support drastically increased the catalytic activity of the nano-Ni2P, enabling D-xylitol synthesis under mild reaction conditions. Notably, the selective hydrogenation of D-xylose to D-xylitol proceeded even under 1 bar of H2 or at room temperature for the first time. The nano-Ni2P/HT catalyst also exhibited the highest activity among previously reported non-noble metal catalysts, with a turnover number of 960. Moreover, the nano-Ni2P/HT catalyst was reusable and applicable to a concentrated D-xylose solution (50 wt %), demonstrating its high potential for the industrial production of D-xylitol.
Selective Hydrogenation of Xylose to Xylitol over Co/SiO2 Catalysts
Audemar, Ma?té,Ramdani, Wahiba,Junhui, Tang,Raluca Ifrim, Andreea,Ungureanu, Adrian,Jér?me, Fran?ois,Royer, Sébastien,de Oliveira Vigier, Karine
, p. 1973 - 1978 (2020)
Xylose can be selectively converted to xylitol in water, with an optimized yield of 98 %, in the presence of a simple silica supported monometallic cobalt – Co/SiO2 – catalyst. This catalyst displays initial outstanding catalytic properties in a proper solvent, the best results being obtained in pure water. Recyclability studies show a moderate deactivation of the catalyst, while selectivity to xylitol remains almost unchanged after 4 cycles, confirming that this catalyst formulation is very promising for the xylitol production process.
The Hofer-Moest decarboxylation of d-glucuronic acid and d-glucuronosides
Stapley, Jonathan A.,BeMiller, James N.
, p. 610 - 613 (2007)
Research was undertaken to effect the oxidative decarboxylation of glycuronosides. Experiments with free d-glucuronic acid and aldonic acids were also executed. Both anodic decarboxylation and variants of the Ruff degradation reaction were investigated. Anodic decarboxylation was found to be the only successful method for the decarboxylation of glucuronosides. It was, therefore, proposed that glycuronosides can only undergo a one-electron oxidation to form an acyloxy radical, which decomposes to form carbon dioxide and a C-5 radical, that is, a Hofer-Moest decarboxylation. The radical is subsequently oxidized to a cation by means of a second one-electron oxidation. The cation undergoes nucleophilic attack from the solvent (water), whose product (a hemiacetal) undergoes a spontaneous hydrolysis to yield a dialdose (xylo-pentodialdose from d-glucuronosides).
Transaldolase/glucose-6-phosphate isomerase bifunctional enzyme and ribulokinase as factors to increase xylitol production from D-arabitol in Gluconobacter oxydans
Sugiyama, Masakazu,Suzuki, Shun-Ichi,Tonouchi, Naoto,Yokozeki, Kenzo
, p. 2524 - 2532 (2003)
Xylitol production from D-arabitol by the membrane and soluble fractions of Gluconobacter oxydans was investigated. Two proteins in the soluble fraction were found to have the ability to increase xylitol production. Both of these xylitol-increasing factor
One-pot selective conversion of hemicellulose (Xylan) to xylitol under mild conditions
Yi, Guangshun,Zhang, Yugen
, p. 1383 - 1387 (2012)
Something from nothing: Hemicellulose is selectively converted into valuable xylitol via a mild hydrogen transfer reaction, with a xylitol yield above 80%. Instead of using high-pressure H2, isopropanol is used as hydrogen source in the presence of a Ru/C catalyst. Furthermore, a selective step-by-step conversion of hemicellulose and cellulose to different polyols in a one-pot process is described. Copyright
