Erythritol

Appl Microbiol Biotechnol. 2010 Apr;86(4):1017-25.

Biotechnological production of erythritol and its applications.[Pubmed: 20186409 ]

Erythritol, a four-carbon polyol, is a biological sweetener with applications in food and pharmaceutical industries. It is also used as a functional sugar substitute in special foods for people with diabetes and obesity because of its unique nutritional properties.
METHODS AND RESULTS:
Erythritol is produced by microbial methods using mostly osmophilic yeasts and has been produced commercially using mutant strains of Aureobasidium sp. and Pseudozyma tsukubaensis. Due to the high yield and productivity in the industrial scale of production, Erythritol serves as an inexpensive starting material for the production of other sugars.
CONCLUSIONS:
This review focuses on the approaches for the efficient Erythritol production, strategies used to enhance Erythritol productivity in microbes, and the potential biotechnological applications of Erythritol.

Acta Diabetol. 2014;51(3):513-6.

Effects of erythritol on endothelial function in patients with type 2 diabetes mellitus: a pilot study.[Pubmed: 24366423]

Sugar substitutes are important in the dietary management of diabetes mellitus. Erythritol is a non-caloric dietary bulk sweetener that reverses endothelial dysfunction in diabetic rats.
METHODS AND RESULTS:
We completed a pilot study to examine the effects of Erythritol on vascular function in patients with type 2 diabetes mellitus. Participants (n = 24) consumed Erythritol 36 g/day as an orange-flavored beverage for 4 weeks and a single dose of 24 g during the baseline and final visits. We assessed vascular function before and after acute (2 h) and chronic (4 weeks) Erythritol consumption. Acute Erythritol improved endothelial function measured by fingertip peripheral arterial tonometry (0.52 ± 0.48 to 0.87 ± 0.29 au, P = 0.005). Chronic Erythritol decreased central pulse pressure (47 ± 13 to 41 ± 9 mmHg, P = 0.02) and tended to decrease carotid-femoral pulse wave velocity (P = 0.06).
CONCLUSIONS:
Thus, Erythritol consumption acutely improved small vessel endothelial function, and chronic treatment reduced central aortic stiffness. Erythritol may be a preferred sugar substitute for patients with diabetes mellitus.

Proc Natl Acad Sci U S A. 2014 Dec 16;111(50):17815-20.

Erythritol feeds the pentose phosphate pathway via three new isomerases leading to D-erythrose-4-phosphate in Brucella.[Pubmed: 25453104]

Erythritol is an important nutrient for several α-2 Proteobacteria, including N2-fixing plant endosymbionts and Brucella, a worldwide pathogen that finds this four-carbon polyol in genital tissues.
METHODS AND RESULTS:
Erythritol metabolism involves phosphorylation to L-Erythritol-4-phosphate by the kinase EryA and oxidation of the latter to L-3-tetrulose 4-phosphate by the dehydrogenase EryB. It is accepted that further steps involve oxidation by the putative dehydrogenase EryC and subsequent decarboxylation to yield triose-phosphates. Accordingly, growth on Erythritol as the sole C source should require aldolase and fructose-1,6-bisphosphatase to produce essential hexose-6-monophosphate. However, we observed that a mutant devoid of fructose-1,6-bisphosphatases grew normally on Erythritol and that EryC, which was assumed to be a dehydrogenase, actually belongs to the xylose isomerase superfamily. Moreover, we found that TpiA2 and RpiB, distant homologs of triose phosphate isomerase and ribose 5-phosphate isomerase B, were necessary, as previously shown for Rhizobium. By using purified recombinant enzymes, we demonstrated that L-3-tetrulose-4-phosphate was converted to D-erythrose 4-phosphate through three previously unknown isomerization reactions catalyzed by EryC (tetrulose-4-phosphate racemase), TpiA2 (D-3-tetrulose-4-phosphate isomerase; renamed EryH), and RpiB (D-erythrose-4-phosphate isomerase; renamed EryI), a pathway fully consistent with the isotopomer distribution of the erythrose-4-phosphate-derived amino acids phenylalanine and tyrosine obtained from bacteria grown on (13)C-labeled Erythritol. D-erythrose-4-phosphate is then converted by enzymes of the pentose phosphate pathway to glyceraldehyde 3-phosphate and fructose 6-phosphate, thus bypassing fructose-1,6-bisphosphatase.
CONCLUSIONS:
This is the first description to our knowledge of a route feeding carbohydrate metabolism exclusively via D-erythrose 4-phosphate, a pathway that may provide clues to the preferential metabolism of Erythritol by Brucella and its role in pathogenicity.

Int J Pharm. 2013 Oct 15;455(1-2):132-7.

A completely solvent-free process for the improvement of erythritol compactibility.[Pubmed: 23891654]

We obtained improvement of Erythritol compactibility by formulating composite particles composed of Erythritol and porous silica using a twin-screw kneader.
METHODS AND RESULTS:
Erythritol-based tablets formulated with composite particles were directly compacted, and we estimated their hardness and the friability. The compression properties of the Erythritol powder bed including composite particles were estimated using a Heckel analysis and force-displacement profiles, and we investigated the physical states of the composite particles by powder X-ray diffractometry, a thermal analysis and a nitrogen gas adsorption study. A direct-compacted Erythritol tablet formulated with composite particles, prepared at the melting temperature of Erythritol (120 °C), exhibited high hardness and low friability. A pressure transmission study revealed the higher plasticity and lower elasticity of an Erythritol powder bed formulated with composite particles prepared at 120 °C. Physical states of the composite particles indicated that Erythritol in the composite particles was adsorbed onto porous silica with a subsequent decrease in the Erythritol crystallinity as a result of high mechanical force at the melting temperature of Erythritol.
CONCLUSIONS:
The improvement of the Erythritol compactibility formulated with composite particles through processing with a twin-screw kneader at 120 °C. This was affected by the reduction of the Erythritol crystallinity in the composite particles.