Isosaccharinic acid

Isosaccharinic acid (ISA) is a six-carbon sugar acid which is formed by the action of calcium hydroxide on lactose and other carbohydrates. It is of interest because it may form in intermediate-level nuclear waste stores when cellulose is degraded by the calcium hydroxide in cements such as Portland cement. The calcium salt of the alpha form of ISA is very crystalline and quite insoluble in cold water, but in hot water it is soluble.

Isosaccharinic acid
Names
IUPAC name
(2S,4S)-2,4,5-Trihydroxy-2-(hydroxymethyl)pentanoic acid
Other names
3-Deoxy-2-C-(hydroxymethyl)-D-erythro-pentonic acid; D-gluco-Isosaccharinic acid; Isosaccharinic acid; α-D-Glucoisosaccharinic acid; α-D-Isosaccharinic acid; α-Glucoisosaccharinic acid; α-Isosaccharinic acid
Identifiers
3D model (JSmol)
ChemSpider
Properties
C6H12O6
Molar mass 180.156 g·mol−1
Melting point 189 to 194 °C (372 to 381 °F; 462 to 467 K)[1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
N verify (what is YN ?)
Infobox references

ISA is thought to form by means of a series of reactions in which calcium ions acting as lewis acids catalyze two of the three steps. The first step is likely to be a rearrangement of the reducing sugar end of the cellulose (or lactose) into a keto sugar, the second step is likely to be a reaction similar to the base catalyzed dehydration which often occurs after an aldol reaction. In this second step an alkoxide (derived from a sugar) takes the role of the hydroxide leaving group, this second step is not likely to require the lewis acidity of the calcium. The final step is a benzilic acid rearrangement from a 1,2-diketone (1,5,6-trihydroxyhexane-2,3-dione) which is formed from the carbohydrate.[2]

Under acidic conditions sugars tend to form furans such as furfural and 5-hydroxymethylfurfural by a series of dehydrations of the carbohydrate.

In acidic solutions the acid tends to form a 5-membered ring (lactone) by forming an ester between the carboxylic acid group and one of the alcohols. When treated under anhydrous conditions with acetone, an acid and a dehydration agent two of the alcohol groups can be protected as a cyclic acetone acetal thus leaving behind only one alcohol,[3] prolonged treatment with 2,2-dimethoxypropane forms a protected form of ISA where all four of the alcohol groups are protected as acetone acetals and the carboxylic acid is in the form of the methyl ester.[4] These protected forms of ISA have been used as a starting material for chiral organic compounds anthracyclines.[4][3]

Relevance for nuclear waste disposal

Since 1993, the diastereomers of isosaccharinic acid have received particular attention in the literature due to its ability to complex a range of radionuclides, potentially affecting the migration of radionuclides.[5][6][7] ISA is formed as a result of interactions between cellulosic materials present within the intermediate level waste inventory various countries and the alkalinity resulting from the use of cementitious materials in the construction of a deep geological repository.[8] Greenfield et al. (1993), have discovered that ISA and constituents formed in a cellulose degradation leachate were capable of forming soluble complexes with thorium, uranium (IV) and plutonium.[9][5][10] In the case of plutonium, ISA concentrations higher than 10−5 M were capable of increasing solubility above pH 12.0, where concentrations of 1-5 × 10−3 M were found to increase the solubility by an order of magnitude from 10−5 to 10−4 M. Allard et al. (2006) found that a concentration of ISA of 2 × 10−3 M could increase plutonium solubility by a factor of 2 × 105.[11] In addition a range of studies on the complexation properties of α-isosaccharinic acid in alkaline solutions with various metals of different valence, including nickel (II), europium (III), americium (III) and thorium (IV), have been conducted.[12][13][14][15][16]

Vercammen et al. (2001) showed that although Ca(α-ISA)2 is sparingly soluble,[17] both europium (III) and thorium (IV) were capable of forming soluble complexes with ISA between pH 10.7 and 13.3, where a mixed metal complex was observed in the presence of thorium.[12] Wieland et al. (2002) also observed that α-ISA prevented the uptake of thorium by hardened cement pastes.[15] Warwick et al. (2003) have also shown that ISA is capable of influencing the solubility of both uranium and nickel through complexation.[13][14] Tits et al. (2005) observed that in the absence of ISA, europium, americium and thorium will sorb onto calcite aggregates present in concrete within an ILW GDF.[16] Should ISA concentrations within the disposal facility exceed 10−5 mol L−1 (2 × 10−5 mol L−1 in the case of Th(IV)), it was reported that the sorption onto calcite would be significantly affected such that the radionuclides studied would no longer be sorbed to the cement and instead be complexed by ISA.

The effect of cellulose degradation products on radionuclide solubility and sorption is the subject of a study from 2013.[18] Cellulose degradation product leachates were first produced by contacting cellulose sources (wood, rad wipes or cotton wool) with calcium hydroxide (pH 12.7) under anaerobic conditions. Analysis of the leachates across 1 000 days suggested that the primary product of the degradation was ISA, although a range of other organic compounds were formed and varied across cellulose source. In these experiments both ISA and X-ISA were able to increase the solubility of europium at pH 12, where in experiments with thorium ISA had a more profound effect on thorium solubility than X-ISA, for which little effect was observed.

More recently, a systematic study was published on the interactions between plutonium, ISA, and cement, as well as sorption.[19] The investigation was focused on repository-like conditions, including high pH due to cementitious materials and low redox potential. The predominant species at various conditions were identified, including quaternary materials such as Ca(II)Pu(IV)(OH)3ISA–H+. The sorption of Pu on cement was found to be significantly lowered due to complexation with ISA.

Microbial activity in a geological disposal facility

ISA also represents a major carbon source within a geological disposal facility (GDF) since it comprises >70% of cellulose degradation products as a result of alkaline hydrolysis. The high pH associated with the massive use of concrete in such a facility means that microbial activity may or may not occur within the alkaline disturbed zone depending on the local microbial consortia intruding upon or surrounding such a facility in the post closure phase.[20] Initial studies have shown that both alpha and beta forms of ISA are readily available for microbial activity under the anaerobic conditions expected within the far field of a disposal facility or within ungrouted waste packages.[21] Since the pH of pore water within the near field of a disposal facility is expected to fall from 13.5 to 12.5 − 10 over tens of thousands of years, the ability of micro-organisms to adapt to these alkaline pH values has also been investigated. Mesophilic consortia have been shown to adapt to a pH of 10 within a number of weeks, ISA degradation ceased above pH 11.0.[22] Microbial consortia from hyperalkaline environments in which exposure to pH > 11.0 has occurred for over a century have also been exposed to ISA generated from the alkaline hydrolysis of organic matter in situ. This consortia was readily capable of degrading ISA.[23] It can also exist as polymicrobial flocculates, which has shown to be able of survival up to pH 12.5.[24] As a result, the impact of microbial activity within a GDF is expected to be through the degradation of ISA's and production of gas, which may create overpressure but also through the generation of 14C bearing gases.[25]

See also

References
  1. Whistler, Roy L.; Richards, G. N. (1958). "Uronic acid fragments from slash pine (Pinus elliotti) and their behavior in alkaline solution". Journal of the American Chemical Society. 80 (18): 4888–4891. doi:10.1021/ja01551a031.
  2. Whistler, Roy L.; BeMiller, J. N. (1960). "4-Deoxy-3-oxo-D-glycero-2-hexulose, the dicarbonyl intermediate in the formation of D-isosaccharinic acids1". Journal of the American Chemical Society. 82 (14): 3705–3707. doi:10.1021/ja01499a058. ISSN 0002-7863.
  3. Florent, J. C.; Ughetto-Monfrin, J.; Monneret, C. (1987). "Anthracyclinones. 2. Isosaccharinic acid as chiral template for the synthesis of (+)-4-demethoxy-9-deacetyl-9-hydroxymethyldaunomycinone and (-)-4-deoxy-gamma-rhodomycinone". The Journal of Organic Chemistry. 52 (6): 1051–1056. doi:10.1021/jo00382a015. ISSN 0022-3263.
  4. Florent, Jean-Claude; Génot, Agnès; Monneret, Claude (1985). "Chiral pool synthesis of tetralin as AB ring segment, precursor of anthracyclines". Tetrahedron Letters. 26 (43): 5295–5298. doi:10.1016/S0040-4039(00)95020-2. ISSN 0040-4039.
  5. Greenfield, B.F.; Hurdus, M.H.; Pilkington, N.J.; Spindler, M.W.; Williams, S.J. (1993). "The degradation of cellulose in the near field of a radioactive waste repository". MRS Proceedings. 333. doi:10.1557/PROC-333-705.
  6. Glaus, M.A; Van Loon, L.R; Achatz, S; Chodura, A; Fischer, K (1999). "Degradation of cellulosic materials under the alkaline conditions of a cementitious repository for low and intermediate level radioactive waste. Part I: Identification of degradation products". Analytica Chimica Acta. 398 (1): 111–122. doi:10.1016/S0003-2670(99)00371-2. ISSN 0003-2670.
  7. Knill, Charles J; Kennedy, John F (2003). "Degradation of cellulose under alkaline conditions". Carbohydrate Polymers. 51 (3): 281–300. doi:10.1016/S0144-8617(02)00183-2. ISSN 0144-8617.
  8. Humphreys, P.N.; Laws, A; Dawson, J. (2010). "A review of cellulose degradation and the fate of degradation products under repository conditions. SERCO/TAS/002274/001. Serco contractors report for the Nuclear Decommissioning Authority (NDA), UK". NDA. Retrieved 5 May 2019. Download pdf.
  9. Greenfield, B.F.; Hurdus, M.H.; Spindler, M.W.; Thomason, H.P. (1997). The effects of the products from the anaerobic degradation of cellulose on the solubility and sorption of radioelements in the near field (Technical report). AEA Technology plc, Harwell, Didcot, Oxfordshire, UK.: Nirex. NSS/R376 and/or NSS/R375.
  10. Greenfield, B.F.; Holtom, G.J.; Hurdus, M.H.; O’Kelly, N.; Pilkington, N.J.; Rosevear, A.; Spindler, M.W.; Williams, S.J. (1995). "The identification and degradation of isosaccharinic acid, a cellulose degradation product". MRS Proceedings. 353. doi:10.1557/PROC-353-1151. ISSN 1946-4274.
  11. Allard, S.; Ekberg, C. (2006). "Complexing properties of α-isosaccharinate: Stability constants, enthalpies and entropies of Th-complexation with uncertainty analysis". Journal of Solution Chemistry. 35 (8): 1173–1186. doi:10.1007/s10953-006-9048-7. ISSN 0095-9782.
  12. Vercammen, K.; Glaus, M.A.; Van Loon, L.R. (2001). "Complexation of Th(IV) and Eu(III) by α-isosaccharinic acid under alkaline conditions". Radiochimica Acta. 89 (6): 393. doi:10.1524/ract.2001.89.6.393. ISSN 2193-3405.
  13. Warwick, Peter; Evans, Nick; Hall, Tony; Vines, Sarah (2003). "Complexation of Ni(II) by α-isosaccharinic acid and gluconic acid from pH 7 to pH 13". Radiochimica Acta. 91 (4): 233–240. doi:10.1524/ract.91.4.233.19971. ISSN 2193-3405.
  14. Warwick, Peter; Evans, Nick; Hall, Tony; Vines, Sarah (2004). "Stability constants of uranium(IV)-α-isosaccharinic acid and gluconic acid complexes". Radiochimica Acta. 92 (12): 897–902. doi:10.1524/ract.92.12.897.55106. ISSN 2193-3405.
  15. Wieland, E.; Tits, J.; Dobler, J. P.; Spieler, P. (2002). "The effect of α-isosaccharinic acid on the stability of and Th(IV) uptake by hardened cement paste". Radiochimica Acta. 90 (9–11): 683–688. doi:10.1524/ract.2002.90.9-11_2002.683. ISSN 2193-3405.
  16. Tits, J.; Wieland, E.; Bradbury, M.H. (2005). "The effect of isosaccharinic acid and gluconic acid on the retention of Eu(III), Am(III) and Th(IV) by calcite". Applied Geochemistry. 20 (11): 2082–2096. Bibcode:2005ApGC...20.2082T. doi:10.1016/j.apgeochem.2005.07.004. ISSN 0883-2927.
  17. Rai, Dhanpat; Rao, Linfeng; Xia, Yuanxian (1998). "Solubility of crystalline calcium isosaccharinate". Journal of Solution Chemistry. 27 (12): 1109–1122. doi:10.1023/A:1022610001043. ISSN 0095-9782.
  18. Randall, M.; Rigby, B.; Thomson, O.; Trivedi, D. (2013). "Assessment of the effects of cellulose degradation products on the behaviour of europium and thorium NNL (12) 12239 Part A – Issue 4 National Nuclear Laboratory, Chadwick House, Warington, UK". NDA. Retrieved 4 May 2019.
  19. Tasi, Agost C.; X. Gaona; D. Fellhauer; M. Böttle; J. Rothe; K. Dardenne; R. Polly; M. Grivé; E. Colàs; J. Bruno; K. Källström; M. Altmaier; H. Geckeis (2018). "Thermodynamic description of the plutonium – α–d–isosaccharinic acid system ii: Formation of quaternary Ca(II)–Pu(IV)–OH–ISA complexes". Applied Geochemistry. 98: 351–366. doi:10.1016/j.apgeochem.2018.06.014. ISSN 0883-2927.
  20. Bassil, Naji M; Bryan, Nicholas; Lloyd, Jonathan R (2014). "Microbial degradation of isosaccharinic acid at high pH". The ISME Journal. 9 (2): 310–320. doi:10.1038/ismej.2014.125. ISSN 1751-7362. PMC 4303625. PMID 25062127.
  21. Janssen, Paul Jaak; Rout, Simon P.; Radford, Jessica; Laws, Andrew P.; Sweeney, Francis; Elmekawy, Ahmed; Gillie, Lisa J.; Humphreys, Paul N. (2014). "Biodegradation of the alkaline cellulose degradation products generated during radioactive waste disposal". PLoS ONE. 9 (9): e107433. Bibcode:2014PLoSO...9j7433R. doi:10.1371/journal.pone.0107433. ISSN 1932-6203. PMC 4182033. PMID 25268118.
  22. Pan, Chongle; Rout, Simon P.; Charles, Christopher J.; Doulgeris, Charalampos; McCarthy, Alan J.; Rooks, Dave J.; Loughnane, J. Paul; Laws, Andrew P.; Humphreys, Paul N. (2015). "Anoxic biodegradation of isosaccharinic acids at alkaline pH by natural microbial communities". PLoS ONE. 10 (9): e0137682. Bibcode:2015PLoSO..1037682R. doi:10.1371/journal.pone.0137682. ISSN 1932-6203. PMC 4569480. PMID 26367005.
  23. Li, Xiangzhen; Rout, Simon P.; Charles, Christopher J.; Garratt, Eva J.; Laws, Andrew P.; Gunn, John; Humphreys, Paul N. (2015). "Evidence of the generation of isosaccharinic acids and their subsequent degradation by local microbial consortia within hyper-alkaline contaminated soils, with relevance to intermediate level radioactive waste disposal". PLoS ONE. 10 (3): e0119164. Bibcode:2015PLoSO..1019164R. doi:10.1371/journal.pone.0119164. ISSN 1932-6203. PMC 4351885. PMID 25748643.
  24. Charles, C. J.; Rout, S. P.; Garratt, E. J.; Patel, K.; Laws, A. P.; Humphreys, P. N.; Stams, Alfons (2015). "The enrichment of an alkaliphilic biofilm consortia capable of the anaerobic degradation of isosaccharinic acid from cellulosic materials incubated within an anthropogenic, hyperalkaline environment". FEMS Microbiology Ecology. 91 (8): fiv085. doi:10.1093/femsec/fiv085. ISSN 1574-6941. PMC 4629871. PMID 26195600.
  25. Doulgeris, Charalampos; Humphreys, Paul; Rout, Simon (2015). "An approach to modelling the impact of 14C release from reactor graphite in a geological disposal facility". Mineralogical Magazine. 79 (6): 1495–1503. Bibcode:2015MinM...79.1495D. doi:10.1180/minmag.2015.079.6.24. ISSN 0026-461X.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.