Ethylene glycol periodate oxidation

Horseradish peroxidase (HRP, EC 1.11.17) was obtained from Huka. The oxidation of carbohydrate moieties of enzyme with periodic acid (0.04 mM in 0.05 mM acetate buffer, pH 5.0) was performed according to Zaborsky and Ogletree (1974). The unreacted periodic acid was removed with 0.025-ethylene glycol. The oxidized enzymes were dialyzed against 50 mM phosphate buffer with pH 6.0 for 18 h. 

Perchloric acid (79% HCIO4/CH2CI2, 0°, 1 h 25°, 3 h, 87% yield) and periodic acid (aq. dioxane, 3 h, quant, yield) cleave 1,3-dioxolanes the latter drives the reaction to completion by oxidation of the ethylene glycol that forms. Yields are substantially higher from cleavage with perchloric acid (3 AHCIO4/THF, 25°, 3 h, 80% yield) than with hydrochloric acid (HCl/HOAc, 65% yield)... 

Laboratory tests of ethylene glycol containing formulations have shown a complete bio-oxidation within 20 days. The rate of bio-oxidation is stationary over the full period. On the other hand, propylene glycol initially degrades more rapidly during the first 5 days of the test to an extent of 62%, slowing to 79% conversion after 20 days. 

The rate of oxidation of ethylene glycol was found268-269 to attain a broad maximum between pH 2.5 and 6. In a very complete study of the effect of pH on the periodate oxidation of carbohydrates, Neumiiller and Vasseur260 showed that the oxidation of maltose, melibiose, methyl a-D-... 

The oxidation may be performed at pH 5.0 by addition of an aqueous solution of sodium metaperiodate. The reaction is allowed to proceed in the dark at 4 °C and after 24 hours the excess periodate is destroyed by the addition of ethylene glycol. The aims in periodate oxidation are to elucidate the number of neighbouring hydroxyl groups by estimating the number of moles of periodate consumed and to determine the structure of the moiety remaining after the reaction. The amount of periodate used in the reaction may be determined in several ways, including titrimetric and spectrophotometric methods. 

Petroleum refineries produce a stream of valuable aromatic compounds called the BTX, or benzene-toluene-xylenes (Ruthven 1984). The Cg compounds can be easily separated from the Ce and C compounds by distillation, and consist of ethyl benzene, o-xylene, m-xylene, and / -xylene. Ethyl benzene is the starting material for styrene, which is used to make polystyrene / -xylene is oxidized to make terephthalic acid, and then condensed with ethylene glycol to make polyester for fibers and films. The buyers of / -xylene are the manufacturers of terephthalic acid, such as BP-Amoco, who in turn sell to the fiber manufacturers such as DuPont and Dow. These are big and sophisticated companies that have strong research and engineering capabilities, and are used to have multiple suppliers. The eventual consumers of adsorbents are the public who consider polyester as one of the choices in fabric and garments, in competition with other synthetic and natural fibers. Their purchases are also dependent on personal income and prosperity. In times of recession, it is always possible for a consumer to downgrade to cheaper fibers and to wear old clothes for a longer period of time before new purchases. 

The test for ethylene glycol was performed by oxidation of the sample with periodic acid and detection of the resulting formaldehyde with fuchsin-sulfurous acid reagent (9). 

Treatment of MFA (1) with cyanogen bromide [6] opened ring G to yield the bromo derivative 3 [7]. Attempts to dehydrobrominate 3 in one step via a base-catalyzed elimination with DBU/CH3CN, KOH/MeOH, or terr-BuOK/DMSO were unsuccessful. However, the required methylene entity could be introduced by converting 3 first to a selenide, then oxidation with periodate, followed by thermolysis in benzene to provide compound 4. Hydrolysis of the cyano group with NaOH in ethylene glycol [8] produced 5 (50% yield). Osmium catalyzed oxidation of 5 in the presence of 4-methylmorpholine A-oxide (NMO) gave a diol, which was cleaved to an aldehyde upon treatment with periodate. Treatment of the aldehyde with sodium cyanoborohydride resulted in an intramolecular reductive animation to yield the desired product PHB (6). 

This mqchanism has been considered >14 in relation to the rates of the periodate oxidation of cis- and trows-glycols, and in connection with Hie effect of the pH of the reaction solution on the rates of oxidation of ethylene glycol, pinacol, and cis- and irans-cydohexene glycols. 

On periodate oxidation and reduction of laminaran, a mannitol residue substituted only at position 1 should yield ethylene glycol on hydrolysis. Since no ethylene glycol was detected, it was concluded that the mannitol is substituted at both positions 1 and 2. Recent studies by Peat and coworkers do not support this conclusion and, also, have indicated other... 

Modifications are made also in order to use this reaction to conjugate nucleosides to erythrocyte surfaces, allowing use of the coated cells as targets for assays of antibody-forming splenic lymphocytes. Nucleoside, 10-20 mg, is oxidized in 1.5 ml of 0.1 M sodium periodate in 0.15M NaHCOa for 20 min at room temperature the reaction is stopped by the addition of 15 /zl of ethylene glycol. Sheep erythrocytes are washed twice with 0.15 M NaHCOs, and 0.5 ml of packed cells is then suspended in 2.0 ml of the bicarbonate solution in a40-ml centrifuge tube. The oxidized nucleoside is added dropwise to the cell suspension and the mixture is kept at room temperature for 15 min. fert-Butylamine borane (Aldrich Chemical Co.), 100 mg in 5 ml of 0.15 M NaHCOs, is added. The suspension is kept at room temperature for 3 min, and the tube is then quickly filled with bicarbonate solution and centrifuged at 1500 rpm for 10 min. 

I schcsche and co-workers " employed the I.emieux-Rudlolf procedure for oxidation of the carbinol phosphate (6) to Di.-mevalonic acid 5-phosphate (7). At the end of the reaction excess periodate was destroyed with ethylene glycol, iodate ion was precipitated as barium Iodate, and cations were removed with Dowex-50. Mevalonic acid phosphate (7) was then isolated ai the crystulline tricyclohexylnmmonlum... 

The O-PS (10 mg) was oxidized with 0.05 mol l-1 sodium metaperiodate (1.6 ml) at 4 °C in the dark for 6 days. Then ethylene glycol (1 ml) was added to destroy the excess of the metaperiodate and stop the reaction. The mixture was stirred at 22 °C for 30 min, followed by reduction with sodium borohydride at 22 °C for 18 h and neutralization with 10% (v/v) AcOH. The solution was dialyzed and lyophilized. Smith-type hydrolysis of the periodate-oxidized and reduced polymer was affected with 0.5 moll-1 TFA at 22 °C for 48 h, the sample was purified on a Bio-Gel P-2 column, and the sugar composition of the product was determined. 

---