Ester degradation

Cellulosics Esters degrade less than cellulose does. 

Wang Y, Fan Y, Gu J-D (2004) Dimethyl phthalate ester degradation by two planktonic and immobilized bacterial consortia. Int Biodeterior Biodegrad 53 93-101... 

All bacteria where nitrate ester degradation has been characterized have very similar enzymes. The enzymes eatalyze the nicotinamide cofactor-dependent reductive eleavage of nitrate esters that produces alcohol and nitrite. Purification of the PETN reduetase from Enterobacter cloacae yielded a monomerie protein of around 40 kilo Daltons, which required NADPH as a co-faetor for aetivity. Similar enzymes were responsible for the nitrate ester-degrading activity in Agrobacterium radiobacter (Snape et al. 1997) - nitrate ester reductase - and in the strains of Pseudomonas fluorescens and Pseudomonas putida (Blehert et al. 1999) - xenobiotic reduetases . All utilize a non-covalently bound flavine mononucleotide as a redox eofactor. 

Wang, J., Liu, P., Shi, H., and Qian, Y. Kinetics of phthalic acid ester degradation by acclimated sludge. Process Biochem., 32(7) 567-571, 1997. 

Figure 3. 2,4-D ester degradation with time. , amount in...

Cholesteryl ester degradation Most dietary cholesterol is present in the free (nonesterified) form, with ten to fifteen percent present in the esterified form. Cholesteryl esters are hydrolyzed by pancreatic cholesterol ester hydrolase (cholesterol esterase), which produces cholesterol plus free fatty acids (see Figure 15.2). Cholesteryl esteh hydrolase activity is greatly increased in the presence of bile salts. ... 

Avoid alcohols (methanol, ethanol, etc.) in the sample preparation solvent due to the following reaction (especially under acidic conditions). This may lead to the formation of an ester degradation product in the diluent. 

The clove bud oil might be a drastic example for ester degradation since the exceptionally high oil content needs long distillation times and stressing distillation conditions. There are, however, other samples where the same problem is foimd to a smaller extent, e.g. for linalylacetate which is a main constituent of lavender oil. 

Capancioni S, Schwach-Abdellaoui K, Kloeti W, et al. In vitro monitoring of poly(ortho ester) degradation by electron paramagnetic resonance imaging. Macromolecules 2003 36(16) 6135-6141. 

Production of 4-Chloro-3-acetoxybutyronitrile (BNOAc) by Ester-Degrading Enzymes... 

Cooper, D.R., Sutton, G.J., and Tighe, B.J. (1973) Poly(alpha -ester) degradation studies. V. Thermal degradation of polyglycolide. / Ptdym. ScL, Part A-1,... 

Muggh, D.S., Burkoth, A.K., Keyser, S. A., Lee, H.R., Anseth, K.S., 1998. Reaction behavior of biodegradable, photo-cross-linkable polyanhydrides. Macromolecules 31, 4120—4125. Ouimet, M.A., Griffin, J., Carbone-Howell, A.L., Wu, W.-H., Stebbins, N.D., Di, R., Uhrich, K.E., 2013. Biodegradable ferulic acid-containing poly (anhydride-ester) degradation products with controlled release and sustained antioxidant activity. Biomacromolecules 14, 854—861. 

Another example of model formulation that simultaneously takes into account reaction and diffusion is given by Thombre and Himmelstein (1985) and Joshi and Himmelstein (1991), who characterized one-dimensional slab and disks of surfaceeroding poly(ortho esters), respectively. They considered a kinetic scheme (the poly (ortho esters) degradation mechanism is slightly different from that of aliphatic... 

Kinetic studies on poly alpha ester degradation have been made using poly-(cycloalkylidene carboxylates) as the substrate. ... 

D.R. Cooper, G.J. Sutton, and B.J. Tighe, Poly a-ester degradation studies. V. Thermal degradation of poly glycollide,/. Polym. Sci. Polym. Chem. Ed., 11 (8), 2045-2056,1973. 

Y. Murakami, Y. Aoyama, M. Kada, and J. L Kikuchi (1978), Macrocyclic enzyme model system Catalysis of ester degradation by a [20] paracyclophane bearing nucleophilic and metal-binding sites. Chem. Commun. 494-496. 

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