Physicochemical degradation

A Malabarba, P Strazzolini, A Depaoli, M Landi, M Berti, B Cavalleri. Teicoplanin, antibiotics from Actinoplanes teichomyceticus nov. sp. VI. Chemical degradation physicochemical and biological properties of acid hydrolysis products. J Antibiot 37 988-999, 1984. 

A study of structural units, where a monomer is examined by physicochemical methods to determine its thermostability, its chemical and physical properties, and its sites of degradation. 

Various monomers have been studied for their physicochemical properties and electronic structures (320, 321). For example, a series of monomers can be synthesized following Mulvaney et al. (310) and then theoretical diagrams and degradation sites are studied (Table 111-61) (134). 

To date, the structural features of pectic polysaccharides and plant cell walls have been studied extensively using chemical analysis and enzymatic degradation. In addition, research on isolation and physicochemical characterisation of pectin from citrus peels, apple peels, sunflower head residues and sugar beet pulp has been reported (2). However, the pectic polysaccharides extracted from wheat straw have only previously been reported by Przeszlakowska (3). The author extracted 0.44% pectic substances from Author to whom correspondence should be addressed. 

The corrosion resistance of lithium electrodes in contact with aprotic organic solvents is due to a particular protective film forming on the electrode surface when it first comes in contact witfi tfie solvent, preventing further interaction of the metal with the solvent. This film thus leads to a certain passivation of lithium, which, however, has the special feature of being efiective only while no current passes through the external circuit. The passive film does not prevent any of the current flow associated with the basic current-generating electrode reaction. The film contains insoluble lithium compounds (oxide, chloride) and products of solvent degradation. Its detailed chemical composition and physicochemical properties depend on the composition of the electrolyte solution and on the various impurity levels in this solution. 

At the laboratory stage, data on substances involved and their mixtures must be gathered material properties, physicochemical data, ecological and toxicological data, costs of raw materials and intermediates, an estimate of product price, energy and equipment costs, etc. These data are needed in simulation programs and to determine toxicity, safety, and impact on the environment. The data on toxicity, degradability, and safety are required by the authorities to execute an approval procedure for the plant. 

Ziemianska J, Adamek E, Sobczak A, Lipska I, Makowski A, Baran W (2010) The study of photocatalytic degradation of sulfonamides applied to municipal wastewater. Physicochem Probl Miner Process 45 127-140... 

Doi R, Sakurai K (2004) Principal components derived from soil physicochemical data explained a land degradation gradient, and suggested the applicability of new indexes for estimation of soil productivity in the Sakaerat Environmental Research Station, Thailand. Int J Sustain Dev World Ecol... 

Since the chemistry of nucleic acids was last discussed in this Series,1 publications on the subject have appeared at an unprecedented rate. Degradation products have been further investigated and their structures are more firmly established. Moreover, studies of the properties of these materials have led to a fuller understanding of the behavior of polynucleotides. Emphasis will be laid on the organic chemistry of nucleic acids, and many physicochemical investigations will not be discussed. The period under review has seen the beginning of an understanding of the biosynthesis of nucleic acids, but space does not allow of a consideration of this aspect of the subject. 

Moreover, a-, p- and y-HBCD diastereoisomers are chiral. Thus HBCD have three pairs of enantiomers (+)a, (—)a, (+)p, (—)p, (+)y and (—)y. The enantiomers have identical physicochemical properties and abiotic degradation rates, but may have different biological and toxicological properties and therefore different biotransformation rates. These transformations may result in nonracemic mixtures of the enantiomers that were industrially synthesized as racemates [16, 19]. The rates of metabolisation process of the enantiomers of chiral environmental pollutants may be significantly different [20],... 

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