Acid-hydrolysable

This occurs naturally as a white solid in various crystalline forms, in all of which six oxygen atoms surround each titanium atom. Titanium dioxide is important as a white pigment, because it is nontoxic. chemically inert and highly opaque, and can be finely ground for paint purposes it is often prepared pure by dissolving the natural form in sulphuric acid, hydrolysing to the hydrated dioxide and heating the latter to make the anhydrous form. 

Candida utilis is grown on sulfite waste Hquor in Western Europe and North America, on sugar cane molasses in Cuba and Taiwan and on ceUulose acid hydrolysates in Eastern Europe and the former Soviet Union. C. ///i/if utilizes hexoses, pentoses, and many organic acids. Sulfite Hquor from hardwoods contains 2—3% fermentable sugars of which 20% are hexoses and 80% pentoses in softwood Hquors the proportions are reversed. The SO2 must be stripped out to allow yeast growth, which is carried out in large, highly-aerated fermentors. Eor continuous fermentations, carried out at pH 4 and 30°C, the dilution rate is 0.27—0.30 (34). 

A radical reaction is sometimes observed to compete with the particularly slow acid hydrolyses of diaziridines derived from formaldehyde. With other diaziridines the radical reaction can be made to predominate by using HCl in carbon tetrachloride solution. Acetaldehyde, butyraldehyde, butylamine and ammonia are obtained from (160) (64CB49). 

Table 6. Acid hydrolyses of glycylglycine with Dowex-50 and HC1 at 54.5 °C82 ...

Arai and Ise91 carried out the acid hydrolyses of dextrin in the presence of copolymers of vinylalcohol and vinylsulfuric acid, 39 (PVS VA). Figure 10 shows... 

The three activation parameters, AG, AH, and AS decreased with polyelectrolyte addition. The decrease in AS suggests that the acceleration is due to the enthalpic loss. We recall that the acid hydrolyses of aliphatic esters with polymeric sulfonic acid was accompanied by decreases in AH and AS 97, 98 ... 

Thus, the determination of the content of Isoleuclne In relation to leucine and phenylalanine can be used as a measure of the relative amount of Hb-F In mixtures. The procedure Involves the chromatographic Isolation of the Hb-F containing zone and the determination of the Isoleucyl, and phenylalanyl content In a 72 hour acid hydrolysate of the hemoglobins In this zone. 

This paper reports on the separation of some fragments obtained by acid hydrolyses of pectin from pea shoot cell walls, which had effect on thin cell-layer explant rhizogenesis. 

The compound, produced as an hydrate from dilute acid hydrolyses of disodium azotetrazolide, exploded on heating for analytical purposes. 

Addition of barium chloride 0.5 M to the acid hydrolysate Suppression of sulfates 81,82... 

Dilute acid (0.5 M- 2.5 M H2S04) - extractable C or carbohydrate - C have also been used as indicators of soil organic matter status (Angers and Mehuys 1989 Chan and Heenan 1999 Shepherd et al. 2001). The acid hydrolysable fraction generally accounts for about 20-40% of total organic C (Rovira and Vallejo 2002) and 65-85% of the total soil carbohydrate pool (Puget et al. 1999). 

Cambella and Antia [385] determined phosphonates in seawater by fractionation of the total phosphorus. The seawater sample was divided into two aliquots. The first was analysed for total phosphorus by the nitrate oxidation method capable of breaking down phosphonates, phosphate esters, nucleotides, and polyphosphates. The second aliquot was added to a suspension of bacterial (Escherichia coli) alkaline phosphatase enzyme, incubated for 2h at 37 °C and subjected to hot acid hydrolysis for 1 h. The resultant hot acid-enzyme sample was assayed for molybdate reactive phosphate which was estimated as the sum of enzyme hydrolysable phosphate and acid hydrolysable... 

It is interesting to note that the A1 -alkylbenzodiazepines can be analysed by a method that involves photodealkylation. The compounds are acid-hydrolysed to benzophenones and run on a plate to separate primary and secondary amines. The plate is then exposed to UV light for 10-15 min, which causes A-dealkylation, and run in the second dimension to identify the primary aminobenzophenones [230]. 

Muhlhauser et al. [51] have discussed methods for the determination of acid hydrolysable phosphorus in sediments. 

Acid hydrolysate of the standard compound from eggs 0.48 0.63 0.38 0.40... 

Fig. 2.148. UV (254 nm) profile of an acidic hydrolysate of an aqueous alcoholic extract of Rubia tinctorum (after 30 min). The mass spectra (sinlge MS) obtained with NI-ESI with ammonia added post-column and the UV-Vis spectra of peaks 3 and 4 are depicted, lucidin primeveroside (1), rubery-thic acid (2), lucidin glucoside (3), alizarin glucoside (4), munjistin (6), alizarin (8), and purpurin (9). Reprinted with permission from G. C. H. Derksen et al. [320].

An appraisal has been made of the available kinetic data on the acid hydrolyses of hydroxyamic acids. For A-substituted hydroxamic acids both A-2 and A-1 paths are recognized, but for primary hydroxamic acids there is evidence only for the A-2... 

Nakamura F, Yamazaki K and Suyama K (1992) Isolation and structural characterization of a new crosslinking amino acid, cyclopentenosine, from the acid hydrolysate of elastin. Biochem Biophys Res Comm 186, 1533-1538. 

Acid hydrolysis under standard conditions (6M HC1, 110 °C, 24 h) leads to partial decomposition of selenocystine and selenocysteine derivatives, thus making quantification of this amino acid by amino acid analysis difficult. Similarly, acid hydrolysis of 5e-[2-(4-pyr-idinyl)ethyl]selenocysteine peptides, obtained by reduction of the selenocystine peptides with NaBH4 and reaction with 4-vinylpyridine, results in partial decomposition. This de-rivatization, however, is useful for the enantiomeric resolution of the acid hydrolysates by capillary zone electrophoresis by applying host-guest complexation with crown ethers.11" 22 ... 

In general, the high specificity of enzymes limits the application of this method, because for the treatment of each wastewater sample it is necessary to use a special consortium of various types of enzymes. Therefore, for practical reasons the acid hydrolysis of wastewater is the preferred laboratory method for the pretreatment of polymers. By the use of acid hydrolysis for one hour at 148°C with 6 mol/1 HCl ( acid hydrolyse kit from Dr. Lange GmbH Berlin 1996 [48]), the polymers are decomposed to their monomers such as monosaccharides, glycerol, fatty acids, or amino acids, respectively. The hydrolysis of wastewater caused in most cases an increase of the BOD measured (Table 6), resulting in an improved concurrence of sensorBOD and BOD5 [53,68]. 

Setlow et al.83 have studied the photolysis of poly dl poly dC (polydeoxyinosinic acid polydeoxycytidylic acid, see Glossary) and poly dA dT. The photochemical changes were estimated by following absorbance changes, by chromatographic separation of acid hydrolysates, and by chromatographic separation of products from enzymatic hydrolysates. 

The existence of photoreversible, but not of heat-reversible, absorbance change in irradiated poly dI dC was taken to prove that the photoproducts are entirely dimers (in contrast to those in poly C irradiations where the product is almost entirely the hydrate82a). It was possible to detect dimers of uracil as well as those of cytosine, by means of the much slower photoreversal of uracil dimers. In the acid hydrolysates of irradiated dl-dC, both uracil dimers and uracil could be identified. Enzymatic hydrolysis (snake venom phosphodiesterase) does not split pyrimidine dimers, and the products of such hydrolysis of irradiated tritium-labeled poly dl dC contained trinucleotides shown by radioactivity to contain cytosine dimers. Thymine dimers were formed in the photolysis of the poly dA dT, and were detected and assayed by the same methods. The yield of thymine dimers in irradiated poly... 

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