Hydrolysis partial acid

The following facts were observed a. Partial acid hydrolysis of the octapeptide yielded a dipeptide of the structure... 

Give the amino acid sequence of hexapeptides that produce the following sets of fragments on partial acid hydrolysis ... 

Fig. 2.— Mass Fragmentogram of Hexosyl-aminohexitols Obtained by Partial, Acid Hydrolysis of Rat-brain Glycopeptides. [Peak I, j8-Gal-(l— 3)-GlcNAcol peak 2, /3-Gal-(l- 4)-GlcNAcol. A, retention time of /3-Gal-(l— 3)-GlcNAcol B, retention time of /3-Gal-(1—>4)-GlcNAcol and C, retention time of/3-Gal-(l— 6)-GlcNAcol. Abscissa, retention time, in minutes. Conditions 1% of OV-225, at 245°, and detection by mass frag-mentography at m/e 276. Reproduced, by permission, from Ref. 65.]...

R. A. Zubarev, V. D. Chivanov, P. Hakansson, B. U. R. Sundqvist, Peptide Sequencing by Partial Acid Hydrolysis and High Resolution Plasma Desorption Mass Spectrometry , Rapid Commun. Mass Spectrom. 1994, 8, 906-912. 

Figure 4. Total ion chromatogram of the methylated mono/oligosaccharide obtained by the partial acid hydrolysis of the bran arabinogalactoglu-curonoxylan.

Table III. Possible Structure of Oligosaccharides Obtained by the Partial Acid Hydrolysis of Rice Bran Arabinogalactoglucuronoxylan...

II. Fractionation and partial acid hydrolysis of water-soluble pectin. An Acad Brasil Cienc 1974 46 349. Molina, M. R., G. De LaFuente, M. A. Batten, and R. Bressani. Decaffein-ation. A process to detoxify coffee pulp. J Agr Food Chem 1974 22(6) 1055. 

Peptide bonds are cleaved in a nonselective, but not in a completely random manner. Based on anchimeric side-chain assistance, steric factors, and bond strains, acid-labile peptide bonds are predicted to include sites containing Asp, Glu, Ser, Thr, Asn, Gin, Gly, and ProJ22l The disulfide topologies of circulin B and cyclopsychotride, backbone-cyclized peptides with three disulfide bonds, were determined by partial hydrolysis for 5 hours.[22 Occasionally, the bond between adjacent half-cystine residues is cleaved due to the nonselective nature of the mechanism of partial acid hydrolysis.[21] By this procedure, in all cases, a complex mixture of peptide fragments is produced which requires careful chromatographic separation by RP-HPLC for subsequent analysis by mass spectrometry (see Section 6.1.6.2.7). 

Structural analysis of isolated amylose and amylopectin components has been carried out by standard methods based on methylation, periodate oxidation, and partial acid hydrolysis studies. Methylation and periodate oxidation studies established the linkage types and frequency of... 

Conversion Partial acid hydrolysis Treatment with hydrochloric acid or ortho-phosphoric acid or sulphuric acid... 

Less is known concerning the partial, acid hydrolysis of alditol polyacetals derived from ketones, compared to those derived from aldehydes. The acid hydrolysis of 1,2 3,4 5,6-tri-O-isopropylidene-D-mannitol to 3,4-O-isopropylidene-D-mannitol55,56 and of l,2 3,4-di-0-isopropylidene-L-rhamnitol to 3,4-O-isopropylidene-L-rhamnitol57 indicates an order of isopropylidene acetal stability of a-threo > a, and this order is supported by the partial hydrolysis of 2,3 4,5-di-O-isopro-pylidene derivatives of dialkyl dithioacetals of D-arabinose58 and D-xylose59 to 2,3-acetals. 

Structural studies on the oligosaccharide derivatives obtained by partial, acid hydrolysis of fully methylated polysaccharides often furnish valuable information on the positions at which the oligosaccharides were linked in the original polysaccharide. When the folly methylated Klebsiella O group 9 lipopolysaccharide,27 which contains D-galactopyranose and D-galactoforanose residues, was subjected to mild, acid hydrolysis, and the product reduced with lithium aluminum deuteride and remethylated with trideuteriomethyl iodide, a good yield of the disaccharide derivative 10 was obtained. 

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