scholarly journals Identification of guanosine diphosphate derivatives of d-xylose, d-glucose and d-galactose in mature strawberry leaves

1967 ◽  
Vol 105 (2) ◽  
pp. 723-728 ◽  
Author(s):  
R. R. Selvendran ◽  
F. A. Isherwood
Keyword(s):  
Isotope Dilution Method ◽  
Dilution Method ◽  
Mild Acid Hydrolysis ◽  
Paper Chromatogram ◽  
Guanosine Diphosphate ◽  
Preliminary Separation ◽  
Layer Chromatography ◽  
Derivatives Of ◽  
Dowex 1 ◽  
Mild Acid

The nucleotides from a trichloroacetic acid extract of mature strawberry leaves were separated into ten main fractions by chromatography on a Dowex 1 (formate form) column with ammonium formate as the eluting agent. One of these fractions, which was suspected to contain not only ADP but also GDP-sugars, was separated into a number of subfractions by further chromatography on a Dowex 1 (formate form) column with the formic acid system as the eluting agent. One of these subfractions was identified from its ultraviolet spectra, from its position on the two ion-exchange columns and by thin-layer chromatography as a GDP-sugar. Mild acid hydrolysis gave GDP and a mixture of sugars. The sugars, after a preliminary separation on a paper chromatogram, were identified by an isotope-dilution method. The sugars were condensed with sodium [14C]cyanide, the [14C]nitriles were hydrolysed and one of the epimeric acids was isolated, either as lactone or amide, by co-crystallization with a non-radioactive carrier. This method distinguishes between enantiomorphic sugars. d-Mannose, d-xylose, d-glucose and d-galactose were present in the proportions 40:10:1:1 respectively. The total amount of the GDP-sugars was approx. 0·1μmole/100g. of fresh leaves.

ON THE VALUE OF SOME PARAMETERS OF ADRENOCORTICAL GLUCOCORTICOID FUNCTION

1963 ◽  
Vol 44 (4) ◽  
pp. 499-504 ◽  
Author(s):  
M. Van Der Straeten ◽  
A. Vermeulen ◽  
N. Orie ◽  
P. Regniers
Keyword(s):  
Urinary Excretion ◽  
Adrenal Cortex ◽  
Isotope Dilution ◽  
Isotope Dilution Method ◽  
Dilution Method ◽  
Steroid Excretion ◽  
Colorimetric Methods

ABSTRACT The authors studied the correlation between cortisol production, as measured by an isotope dilution method, and the urinary excretion of total and free Porter-Silber chromogens, as well as of 17-ketogenic steroids. Although a significant correlation exists between total Porter-Silber chromogens, 17-ketogenic steroid excretion and cortisol production, discrepancies are occasionally observed. Hence, different colorimetric methods should be used to assess the glucocorticoid activity of the adrenal cortex.

Amino acid sequence of cyanogen bromide fragment CB5 of human hemopexin

1989 ◽  
Vol 54 (3) ◽  
pp. 803-810 ◽  
Author(s):  
Ivan Kluh ◽  
Ladislav Morávek ◽  
Manfred Pavlík
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Acid Hydrolysis ◽  
Cyanogen Bromide ◽  
Polypeptide Chain ◽  
Amino Acid Residues ◽  
Mild Acid Hydrolysis ◽  
Methionine Residue ◽  
Cyanogen Bromide Fragment ◽  
Mild Acid

Cyanogen bromide fragment CB5 represents the region of the polypeptide chain of hemopexin between the fourth and fifth methionine residue (residues 232-352). It contains 120 amino acid residues in the following sequence: Arg-Cys-Ser-Pro-His-Leu-Val-Leu-Ser-Ala-Leu-Thr-Ser-Asp-Asn-His-Gly-Ala-Thr-Tyr-Ala-Phe-Ser-Gly-Thr-His-Tyr-Trp-Arg-Leu-Asp-Thr-Ser-Arg-Asp-Gly-Trp-His-Ser-Trp-Pro-Ile-Ala-His-Gln-Trp-Pro-Gln-Gly-Pro-Ser-Ala-Val-Asp-Ala-Ala-Phe-Ser-Trp-Glu-Glu-Lys-Leu-Tyr-Leu-Val-Gln-Gly-Thr-Gln-Val-Tyr-Val-Phe-Leu-Thr-Lys-Gly-Gly-Tyr-Thr-Leu-Val-Ser-Gly-Tyr-Pro-Lys-Arg-Leu-Glu-Lys-Glu-Val-Gly-Thr-Pro-His-Gly-Ile-Ile-Leu-Asp-Ser-Val-Asp-Ala-Ala-Phe-Ile-Cys-Pro-Gly-Ser-Ser-Arg-Leu-His-Ile-Met. The sequence was derived from the data on peptides prepared by cleavage of fragment CB5 by mild acid hydrolysis, by trypsin and chymotrypsin.

scholarly journals A New Look at the Enterobacterial Common Antigen Forms Obtained during Rough Lipopolysaccharides Purification

2021 ◽  
Vol 22 (2) ◽  
pp. 701
Author(s):  
Tomasz K Gozdziewicz ◽  
Anna Maciejewska ◽  
Alona Tsybulska ◽  
Czeslaw Lugowski ◽  
Jolanta Lukasiewicz
Keyword(s):  
Current Knowledge ◽  
Membrane Integrity ◽  
Gel Filtration ◽  
Common Antigen ◽  
Mild Acid Hydrolysis ◽  
Enterobacterial Common Antigen ◽  
Lipopolysaccharide Endotoxin ◽  
Lipid Moiety ◽  
Detailed Composition ◽  
Mild Acid

Enterobacterial common antigen (ECA) is a conserved antigen expressed by enterobacteria. It is built by trisaccharide repeating units: →3)-α-D-Fucp4NAc-(1→4)-β-D-ManpNAcA-(1→4)-α-D-GlcpNAc-(1→ and occurs in three forms: as surface-bound linear polysaccharides linked to a phosphoglyceride (ECAPG) or lipopolysaccharide − endotoxin (ECALPS), and cyclic form (ECACYC). ECA maintains, outer membrane integrity, immunogenicity, and viability of enterobacteria. A supernatant obtained after LPS ultracentrifugation was reported as a source for ECA isolation, but it has never been assessed for detailed composition besides ECACYC. We used mild acid hydrolysis and gel filtration, or zwitterionic-hydrophilic interaction liquid (ZIC®HILIC) chromatography combined with mass spectrometry for purification, fractionation, and structural analysis of rough Shigella sonnei and Escherichia coli R1 and K12 crude LPS preparations. Presented work is the first report concerning complex characteristic of all ECA forms present in LPS-derived supernatants. We demonstrated high heterogeneity of the supernatant-derived ECA that contaminate LPS purified by ultracentrifugation. Not only previously reported O-acetylated tetrameric, pentameric, and hexameric ECACYC have been identified, but also devoid of lipid moiety linear ECA built from 7 to 11 repeating units. Described results were common for all selected strains. The origin of linear ECA is discussed against the current knowledge about ECAPG and ECALPS.

Pigments of marine animals. XI. Angular naphthopyrones from the crinoid Comanthus parvicirrus timorensis

1971 ◽  
Vol 24 (7) ◽  
pp. 1487 ◽  
Author(s):  
IR Smith ◽  
MD Sutherland
Keyword(s):  
Methyl Ether ◽  
Dry Weight ◽  
Water Soluble ◽  
Spectral Studies ◽  
Mild Acid Hydrolysis ◽  
Marine Animals ◽  
Yellow Colour ◽  
Methoxy Derivative ◽  
Colour Variant ◽  
Mild Acid

Green specimens of the comatulid crinoid, Comanthus parvicirrus timorensis J. Muller, yield to acetone three yellow water-soluble colouring matters, comaparvin sulphate, 6-methoxycomaparvin sulphate, and 6-methoxycomaparvin 5-methyl ether sulphate in approximately 0.1 %, 0.7 %, and 0.7 % yield respectively of the dry weight of the animal, Mild acid hydrolysis yields the corresponding phenols, the structures of which have been deduced largely by spectral studies as very probably 5,8-dihydroxy-10-methoxy-2-n-propyl-4H-naphtho[1,2-b]pyran-4-one (1), the 6-methoxy derivative of (1), and the 6-methoxy methyl ether of (1) respectively. A yellow colour variant of the same species yielded the same colouring matters in slightly different proportions. The calcareous skeleton contains what are probably polyhydroxynaphthoquinones in combined form.

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