364
J. T . D I N G L E A N D M. W E B B
susceptible to degradation during hydrolytic procedures, but such
conditions favour the interaction of sugars and residual amino acids.
In an attempt to reduce losses due to such interactions Dixon (1955)
introduced Dowex-50 ( H
1 +
) as a hydrolytic agent. The procedure
described recently by O'Colla, O'Donnell and Feeley (1962) also
appears potentially of value for the hydrolysis under mild conditions
of at least certain acid mucopolysaccharides. Generally, however,
dilute acid is used for the hydrolysis of these substances, conditions
being chosen to give a compromise between maximum hydrolysis and
minimum destruction. It is usual to establish for each mucopolysaccharide the optimum conditions of hydrolysis both for amino sugar
estimations (e.g. Johansen, Marshall and Neuberger, 1961) and for
those of other carbohydrates (Bragg and Hough, 1961). Incomplete
hydrolysis yields a number of partial degradation products. From
partial hydrolysates of chondroitin sulphate, hyaluronic acid, keratosulphate, /^-heparin and tissue specimens, for example, chondrosin,
hyalobionic acid, glucosamine and galactosamine have been recovered
by chromatography on ion-exchange resins (Hallen, 1959).
H. I N F R A - R E D A N A L Y S I S
Although the isomeric chondroitin sulphates are linear polyelectrolytes with similar configuration and charge relationships, they may
be identified by infra-red analysis as well as by their other physical
properties, e.g. intrinsic viscosity, solubility, and electrophoretic
mobility (Mathews, 1959). Infra-red analysis seems of particular value
in Tissue Culture work since it is directly applicable to the small
amounts of mucopolysaccharide available without prior hydrolysis.
Adams (1960) identified the mucopolysaccharide components of a
mucoprotein (43 mg) 5 isolated from the condyles of the tibiae and femora
from the 12- to 15-day chick embryo, as chondroitin sulphate-A by infrared spectroscopy. Studies by Lloyd, Dodgson, Price and Rose (1961)
have shown that absorption bands, attributed to the S = 0 stretching
vibration and C-O-S vibration, are lost on chemical elimination of
the sulphate groups. Studies with model compounds (hexose and
hexosamine sulphates) show that infra-red can provide evidence for
the location of S 0 4
2 ~ on particular C-atoms (Suzuki and Strominger,
1960b; Suzuki, 1960; Lloyd and Dodgson, 1961). The sulphated
tetrasaccharides, obtained on digestion of chondroitin sulphate-A and
chondroitin sulphate-C with testicular hyaluronidase retain the differences in infra-red spectra observed for the parent compounds (Hoffman, Linker and Meyer, 1958).
J. T . D I N G L E A N D M. W E B B
susceptible to degradation during hydrolytic procedures, but such
conditions favour the interaction of sugars and residual amino acids.
In an attempt to reduce losses due to such interactions Dixon (1955)
introduced Dowex-50 ( H
1 +
) as a hydrolytic agent. The procedure
described recently by O'Colla, O'Donnell and Feeley (1962) also
appears potentially of value for the hydrolysis under mild conditions
of at least certain acid mucopolysaccharides. Generally, however,
dilute acid is used for the hydrolysis of these substances, conditions
being chosen to give a compromise between maximum hydrolysis and
minimum destruction. It is usual to establish for each mucopolysaccharide the optimum conditions of hydrolysis both for amino sugar
estimations (e.g. Johansen, Marshall and Neuberger, 1961) and for
those of other carbohydrates (Bragg and Hough, 1961). Incomplete
hydrolysis yields a number of partial degradation products. From
partial hydrolysates of chondroitin sulphate, hyaluronic acid, keratosulphate, /^-heparin and tissue specimens, for example, chondrosin,
hyalobionic acid, glucosamine and galactosamine have been recovered
by chromatography on ion-exchange resins (Hallen, 1959).
H. I N F R A - R E D A N A L Y S I S
Although the isomeric chondroitin sulphates are linear polyelectrolytes with similar configuration and charge relationships, they may
be identified by infra-red analysis as well as by their other physical
properties, e.g. intrinsic viscosity, solubility, and electrophoretic
mobility (Mathews, 1959). Infra-red analysis seems of particular value
in Tissue Culture work since it is directly applicable to the small
amounts of mucopolysaccharide available without prior hydrolysis.
Adams (1960) identified the mucopolysaccharide components of a
mucoprotein (43 mg) 5 isolated from the condyles of the tibiae and femora
from the 12- to 15-day chick embryo, as chondroitin sulphate-A by infrared spectroscopy. Studies by Lloyd, Dodgson, Price and Rose (1961)
have shown that absorption bands, attributed to the S = 0 stretching
vibration and C-O-S vibration, are lost on chemical elimination of
the sulphate groups. Studies with model compounds (hexose and
hexosamine sulphates) show that infra-red can provide evidence for
the location of S 0 4
2 ~ on particular C-atoms (Suzuki and Strominger,
1960b; Suzuki, 1960; Lloyd and Dodgson, 1961). The sulphated
tetrasaccharides, obtained on digestion of chondroitin sulphate-A and
chondroitin sulphate-C with testicular hyaluronidase retain the differences in infra-red spectra observed for the parent compounds (Hoffman, Linker and Meyer, 1958).