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Glycosaminoglycans Glycoproteins and Glycolipids.

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Glycosaminoglycans, Glycoproteins, and Glycolipids
At the suggestion of R . W. Jeanloz the Retina Foundation of
Boston organized an international symposium on the chemistry of the three title substances at Swampscott, Mass.
(U.S.A.) from July 22nd to July 2Sth, 1964. The following
topics were discussed: 1. the sugar sequences in glycolipids
and glycoproteins; 2. the degradation of glycosaminoglycans
and glycoproteins by redox systems and radiation; 3. the
physicochemical properties and biological importance of
glycosaminoglycan and glycoprotein solutions; 4. the covalent bonds between amino acids and sugars in glycoproteins;
and 5. the biosynthesis of the carbohydrate portion of glycoproteins and glycolipids.
1. Sugar Sequences in Glycolipids and Glycoproteins
Richard Kulzn (Heidelberg, Germany) reported on the isolation of a chromatographically pure glycoliposialoprotein
(mucolipid A) which gave a uniform sedimentation pattern
in the analytical ultracentrifuge and exhibited high acetylcholine esterase activity. After mild treatment with chloroform plus methanol, this afforded a ganglioside-rich component. All the analyses carried out on this product to date
indicate an ester-like and/or lactone-like linkage between the
gangliosides.
E. KIenk (Koln, Germany) reported o n the occurrence of
Tay-Sachs gangliosides in normal brain.
P. Stoffyyn (Belmont, Mass., U.S.A.) reported on a general
method for estimating the 01- or @-configuration of the
glycosidic bond in cerebrosides. Hydrolysis and hydrogenation of phrenosine affords psychosine which was oxidized
with NaI04, the palmitaldehyde formed being extracted with
ether and estimated by gas chromatography. The aldehydes
from the aqueous phase were compared with the products obtained from control substances. In the case of phrenosine,
they agreed with the aldehydes obtained from I-D-glyCeryl
@-D-galactoside, indicating a @-linkage. The method cannot
be applied to disaccharides.
G . T. Barry (Knoxville, Tenn., U.S.A.) hydrolysed the glycopeptides from Citrobocter Frerindii with acid and obtained an
amino acid which gave a yellow coloration with ninhydrin
and had the same Rf-values on paper chromatograms as synthetic 4-hydroxyleucine. This is formed during the hydrolysis
from r-fucosamine, which has thus been detected for the first
time in Gram-negative bacteria. G. F. Springer (Evanston,
Ill., U.S.A.) carried out the isolation and partial characterization of specific haptenes from M and N blood group substances. NN- and N-like blood group substances from erythrocytes and meconium have the structure hexosaminesialic acid-methylpentose as long as they are still biologically
active. H. Hotta (Evanston, Ill., U.S.A.) called attention to
the high content (33-34 %) ofsialic acidin N-active haptenes.
G. M. W. Cook (Los Angeles, Calif., U.S.A.) achieved a successful separation of M and N blood group glycoproteins by
treatment with pronase and subsequent chromatography o n
Sephadex and DEAE-cellulose. Preliminary identification of
the cleavage products indicated that their primary structures
are different.
F. Egarni (Tokyo, Japan) found the acidic heteropolysaccharides hovatin-sulfuric acid and hovaminic acid in the liver of
marine gastropods; these acids contain fucose, mannose,
glucose, galactose, and galactosamine; the former also contains sialic acid. But hovarninic acid also reacts with thiobarbituric acid.
On hydrolysis of ovomucoid, J . Montreuil (Lille, France)
obtained 15 cleavage products which led to the following
tentative structure for ovomucoid [*I:
I60
+Gal+GN-Ac-Man
.
Man+Man+Man+GN-Ac-Asp+Thr
L.
Gal +Man +GN-Ac+Man
R. G. Spiro (Boston, Mass., U.S.A.) degraded thyreoglobulin by four different methods into two glycoproteins with
molecular weights of 1250 and 4100. The smaller fraction contains no sialic acid.
2. Degradation of Glycosaminoglycans and
Glycoproteins by Redox Systems and Radiation
L. Sundblad (Stockholm, Sweden) and W . Pigman (New York,
U.S.A.) spoke about the effect of X-rays on the viscosity of
hyaluronic acid and on the redox depolymerization of the
same substance and other polymers. The viscosities of solutions containing polysaccharides or synthetic polymers are
reduced both by irradiation and by the action of autoxidants such as ascorbic acid or cysteine. Chemical bonds
are cleaved by the free radicals formed. G. 0. Philips (Cardiff,
Britain) was able to show that the same radiation dose had
different effects, depending on the state of aggregation (crystalline, freeze-dried) of the substrate. K . S. Dogson (Cardiff,
Britain) irradiated the 6-0-sulfates of various monohexoses
with X-rays and found that the glucose ester was the most
stable.
3 . Physicochemical Properties and Biological
Importance of Glycosaminoglycan and
Glycoprotein Solutions
M . B. Muthews (Chicago, I l l . , U.S.A.) reported on the molecular evolution of connective tissue. Although its content of
chondroitin sulfate C has remained unaltered, that of chondroitin sulfate A is much higher in evolutionary primitive animals and decreases on rising in the evolutionary scale.
L. Sundblad (Stockholm, Sweden) studied the ratios of some
proteins and mucoproteins in the synovial fluid and serum of
patients with and without arthritis. In those with rheumatic
arthritis only alterations in the proteins were observed.
H. Faillard (Koln and Bochum, Germany) reported on the
effect of enzymes on the physiological activity of intrinsicfactor mucoids. The loss of activity after treatment with
neuraminidase could be compensated by the addition of
strongly acidic ion exchangers. Both its bonded sialic acid
and the ion exchanger make the mucoid trypsin-resistant. Its
bonding capacity for vitamin B12 is not affected by the treatment with neuraminidase.
4. Covalent Bonds between Amino Acids and Sugars
in Glycoproteins
A . Dorfman (Chicago, Ill., U.S.A.) found that patients suffering from gargoylism d o not have chondroitin sulfate B attached in the normal fashion to a protein; instead, it is extremely soluble. L. Roden (Chicago, Ill., U.S.A.) studied the
sugar-protein bond in acidic mucopolysaccharide/protein
complexes and isolated xylosylserine and galactosyl-xylosylserine from heparin; this shows the significance of xylose as
the bonding unit for attaching the mucopolysaccharide to the
protein. The following structure was proposed:
Protein
+GN +Gal+Xyl+Serine
Protein
[*] G N = glucosamine, Ac = acetyl.
Angew. Chem. interntit,Edit. Vol. 4 (1965)
No. 2
5. Bios ynthe s is of the C a r b o h y d r a t e P o r t i o n of
G l y c o p r o t e i n s and G l y c o l i p i d s
T he intermediates in the biosynthesis of plasma glycoproteins
were discussed by R . J . Winzler (Chicago, Ill., U . S . A . ) .
[14C]Glucosamine is rapidly removed from the plasma an d
converted by microsome fractions from liver homogenates into
UDP-N-acetylglucosamine vier a series of still unknown intermediates. T he product transfers th e acetylglucosamine residue
to a n acceptor (peptide chain). Since no radioactivc oligosaccharides were found. it is assumed that oligosaccharide
units a re formed by interlinking of individual sugars. S . Roseman (Ann Arbor, Mich., U.S.A.) gave an excellent survey of
the investigations being carried o u t in his laboratories. Fo u r
enzyme systems catalyse the transfer c f sialic acid (as C M P -
sialic acid) to acceptors: I . Lcoli extracts (transfer t o colominic acid); 2. mammary tissue from lactating rats (transfer
t o low molecular-weight p-D-galactosides, e . g . lactose); 3. an
enzyme from the submaxillary glands of sheep (transfer t o
sheep mucin an d fetuin treated with neuraminidase); an d 4.
a soluble enzyme from goat colostrum, which incorporates
sialic acid into high a n d low molecular-weight substances.
With the last enzyme an d lactose as substrate, 2+3-sialyllactose is not formed as with the enzyme from the mammary
tissue o f lactating rats, but the 2+6-isomer is formed instead.
Th e isolation of nucleotides with t h e general structure sialic
acid -+Gal + G N - A c -+U DP makes it again appear less
likely t h at the transfer of sialic acid is t h e last step
in the biosynthesis of the carbohydrate chains in glycoproteins.
[VB 864/168 IE]
German version: Angew. Chem. 77, 176 ( 1 9 6 5 )
4th International Congress on Detergents
T h e 4th International Congress o n Detergents was held in
Brussels (Belgium) from September 7th t o 12th, 1964 [*I. Th e
program was divided into three main groups: Th e chemistry
of detergents (Section A), the physics o f detergents (Section
B), and applications of detergents (Section C).
T h e world output of surfactants in 1963 was 22. 106 tons,
according t o W . Hagge, Leverkusen (Germany). Th e increase
in production of detergents since 1958 lies above the average
increase for the overall production o f chemicals an d approaches the rate of increase o f plastics production. If the
index of 100 is taken for th e year 1958, then the index for the
world output of surfactants in 1963 is 177, for plastics it I S
a bout 200, and for th e average of all chemical products it is
a bout 155.
G. G. Eberhrwdt and W . A . Butte, Marcus Hook, Pa. (U.S.A.),
reported on a catalytic telomerization using aromatic hydrocarbons a s telogens a n d ethylene a s taxogen; this process
leads t o liquid or wax-like products, depending on the
partial pressure of t h e ethylene. Th e catalyst for the reaction
is a n organolithium co m p o u n d , e.g. butyl-lithium in hexane,
which is chelated by a tertiary amine such as triethylenediamine or N,N'-tetramethylethylenediamine.Catalytic systems of this type accelerate th e rates of chain propagation an d
transmetallation so much that the telomerization can proceed
under mild conditions. Th e am in e component must not
contain a ny active hydrogen (including aromatic, allylic, or
benzylic hydrogens). This is why tertiary aliphatic amines ar e
used; moreover, a n excess must b e used, since the equilibria
(a) and (b) must be displaced t o th e right as much a s possible.
LiR I - N R ~ \.R3N.LiR -t NR3
<--
R3N.LiR
la)
(R3N)2.LiR
(b)
The telomerization can only be carried o u t with e t h y l e n e
as taxogen, for all other olefins tend t o act preferentially as
telogens because of their acidic allylic hydrogens. If benzene
is used a s telogen, then I-phenylalkanes ar e obtained with
alkyl chain lengths in statistical distribution. In contrast,
with toluene, the transmetallation occurs in th e side chain.
Here, too, a statistical distribution results, th e products being
90 %, I-phenylalkanes with uneven numbers of carbon at o ms
I -(m-methylpheny1)alkanes. T h e o p tim u m tema nd 10
perature for the reaction lies between 105 an d 115 "C.
T w o lectures were devoted t o alkylation o f aromatics. H . M .
Friedmrin, Cranford, N.J. (U.S.A.), described the reaction
[*I The reports given at the Congress are to be published
in three
volumes by Gordon and Breach, Science Publishers, Inc.,
150 Fifth Avenue, New York 11, N.Y. (U.S.A.), by the middle
of 1965.
4 i i ~ e w Chem.
.
interncct. Edit.
VcI. 4 (1965)
No. 2
of naphthalene with nonene (propene trimer), which is
carried o u t as a discontinuous process. T h e catalyst used
consists of 50 %, BF3 in 85 %, H3P04 an d has t h e advantages
over conventional Friedel-Crafts catalysts such a s H 2 S 0 4 and
96 02 A12C1,j o r AIC13-HCI [cf. the lecture by R. MortinezGoyol, Madrid (Spain), o n the production of dodecylbenzene
by alkylation o f benzene with propene tetramer] of affording
higher yields o f monoalkylated naphthalenes an d of yielding
products of better color. Th e highest yields of monoalkylnaphthalenes a r e obtained between 45 an d 5OoC (0.8 mole
plus 0.03-0.05 mole of dialkylnaphthalenes an d 0.15 mole
o f unchanged naphthalene). lncrease in the concentration of
catalyst from 8.1 t o 15.0 :( does not result in any significant
increase in t h e yield of nionoalkylated product. T h e olefin :
naphthalene ratio used is I : 1 ; this is remarkable, since in all
other alkylation reactions t h e aromatic component must be
used in excess.
Another important topic dealt with was the synthesis of nonionic detergents. W. T. Weller, Port Sunlight, Cheshire
(England), isolated pure poly(ethy1ene glycols) of formula
HO(C2H20)nH, where n = 1-6, by fractional distillation of
a complex mixture of polyglycols ( SH ELL PEG 200); t he
purity of the products was checked by gas chromatography.
T h e monosodium salts of t h e pure glycols were then treated
with t h e p-toluenesulfonate of a fatty alcohol; this led t o
non-ionic detergents of general formula RO(C2H40),H,
~~
C12H25, an d n = 1-6. R. Celcrdes, Barwhere R = C I O Hor
celona (Spain), and C. Payuot, Bellevue (France), reported on
t h e preparation o f esters o f poly(ethy1ene glycols) by alcoholysis (transesterification) of fatty acid methyl esters with
the polyglycols.
G. L. Hollis, Billingham, Durhamshire (England), spoke
ab o u t so me regularities in systems containing ethylene-oxide
condensation products. Straight-chain an d branched primary
alcohols a n d branched alkylphenols were condensed with
ethylene oxide, an d t h e surfactant properties of the products
were investigated. These properties vary with the content of
ethylene oxide, b u t nonetheless in every series there is a
limiting value for the hydrophobic chain length beyond which
no improvements in surfactivity can be obtained independent
o f t h e ethylene-oxide content. Examples were given o f how
t h e incorporation o f propylene oxide into the chains can
improve the surfactant properties.
D . L. Bailey, J . H. Petersen, an d W . G. Reid, Tonawanda,
N.Y. (U.S.A.),considered siloxanejalkylene oxide copolymers
a s an unusual class of non-ionic detergents. T h e properties of
methylsiloxane/alkylene oxide copolymers(1) were compared
with those o f conventional surfactants.
161
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