Journal
of
MOLECULAR STRUCTURE ELSEVIER
Journal
of Molecular
Structure
349 (1995)
Raman
Vibrational
401-404
Activity
Optical
of
Disaccharides A.
F. Bell,
L. Hecht
Chemistry
and
Department,
L. D. Barron The
University,
Glasgow
G12 8QQ,
United
Kingdom.
1. INTRODUCTION Vibrational Raman
Raman
scattered
optical
light
from
circularly
polarized
solution
stereochemistry
particularly in
the
the
normal
anomeric
features
groups
assignments
to
is
the
the
together
by the
is
6 of
then two
a
C-O-C
bond
known
carbon
atom
hand
trapped
example
to
or
of
does
undergo
conformation
particular feature
Previous
here to
the are
studies
have
perspective,
relative
in determining
left
of
coupled on
including
and
attention
and
probe
extensively
a new
presented
and
u-
or
that the
as of
form
not
described
all
dominant
disposition
extends
the the
of
the
ROA
glycosidic
link
conformation
directly formula
on
the
whether the
Cl-01
links
is
to
This
link
carbon of
of
the
bond
glycosidic
numbering
can
atom
form 1, 2, 3,
then
residue.
atom
of link
on
of
may
the have
residue
axial
and
by
naming
oxygen scheme
If
it
a residue,
mixture
The
non-reducing
possible
joined
a residue,
an equilibrium
Figure 1 for the a(l-4) linked disaccharide, D-maltose. 0022-2860/95/$09.50 0 1995Elsevier Science B.V. All rights reserved SSDI 0022-2860(95)08794-X
carbon residue.
atomic
residues
a non-reducing
anomeric
a reducing
with
and
either carbon
is called
these
attached
D-glucose link.
and
producing
depending of
glycosidic
the
as
form
two
anomeric
and
mutarotation is
of
residue
the
involve
8-anomeric are
the
one
classification
structural
consist
involves
8-configuration
Further
atoms
link
anomeric
link
forms
in the
respectively. carbon
If the
the
it is free an u-
and
right
in
Carbohydrates
are
spectrum.
work
to
Cl-3 1.
stereochemistry
The
here
anomeric
anomeric
either
group C4,Sl.
discussed
in a single
other
ROA
difference
chiroptical
coordinates
information,
single
respect
a new
molecules
rich
intensity
polysaccharides.
another.
trapped
the
a
with
important
disaccharides
between 4, or
CH,OH
disaccharides
most
and
oligoAll
in
the ring
with
normal
provide
small
as
monosaccharide
of
around
molecules
biological
can
the
is emerging
as the
resulting
configuration,
hydroxyl
di-,
of
ROA
(ROA),
chiral light,
samples
modes that
central
which
incident
favourable
demonstrated
activity
is
is
equatorial, the
two
atom.
An
shown
in
402
Non-reducing residue
Reducing residue
OH 1 The structural
Figure
formula
and numbering
scheme
for
D-maltose
2. ROA OF DISACCHARIDES The ROA
spectra
number
of
signals
similar
intensities, The two
new
normal
important
Wavenumber
ROA
Table
arising
couplet
to
to
from
centred
Couplet
glycosidic
display
addition
to
have
types
quite
and width
disaccharide
of low
linkage
wavenumber
type and
configuration
many
different
and conformations.
of
have been
exo-
and
in monosaccharides link
calculated
has been
found
assigned
endocyclic
C61 with
for in all
glycosidic position of ROA
disaccharides
couplet
CCO, C71.
the disaccharides
ROA couplet
and sign
by
additional
1
Position
a
at w 430 and 917 cm-‘.
spectrum
mixtures
at IV 430 cm-’
residues
430 cm”)
the ROA
complex
in
can
linkage
are found (-
of
link,
signals
different
deformations the
only D-glucose
glycosidic
These
signals
in this region bending
the
for
signs,
of these
analysis
and OCO
containing
itself.
Glycoaidic
modes
coordinate COC
contributions A
sensitive
D-glucose
or even opposite
The normal CCC,
signals to
most
2.1 Low
of disaccharides
deconvoluted couplet
D-maltose
~~(1-4) ax.-eq.
431 (+,-)
31
D-cellobiose
p(l-4)
eq.-eq.
440 (-,+I
34
D-isomaltose
ar(l-6) ax.-eq.
424 (+,-)
39
D-gentiobiose
B(l-6)
eq.-eq.
420 (-,+)
41
D-laminaribiose
f5(1-3) eq.-eq.
425 (-,+)
33
D-trehalose
cr(l-1) ax.-ax.
431 (+,-I
19
width
403
consisting
of
D-glucose
and negative
at
positive
at
centred
within
the
ROA
high
that
the
generating spectrum making the
wavenumber change
it has similar centre
the ROA
signals.
D-glucose
important and
width
between
dependency
is
bands
contributing
for
going
This couplet is positive at species and negative at low
species.
The
fact
a-linked
to
non-reducing
B-linked
as no couplet that the rest of
is
signs
species
play
low and
couplet
the
and that
residue
In addition,
this
and that
in all the disaccharides
the
that
all the disaccharides from
origins of
so far.
a-linked
B-linked
it is possible
of
dependence Raman
for
strongly
deformations
a crucial
is in evidence the glycosidic
role
in
in the ROA link is also
a
Table
of
this
the
function signals
ROA
linkage of
together
ROA
I, which
with
lists
the centre
couplet, type
the
it
is
and
the
differences
in
the
appearance
of opposite
wavenumber
clear
that
width
of
together
there this
is
a
couplet.
with strong This
the
separation
of
the
parent
of
additional
Raman
bands
sign for the two
anomeric
forms.
ROA
L.l _5.0x103
Figure
2
The for
backscattered the
of
contributions.
inspection
sign
studied
for
on
anomeric of
From
residues wavenumber
a + 20 cm -’ range
signals
suggests about
high
range
cm-’
Raman ++ 350
to
(IR 1500
+
IL)
cm-’
and
ROA
in aqueous
(IR
-
solution.
IL)
spectra
of
D-maltose
404
2.2 The One
917 an-1
of
couplet
the
positive
D-glucose, the
at low is
has two
ar(l-61 linked couplet
and negative to
glycosidic
links
or-cyclodextrin
this
per
of
double
molecules
couplet
wavenumber
and
broaden
deformations
are
intimately
(In
is
of found
the
to
sign
collapse This
in the
in
In addition,
reversed
of
largest
value
in
D-maltose shift
indicates
modes
in
intensity
intensity,
clearly
normal
a
D-maltotriose,
is
the
groups
is
at w 917 cm-’ in
trimer,
than the
hydroxyl
considerably. involved
the
ac-cyclodextrin
greater
the
spectra
disaccharides.
in
and
ROA
centred
the 8-linked
magnitude
deuteration
disaccharide
at high wavenumber
in any of
D-isomaltose.
an order
Upon
in the
approximately
disaccharide,
is almost
features
not appear
found
encountered.)
Couplet
interesting
and does
intensity
which
Glycosidic
most
the this
usually and
to
that
lower C-O-H
responsible
for
this
couplet. In a normal repeating
coordinate
unit,
described
from
assigned
In
to
atoms
addition,
a
C-O-H
that
coordinates
of the glycosidic
C-O-H
hydrogen persist
ROA
found
some
degree
band
D-maltose
calculated
mode. can
be
to
in aqueous
band All
the
that
the of
at
above to
cm-’
cm-’
lead
for
the
coordinates
intramolecular
and
important
to
was
stretching
stretching
OZ-H.a.03’
was noted
and C3’-OH
923
C-O-C
D-maltose
is also
were
data
the
the ring
structure
solution
946
and C2-OH
observed
assigned with
suggest
crystal
at
is the dimer
link and contributions
Raman
link interacting the
which
but also the ring atoms
second
and
in
for
the or(l-4)
couplet
deformations, bond
to
a
of
deformation
conclusion and
this
sensitive
vibration
the linkage
deformations.
of amylose,
conformation
a
as a skeletal
not only
analysis
thought
the
to
generation
of this couplet. The
sign
consequence the two
change
in
D-isomaltose
of the different
molecules
linkage
relative
have the same absolute
This demonstrates
to
conformations
the conformational
D-maltose
these
configuration
sensitivity
two
is
probably
molecules
at all
adopt
the chiral
a as
centres.
of the couplet.
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L. D. Barron
2.
Z. Q. Wen,
L. Hecht
and L. Hecht,
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3. Z. Q. Wen,
L. Hecht
and L. D. Barron,
4.
L. D. Barron,
5.
Z. Q. Wen,
6. M. Dauchez,
Adv.
A. R. Gargaro
Spectrosc.,
21 (19941 235.
Protein
Science,
and Z. Q. Wen, Carbohydr. and G. Vergoten,
443.
3 (1994) 435. Res., 210 (19901 39.
L. D. Barron and L. Hecht, J. Am. Chem. Sot., P. Derreumaux
116 (1994)
11.5(1993) 28.5.
J. Comput.
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Lagant,
Legrand
14 (19921
263. 7. M.
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G.