th  - 1988 - 51st ENC Conference

2 ~ I SOLID-STATE NMR STUDY OF THE STRUCTURE AND
DYNAMICS OF PLANT POLYESTERS AND INTACT PLANT CUTICLE.
Joel R. Garbow', Tatyana Zlotnik-Mazori ~, Lisa M. Ferrantello ~ and Ruth E. Stark ~. .
Life Sciences NMR Center, Monsanto Company, St. Louis, MO 63198 and #Department of
Chemistry, College of Staten Island, City University of New York, Staten Island, NY 10301.
Cutin and suberin are the structural polymers of plant cuticle, functioning in conjunction
with lipid waxes and carbohydrate cell walls as effective barriers to the environment. In this
poster, we report on a high-resolution solid-state 13C NMR study of these plant polyesters,
designed to determine how their substituted fatty-acid constituents are linked together in
a functionally useful way. Additional molecular information is derived from NMR analysis
of cutin-wax and suberin-cell wall assemblies, as well as from solid residues remaining after
partial depolymerization.
Cross-polarization magic-angle spinning 13C NMR spectra with dipolar decoupling have
been used to identify and quantitate the magnetically distinct carbons of these solid biopoly-
mers. In samples for which a subset of the aliphatic carbons is sufficiently flexible to yield
direct-polarization spectra with scalar decoupling, a quantitative comparison of immobile
and mobile groups has been made. 13C and 1H spin-relaxation experiments (Tip(C), Tip(H)
and TI(C)) have been used to probe polyester motions in the kHz and MHz frequency
regimes, to examine crosslink structures that maintain cuticle integrity and to explore the
nature of cutin-wax and suberin-cell wall interactions.
-- 3o j
A STATIC NMR IMAGE OF A ROTATING OBJECT
S. Matsui,* K. Sekihara, H. Shiono, and H. Kohno
Central Research Laboratory, Hitachi, Ltd.
P.O. Box 2, Kokubunji, Tokyo 185, Japan
An approach to imaging of a rotating object is described and demonstrated experimentally.
The principle is to apply field gradients such that the NMR signal from the
rotating object observed under the applied gradients results in appropriate scanning
in the spatial frequency domain, or the k space. The scanning pattern must cover the
k space as uniformly as possible. A static image of the rotating object can be obtained
from such a scanning pattern by suitable data processing.
When the whole object is moving, one must consider the field gradients in the
moving object frame, 6 (t), (not in the laboratory frame, CR(t)). Then, the signal
r
scanning pattern in the object-frame k space is
r
r
Here, D_ is a transformation depending on the object motion. In the case of rotation
about t~e Y axis at an angular frequency(u s , D G is given by
0 no/
D G = 0 s 1 st
t 0 cos ~ t
-sin ~s s
In our preliminary two-dimensional (x,z) experiment, a gradient sequence in the
laboratory frame, ~R(t) = (GoW t, 0, Go), was applied to obtain a spiral scanning
pattern in the object frame, k ~t) = (~G~tsinw t, 0, ~G^tcos~ t). A phantom,
r u U s
consisting of two water-filled capillaries ~l.SSand 2 mm i.d.), was rotated at 180
Hz. The obtained proton image was consistent with the dimensions of the phantom.
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