BIOCHEMICAL
Vol. 76, No. 2, 1977
AND BIOPHYSICAL
RESEARCH COMMUNICATIONS
PROTECTION OF CHLOROPHYLL BY PHOSPHOLIPIDS William Department
Received
March
Stillwell
FROM PHOTOOXIDATION
and H. Ti Tien
of Biophysics, East Lansing,
Michigan Michigan
State 48824
University
21,1977
SUMMARY: Rapid photooxidation of chlorophyll in chloroform was shown to be partly inhibited by various biologically significant compounds including Scarotene, xanthophyll and several synthetic and natural phospholipids. Protection from bleaching by phospholipids was most evident for the phosphatidyl cholines and was less for the phosphatidyl ethanolamines. Protection was independent of the chain length and unsaturation of the esterified fatty acids and depended primarily on the nature of the polar head group of the phospholipids. The irreversible for
many years.
quantasomes
Bleaching
(4),
of chlorophyll the
could
the
(10)
have
be slowed
has been
proposed
to higher
membrane. also It
However,
be playing
in;
the
in liposomes
D,L-a-cephalin
and phosphatidyl
monooleate,
(E)
ethanolamine,
brain
(B),
(E),
L-a-phosphatidyl
(F) > asolectin
best
(A),
(D),
monostearate
in preventing
the polar
more
glyceryl
were
following
was obtained egg>
lecithin
from bovine
choline
glyceryl
the
> L-a-phosphatidyl
extract,
extracts,
Since
monoricinoleate,
II-s
from
and
some protection.
materials III-E
ethanolamine,
lecithin
intermediate.
type
with
of light
photooxidation,
biological
(G) and (H),
in phosphatidyl
amounts
from
(vegetable)
type
cholines,
from
chlorophyll
(H),
eggs >
(C) > brain
The phosphatidyl
the ravages
from
choline
IX-E
brain
chlorophyll provided
extracted
type
bovine
RESEARCH COMMUNICATIONS
of chlorophyll
L-a-phosphatidyl
L-a-lecithin
(A).
tested
of phospholipids
(Figure
II
in protecting
AND BIOPHYSICAL
for
(adjacent
maximum protection ring
of chlorophyll
BIOCHEMICAL
Vol. 76, No. 2, 1977
The aerobic choline,
Figure 4. L-a-phosphatidyl
in
the lipid
of chlorophyll to in free
photodegradation type III-E/chlorophyll
is partly
bilayer toward
responsible
photooxidation
compounds
were
also
chlorophyll
from
Figure
Chlorophyll
was very
3.
photooxidized
in the
pheophytins)
to prevent shown
about
(Figure
the marked
to the
increase
of the
in stability
and quantasomes
solutions
unstable of acetic
for
a long
These
the photooxidation to signiciantly
results
as opposed
acid.
Acid
time.
the as the
for
their
was rapid
lability
Some protection
protecting
in
was afforded
by
(a compound
(2,6)).
of photobleaching,
classic
in
when
(resulting
and benzoquinone
rate
ability
are presented
of bacteriochlorophyll slow
as effective
to test
and degradation
the antioxidant-a-tocopherol
one fifth
Xanthophyll however,
agent,
it
was
B-carotene
3).
Recently liposomes
for
photooxidation.
presence
has been known
the base-pyridine,
only
of chlorophyll as a function mole ratio.
in chloroplasts
added
to protect
was also
RESEARCH COMMUNICATIONS
solution.
Other
known
AND BIOPHYSICAL
several
papers
in an attempt
was demonstrated
have appeared
to model
on incorporation
the thylakoid
to be much more resistant
membrane to photooxidation
237
of chlorophyll (15-18).
into
Chlorophyll
in liposomes
than
Vol. 76, No. 2, 1977
in free
solution
(6).
the protection outlined is
In free by the
solution time
increase than
Therefore,
of phospholipids 4 the
phosphatidyl
the
in liposomes, range
increase
in
of chlorophyll
presence
of such hyrophobic
well
as water
of degrdation
does not
its
stability free
efficiency
ACKNOWLEDGEMENTS: This Service Grant, GM-14971.
30 molecules ratio
about
1.
further
can not
solution
photooxidation appears
accommodate
of phospholipid. is well
into
of chlorophyll
to be the result bilayer
as e-carotene
be incorporation
as well
the
was supported
are
currently
by a United
-in
of proper as the immediate
and xanthophyll.
of appropriate
Such studies work
reaches
photooxidation.
in the phospholipid
proteins.
in chloroform
maximum protecting ratio
of
as
ratio.
liposomes
toward
molecules
of chlorophyll
in a substantial
per
terms
III-E/chlorophyll
mole
result
chlorophyll
be provided soluble
type
reaches
in
of chlorophyll
choline,
of chlorophyll
for in
to that
might
rate
the phospholipidJchlorophyl1
orientation
stability
be understood
to the photooxidation
Chlorophyll-containing
one molecule
as opposed
could
choline/chlorophyll
choline
in protection. about
stability
choline
phosphatidyl
phosphatidyl
The great
increased
AND BIOPHYSICAL RESEARCH COMMUNICATIONS
the L-a-phosphatidyl
maximum protection
vivo
This
In Figure
against
Additional
more
role
here.
plotted
BIOCHEMICAL
Additional
lipoproteins
as
in progress. States
Public
Health
REFERENCES: 1. 2. 3. 4. 5. 6. 7. a. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18.
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