TetrahedronLetters No. 4, pp 307 - 310, 1974.
BIOSYETBESIS
PergsmonPress. Printed in Grert Britsia.
OF THE SECURINEGA
SPECIFIC
INCORPORATION
ALKALOIDS-I.
OF TYROSINB.
Ronald J. Parry Department
Of Chemistry,
Waltham,
Brandeis University
Massachusetts,
U.S.A.
(Receivedin USA 2 November 1973; receivedin UK for publication10 Plants of the genus Securinega of unique tetracyclic
alkaloids
We wish to report experiments novel biosynthetic Sufficient
(family Euphorbiaceae)
of which securinine
indicating
investigation
from L-lysine;
this prediction. of the remaining
2
evidence
a group
(1) is the most abundant.
that these alkaloids
of the biogenesis
preliminary
Much greater
1
are formed by a
of piperidine
that the piperidine
experiments
interest surrounds
or tyrosine.
ring of 1 will be
the question
support
of the origin
skeleton.
of the alkaloid might be derived
such as phenylalanine
alkaloids has
in our laboratory
eight carbon atoms in the securinine
to us that this portion amino-acid
elaborate
1973)
pathway.
been carried out to allow one to predict derived
December
It occurred
from an aromatic
This communication
presents
serves as a specific pre-
that L-tyrosine, but not L-phenylalanine,
cursor of securinine. Administration
of DL-2-14 C-tyrosine
to young Securinega
suffruticosa
(Pallas) Rehder plants by the cotton wick method gave after 14 days radioactive securinine
(0.007% incorporation).
3
Administration
of 'H(G)-L-phenyl-
alanine to _S. suffruticosa
under similar conditions
yielded radioinactive
urinine.
suggests
cannot convert L-phenyl-
alanine
This observation
that Securinega
into L-tyrosine by hydroxylation;
in other Angiosperms.
2
The purified
this phenomenon
radioactive 307
sec-
has been observed
securinine
obtained by
308
No. 4
administration piperidine
of 2-i4 C-DGtyrosine
was degraded
to N-methyl-2-(o-vinylphenyl) sequence: 495
(2) by means of the following reaction
zzo4
,
LiA1I-b, q
g
Hofmann Elim.
CHsI
l
EH20
l
-
Cleavage
of the vinyl group present
the liberated
in 2 with osmate-periodate
formaldehyde with dimedone
yielded
radioactive
aldehyde.
The specific activity of the purified
responded
to 92% of the activity of the piperidine
via a benzoquinolizine
and subsequent
recyclization:
derivative
dimedone-form-
dimedone-formaldehyde
cor-
derivative -2.
This result prompts us to suggest that the biosynthesis proceed
and trapping of
of securinine
(2) which undergoes
ring-fission
-----+ 4 0
Ii
Ho
,/
Y
6’
-____
l
F -1
0
may
lo.
WY
4
Similar ring-fission phenanthridine synthesis
alkaloids
are associated with the biosynthesis
from protoberberine
of the quinoline
In conjunction which
processes
alkaloids
attached
to the nitrogen
and with the bio-
from indolic precursors.
the structure lo of phyllantidine
is of interest:
8,9 (4)
it appears that the oxygen
atom of 4 may correspond
We are continuing
oxygen of tyrosine. of Securinega
of Cinchona
with the above proposal,
occurs in -S. suffruticosa
precursors'
of benzo-
to the phenolic
hydroxyl
to pursue these and other aspects
alkaloid biosynthesis.
Acknowledgements: We wish to thank the Chemistry
department
for a starter grant.
Special
thanks are due to Prof. T. C. Huang for supplying us with S. suffruticosa seeds and to Dr. Seiichi Saito for a generous gift of securinine.
References: 1.
V. Snieckus,
"The Securinega
Alkaloids"
in The Alkaloids,
p. 425 ff, F.d. by R. I-l.F. Manske, Academic 2.
I. D. Spenaer,
"The Biosynthesis
Secondary Metabolites"
Press, New York, 1973.
of Alkaloids
in Comprehensive
Vol. XIV,
and of Other Nitrogenous
Biochemistry,
Ed. by M. Florkin and E. I-I.StOtsj Elsevier Publishing
Vol. 20, p. 231 ff, Co., Amsterdam,
1968. 3.
Incorporation
4.
2. Horii, M. Ikeda, Y. Yamawki, Tetrahedron,
based
2,
on quantity
2101
of I.-tyrosine administered. Y. Tamura, S. Saito, and K. Kodera,
(1963).
5.
T. Nakano, T. H. Yang, and S. Terao, Tetrahedron,
6.
A. R. Rattersby,
R. Binks, W. Laurie, G. V. Parry, and B. R. Webster,
J. Chem. Sot., 7459 7.
A. R. Hattersby,
19, 609 (1963). =
(1965).
R. J. Francis, E. A. Ruveda, and J.Staunton,
Commun., 89 (1965).
Chem.
No. 4
310
8.
A- R. Battersby and R. J. Parry, Chem. commun.,
9.
A. R. Battersby and R. J. Parry, ibid., 31 (1971).
10.
Z. Horii, T. Imanishi, M. Yamauchi, Munavalli,
Tetrahedron
M.
30 (1971).
Hanaoka, J. Parello, and S.
Lett., 1877 (1972).