in etwa 30proz. Ausbeute ./VMethylpiperidyl(2)essig
Die Ergebnisse zeigen, daß das heterocyclische Ge
säure und CHJ3 mit 52 bzw. 44% der eingesetzten spe rüst der Pa/ncaAlkaloide auf dem LysinCadaverin
zifischen Radioaktivität. Das bedeutet, daß sich die Mar Wege aufgebaut wird und mit Acetat (gegebenenfalls
kierungen beider Bruchstücke ungefähr wie 1:1 verhal Acetoacetat) in Reaktion tritt. Dabei dürften J 1Pipe
ten, während sie bei einer Biosynthese des Methyliso
pelletierins aus 4 Acetateinheiten im Verhältnis 3:1
rideinVerbindungen wie das in jungem Gewebe von
Punica granatum nachgewiesene 3[J1Piperideyl(2')]
stehen sollten. Im Methioninversuch (Versuch 6) erwies propylen (4)8, in das ebenfalls Lysin[U14C] inkorpo
sich Isopelletierin (1) als radioaktivitätsfrei. Die mar riert werden konnte9, die Rolle von Intermediären
kierten Alkaloide Methylisopelletierin (2) und Pseudo spielen. Über den Zeitpunkt der Methylierung ist noch
pelletierin (3) wurden einer Entmethylierung unter nichts bekannt. Obgleich Pipecolinsäure in Pflanzen
worfen 1. Dabei entfielen 95 bzw. 93% der spezifischen ebenfalls aus Lysin gebildet wird10 hat sie für die
Radioaktivität auf die in Form des Triäthylmethyl Biosynthese der PimtcaAlkaloide keine Bedeutung
ammoniumjodids isolierten Methylgruppen.
(Einbauversuch 1).
7
8
A. A. s ir o t e n k o , Mikrochim. Acta [Wien] 1955, 1.
M. E.
chemistry
9
0
B. T. c r o M w e L L , „The Biogenesis of Piperidine Alkaloids“,
in: J. B. r id h a M u. T. s w a in , „Biosynthetic Pathways in
Higher Plants“, Academic Press, London 1965, S. 147.
H. r . s c h ü t te u . G. s e e L ig , Z. Naturforschg. 22 b, 824
r
o b e r t s , B. T. c r o M w e L L u . D. E.
, 771 [1967].
w
e b s t e r , Phyto
P
6
1
[
1967].
Uptake of Polynucleotides by Intact Mammalian buffer pH 7; 0.066
M
NaCl] and keeping this solution at
2
0° for 5 minutes. Poly C: I was prepared accordingly.
From Tab. 1 the following results can be deduced.
Poly U is capable only of adsorption to the cell wall
Cells (IV)*: Synthetic Homoribopolynucleotides
P. L. s ch eLL
and is prone to easy degradation which already occurs
during incubation at 30°. The decreased uptake at this
MaxPlanckInstitut für experimentelle Medizin,
Abteilung Chemie, Göttingen/Germany
3
0° incubation which is in contrast to RNA and the
(Z. Naturforschg. 23 b, 1117—1119 [1968] ; eingegangen am 25. März 1968)
other ribopolymers, provides additional evidence that
uptake in these latter cases cannot be explained by a
succession of polymer degradation, uptake of the frag
ments, and reassembly occurring inside the cell.
Uptake of poly A proceeds similar to that of RNA
with the exception that it occurs in smaller amounts.
When the double strand poly A : U is offered to the
cells, however, the amounts of material taken up into
the cell are increased remarkably as compared to the
single partners. This experiment has been carried out
by complexing poly UH3 and polyAC147. The same
results have been obtained when samples containing
poly UH3:A and samples containing poly U:AH3
were both treated analogously (Tab. 1).
L a M p so n et al. 1 and F ie L d et al. 2 reported recently
that poly C : Poly I (poly C : I) doublestrands can
induce in vitro as well as in vivo interferon formation
in mammalian cell lines. Microgram amounts suffice
to induce 100 fold stimulation of the effect. The present
note is intended to serve as a preliminary report on ex
periments in which the uptake of synthetic ribohomo
polymers and double strands thereof by Ehrlich ascites
tumor cells have been determined. Based on those
results a hypothetical possibility for interferon induc
tion by poly I : C has been lined out.
The experiments have been carried out with mouse
Ehrlich ascites tumor cells using the methods pre
viously applied for RNA uptake into such cells 3>4. The
Poly A and poly U being found inside the cells are
methods of differentiating uptake into the cell and ad practically equimolar which makes likely their entering
sorption at the cell wall by RNAse treatment have also as a double strand complex. The portion of polymers
been used according to this previous work. Poly AH3, adsorbed to the cell wall appears to contain a higher
poly UH3, poly CH3, and poly IC14 have been ob proportion of poly U. This has been determined by
tained by Schwarz Inc.; poly A is a kind gift of Dr. s t e r n -
RNAse washing of the cells. PolyA:U2 is taken up to
b a c h from this institute. Doublestrand formation5’6 a higher extent (additional 30 —50%) when compared
has been established by adding equimolar amounts of with double strands of the same molarity and radio
poly U in solution to a poly A solution [0.05
M
phosphate activity. The possibility of an equilibrium between
*
1
No. Ill of this series appeared in Hoppe Seyler’ Z. physiol.
3
P. L. s c h e L L , Z. Naturforschg. 2 2 b, 529 [1967].
Chem. 349, 14 [1968], for Nos. I and II see also citations
4 P. L. S c h e l l , Z. Naturforschg. 2 2 b, 995 [1967]
.
1
. c. 3’4.
5
6
7
G.
[Amsterdam] 2 6 , 457 [1957].
a v ie s and A. r ic h , J. Amer. chem. Soc. 80, 1003
F e L se n F e L d and A. r ic h , Biochim. biophysica Acta
G. P. L a M Pso n , A. A.
t y t e L L , A. K. F ie L d , M. M. n e M e s ,
and M. R.
h
iL L e M a n n , Proc. nat. Acad. Sei. USA 58, 782
d . r . d
[1967].
[1958].
P. L. s c h e L L , in preparation.
2
A. K. F ie L d , A. A. t y t e L L , G. P. L a M Pso n , and M. R. h iL L e -
M a n , Proc. nat. Acad. Sei. USA 58, 1004 [1967].
-
10.1515/znb-1968-0824
Downloaded from De Gruyter Online at 09/12/2016 12:24:25AM
via free access
Liebisch
