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Correlation between Phosphorylation and Chlorophyll-b Dissociation in Photosynthesis.

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[4]Peralkylated diazabutadienes ( 1 ) (R = CH3, R' = cyclopropyl, cyclohexyl, or benzyl) can be obtained in 10-35 yo yield
by direct condensation of biacetyl and a primary amine in
benzene at 980 "C.
[5] In view of the lower donor strength of compounds (Z),
comparison of the CO stretching frequencies of 2,2'-bipyridylnickel dicarbonyl [6] and the diazabutadienenickel dicarbonyls
(7) (e.g. R = OCH,: A1 = 2012, B2 = 1946 cm-l in Nujol)
leads to the expectation that bisdiazabutadienenickel(0j will
exist (cf. also [7]).
[6] R . S . Nyholm and L. N . Short, J. chem. SOC. (London) 1953,
2670.
[7] H . Behrens and A . Miiller, 2. anorg. allg. Chem. 341, 124
(1965).
120'6, resembled (I).THF in properties, and were analogously identified.
Received: March 22nd, 1966
[Z 183/19 IE]
German version: Angew. Chem. 78, 549 (1966)
[I] E. Wiberg, 0 . Stecher, H . J. Andraschrck, L. Kreuzbichler,
and E. Staude, Angew. Chem. 75, 516 (1963); Angew. Chem.
internat. Edit. 2, 507 (1963).
[2] R . Egger, Dissertation, Universitat Miinchen, I96 I .
Correlation between Phosphorylation and
Chlorophyll-b Dissociation in Photosynthesis
By Dr. B. Rumberg, Dipl.-Phys. P. Schmidt-Mende,
Dipl.-Ing. U. Siggel, and Prof. Dr. H. T. Witt
Germyl Compounds of Strontium, Barium, and Zinc
By Univ.-Doz. Dr. E. Amberger, Dipl.-Chem. W. Stoeger,
and Dr. R. Honigschmid-Grossich
lnstitut fur Anorganische Chemie
der Universitat Munchen (Germany)
Whereas silyl, MII(SiR3)2, and stannyl derivatives,
MII(SnR3)2, (R = CH3, C6H5) of the elements of the second
main group and sub-group have been extensively studied [ I '21,
analogous germyl compounds MII(GeR3)z have hitherto been
unknown.
Hexaphenyldigermane reacts with strontium or barium in
the molecular ratio 1 : 1 in liquid ammonia at -4o"C, giving
bis(triphenylgermyl)metal derivatives ( I ) .
(C6H5)3Ge-Ge(C6H&
(MI1
-
+ MI1
--f
MII[G~(C~HS)~IZ
Sr, Ba)
(1)
After removal of the ammonia at -35 "C the products are
extracted with tetrahydrofuran as yellow solutions, whence
they are recovered by evaporation of the tetrahydrofuran
and drying in vacuo,(2 days at 40 "C) as T H F adducts ( 1 : 1 ) .
They decompose with blackening without melting at 40 to
45 "C (Sr) and 60 to 70 "C (Ba). The adducts are sensitive to
air and somewhat to light, reduce AgN03 to Ag, and are
soluble in ammonia but insoluble in benzene and hydrocarbons; they are unstable in solution. Their compositions
were proved by determination of the content of alkalineearth metal and by C-H analysis. The THF-free compounds
( I ) could not be obtained.
Only small amounts of hydrogen are obtained on hydrolysis
with moist methanol because of the stability of triphenylgermane against hydrolysis :
Max-Volmer-Institut fur Physikalische Chemie,
Technische Universitat Berlin (Germany)
In the primary processes of photosynthesis, electrons are
transferred from water to triphosphopyridine nucleotide.
The rate of the electron transport is characterized by the rate
of the oxygen production which takes place simultaneously;
the intermediates can be identified by the wavelength of
absorption changes on irradiation with flashes of light. The
mechanism of the electron transport follows inter alia from
the analysis of the kinetics of absorption changesW A
cyclic and a non-cyclic phosphorylation can be coupled with
the electron transport [21.
The absorption changes at 478, 515, and 648 m p are caused
by a reaction ofchlorophyll-b (Chl-b). This reaction, however,
evidently does not participate directly in the electron transport 131. Addition of ethanol eliminates the absorption
changes of Chl-b without affecting those of Chl-aI, Cyt-f,
Cyt-b, and plastoquinone (PQ), or the oxygen production.
We have now found that the reaction of Chl-b is related
directly to phosphorylation coupled to electron transport :
The electron transport is not affected when the phosphorylation is blocked by a specific poison, such as desaspidine
[2,4J. Confirmation of these results is shown in Fig. 1 .
02
A
cyt-I
A
A T P n cycl
rn
+ ZnCll
2 MIGe(C6H5)3
( M I = K, Na)
-+
Zn[Ge(C6H5)3]2+ 2 MICl
(2)
After removal of theammonia in vacuo at -35 "C the product
(2) was extracted into tetrahydrofuran (yellow solution). On
evaporation of the solvent there remained a yellow adduct
(2).THF [reaction with KGe(C6H5)3] or a pale yellow
adduct Zn[Ge(C6H5)312.0.5THF.O,5NH3 [reaction with
NaGe(C6H5)3]. Both these adducts decomposed at 110 to
522
Chi-a,
o Chl-b
\
The triphenylgermane formed, and the tetrahydrofuran
liberated from the THF adducts by heating in vacuo, were
identified by infrared spectroscopy. Ammonolysis, as observed for the analogous silyl compounds "1, could not be
established.
Preparation of bis(triphenylgermyl)zinr. (2) was achieved by
reaction of zinc chloride with triphenylgermyl-sodium or
-potassium in liquid ammonia (molar ratio 1 : 2, -40 "C).
PO
Cyt-b
Desaspidine Concentration
-
Fig. 1 . Oxygen production, non-cyclic phosphorylation, cyclic phosphorylation, and absorption changes of plastoquinone (PQ) (at 254 mp),
cytochrome-b (Cyt-b) (at 405 mu), cytochrome-f (Cyt-f) (at 405 mg),
chlorophyll-aI (Chl-aI) (at 703 mu), and chlorophyll-b (Chl-b) (at
515 mw), as a function of the desaspidine concentration in illuminated
spinach chloroplasts.
The 100
rates correspond to 38 wnols Od(h.m& ChI) for the O r
production, to 116 ymole ATP/(h.mg Chl) for the non-cyclic, and to
240 winole ATP/(h.mg Chl) for the cyclic phosphorylation. All measurements were performed 10 min after addition of desaspidine. Excitation
time 5 min for 02-production, 0.02 sec for absorption change; light
intensity 3 x 105 ergs cm-2 sec-1. Temperature 20
Reaction volume 3 mi; chlorophyll content 0.1 mg. Additives (in
ymole) for 02-production: tris buffer 150 (= pH 7.2), KIFe(CN)6 10;
for non-cyclic phosphorylation: tris buffer 80 (= pH 81, MgC 1210.
K 2 H P 0 4 20, A D P 10, benzylviologen 0.1; for cyclic phosphorylation
(anaerobic): tris buffer 80 (= pH 8), MgC12 10, KzHP04 20, A D P 10,
N-methylphenazoniuin methyl sulfate 0. I , N-(p-chloropheny1)-N',N-dimethylurea 0.06; for absorption changes: as for 02-production or noncyclic phosphorylation. Oxygen determined manometrically, ATP uitlr
32P according to 161. Separation of the absorption changes of cytochromes according to [71.
Angew. Chem. internat. Edit.
/ Vol. 5 (1966) J No. 5
At desaspidine concentrations of 10-7 M the cyclic and the
non-cyclic phosphorylation (measured by the formation of
ATP) and the electron transport (measured by 02-production)
are unchanged. With 10-6 M desaspidine, cyclic phosphorylation is blocked, and only at 2 x 10-5 M non-cyclic
phosphorylation as well. The 02-production, i.e. the electron
transport, is not blocked at desaspidine concentrations below
2xlO-4M. The absorption changes of the participants of
electron transport such as Chl-at, Cyt-f, Cyt-b, and PQ
show the same dependence on the concentration of desaspidine as the 02-production. However, the reaction of Chl-b
parallels the behavior of the non-cyclic phosphorylation
(Fig. 1). Addition of ethanol also blocks phosphorylation
without interrupting the electron transport 151.
From the position of the absorption changes of chlorophyll-b
it can he supposed that a dissociation of H+-ions[sl from
chlorophyll-b takes place. Obviously phosphorylation and
this dissociation (pH-change) are related to each other.
Received: April 12th, 1966
[Z 202 IE]
German version: Angew. Chem. 78, 550 (1966)
[ I ] H . T . Witt, B. Rumberg, P. Schmidt-Mende, U . Siggel,
B. Skerra, J. Vater, and J . Weikard, Angew. Chem. 77, 821
(1965); Angew. Chem. internat. Edit. 4, 799 (1965).
121 Z.Grornet-Elhananand D.I.Arnon, PlantPhysiol.40, 1060( 1965).
[ 3 ] B. Rumberg, P . Schmidt-Mende, B. Skerra, J . Vater, J . Weikard, and H . T . Witt, Z . Naturforsch. ZOb, 1085 (1965).
[4] H . Baltscheffsky and D . Y . de Kiewiet, Acta chem. scand. 18,
24G5 (1964).
[5] H . Baltschqffsky, Acta chem. scand. 17, 308 (1963).
[6] M . Avron, Biochim. biophysica Acta 40,257 (1960).
[7] B. Rumberg, Biochim. biophysica Acta 102, 354 (1965).
[8] A. Weller, J. Amer. chem. SOC.76, 5819 (1954).
CONFERENCE R E P 0 RTS
Recent Results of Antibiotics Research
Ch. Tnmm, Base1 (Switzerland)
T o date, 14 antibiotics termed verrucarines and roridines [ I ]
have been isolated from Myrothecium verrucaria and M .
roridum. The principal products are antifungal and, in particular, potent cytostatic agents; however, they are also very
toxic
Verrucarine E, one of the minor N-containing metabolites, has
been assigned the structure of the hitherto unknown 4-acetyl2-hydroxymethylpyrrole (I). On basic hydrolysis, verrucarines A, B, J, and H, and roridines A , D, and E, yield the
same sesquiterpene alcohol, verrucarol (C15H2204), but they
differ in the products of acidic hydrolysis. Verrucarine A
(C27H3409) gives cis,trans-muconic acid and verrucarinolactone (C6H1003), verrucarine B (C27H3209) gives cis,transmuconic acid and 2,3-epoxy-3-methyl-5-valerolactone
(CsH802); verrucarine J (C27H3208) gives cis,trans-muconic
acid and the known 3-methyl-2-pentenolactone (anhydromevalolactone) (C6HsO) ; roridine A (C29H4009) gives
roridinic acid (C14H2207), roridine D (C29H3808) gives anhydroepoxyroridinic acid (C14H2007) ; roridine E (C29H3808)
gives anhydrororidinic acid (C14H2006); and verrucarine H
(C29H3608) gives 3-methyl-2-pentenolactone and myrothecinic acid (CsHloOs). The structures and stereochemistry of
the new lactones and dicarboxylic acids have been elucidated.
The constitutions of verrucarol (2) and roridine C (= trichodermol) (3) were derived by correlation with trichothecolone
and trichodermine [21.
(4)
degradation experiments showed that the radioactivity of the
verrucarinic acid was derived from C-2 of mevalonate.
[Lectures given at Freiburg, Gottingen, and Marburg
(Germany), on December 3rd, 1965, and January 20th and
21st, 19461
[VB 9831290 IE]
German version: Angew. Chem. 78, 496 (1966)
[ l ] E. Harri el al., Helv. chim. Acta 45, 839 (1962); B. Bohner ef
a/., ibid. 48, 1079 (1965).
[2] J . Gutzwiller et al., Helv. chim. Acta 47, 2234 (1964); J.
Gutzwiller, Ch. Tamm, and H . P. Sigg, Tetrahedron Letters
1965,4495.
131 J. GutzwiNer and Ch. Tamm. Helv. chim. Acta 48, 157, 177
(1965); W. Ziircher, J . Gutzwiller, and Ch. Tamm, ibid. 48, 840
(1965); E. Fetz, B. Bohner, and Ch. Tamm, ibid. 48, 1669 (1965).
Synthesis and Decomposition of Organic Peroxides
A . Rieche, Berlin (Germany)
( 1)
(2) R = OH:
(3)R = H
Numerous rearrangements were observed with verrucarol
and trichothecolone, some of which were discussed in detail.
Oxidative degradations and partial hydrolyses showed that
the above hydrolysis products are linked in the original antibiotics in the form of macrocyclic di- and tri-estersc31. For
instance, formulae (4) and (5) were derived for the two
principal metabolites verrucarine A and roridine A, respectively. These many-membered cyclic esters present a new
structural type.
Experiments on the biosynthesis of verrucarine A and roridine A with [2-14C]mevalonate show that mevalonate is a
biogenetic precursor of verrucarol and verrucarinic acid;
Angew. Chem. internat. Edit.
1 Vol. 5
(1966) J No. 5
According to the “RH scheme”rl1 of oxygen attack on
organic compounds, the first products to be isolated are
alkyl hydroperoxides, in accordance with reaction (a). The
radicals initiating the chain reaction are formed, according
to Dulog, by dehydrogenation [reaction (b)]. The hydroperoxides act autocatalytically by partial decomposition into radicals [reactions (c) and (d)].
RHf02
+ ROOH
(a)
RH+02
ROOH
+ R*+.OOH
(b)
+ RO.+.OH
2 ROOH
+ RO*+ ROO.+ HzO
(c)
(d)
Decomposition of hydroperoxides and peroxidation are
reactions of the same order: at very low concentrations they
are usually of the first order, at higher concentrations of the
second order (owing to dimerization). In ethers, hydroperoxides decompose at all concentrations by a reaction of the
first order; here adducts ROOH.R’OR” are present.
523
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