close

Вход

Забыли?

вход по аккаунту

?

Graphical Abstract Angew. Chem. Int. Ed. 122006

код для вставкиСкачать
Contents
The following Communications have been judged by at least two referees to be “very
important papers” and will be published online at www.angewandte.org soon:
D. Curran,* G. Moura-Letts, M. Pohlman
Solution-Phase Mixture Synthesis with Fluorous Tagging
En Route: Total Synthesis of an Eight-Member Stereoisomer
Library of Passifloricins
H. Zhang, H. Xia,* G. He, T. B. Wen, L. Gong, G. Jia*
Synthesis and Characterization of Stable Ruthenabenzenes
X. Mo, Y. An, C.-S. Yun, S. Yu*
Nanoparticle-Assisted Visualization of Binding Interactions
between Collagen Mimetic Peptide and Collagen Fibers
M. Harney, Y. Zhang, L. Sita*
Discrete, Multiblock Isotactic–Atactic Stereoblock Polypropene
Microstructures of Differing Block Architectures by
Programmable Stereomodulated Living Ziegler–Natta
Polymerization
Y. Weizmann, Z. Cheglakov, V. Pavlov, I. Willner*
Autonomous Fueled Mechanical Replication of Nucleic Acid
Templates for the Amplified Optical Detection of DNA
B. Botta, F. Caporuscio, D. Subissati, A. Tafi,* M. Botta, A. Filippi,
M. Speranza*
Flattened-Cone 2,8,14,20-Tetrakis(l-valinamido)[4]resorcinarene:
Enantioselective Allosteric Receptors in the Gas Phase
News
Chemiedozententagung 2006: Awards to B. Giese and M.-J. Crawford; ADUC Prizes
1836
Books
Chemistry and Technology of
Emulsion Polymerisation
Alex M. van Herk
reviewed by P. M. Cunningham
1837
Highlights
Chemical Evolution
M. Rueping*
1838 – 1840
Aldol Reactions within the RNA World
Keep the fire burning: It is hard to find
new aspects to the aldol reaction, as a
wealth of diastereoselective and enantioselective examples with a range of catalysts are known. However, recent work on
template-mediated cross-aldol reactions
and ribozyme-catalyzed aldol reactions
show that this topic is still hot. Both
reports are relevant to the theory of the
RNA world.
Protein Modification
J. H. van Maarseveen,* J. N. H. Reek,
J. W. Back
1841 – 1843
Transition-Metal Catalysis as a Tool for the
Covalent Labeling of Proteins
1824
They make a good couple: Protein modification the transition-metal catalysis
enables the selective labeling of proteins
and has been demonstrated in complex
mixtures. Current examples of such
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
coupling reactions are the Ir-catalyzed
reductive amination of lysine residues and
the alkylation of tryptophan residues by
Rh carbenes in proteins under aqueous
conditions (see scheme).
Angew. Chem. Int. Ed. 2006, 45, 1824 – 1834
Angewandte
Chemie
Minireviews
Reaction Kinetics
Fact or Myth? Selectivity is the distance
between the correlation lines for two
substrates Bj. You may confirm by trial
that it is impossible to draw a large
number of non-intersecting correlation
lines on this graph, all of which converge
when going from left to right, as required
by the still widely accepted reactivity–
selectivity principle (RSP).
H. Mayr,* A. R. Ofial
1844 – 1854
The Reactivity–Selectivity Principle: An
Imperishable Myth in Organic Chemistry
Reviews
In the past 20 years, DNA has been
established as a powerful material for
molecular constructions at the nanometer
scale. The ability to design building blocks
from DNA containing well-defined secondary structure motifs (a–f, in the
scheme) allows the assembly of large
supramolecular arrays, scaffolds, and
even mechanical and logical nanodevices.
Nanoscience
U. Feldkamp,*
C. M. Niemeyer*
1856 – 1876
Rational Design of DNA
Nanoarchitectures
Communications
Foldamers
A. Khan, C. Kaiser, S. Hecht* 1878 – 1881
Prototype of a Photoswitchable Foldamer
Know where to fold ’em: A foldamer
exhibiting a light-induced helix–coil transition (see scheme) can be constructed by
introducing a photochromic azobenzene
moiety (red) into the center of an amphiphilic phenylene ethynylene backbone
(blue). This system gives insight into
folding and unfolding mechanisms and
promises applications in photoresponsive
(bio)materials and “smart” delivery devices based on photoresponsive dynamic
receptors.
For the USA and Canada:
ANGEWANDTE CHEMIE International
Edition (ISSN 1433-7851) is published weekly
by Wiley-VCH PO Box 191161, D 69451 Weinheim, Germany. Air freight and mailing in the
USA by Publications Expediting Inc. 200
Meacham Ave., Elmont, NY 11003. Periodicals
postage paid at Jamaica NY 11431. US POSTMASTER: send address changes to Angewandte
Chemie, Wiley-VCH, 111 River Street, Hoboken,
NJ 07030. Annual subscription price for institutions: US$ 5685/5168 (valid for print and
electronic / print or electronic delivery); for
individuals who are personal members of a
Angew. Chem. Int. Ed. 2006, 45, 1824 – 1834
national chemical society prices are available
on request. Postage and handling charges
included. All prices are subject to local VAT/
sales tax.
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
1825
Angewandte
Chemie
Redox-based chemotherapy: The irreversible inhibition of human glutathione
reductase results in a unique S-AuI-S
coordination, which was determined
crystallographically. The chemotherapeutic potential of phosphine–metal complexes was probed by kinetic analysis of
the fast and effective inhibition of redox
enzymes as well as by DNA-interaction
studies and cell-proliferation tests.
Enzyme Inhibitors
Like a Russian doll: In the nanomolecule
Sc24C10I30, an outer I30 envelope (pink)
surrounds a Sc20 T3 supertetrahedron
(blue), which is filled by a C10 T2 supertetrahedron (gray), which, in turn, is filled
by a Sc4 T1 tetrahedron (light gray), containing two electrons in a four-center, twoelectron bond.
Iodine Supertetrahedra
Get a grip: A tailor-made ligand bearing
12 thioether groups can act as a “gripper”
for the Au55 cluster to give thermally
stable, monofunctionalized labels for
biomolecules (see scheme). Conjugates
of the gold cluster with DNA strands can
act as efficient fluorescence quenchers
and can survive the harsh thermal conditions of PCR experiments.
The damage to biological systems by highenergy quanta occurs mainly through
secondary species created in the ionization path. Interaction of the low-energy
(0–3 eV) electrons with thymidine (Td) in
the gas phase was investigated. These
electrons induce loss of hydrogen from
the N3 position and scission of the N1
C1 bond. The transfer of excess electrons,
initially localized on thymine, to the sugar
moiety was not observed.
Angew. Chem. Int. Ed. 2006, 45, 1824 – 1834
S. Urig, K. Fritz-Wolf, R. RIau,
C. Herold-Mende, K. TJth,
E. Davioud-Charvet,
K. Becker*
1881 – 1886
Undressing of Phosphine Gold(i)
Complexes as Irreversible Inhibitors of
Human Disulfide Reductases
L. Jongen, A.-V. Mudring,*
G. Meyer*
1886 – 1889
The Molecular Solid Sc24C10I30 : A
Truncated, Hollow T4 Supertetrahedron of
Iodine Filled with a T3 Supertetrahedron
of Scandium That Encapsulates the
Adamantoid Cluster Sc4C10
DNA Nanotechnology
W. M. Pankau, S. MKnninghoff,
G. von Kiedrowski*
1889 – 1891
Thermostable and Monoconjugable Gold
Clusters with a Dodecadentate Thioether
Ligand Gripper
DNA Strand Breaks
S. Ptasińska, S. Denifl, S. Gohlke,
P. Scheier, E. Illenberger,*
T. D. MMrk
1893 – 1896
Decomposition of Thymidine by LowEnergy Electrons: Implications for the
Molecular Mechanisms of Single-Strand
Breaks in DNA
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
1827
Contents
Gold Catalysis
N. Morita, N. Krause*
1897 – 1899
The First Gold-Catalyzed CS Bond
Formation: Cycloisomerization of
a-Thioallenes to 2,5-Dihydrothiophenes
Synthetic Methods
S. Beligny, S. Eibauer, S. Maechling,
S. Blechert*
1900 – 1903
Sequential Catalysis: A Metathesis/
Dihydroxylation Sequence
Azides
M. D. Walter, F. Weber, G. WolmershMuser,
H. Sitzmann*
1903 – 1905
A Hexanuclear Ytterbium Complex Anion
with Fourteen Azido Ligands
Morphogenesis (1)
H. Tlatlik, P. Simon, A. Kawska, D. Zahn,
R. Kniep*
1905 – 1910
Biomimetic Fluorapatite–Gelatine
Nanocomposites: Pre-Structuring of
Gelatine Matrices by Ion Impregnation
and Its Effect on Form Development
1828
www.angewandte.org
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
One good ring deserves another: A highly
efficient and stereoselective cycloisomerization of a-thioallenes to 2,5-dihydrothiophenes is the first example of a goldcatalyzed carbon–sulfur bond formation
(see scheme, X = Cl, I). Both gold(i) and
gold(iii) salts can be used as the precatalyst, with AuCl and AuI giving the best
yields. The method is of interest for the
stereoselective synthesis of biologically
active 2,5-disubstituted dihydro- or tetrahydrothiophenes.
A real step-saver: A single ruthenium–
carbene complex catalyzes a sequence of
two reactions, namely, a metathesis reaction (ring-closing or cross metathesis)
and subsequent dihydroxylation of the
newly formed double bond. A variety of
cyclic and acyclic cis-diols were prepared
in good yields (see scheme). This new
methodology provides an interesting
alternative to the pinacol coupling.
Bridge to ytterbium: In the hexanuclear
cluster ion [(4CpYb)6(N3)14]2 (4Cp =
C5H(CHMe2)4), the Yb3+ centers are
arranged in a distorted octahedron (see
Figure; Yb red, N blue, C white). The
twelve edges of the octahedron are
bridged by ten m1,3-N3 and two m1,1-N3
ligands. Two additional azido ligands
located within the cluster cavity act as
m1,1,3-N3 bridges.
Form follows the ion: The morphogenesis
of fluorapatite–gelatine nanocomposites
is studied from both electron microscopy
and atomistic simulation revealing ion
impregnation effects on the growth
mechanisms. Depending on the ionic
species used for pre-treatment of the
organic component dramatic changes of
the mesoscopic structuring are observed.
Angew. Chem. Int. Ed. 2006, 45, 1824 – 1834
Angewandte
Chemie
The seeder of the pack: The electrical
potential distribution (see phase image of
an electron hologram) around the basal
plane close to the prism faces of a
hexagonal fluorapatite–gelatine nanocomposite seed influences the growth of
the nanocomposite. The seed consists of
elementary dipoles on the nanometer
scale, which all have the same orientation
along the c axis of the composite seed.
Further form development of the seed
leads to fractal patterns.
Morphogenesis (2)
Beauty is in the I of the beholder: Metalion coordination and I···I halogen bonding
direct the self-assembly of achiral starting
materials (a calix[4]arene tetraamide,
BaI2·2 H2O, and 1,8-diiodoperfluorooctane) into a homochiral supramolecular
complex containing double helices (see
structure; Ba light purple, I purple,
F green, O red, N blue, C gray; one double
helix in red and yellow).
Supramolecular Chemistry
Angew. Chem. Int. Ed. 2006, 45, 1824 – 1834
P. Simon, D. Zahn, H. Lichte,
R. Kniep*
1911 – 1915
Intrinsic Electric Dipole Fields and the
Induction of Hierarchical Form
Developments in Fluorapatite–Gelatine
Nanocomposites: A General Principle for
Morphogenesis of Biominerals?
A. Casnati, R. Liantonio, P. Metrangolo,*
G. Resnati,* R. Ungaro,
F. Ugozzoli*
1915 – 1918
Molecular and Supramolecular
Homochirality: Enantiopure
Perfluorocarbon Rotamers and HalogenBonded Fluorous Double Helices
Taking control with DNA: Covalently
attached double-stranded DNA constraints can control the conformations of
other macromolecules. A variety of
approaches (including competitive
ligand–aptamer interactions) were used
to modulate the effects of such constraints on the structure of a large RNA
molecule.
DNA Nanotechnology
The quest is over: A tricyclic amide-based
anion receptor has been synthesized by
connecting two monocyclic precursors.
The receptor is highly selective for the
binding of the elusive bifluoride anion
HF2, and the adduct represents the first
structural example of an encapsulated
bifluoride. The bifluoride lies midway
between the two macrocycles making up
the tricycle and is held by four hydrogenbonding contacts with the macrocyclic
amides.
Anion Sensor
C. V. Miduturu,
S. K. Silverman*
1918 – 1921
Modulation of DNA Constraints That
Control Macromolecular Folding
S. O. Kang, D. Powell, V. W. Day,
K. Bowman-James*
1921 – 1925
Trapped Bifluoride
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
1829
Contents
Lanthanide Luminescence
Y. Wada,* M. Sato,
Y. Tsukahara
All the colors of the rainbow can be
observed upon excitation of a zeolite
crystal incorporated with varying quantities of Eu3+ and Tb3+ ions as well as a
sensitizer molecule (benzophenone or 4acetylbiphenyl) in its framework structure
(see picture). The colors can be fine-tuned
by varying the amounts of the three
components as well as the excitation
wavelength and temperature.
1925 – 1928
Fine Control of Red–Green–Blue
Photoluminescence in Zeolites
Incorporated with Rare-Earth Ions and
a Photosensitizer
Liquid Crystals
R. A. Reddy, G. Dantlgraber,
U. Baumeister,
C. Tschierske*
1928 – 1933
Liquid-Crystalline Quaternary Block
Molecules Incorporating Bent-Core Units
Heterogeneous Catalysis
D. M. Marcus, M. J. Hayman, Y. M. Blau,
D. R. Guenther, J. O. Ehresmann,
P. W. Kletnieks, J. F. Haw*
1933 – 1935
Mechanistically Significant Details of the
H/D Exchange Reactions of Propene over
Acidic Zeolite Catalysts
Marcus Theory
J. VandeVondele,* M. Sulpizi,
M. Sprik
1936 – 1938
From Solvent Fluctuations to Quantitative
Redox Properties of Quinones in
Methanol and Acetonitrile
1830
www.angewandte.org
A flick of a switch: The combination of
fluorinated segments and oligo(dimethylsiloxane) units with bent mesogenic cores
leads to new liquid-crystalline materials
(see picture) that display a temperature-
dependent change from ferroelectric to
antiferroelectric switching. Such materials
have potential use in, for example, fastswitching electrooptical microdisplays.
Quid pro quo: Hydrogen–deuterium
exchange of propene on solid acid catalysts was studied at 573 and 673 K with a
reaction time of 3 s (see scheme). At low
partial pressures and temperatures,
H/D exchange produced [D5]propene as
the main product. Complete deuteration
([D6]propene) was observed only at a
higher temperature with the most acidic
catalyst.
The effects of substituents and solvent on
the redox properties of quinones were
studied within the framework of Marcus
theory. The relative redox potentials and
reorganization energies in methanol and
acetonitrile were computed with a fully
atomistic method based on DFT and
molecular dynamics (see model of the
radical anion of benzoquinone in methanol). Hydrogen bonding contributes
0.2 eV to the reorganization energy in
methanol.
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2006, 45, 1824 – 1834
Angewandte
Chemie
Coordination Polymers
Second generation diazadibenzoperylene
dendrimers (yellow units) undergo
supramolecular polymerization with Ag+
ions (green spheres) to afford rigid-rod
coordination polymers, as confirmed by
atomic force microscopy studies (see
image). Such cylindrical coordination
polymers constitute a new class of
p-conjugated materials linked by metal
centers which may find application in
nanoscale electronic devices.
F. WUrthner,* V. Stepanenko,
A. Sautter
1939 – 1942
Rigid-Rod Metallosupramolecular
Polymers of Dendronized
Diazadibenzoperylene Dyes
The long and the short of it: A short
oligonucleotide is designed to selfassemble into micrometer-long nanotubes, which further serve as templates to
fabricate metallic nanowires. This study
addresses the question: what is the
minimum number of DNA strands that
are required for self-assembly of welldefined DNA nanostructures?
DNA
H. Liu, Y. Chen, Y. He, A. E. Ribbe,
C. Mao*
1942 – 1945
Approaching The Limit: Can One DNA
Oligonucleotide Assemble into Large
Nanostructures?
Reaction Mechanisms
J. Huang, L. Zhou, H. Jiang* 1945 – 1949
The direct approach: The unprecedented
result of the title reaction (see scheme) is
explained by a mechanism involving
competition between p-allylpalladation
through cleavage of the CO bond and
the insertion of an alkene. The procedure
provides a highly stereo- and regioselective method to construct 1,4-dienes in an
economical and environmentally benign
manner.
Palladium-Catalyzed Allylation of Alkynes
with Allyl Alcohol in Aqueous Media:
Highly Regio- and Stereoselective
Synthesis of 1,4-Dienes
Synthetic Methods
Y. Zhang, C.-J. Li*
An unlikely couple: CC bonds can be
formed between ethers and methylene
compounds by cross-dehydrogenativecoupling (see scheme; DDQ = 2,3-di-
Angew. Chem. Int. Ed. 2006, 45, 1824 – 1834
chloro-5,6-dicyanobenzoquinone). This
straightforward reaction employs mild
conditions and simple catalysts and
allows reasonably high yields.
1949 – 1952
Highly Efficient Cross-DehydrogenativeCoupling between Ethers and Active
Methylene Compounds
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
1831
Contents
Synthetic Methods
I. Ibrahem, A. CJrdova*
1952 – 1956
Direct Catalytic Intermolecular a-Allylic
Alkylation of Aldehydes by Combination of
Transition-Metal and Organocatalysis
Polyoxometalates
A. Yoshida, M. Yoshimura, K. Uehara,
S. Hikichi, N. Mizuno*
1956 – 1960
Formation of S-Shaped
Disilicoicosatungstate and Efficient
Baeyer–Villiger Oxidation with Hydrogen
Peroxide
All in the same pot together: The direct
catalytic a-allylic alkylation of aldehydes
and cyclic ketones is achieved by using a
simple, unprecedented one-pot procedure. Transition-metal and enamine cata-
Partial protonation of a divacant lacunary
Keggin-type silicodecatungstate in an
anhydrous organic solvent led to dehydrative condensation and formation of a
novel S-shaped disilicoicosatungstate
(see picture). The S-shaped cluster efficiently promotes Baeyer–Villiger oxidation
of cycloalkanones with high turnover
numbers (TONs, 1900) and high
selectivities ( 90 %) for the corresponding lactones.
Protein-Structure Determination
Z. Lin, Y. Q. Xu, S. Yang,
D. W. Yang*
1960 – 1963
Sequence-Specific Assignment of
Aromatic Resonances of Uniformly
13 15
C, N-Labeled Proteins by Using 13C- and
15
N-Edited NOESY Spectra
Photosynthesis
H. Ishikita, J. Biesiadka, B. Loll,
1964 – 1965
W. Saenger, E.-W. Knapp*
Cationic State of Accessory Chlorophyll
and Electron Transfer through Pheophytin
to Plastoquinone in Photosystem II
1832
www.angewandte.org
lysis are combined so that a-allylic alkylated aldehydes and cyclic ketones are
formed in high yield with a direct catalytic
chemo- and regioselective method.
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
NOESY neighbors: A single 3D 13C- and
15
N-edited NOESY experiment can be
used to assign aromatic side-chain resonance signals of 13C,15N-labeled proteins
on the basis of prior assignments of the
signals of backbone and aliphatic sidechain groups. This strategy will improve
the precision of protein structures, especially of large proteins.
It must be charged: The redox potential
difference between pheophytin (PheoD1)
and primary plastoquinone in the electron
transfer in photosystem II from accessory
chlorophyll on the D1 branch (ChlD1) is
consistent with the free-energy difference
estimated from kinetic studies only when
computed for the cationic state ChlþD1.
YD = symmetry related redox-inactive
tyrosine, YZ = redox-active tyrosine.
Angew. Chem. Int. Ed. 2006, 45, 1824 – 1834
Angewandte
Chemie
Cyclizations
M. Harmata,* P. Zheng, P. R. Schreiner,*
A. Navarro-VWzquez
1966 – 1971
Deantiaromatization as a Driving Force in
an Electrocyclic Reaction
But how does it smell? Theory and
experiment support the notion that
“deantiaromatization” can serve as a
driving force in the 8-p-electron electrocyclization of a cyclopentadienone (see
scheme; TEA = triethylamine; TFE = trifluoroethanol). The reaction proceeds in
synthetically useful yields and could be
applicable to the synthesis of the antiviral
agent hamigeran B.
Unexpected selectivity: [60]Fullerene and
CF3I react selectively at 440 8C to synthesize C60(CF3)12. In the product with S6
symmetry, 12 CF3 groups form a continuous loop of alternating para- and metaC6(CF3)2 hexagons. In the crystal, the
chains of molecules are strengthened
owing to stacking interactions and
shielding effects from the CF3 groups,
thus accounting for the low volatility and
solubility of the compound.
Fullerenes
S. I. Troyanov,* A. Dimitrov,
E. Kemnitz*
1971 – 1974
Selective Synthesis of a
Trifluoromethylated Fullerene and the
Crystal Structure of C60(CF3)12
Enzyme Fidelity
H. O. Sintim, E. T. Kool*
1974 – 1979
Remarkable Sensitivity to DNA Base
Shape in the DNA Polymerase Active Site
Shaping up: DNA polymerase I can distinguish easily and with high sensitivity
between nucleobases that have the same
size but differ in shape. The shape, altered
through variation in the position of the
halogen substituent(s), plays more of a
prominent role in base-pairing efficiency
and selectivity than other factors.
Cycloadditions
X.-X. Yan, Q. Peng, Y. Zhang, K. Zhang,
W. Hong, X.-L. Hou,*
Y.-D. Wu
1979 – 1983
Electronic properties of the ligands switch
the diastereoselectivity in the Cu-catalyzed 1,3-dipolar cycloaddition of azomethine ylides to nitroalkenes: exo- or endo-
Angew. Chem. Int. Ed. 2006, 45, 1824 – 1834
pyrrolidines were obtained with high diastereo- and enantioselectivities in the
presence of different chiral (phosphanylferrocenyl)oxazoline ligands (e.g. 3 a, b).
A Highly Enantio- and Diastereoselective
Cu-Catalyzed 1,3-Dipolar Cycloaddition of
Azomethine Ylides with Nitroalkenes
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
1833
Contents
Service
Keywords
1984
Authors
1985
Preview
1987
For more information on
ChemMedChem see
www.chemmedchem.org
Corrigenda
*
Molecular Recognition of a Three-Way
DNA Junction by a
Metallosupramolecular Helicate
The correct spelling of the surname of the first author of this Communication is Oleksy,
as shown in the author list here.
A. Oleksy, A. G. Blanco, R. Boer, I. UsJn,
J. AymamY, A. Rodger, M. J. Hannon,*
M. Coll*
1227–1231
Angew. Chem. Int. Ed. 2006, 45
DOI 10.1002/anie.200503822
Transcription and Amplification of
Molecular Chirality to Oppositely Biased
Supramolecular p Helices
In the cover picture text of Issue 7, page 1005 there are two errors: first, the DNA helix
which Janus is holding in his right hand is not left but right-handed—just as it is
supposed to be. Second, Janus is in fact a Roman and not a Greek God. The editors and
authors apologize for these oversights.
A. Ajayaghosh,* R. Varghese, S. J. George,
C. Vijayakumar
1141–1144
Angew. Chem. Int. Ed. 2006, 45
DOI 10.1002/anie.200503142
1834
www.angewandte.org
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2006, 45, 1824 – 1834
Документ
Категория
Без категории
Просмотров
0
Размер файла
1 740 Кб
Теги
abstract, 122006, int, angel, chem, graphical
1/--страниц
Пожаловаться на содержимое документа