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1.
Tomáš Trojan Jindřich Jindřich Vladimír Vrkoslav Ivan Jelínek Juraj Dian 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):343-348
A set of permethylated 6I-(ω-alkenoyl)-6I-amino-6I-deoxy-β-cyclodextrin derivatives with different chain length of the alkenoyl group (used as a spacer) was synthesized. These
derivatives were attached by photochemically activated hydrosilylation reaction to the surface of porous silicon. Photoluminescence
response of the modified PS to controlled concentrations of various molecules in gas phase revealed strong host-guest interactions
between β-cyclodextrin and the detected molecules. The strongest interaction was observed for aromatic molecules, which have
the optimal size to fit into the β-cyclodextrin molecular cavity. 相似文献
2.
Mircea Grigoras Daniel Gheorghe Conduruta 《Journal of inclusion phenomena and macrocyclic chemistry》2006,54(1-2):101-107
A β-cyclodextrin (β-CD)/aniline inclusion complex has been synthesized in aqueous solution and characterized by FT-IR and 1H-NMR spectroscopy, chemical analysis and thermogravimetric method. By elemental analysis and 1H-NMR spectroscopy a complex with stoichiometry 1:1.95 and 1:1.8 (β-CD/aniline) respectively, is found. The complexed aniline
was polymerized by chemical oxidative polymerization using ammonium peroxydisulfate in water (pH = 7) and 1M HCl aqueous solution.
In both cases, after an induction period, insoluble polyanilines (PANIs) are obtained, however, in water at pH = 7, a polypseudorotaxane
architecture containing a β-CD molecule to ~14 aniline units has resulted. In acidic conditions, anilinium cation is highly
hydrophilic and inclusion complex has a strong tendency to dissociate to free molecules and emeraldine salt of PANI, free
of host molecules is synthesized. 相似文献
3.
Omar M. Ali 《Monatshefte für Chemie / Chemical Monthly》2007,55(11):917-922
2-(Arylamino)pyrimidin-4-ones were synthesized, silylated, and condensed with l,2,3,5-tetra-O-acetyl-β- d-ribofuranoside to afford the corresponding N
2-aryl protected isocytidines. Deprotection of the acetylated isocytidines using saturated NH3 in MeOH solution gave 1-(β-d-ribofuranosyl)-2-(arylamino)-4-pyrimidinones. Methyl 2-deoxy-3,5-di-O-toluyl-α/β-d-ribofuranoside was prepared and condensed with the previously silylated bases to afford the anomeric mixture of protected
nucleosides. The pure β-anomers were synthesized with better yield by treating the sodium salts of N
2-arylisocytosine derivatives with 2-deoxy-3,5-di-O-toluyl-α-d-ribofuranosyl chloride. Deprotection of the latter anomers afforded the corresponding free hydroxyl derivatives. The synthesized
free nucleosides are under antiviral and oligonucleotide investigations. 相似文献
4.
Omar M. Ali 《Monatshefte für Chemie / Chemical Monthly》2007,138(9):917-922
Summary. 2-(Arylamino)pyrimidin-4-ones were synthesized, silylated, and condensed with l,2,3,5-tetra-O-acetyl-β- d-ribofuranoside to afford the corresponding N
2-aryl protected isocytidines. Deprotection of the acetylated isocytidines using saturated NH3 in MeOH solution gave 1-(β-d-ribofuranosyl)-2-(arylamino)-4-pyrimidinones. Methyl 2-deoxy-3,5-di-O-toluyl-α/β-d-ribofuranoside was prepared and condensed with the previously silylated bases to afford the anomeric mixture of protected
nucleosides. The pure β-anomers were synthesized with better yield by treating the sodium salts of N
2-arylisocytosine derivatives with 2-deoxy-3,5-di-O-toluyl-α-d-ribofuranosyl chloride. Deprotection of the latter anomers afforded the corresponding free hydroxyl derivatives. The synthesized
free nucleosides are under antiviral and oligonucleotide investigations. 相似文献
5.
Stela Dimitrova Kostantsa Pavlova Ludmil Lukanov Plamen Zagorchev 《Applied biochemistry and biotechnology》2010,162(3):795-804
The effect of different doses of visible (Vis), ultraviolet-А (UVA), and mixed light (UVA + Vis) upon coenzyme Q10 (CoQ10) and β-carotene synthesis and biomass yield by the Sporobolomyces salmonicolor AL1, Cryptococcus albidus AS55, Cryptococcus laurentii AS56, and C. laurentii AS58 strains isolated from Antarctic samples was investigated. The β-carotene concentration in the red strain biomass increased
by 52% under irradiation with 11 J/cm2 Vis, and the CoQ10 concentration rose by 37% in relation to the control quantity obtained through dark cultivation. Under irradiation with 6 J/cm2 UVA, the S. salmonicolor AL1 strain synthesized 15% more β-carotene; C. albidus AS55, 22%; C. laurentii AS56, 44%; and C. laurentii AS58, 35% in relation to the control quantity. Irradiation with a low UVА + Vis dose significantly stimulated β-carotene biosynthesis
by the strains of the Cryptococcus genus (87%, 138%, and 100%), whereas S. salmonicolor AL1 increased the β-carotene content to a smaller degree (55%). Higher doses of all three irradiation types inhibited β-carotene
accumulation. Vis suppressed CoQ10 biosynthesis in the Cryptococcus strains, whereas UVА and UVА + Vis inhibited it in all four strains. The S. salmonicolor AL1 strain pre-treated with 0.02 J/cm2 UVA synthesized twice as much CoQ10 and β-carotene when cultivated in the presence of Vis light in an 11-J/cm2 dose. 相似文献
6.
Cezary A. Kozlowski Tomasz Girek WladysŁaw Walkowiak Jolanta Kozlowska 《Journal of inclusion phenomena and macrocyclic chemistry》2006,55(1-2):71-77
β-Cyclodextrin (β-CD) polymers were prepared by cross-linking of β-CD with phtalic and 3-nitrophtalic anhydride in anhydrous N,N-dimethylformamide (DMF) in the presence of NaH. The weight-average molecular weight (M
W) and the chemical structure of the polymers were determined using high performance size exclusion chromatography (HPSEC) with refractive index (RI) detector, and 1H NMR spectroscopy. The molecular weight of the polymer increased with molar ratio of substrates and reaction temperature. 1H NMR spectra revealed that the β-CD polymers contained both mono- and diesters of phtalic and 3-nitrophtalic acids. In the case of phtalic moieties about four or five diester moieties groups and for 3-nitrophtalic moieties about to or three diester moieties are linkages for β-CD molecule, respectively. Results of copper(II) flotation obtained with the use of nonylphenol polyoxyethyl glycol ether as an non-anionic surfactant and β-CD polymers as complexation collector agent, show␣that the removal of Cu2+ decreases with increase of molecular mass of β-CD polymers linked by phtalic or␣3-nitrophtalic anhydrides. For both derivatives with pH increase the copper(II) removal increase. The highest flotation removal, i.e. 93%, was found for β-CD polymers synthesized at 100 °C with molar ratio CD:NaH:3-nitrophtalic anhydride equal to 1:7:7. 相似文献
7.
A series of new aromatic esters based on 4,16-pregnadiene-6,20-dione skeleton, namely 3β-benzoyloxy-4,16-pregnadiene-6,20-dione
and 3β-furoyloxy-4,16-pregnadiene- 6,20-dione, which may be good inhibitors for the 5α-reductase enzyme and show high antiandrogenic
activity, were synthesized starting from diosgenin. The structures of the steroids were characterized by elemental analysis,
1H NMR, 13C NMR, IR and mass spectrum. Single crystal X-ray diffraction measurement on one of the new compounds, 3β-(p-methoxybenzoyloxy)-4,16-pregnadiene-6,20-dione revealed that the A, B, C, and D ring adopted half chair, distorted chair,
distorted chair, and distorted envelope conformation, respectively. The molecules in the crystal were packed face-to-face
at the normal van der Waals distances. 相似文献
8.
A series of 1,5-disubstituted 3-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)-2-pyrazolines were synthesized by the reaction of α,β-unsaturated ketones derived from dehydroacetic acid and
hydrazine in hot acetic acid or propionic acid. The structures of all new compounds were elucidated by microanalyses, 1H and 13C NMR, IR, and mass spectroscopic measurements. 相似文献
9.
Sofia Nikolaou Sérgio Hiroshi Toma Vagner Roberto de Souza Juliano B. Alves Koiti Araki Henrique Eisi Toma 《Transition Metal Chemistry》2011,36(7):775-783
The triruthenium carboxylate cluster [Ru3O(OAc)6(py)2(bpp)]+ (OAc = acetate) containing the bridging 1,3-bis(4-pyridyl)propane (bpp) ligand, and its dimeric species [{Ru3O(OAc)6(py2)}2(μ-bpp)]2+ were synthesized in order to investigate their inclusion compounds with β-cyclodextrin (β-CD). Characterization of the complexes
was carried out based on spectroscopic, electrochemical and spectroelectrochemical techniques, while the formation of inclusion
complexes was evaluated using 1H NMR/NOESY spectroscopy. Since bpp is a flexible ligand, a DFT study was carried out in order to characterize its conformational
isomers and their possible role in the host–guest chemistry with β-CD. Instead of observing the formation of inclusion compounds
with different stoichiometries, we observed the formation of 1:1 bpp/β-CD compounds in which the bpp ligand assumes different
conformations. The assembly of polymetallic rotaxane species was successfully demonstrated by monitoring the 1H NMR spectra of the monomeric cluster species in the presence of aquapentacyanoferrate(II) ions and β-CD. 相似文献
10.
Two new bisazo chromophores—derivatives of bis-2,2-(4-hydroxyphenyl)propane (bisphenol A), heterocyclic amines (2-aminobenzothiazole,
and 2-amino-6-nitrobenzothiazole) and aniline—were synthesized. Nonlinear optical properties of these chromophores were studied
by solvatochromic method (obtained compounds have βCT value ∼10−29 esu). Dependence among the structure of molecules, their dipole moments, and first hyperpolarizabilities was considered on
the basis of semi-empirical calculations. A correlation between the measured and calculated β values was studied. The NLO
chromophores were used as special monomers to synthesize copolyarylates. The basic characterization of obtained polymers was
carried out. 相似文献
11.
Summary. A series of 1,5-disubstituted 3-(4-hydroxy-6-methyl-2-oxo-2H-pyran-3-yl)-2-pyrazolines were synthesized by the reaction of α,β-unsaturated ketones derived from dehydroacetic acid and
hydrazine in hot acetic acid or propionic acid. The structures of all new compounds were elucidated by microanalyses, 1H and 13C NMR, IR, and mass spectroscopic measurements. 相似文献
12.
Yu. E. Shapiro V. Ya. Gorbatyuk L. N. Yakubovskaya K. S. Andronati S. A. Andronati 《Journal of Structural Chemistry》1996,37(5):747-758
Understanding the mechanisms of mutual recognition and complementary binding of molecules in guest-host complexes is based
on analysis of their spatial structure. As guest-host complexes, we have synthesized inclusion compounds of 1,4-benzodiazepine
anxiolytic agents gidazepam and cinazepam with β-cyclodextrin, in which these anxiolytic agents manifest increased biological
accessibility. The spatial structure of the complexes was determined from the two-dimensional NOESY spectra and analysis of
the fragmentary mobility of the guest and host molecules, characterized by spin-lattice relaxation times T1 of the13C nuclei. An analysis of d-contacts showed that the 5-phenyl ring is completely enclosed in the inner hydrophobic cavity of
β-CD [(C2′ H-C4′ H)-CIIH(CIVH), CVH (CIIIH, CVIH2), CVIOH]. For the 1:1 complex, intense d-contracts of C8H with CVIOH indicate that C8H is located in the vicinity of both wide and narrow bases of the bracelet. This is only possible for the 2:2 complex, in
which both β-CD molecules approach each other by their wide and narrow bases. A comparison between the schemes of d-contacts
for the 2:2 and 2:1 associates proves that the β-CD molecules have the same spatial orientation in the dimer. The difference
is in the fact that the hydrazinocarbonyl fragment of gidazepam and the hemisuccinate fragment of cinazepam penetrate into
an empty molecule of the 2:1 β-CD complex (NH2-CIH contact). The intensities of the cross peaks were measured, due to which the interatomic distances between the guest
and host molecules were calculated and the spatial structure of the clathrates was established. The benzodiazepine derivatives
are embedded differently into the clathrate molecule, as shown by the value of the angle between the symmetry axis of β-CD
and the axis through the centers of the aromatic rings: 0° for gidazepam and 60° for cinazepam. This is a consequence of the
fact that the substituents forming hydrogen bonds with hydroxyl groups at the wide base of the β-CD bracelet lie in different
positions: the hydrazinocarbonylmethyl fragment of gidazepam lies at N1, and the hemisuccinate fragment of cinazepam is at C3.
A. V. Bogatskii Physicochemical Institute, Ukrainian National Academy of Sciences. Translated fromZhurnal Strukturnoi Khimii, Vol. 37, No. 5, pp. 876–890, September–October, 1996.
Translated by L. Smolina 相似文献
13.
Yuxiang Ou Huiping Jia Yongjiang Xu Boren Chen Guangyu Fan Lihua Liu Fuping Zheng Zelin Pan Cai Wang 《中国科学B辑(英文版)》1999,42(2):217-224
A polycyclic caged compound with high strain—hexanitrohexaazaisowurtzitane (HNIW)—has been synthesized via a three-step reaction:
condensation, hydrogenolysis debenzylation and nitrolysis, starting with benzylamine and glyoxal. HNIW is the most powerful
high energy density compound (HEDC) ever tested. β-HNIW possesses a caged structure consisting of two five-membered rings
and one six-membered ring with a nitro group attached to each of the six bridging nitrogens. The nitro group lies basically
within a plane. The lengths of C—C bonds of β-HNIW range from 0. 156 nm to 0.159 nm, 0.002–0.005 nm longer than the sp3 C-C bond. The β-HNIW’s crystal belongs to orthorhombic system and space groupPca21 with parameters:a = 0.9670 (2),b = 1.1616 (2),c = 1.3032 (3) nm;V = 1.4638(5) nm3,Z = 4; Dc = 1.989 g/cm3 and Dm = 1.982 g/cm3.
Project supported by the Advanced Research Funds (12060451867) from the Commission of Science and Technology for National
Defence. 相似文献
14.
Ves’kina N. A. Afon’kina S. R. Odinokov V. N. 《Russian Journal of Organic Chemistry》2011,47(11):1767-1771
The reduction of ponasterone A diacetonide with lithium in liquid ammonia stereospecifically led to 7,8β-dihydroanalogs of
5α- and 5β-epimers of ponasterone A and 7,8β-dihydro-6α-hydroxy derivative. 7,8β-Dihydroponasterone A, phytoecdysteroid from
the needles of Japanise yew Taxus cuspidata, and its 5α-epimer were synthesized. 相似文献
15.
E-(4-β-D-Allopyranosyloxyphenyl)-1-(4-substituted phenyl)propenone derivatives (1a–g) have been synthesized by the Claisen-Schmidt condensation of helicid with 4-substituted acetophenone using 10% NaOH aqueous
solution as a catalyst. 6H-2-Amino-4-aryl-6-(4-β-D-allopyranosyloxyphenyl)-1,3-thiazine (2a–g) were synthesized by the 1,4-Michael reaction of 1a–g with thiourea. The structures of all the new products were established by 1H NMR, IR, and MS spectroscopy. Compound 2b (200 mg·kg–1) showed better sedative-hypnotic activity, so further modification of helicid should be worthwhile. 相似文献
16.
Tian S.-J. Xi G.-X. Cheng Q.-T. Lou X.-D. Li J.-H. 《Journal of Thermal Analysis and Calorimetry》1998,53(3):825-833
The inclusion complex of benzaldehyde (BA) with β-cyclodextrin (β-CD) was prepared and was studied by thermal analysis and
X-ray diffractometry. The composition of the complex was identified by TG and elemental analysis as β-CD·BA·9H2O. TG and DSC studies showed that the thermal dissociation of β-CD·BA·9H2O took place in three stages: dehydration in the range 70-120°C; dissociation of β-CD·BA in the range 235-270°C; and decomposition
of β-CD above 280°C. The kinetics of dissociation of β-CD·BA in flowing dry nitrogen was studied by means of TG both at constant
temperature and at linearly increasing temperature. The results showed that the dissociation of β-CD·BA was dominated by a
one-dimensional random nucleation and subsequent growth process (A2). The activation energy E was 124. 8 kJ mol-1, and the pre-exponential factor A 5.04·1011 min-1.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
17.
Cellulose was dissolved in lithium chloride/1,3-dimethyl-2-imidazolidinone (LiCl/DMI), and reacted with alkylketene dimers
(AKDs) under non-aqueous and homogeneous conditions to prepare cellulose/AKD β-ketoesters with high degrees of substitution
(DS). Six AKDs synthesized from octanoic, decanoic, dodecanoic, tetradecanoic, hexadecanoic and octadecanoic acids via their
fatty acid chlorides were used in this study. The cellulose/AKD β-ketoesters obtained were gummy solid at room temperature,
and had DS values ranging from 1.9 to 2.9. Cellulose/fatty acid esters with DS 2.5–2.9 were also prepared as references. 13C-NMR spectra of the cellulose/AKD β-ketoesters showed that cellulose carbons and substituent carbons close to cellulose chains
were restricted in motion and behaved like solid in solutions. In contrast, the cellulose/fatty acid esters did not demonstrate
such anomalous 13C-NMR spectra. The unique 13C-NMR patterns are characteristic for the cellulose/AKD β-ketoesters, which have long and branched alkyl substituents in each
anhydroglucose unit. Size-exclusion chromatography furnished with multi-angle laser light scattering (SEC-MALLS) revealed,
on the other hand, that all cellulose/AKD β-ketoesters and cellulose/fatty acid esters prepared had flexible or random-coil
conformations in tetrahydrofuran (THF). There were no clear differences in conformation or stiffness of cellulose chains between
cellulose/AKD β-ketoesters and cellulose/fatty acid esters. 相似文献
18.
S. N. Podyachev S. N. Sudakova A. K. Galiev A. R. Mustafina V. V. Syakaev R. R. Shagidullin I. Bauer A. I. Konovalov 《Russian Chemical Bulletin》2006,55(11):2000-2007
New chelating ligands consisting of three β-diketone fragments, viz., 1,3,5-tris[(acetylaceton-3-yl)methyl]benzene, 1,3,5-tris[(benzoylaceton-3-yl)methyl]benzene, and 1,3,5-tris[(dibenzoylmethan-1-yl)methyl]benzene,
linked to each other through the mesitylene spacer were synthesized by the reaction of 1,3,5-tris(bromomethyl)benzene with
the corresponding β-diketone sodium salt. The acidity of these compounds and their complexation properties were studied by
pH-potentiometry in aqueous-ethanol solutions. Tris(β-diketones) form mononuclear complexes with lanthanide ions, whose stability
increases in the series La3+ < Gd3+ < Lu3+. 1,3,5-Tris[(acetylaceton-3-yl)methyl]benzene forms both mononuclear and polynuclear complexes with the Ni2+ and Cu2+ ions. The stability constants and selectivity of complex formation increase substantially with an increase in the degree
of deprotonation of the ligands, thus indicating that all deprotonated chelate groups are involved in coordination with the
metal ion. The replacement of the methyl groups by the phenyl substituents in the β-diketone fragments of the molecules affects
substantially the composition and stability of the complexes formed.
Dedicated to Academician O. M. Nefedov on the occasion of his 75th birthday.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1926–1933, November, 2006. 相似文献
19.
The molecular geometry and electronic structure of hydroxy-substituted naphthazarin (NZ)-7-ethyl-2,3,5,6,8-pentahydroxy-1,4-naphthoquinone
(echinochrome A, (Et)NZ(β-OH)3, 1) were calculated by the B3LYP/6-311G(d) method. The influence of the (i) character of the β-OH groups dissociation and (ii)
conformational mobility of molecule 1 and the anions, radicals, and radical anions derived from 1 on the energy of their reactions with hydroperoxyl radical was studied by the (U)B3LYP/6-31G and (U)B3LYP/6-311G(d) methods.
The enol-enolic tautomerism due to the transfer of hydrogen atoms of α-OH groups and rotational isomerism of the β-OH groups
at the C(2) and C(3) atoms and of the α-OH groups at the C(5) and C(8) atoms were studied. The equilibrium in the gas-phase
reaction 1 + •OOH ⇄ (Et)(HO-β)2NZ(β-O•) + HOOH (1) (quenching of hydroperoxyl radical) is shifted to the separated reagents. Heterolysis of the O—H bond in one
of the three β-hydroxy groups considerably reduces the energy of subsequent O—H bond homolysis in either of the two remaining
β-hydroxy groups. As a consequence, the reaction (Et)(HO-β)2NZ(β-O−) + •OOH ⇄ (Et)(HO-β,−O-β)NZ(β-O•) + HOOH (2) (quenching of hydroperoxyl radical) becomes exothermic and the equilibrium is shifted to the formation of hydrogen
peroxide. The Gibbs energy gain in reaction (2) varies from −6.4 to −10.9 kcal mol−1 depending on which β-hydroxy group is involved in the O—H bond homolysis.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 400–415, March, 2007. 相似文献
20.
Sandrine Bourgoin-Voillard Emilie-Laure Zins Françoise Fournier Yves Jacquot Carlos Afonso Claude Pèpe Guy Leclercq Jean-Claude Tabet 《Journal of the American Society for Mass Spectrometry》2009,20(12):2318-2333
The affinity of estradiol derivatives for the estrogen receptor (ER) depends strongly on nature and stereochemistry of substituents
in C(11) position of the 17β-estradiol (I). In this work, the stereochemistry effects of the 11α-OH-17β-estradiol (IIIα) and 11β-OH-17β-estradiol (IIIβ) were investigated using CID experiments and gas-phase acidity (ΔHacid∘) determination. The CID experiments showed that the steroids decompose via different pathways involving competitive dissociations
with rate constants depending upon the α/β C(11) stereochemistry. It was shown that the fragmentations of both deprotonated [IIIα-H]− and [IIIβ-H]− epimers were initiated by the deprotonation of the most acidic site, i.e. the phenolic hydroxyl at C(3). This view was confirmed by H/D exchange and double resonance experiments. Furthermore, the ΔHacid∘ of both epimers (IIIα and IIIβ), 17β-estradiol (I), and 17-desoxyestradiol (II) was determined using the extended Cooks’ kinetic method. The resulting values allowed us to classify steroids as a function
of their gas-phase acidity as follows: (IIIβ)≫(II)>(I)>(IIIα). Interestingly, the α/β C(11) stereochemistry appeared to influence strongly the gas-phase acidity. This phenomenon could be explained through stereospecific
proton interaction with π-orbital cloud of A ring, which was confirmed by theoretical calculation. 相似文献