共查询到20条相似文献,搜索用时 31 毫秒
1.
A. V. Tarantin V. A. Glushkov K. Yu. Suponitskii A. A. Kudryashov O. A. Maiorova A. G. Tolstikov 《Russian Journal of Organic Chemistry》2010,46(10):1479-1489
Glyoxylate and arylglyoxal imines based on 12-aminodehydroabietic acid undergo hetero-Diels—Alder (Povarov) reaction with
ethyl vinyl ether, cyclopentadiene, and indene to give, respectively, methyl (8aR,9R,12aS)-3-aroyl-5-isopropyl–9,12a-dimethyl–7,8,8a,9,10,11,12,12a-octahydronaphtho[1,2-f]quinoline-9-carboxylates, methyl (7R,10aS,10dR,13aS)-1-aroyl–3-isopropyl–7,10a-dimethyl–2,5,6,6a,7,8,9,10,10a,10d,13,13a-dodecahydro-1H-naphtho[1,2-f]cyclopenta[c]quinoline-7-carboxylates, and methyl (6aS,11bS,11eS,15R,15aR)-6-aroyl–4-isopropyl–11e,15-dimethyl–2,5,6,6a,7,11b,11e,12,13,14,15,15a-1H-dodecahydroindeno[2,1-c]-naphtho[1,2-f]quinoline-15-carboxylates. 相似文献
2.
E. N. Adamenko L. L. Frolova M. V. Panteleeva A. V. Kuchin 《Chemistry of Natural Compounds》2007,43(1):59-62
Optically active camphordihydro-2,3-pyrazine and camphorquinoxaline were prepared from camphoroquinone enantiomers. It was
shown that (1S,4R)-(+)-camphoroquinone was formed by oxidation of (1S,3R, 4R)-(−)-3-bromocamphor and (1R,4S)-(−)-camphoroquinone from (1R,3S, 4S)-(+)-3-bromocamphor, respectively. Camphor anhydride was a side product (6–10%) of the reaction.
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Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 50–52, January–February, 2007. 相似文献
3.
Campanelli Anna Rita Domenicano Aldo Macchiagodena Marina Ramondo Fabio 《Structural chemistry》2011,22(5):1131-1141
Reference values of the structural substituent parameters, S
E and S
R, measuring the electronegativity and resonance effects, respectively, of functional groups (Campanelli et al. J Phys Chem
A 107:6429–6440, 2003) have been determined from the benzene ring geometries of 100 Ph–X species, including different conformations of the same
molecule. Geometries have been obtained by quantum chemical calculations at the HF/6-31G*, HF/6-311++G**, and B3LYP/6-311++G**
levels of theory. The substituent parameters from HF/6-311++G** calculations are in close agreement with those determined
at the HF/6-31G* level. Using the B3LYP density functional yields S
E and S
R values which—in general—correlate well with the corresponding HF values. Exceptions occur with some charged groups, and,
in the case of S
E, with a few dipolar groups having very high or low electronegativities. S
R values from B3LYP calculations are about 22% smaller than the corresponding HF values. The variations of the benzene ring
geometry caused by electronegativity, resonance, and steric effects are illustrated in some detail. 相似文献
4.
Cycloadsurgenin, 20R,24 S-epoxycycloartan-6α,25-diol-3,16-dione, was partially synthesized in four steps from cyclosieversigenin. Side products with the structures 17E,24S-cycloart-17-en-6α,24,25-triol-3,16-dione and 17Z,24 S-cycloart-17-en-6α,24,25-triol-3,16-dione were obtained in addition to the desired product.
Presented at the 1st International Symposim on Edible Plant Resources and the Bioactive Ingredients, Xinjiang, China, July
25–27, 2008.
Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 591–595, November–December, 2008. 相似文献
5.
Summary Reinvestigation by HPLC of the petals ofLilium tigrinum and the isolation of some minor compounds is reported. Using HPLC-controlled, preparative-column chromatography, 5,6-diakarpoxanthin
(6), 6-epikarpoxanthin (2), 5,6-diacapsokarpoxanthin (8), and 9Z-antheraxanthin (9Z-13) were isolated and characterized. Based on spectroscopic data the absolute configurations of6 and8 were identical with those originating from paprika, thus the 5,6-diakarpoxanthin (6) and 5,6-diacapsokarpoxanthin (8) have the 3S, 5S, 6S configuration and 6-epikarpoxanthin (2) has the 3S, 5R, 6S configuration.
Presented at: Balaton Symposium on High-Performance Separation Methods, Siófok, Hungary, September 3–5, 1997. 相似文献
6.
G. Yu. Ishmuratov R. Ya. Kharisov M. P. Yakovleva R. R. Muslukhov E. G. Galkin V. S. Shmakov T. V. Khakimova G. A. Tolstikov 《Russian Chemical Bulletin》2000,49(4):717-721
An enantioselective (ee−50%) four-step synthesis of (S)-6-methylhept-5-en-2-ol (“sulcatol”), which is the aggregation pheromone ofGnathotrichus sulcatus, from 3S,7-dimethylocta-1,6-diene was developed.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 713–717, April, 2000. 相似文献
7.
N. N. Trofimova A. S. Gromova V. I. Lutsky A. A. Semenov S. A. Avilov A. I. Kalinovsky D. Li N. L. Owen 《Russian Chemical Bulletin》1998,47(7):1395-1398
Two triterpenoid diglycosides of the cycloartane series were isolated from the terrestrial part ofThalictrum minus L. (Ranunculaceae). Genins of these glycosides are side-chain structural isomers—3-O-β-d-galactopyranosyl-29-O-β-d-glucopyranosyl-9β, 19-cyclo-20(S)-lanost-24(Z)-ene-3β, 16β, 22(S), 26, 29-pentaol and 3-O-β-d-galactopyranosyl-29-O-β-d-glucopyranosyl-9β, 19-cyclo-20(S)-lanost-25-ene-3β, 16β,22(S), 24ζ, 29-pentaol. The structures of these glycosides were established using 1D and 2D NMR spectroscopy and FAB mass spectrometry.
For Part 9, see Ref. 1.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1434–1437, July, 1998. 相似文献
8.
K. V. Yusenko I. A. Baidina E. A. Shusharina S. A. Gromilov 《Journal of Structural Chemistry》2008,49(1):170-174
The [Ru(NH3)5Cl]2[Re6S8(CN)6]·3H2O salt was obtained; its crystal structure was analyzed: a = 10.7713(9) Å, b = 13.9602(11) Å, c = 14.7956(11) Å, α = 91.961(3)°, β = 109.985(3)°, γ = 110.030(3)°, V = 1935.3(3) Å3, space group P1ˉ, Z = 2, d
calc = 3.441 g/cm3. In the cluster anion, the Re-Re distances lie in the range from 2.594 Å to 2.612 Å. For two crystallographically independent
complex cations, Ru-Nav is 2.105 Å, and Ru-Clav 2.329 Å. A pseudohexagonal motif of the structure was found.
Original Russian Text Copyright ? 2008 by K. V. Yusenko, I. A. Baidina, E. A. Shusharina, and S. A. Gromilov
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Translated from Zhurnal Strukturnoi Khimii, Vol. 49, No. 1, pp. 178–181, January–February, 2008. 相似文献
9.
N. N. Trofimova A. S. Gromova V. I. Lutsky A. A. Semenov S. A. Avilov D. Li N. L. Owen 《Russian Chemical Bulletin》1999,48(3):596-599
From the terrestrial part ofThalictrum minus L. (Ranunculaceae) a novel triterpenoid diglycoside was isolated. The genin of this glycoside is a new cycloartane triterpenoid.
The structure of the glycoside was established on the basis of 1D and 2D NMR spectroscopy and FAB mass spectrometry as 22S,25-epoxy-3-O-β-d-galactopyranosyl-29-O-β-d-glucopyranosyl-9β, 19-cyclo-20S-lanostane-3β,16β,24S,29-tetrol.
For Part 10 see Ref. 1.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 602–605, March, 1999. 相似文献
10.
Kammerer B Kahlich R Ufer M Schenkel A Laufer S Gleiter CH 《Analytical and bioanalytical chemistry》2005,383(6):909-917
Phenprocoumon belongs to the group of vitamin K antagonists (VKAs), for example warfarin and acenocoumarol. It is widely used
for therapeutic anticoagulation and clinically administered as a racemate. Both enantiomers are partially metabolized by the
polymorphic CYP2C9 enzyme. The pharmacokinetics are, however, substantially less dependent on CYP2C9 activity or genotype
than for other CYP2C9-metabolised VKAs, and pharmacokinetic differences for the enantiomers are only minor. We have investigated
the stereospecific pharmacokinetics of the monohydroxylated phenprocoumon metabolites in human plasma by achiral–chiral LC–LC–MS–MS
coupling. In addition to the known metabolites, 4′-, 6-, and 7-hydroxyphenprocoumon, two other monohydroxylated metabolites
(M1 and M2) were detected in plasma and human liver microsomal incubations. One of these was identified as 2′-hydroxyphenprocoumon
by comparison with synthetic standards; the other seemed to be a side-chain-hydroxylated derivative. Analysis of enantiomeric
metabolite ratios after a single oral dose of phenprocoumon revealed changes over time with an overall preponderance of the
respective (R) enantiomers. The minor role of CYP2C9 in 4′-hydroxy-PPC formation and the effect of CYP2C9 genotype for (S)-6- and (S)-7-hydroxy-PPC were confirmed. M1 and M2 are formed highly stereoselectively, without dependence on CYP2C9 genotype. These
may be interpreted as alternative metabolic pathways that render phenprocoumon less dependent on CYP2C9 activity or genotype. 相似文献
11.
G. Yu. Ishmuratov M. P. Yakovleva R. Ya. Kharisov I. M. Muslimova R. R. Muslukhov R. L. Safiullin G. A. Tolstikov 《Russian Chemical Bulletin》1997,46(5):1033-1035
An enantiospecific synthesis of (S)-(+)-3-methylheneicosan-2-one, an analog of the sex pheromone of the German cockroach (Blatella germanica L.), was carried out through selective transformations of (3R,6S)-3,7-dimethyloctane-6-olide obtained from (−)-menthonevia the Baeyer—Villiger reaction.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1071–1073, May, 1997. 相似文献
12.
Qiong-ming Xu Quan Li Yan-li Liu Yu-lin Feng Shi-lin Yang Xiao-ran Li 《Chemistry of Natural Compounds》2010,46(3):366-369
In the search for platelet-activating-factor (PAF) antagonists, two new lignan compounds were isolated from the leaves of
Syringa reticulata Hara var. mandshurica. Their structures were elucidated as (7R,8S, 8'S)-3,4,3',4'-dimethylenedioxy-8,9-dihydroxy-8.8', 7-O-9'-lignan (mandshuricol A) and (7R,8S,8'S)-3',4'methylenedioxy-4-methoxy-3,8,9-trihydroxy-8.8', 7-O-9'-lignan (mandshuricol B), Mandshuricol A and B showed antagonistic activity on PAF in the [3H] PAF receptor binding assay with IC50 values of 4.8 × 10–5 M and 3.5 × 10–5 M, respectively. 相似文献
13.
M. D. Alaniya N. F. Chkadua T. I. Gigoshvili E. P. Kemertelidze 《Chemistry of Natural Compounds》2006,42(4):445-448
The new cycloartane glycoside cycloascauloside A with the structure 20S,24R-epoxycycloartan-3β, 6α,16β,25-tetraol 3-O-[α-L-rhamnopyranosyl(1→6)]-β-D-(2′-O-acetyl)-glucopyranoside was isolated from leaves of Astragalus caucasicus Pall. The structure was established based on IR, PMR, and 13C NMR spectra and physicochemical properties of the compound itself and the products of its chemical transformations.
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Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 359–361, July–August, 2006. 相似文献
14.
Quinolin-8-ol-bonded polyurethane foam (Ox-PUF) was synthesized by coupling the polyurethane foam matrix with oxine through
an azo (-N=N-) group. The chromatographic retention behavior of Ag+, Pb2+, and Al3+ onto the Ox-PUF was studied. The extraction of Ag+, Pb2+, and Al3+ was accomplished within 15–20 min at pH ranges of 1–4, 4–6, and 6–12, respectively. The kinetics and thermodynamics of the
sorption of tested metal ions onto Ox-PUF have been studied. The average values of ΔH, ΔS, ΔG; k
1, k
−1, k′, and t
1/2 at 298 K were −28.7 kJ/mol, 210.1 J/(mol K), −6.74 kJ/mol, 0.095, 0.01, 0.113, and 7.184 min, respectively. The sorption
capacities of the Ox-PUF were 0.16, 0.07, and 0.59 mmol/g for Ag+, Pb2+, and Al3+, correspondingly. The proposed method has been successfully applied to the preconcentration and removal of tested metal ions
from wastewater. Recoveries between 80 and 99% were obtained (RSD ∼ 7).
The text was submitted by the authors in English. 相似文献
15.
Synthesis of 20S-protopanaxadiol 20-O-β-D-glucopyranoside, a metabolite of Panax ginseng glycosides, and compounds related to it 总被引:1,自引:0,他引:1
A preparative semi-synthetic method was developed to prepare 20S-protopanaxadiol 20-O-β-Dglucopyranoside (1), a metabolite of Panax ginseng glycosides. The 20-O-•-D-glucopyranosides of 20S-hydroxydammar-24-en-3,12-dione, 3β,20S-dihydroxydammar-24-en-12-one, and 3β,12α, 20S-trihydroxydammar-24-ene were synthesized for the first time.
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Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 364–369, July–August, 2006. 相似文献
16.
《Acta Crystallographica. Section C, Structural Chemistry》2018,74(5):564-570
As part of a project studying the secondary metabolites extracted from the Chilean flora, we report herein three new β‐agarofuran sesquiterpenes, namely (1S,4S,5S,6R,7R,8R,9R,10S)‐6‐acetoxy‐4,9‐dihydroxy‐2,2,5a,9‐tetramethyloctahydro‐2H‐3,9a‐methanobenzo[b]oxepine‐5,10‐diyl bis(furan‐3‐carboxylate), C27H32O11, ( II ), (1S,4S,5S,6R,7R,9S,10S)‐6‐acetoxy‐9‐hydroxy‐2,2,5a,9‐tetramethyloctahydro‐2H‐3,9a‐methanobenzo[b]oxepine‐5,10‐diyl bis(furan‐3‐carboxylate), C27H32O10, ( III ), and (1S,4S,5S,6R,7R,9S,10S)‐6‐acetoxy‐10‐(benzoyloxy)‐9‐hydroxy‐2,2,5a,9‐tetramethyloctahydro‐2H‐3,9a‐methanobenzo[b]oxepin‐5‐yl furan‐3‐carboxylate, C29H34O9, ( IV ), obtained from the seeds of Maytenus boaria and closely associated with a recently published relative [Paz et al. (2017). Acta Cryst. C 73 , 451–457]. In the (isomorphic) structures of ( II ) and ( III ), the central decalin system is esterified with an acetate group at site 1 and furoate groups at sites 6 and 9, and differ at site 8, with an OH group in ( II ) and no substituent in ( III ). This position is also unsubstituted in ( IV ), with site 6 being occupied by a benzoate group. The chirality of the skeletons is described as 1S,4S,5S,6R,7R,8R,9R,10S in ( II ) and 1S,4S,5S,6R,7R,9S,10S in ( III ) and ( IV ), matching the chirality suggested by NMR studies. This difference in the chirality sequence among the title structures (in spite of the fact that the three skeletons are absolutely isostructural) is due to the differences in the environment of site 8, i.e. OH in ( II ) and H in ( III ) and ( IV ). This diversity in substitution, in turn, is responsible for the differences in the hydrogen‐bonding schemes, which is discussed. 相似文献
17.
Photochromic acrylates containing both biphenylene and spiro-oxazine moieties with a chiral substituent and the related polymers were prepared and yielded photochromic chiral liquid crystalline systems. The photochromic acrylates containing both an undecamethylene group and a (2S, 3S)-2-chloro-3-methylpentanoyloxy group (A11SOP) or a (-)-menthoxyacetoxy group (A11SOM) gave a supercooled mesophase; the latter reflected right-handed visible light (blue colour) at room temperature. On the other hand, the photochromic acrylate containing both the (R)-(-)-2-methylpropylene and (2S, 3S)-2-chloro-3-methylpentanoyloxy groups (A3SOP) showed no mesophase. The related homopolymers, PA11SOP and PA11SOM, did not exhibit mesophases because of steric hindrance between the side groups of the polymers. However, only PA11SOM exhibited shear-induced birefringence under 100-104°C. Several copolymers consisting of the nematogenic monomer, 4-[4-(6-acryloyloxyhexyloxy)benzoyloxy]benzonitrile (A6CN), and A11SOP or A11SOM possessed a smectic phase due to reduction of the steric hindrance between the potentially smectogenic A11SOP or A11SOM moieties. 相似文献
18.
M.-H. Wang Z.-C. Tan Q. Shi L.-X. Sun T. Zhang 《Journal of Thermal Analysis and Calorimetry》2006,84(2):413-418
The
heat capacities of 2-benzoylpyridine were measured with an automated adiabatic
calorimeter over the temperature range from 80 to 340 K. The melting point,
molar enthalpy, ΔfusHm,
and entropy, ΔfusSm,
of fusion of this compound were determined to be 316.49±0.04 K, 20.91±0.03
kJ mol–1 and 66.07±0.05 J mol–1
K–1, respectively. The purity of the compound
was calculated to be 99.60 mol% by using the fractional melting technique.
The thermodynamic functions (HT–H298.15) and (ST–S298.15) were calculated based
on the heat capacity measurements in the temperature range of 80–340
K with an interval of 5 K. The thermal properties of the compound were further
investigated by differential scanning calorimetry (DSC). From the DSC curve,
the temperature corresponding to the maximum evaporation rate, the molar enthalpy
and entropy of evaporation were determined to be 556.3±0.1 K, 51.3±0.2
kJ mol–1 and 92.2±0.4 J K–1
mol–1, respectively, under the experimental
conditions. 相似文献
19.
The results of quantum chemical calculations of the electronic structure and geometry of octahedral clusters [Mo6S8(CN)6]6−, [Mo6Se8(CN)6]6−, [Re6S8(CN)6]4−, and Rh6(CO)16 by the ab initio SCF (RHF) and DFT (B3LYP) methods with various basis sets are presented. The electronic states of the clusters under study
in ideal spherically symmetric potential were classified in the orbital quantum number l (1s, 1p, 1d, 1f, 1g, 1h, 1i), l = 0–6. In real crystal field with Oh symmetry these states are split. The calculated new electronic states were matched to the irreducible representations of
the point symmetry group Oh. The polarizabilities of the compounds considered are 55–65 Å3. A new model for the electronic structure of octahedral clusters containing M6 groups was proposed. The model is based on the idea of free electrons moving in spherically symmetric potential field.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2617–2624, December, 2005. 相似文献
20.
Two new lignans were isolated with two other known compounds, eusiderin A and eusiderin I, from Eusideroxylon zwageri (billian). The two new lignans have isomeric structure. The structures of the new lignans were determined to be (2R,3R,4S)-2,3-dimethyl-6,7-dimethoxy-4-ethoxy (3′,4′,5′-trimethoxybenzene)-1,5-dihydroxytetralin and (2R,3S,4S)-2,3-dimethyl-6,7-dimethoxy-4-ethoxy(3′,4′,5′-trimethoxybenzene)-1,5-dihydroxytetralin.
Published in Khimiya Prirodnykh Soedinenii, No. 3, pp. 303–305, May–June, 2009. 相似文献