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1.
Seeds of Astragalus cicer L. (Fabaceae) afforded a galactomannan (5.90% yield of seed mass) of molecular weight 1064 kDa, solutions of which had high
viscosity [η] 925.5 mL/g and optical activity [α]D +71.9°. The galactomannan consisted of galactose and mannose units in a 1:1.39 ratio. Physicochemical methods established
that the main chain of the polysaccharide consisted of 1,4-β-D-mannopyranose units substituted at 72% of the C-6 positions by single α-D-galactopyranose units. The content of variously substituted galactose mannobiose units Man–Man, (Gal)Man–Man/Man–Man(Gal)
and (Gal)Man–Man(Gal) in the galactomannan were 18.7, 19.8, and 61.5%, respectively. 相似文献
2.
Galactomannans with galactose:mannose ratios 1:1.48 and 1:1.33, [α]D +67.9 and +76.4°, [η] 870.3 and 1337.1 mL/g, and molecular weights 999 and 1549 kDa, respectively, were isolated in 0.59
and 4.65% yields (of seed mass) from seeds of Astragalus alpinus and A. tibetanus (Fabaceae). Physicochemical methods (CrO3 oxidation; methylation–GC/MS; IR, NMR, and 13C spectroscopy) found that the main polysaccharide chain consisted of 1,4-β-D-mannopyranose units substituted 67.5% (A. alpinus) and 75.2% (A. tibetanus) at the C-6 position by single α -D-galactopyranose units. The contents of mannobiose blocks Man–Man, (Gal)Man–Man/Man–Man(Gal), and (Gal)Man–Man(Gal) variously
substituted with galactose were according to 13C NMR spectroscopy 15.9, 55.5, and 28.6% in A. alpinus galactomannan and 9.9, 42.3, and 47.8% in A. tibetanus galactomannan. 相似文献
3.
Galactomannan (yield 1.73% of seed mass) with molecular weight 808 kDa was isolated from seeds of Gueldenstaedtia monophylla Fisch. (Fabaceae). Its solutions were typically highly viscous with [η] 664.7 mL/g and optically active with [α]D +45.2°. It consisted of galactose and mannose in a 1:1.91 ratio. Physical chemical methods established that the principal
chain of the polysaccharide consisted of 1,4-β-D-mannopyranose units substituted 50.1% in the C-6-position by single α-D-galactopyranose units and traces of 6-O-α-galactopyranosylgalactopyranose. The contents of mannobiose blocks substituted by galactose Man–Man, (Gal)Man–Man/Man–Man(Gal),
and (Gal)Man–Man(Gal) in the galactomannan macromolecule were 23, 42, and 35%, respectively. 相似文献
4.
Galactomannan of molecular weight 472 kDa was isolated from Astragalus danicus Retz. (Fabaceae) seeds and consisted of galactose and mannose units in a 1:1.40 molar ratio. The main chain of the macromolecule
was constructed of 1,4-β-D-mannopyranose units, 71% of which were substituted at C-6 by single α-D-galactopyranose units.
Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 255257, May-June, 2009. 相似文献
5.
R. K. Rakhmanberdyeva 《Chemistry of Natural Compounds》2004,40(3):215-217
Galactomannan with a galactose:mannose ratio 1:1.1 and molecular weight 79,000 was obtained from Gleditsia delavayi seeds by fractional precipitation of the water-soluble polysaccharides. Methylation, oxidation by chromic acid and periodate, and partial acid hydrolysis established that the principal galactomannan macromolecule consisted of -1.4 mannopyranose units substituted at C-6 by -galactopyranoses. 相似文献
6.
R. P. Gorshkova V. V. Isakov V. A. Denisenko E. L. Nazarenko E. P. Ivanova L. S. Shevchenko 《Chemistry of Natural Compounds》2008,44(5):549-551
The O-specific polysaccharide of Alteromonas addita type strain KMM 3600T is constructed of trisaccharide repeat units containing L-rhamnose, D-glucose, and D-galactose. It
was established that the O-specific polysaccharide consists of trisaccharide repeat units with the structure →3)-α-D-Galp-(1→3)-α-L-Rhap-(1→3)-α-D-Glcp-(1→ based on monosaccharide analysis, Smith degradation, PMR and 13C NMR spectroscopy, and two-dimensional COSY, HSQC, and HMBC.
Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 445–447, September-October, 2008. 相似文献
7.
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
8.
A. A. Semioshkin P. V. Petrovskii D. Gabel B. Brellochs V. I. Bregadze 《Russian Chemical Bulletin》1998,47(5):950-955
The sodium salt of [B12H12]2− dianion reacts with carboxylic acid halides to give a mixture of B-acylated product [B12H11COR]2− and an unstable intermediate, the latter undergoing hydrolysis to form [B12H11OH]2−. The ratio of the products formed depends on the nature of the radical R. The reaction mechanism was studied by NMR spectroscopy.
A number of novel [B12H11COR]2− compounds were synthesized; their structures were confirmed by NMR and IR spectral data.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 980–985, May, 1998. 相似文献
9.
A. A. Abdoh M. B. Zughul J. Eric. D. Davies A. A. Badwan 《Journal of inclusion phenomena and macrocyclic chemistry》2007,57(1-4):503-510
Guest–host interactions were examined for neutral diclofenac (Diclo) and Diclofenac sodium (Diclo sodium) with each of the
cyclodextrin (CD) derivatives: α-CD, β-CD, γ-CD and 2-hydroxypropyl-β-cyclodextrin (HP-β-CD), all in 0.05 M aqueous phosphate
buffer solution adjusted to 0.2 M ionic strength with NaCl at 20 °C, and with β-CD at different pHs and temperatures. The
pH solubility profiles were measured to obtain the acid–base ionization constants (pK
as) for Diclo in the presence and absence of β-CD. Phase solubility diagrams (PSDs) were also measured and analyzed through
rigorous procedures to obtain estimates of the complex formation constants for Diclo/CD and Diclo sodium/CD complexation in
aqueous solutions. The results indicate that both Diclo and Diclo sodium form soluble 1:1 complexes with α-, β-, and HP-β-CD.
In contrast, Diclo forms soluble 1:1 Diclo/γ-CD complexes, while Diclo sodium forms 1:1 and 2:1 Diclo/γ-CD, but the 1:1 complex
saturates at 5.8 mM γ-CD with a solubility product constant (pK
sp = 5.5). Therefore, though overall complex stabilities were found to follow the decreasing order: γ-CD > HP-β-CD > β-CD > α-CD,
some complex precipitation problems may be faced with aqueous formulations of Diclo sodium with γ-CD, where the overall concentration
of the latter exceeds 5.8 mM γ-CD. Both 1H-NMR spectroscopic and molecular mechanical modeling (MM+) studies of Diclo/β-CD indicate the possible formation of soluble isomeric 1:1 complexes in water. 相似文献
10.
An extracellular thermostable α-galactosidase producing Aspergillus terreus
GR strain was isolated from soil sample using guar gum as sole source of carbon. It was purified to apparent homogeneity by
acetone precipitation, gel filtration followed by DEAE-Sephacel chromatographic step. The purified enzyme showed a single
band after sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The molecular weight of the purified enzyme
after SDS-PAGE was 108 kDa. The enzyme showed optimum pH and temperature of 5.0 and 65 °C, respectively, for artificial substrate
pNPαGal. α-Galactosidase from A. terreus
GR is found to be thermostable, as it was not inactivated after heating at 65 °C for 40 min. The K
m for pNPαGal, oNPαGal, raffinose, and stachyose are 0.1, 0.28, 0.42, and 0.33 mM, respectively. Inhibitors such as 1,10-phenanthroline,
phenylmethylsulfonyl fluoride, ethylenediaminetetraacetic acid, mercaptoethanol, and urea have no effect, whereas N-bromosuccinamide inhibited enzyme activity by 100%. Among metal ions tested, Mg2+, Ni2+, Ca2+, Co2+, and Mn2+ had no effect on enzyme activity, but Ag+, Hg2+, and Cu2+ have inhibited complete activity. 相似文献
11.
R. K. Rakhmanberdyeva 《Chemistry of Natural Compounds》2009,45(2):145-147
A polysaccharide with MW 25,000 consisting of arabinose, galactose, and mannose units in a 1:2.8:3.2 ratio was isolated from
Gleditsia macracantha seeds. Chemical and spectral methods established that the polysaccharide was a branched galactomannan with side branches
consisting of arabinose units.
Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 128-130, March-April, 2009. 相似文献
12.
The molecular structure of 23,24,25,26,27,29,30-heptamethyl-19,28-oxahexacyclo[15.13.18.017,18.013,14.08,9.05,10]tetracos-3-yl acetate III. Compound III C32H52O3 crystallizes in the monoclinic crystal system with the unit cell parameters a = 13.265(15) ?, b = 6.481(7) ?, c = 32.274(4) ?, β = 99.333(2)°, space group C2, Z = 4, d = 1.176 g/cm3.
Original Russian Text Copyright ? 2009 by N. I. Medvedeva, O. B. Flechter, and A. A. Korlyukov
__________
Translated from Zhurnal Strukturnoi Khimii, Vol. 50, No. 2, pp. 399–401, March–April, 2009. 相似文献
13.
Two new polyhydroxysteroids and five new glycosides were isolated from the starfishCeramaster patagonicus and their structures were elucidated: 5α-cholestane-3β,6α,15β,16β,26-pentol, (22E)-5α-cholest-22-ene-3β,6α,8,15α,24-pentol, (22E)-28-O-[O-(2-O-methyl-β-d-xylopyranosyl)-(1→2)-β-d-galactofuranosyl]-24-hydroxymethyl-5α-cholest-22-ene-3β,4β, 6α,8,15β,16β,28-heptol (ceramasteroside C1), (22E)-28-O-[O-(2,4-di-O-methyl-β-d-xylopyranosyl)-(1→2)-β-d-galactofuranosyl]-24-hydroxymethyl-5α-cholest-22-ene-3β, 6α,8,15β,16β,28-hexol (ceramasteroside C2), (22E)-28-O-[O-methyl-β-d-xylopyranosyl)-(1→2)-β-d-galactofuranosyl]-24-hydroxymethyl-5α-cholest-22-ene-3β,6α,8,15β,16β 28-hexol (eramasteroside C3), (22E)-28-O-[O-(2-O-methyl-β-d-xylopyranosyl)-(1→2)-β-d-galactofuranosyl]-24-methyl-5α-cholest-22-ene-3β,4β,6α,8, 15β, 26-hexol (ceramasteroside C4), and (22E)-28-O-[O-(2-O-methyl-β-d-xylopyranosyl)-(1→2)-β-d-xylopyranosyl]-5α-cholest-22-ene-3β,6α,8,15β,24-pentol (ceramasteroside C5)). Three known polyhydroxysteroids (24-methylene-5α-cholestane-3β,6α,8,15β,16β,26-hexol, 5α-cholestane-3β,6α,8,15β,16β,26-hexol,
and 5α-cholestane-3β,6β,15α,16β,26-pentol) were also isolated.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 190–195, January, 1997. 相似文献
14.
N. N. Pogodaeva S. V. Fedorov L. V. Kanitskaya A. A. Semenov 《Russian Chemical Bulletin》2000,49(11):1905-1909
A new flavonoid oligoside,viz. 3-O-[3,4-)di-O-acetyl-β-xylopyranosyl)-α-rhamnopyranosyl]-7-o-(α-rhamnopyranosyl)kaempferol, was isolated from the above-ground part of the plantAconitum barbatum Pers. The product was identified by spectral methods.
Published inIzvestiyu Akademii Nauk. Seriya Khimicheskaya. No. 11, pp. 1935–1937, November, 2000. 相似文献
15.
Yuanyuan Cong Rena Kasimu Hui Dai Palida Abulizi Ping Sheng Xiaoming Gao Pengfei Tu 《Chemistry of Natural Compounds》2009,45(1):11-13
A neutral polysaccharide Gi-A1 was isolated from the roots of Glycyrrhiza inflata Bat. It had a molecular mass of over 2000 kDa
and showed [α]D20 + 81.4° (c 1.05, H2O). Acid hydrolysis and methylation analysis indicated that Gi-A1 was mainly composed of α-D-glucose, α-L-arabinose, and α-D-galactose
with a molar ratio of 8.0:1.8:1.0. It can significantly stimulate spleen cell proliferation in vitro (P < 0.01).
Published in Khimiya Prirodnykh Soedinenii, No. 1, pp. 13–14, January–February, 2009. 相似文献
16.
Two new neodymium complexes, [Nd2(abglyH)6(2,2′-bipy)2(H2O)2] · 4H2O 1 and {[Nd(abglyH)3(H2O)2] · (4,4′-bipy) · 7H2O}n
2 (abglyH2 = N-P-acetamidobenzenesulfonyl-glycine acid, 2,2′-bipy = 2,2′-bipyridine, 4,4′-bipy = 4,4′-bipyridine), have been synthesized and
their structures have been measured by X-ray crystallography. In 1, nine-coordinated Nd(III) ions are bridged by two syn–syn bidentate and two tridentate bridging carboxylate groups from four different abglyH− anions to form dinuclear motifs, which are further connected into a 3-D supramolecular framework via hydrogen bonds between
the binuclear motifs and the uncoordinated water molecules. In 2, eight-coordinated Nd(III) ions are linked by six carboxylate groups adopting a syn–syn bidentate bridging fashion to form a 1-D inorganic–organic alternating linear chain. These polymeric chains generate microchannels
extending along the a direction, and these cavities are occupied by discrete tetradecameric water clusters, which interact with their surroundings
and finally furnish the 3-D supramolecular network via hydrogen bonds. At the same time, π–π stacking interactions between
benzene rings from abglyH− anions also play an important role in stabilizing the network. 相似文献
17.
The composition of water-soluble polysaccharides from the aerial part of Lophanthus chinensis Benth. (Lamiaceae) was studied. The dominant polymer LCWH-2, which was a partially acetylated glucoarabinogalactan, the main chain of which was constructed of α-(1→6)-bonded galactopyranose, was isolated and characterized. Atoms C-2 and C-3 of the main chain had branches of single
glucopyranose and arabinopyranose units and short chains of (1→3)-bonded arabinose.
Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 258–260, May–June, 2009. 相似文献
18.
L. N. Yang F. Xu L. X. Sun Z. C. Tan H. D. Tan Z. B. Zhao J. G. Liang 《Journal of Thermal Analysis and Calorimetry》2006,85(3):807-810
A microcalorimetric
technique based on the bacterial heat output was applied to evaluate the influence
of antibiotics PIP (Piperacillin Sodium)
and composite preparation of PIP and SBT (Sulbactam
Sodium) on the growth of E. coli
DH5α. The power–time curves of the growth metabolism of E. coli DH5α were studied using a TAM Air Isothermal
Microcalorimeter at 37°C. By analyzing the power–time curves, the
parameters such as growth rate constants (k),
inhibitory ratio (I), the maximum heat
power (P
m) and the
time of the maximum heat power (t
m)
were obtained. The results show that different concentrations of antibiotics
affect the growth metabolism of E. coli
DH5α. The PIP in the concentration range of 0–0.05 μg mL–1
has a stimulatory effect on the E. coli
DH5α growth, while the PIP of higher concentrations (0.05 –0.25
μg mL–1) can inhibit its growth. It seems
that the composite preparation composed of PIP and SBT cannot improve the
inhibitory effect on E. coli DH5α
as compared with the PIP. 相似文献
19.
P. I. Abronina L. V. Backinowsky A. A. Grachev S. L. Sedinkin N. N. Malysheva 《Russian Chemical Bulletin》2005,54(5):1287-1293
Methyl 2,4-di-O-benzoyl-α-D-mannopyranoside was used as a key intermediate in the synthesis of 3,6-branched mannopentaoside bearing one terminal D-[1-13C]mannopyranose residue, viz., methyl 6-O-[3,6-di-O-(α-D-mannopyranosyl)-α-D-mannopyranosyl)-3-O-{α -D-[1-13C]mannopyranosyl}-α-D-mannopyranoside.
Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday.
__________
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1250–1255, May, 2005. 相似文献
20.
Abstract Two novel organic–inorganic composite phosphotungstates, [H9{Ce(α-PW11O39)2}Cu(en)2] · 6H2O (1) and H7[Cu(en)2{Er(α-PW11O39)2}Cu(en)2] · 12H2O (2) (en = ethylenediamine) have been synthesized by the hydrothermal reaction of the trivacant Keggin polyoxoanion [α-A-PW9O34]9− with CeIII or ErIII ions in the presence of Cu2+ ions and en, and structurally characterized by IR spectra, elemental analysis and thermogravimetric analysis. X-ray crystallographic
analyses indicate that they are all built by sandwich-type [Ln(α-PW11O39)2]11− (Ln = CeIII, ErIII) polyoxoanions and [Cu(en)2]2+ cations generating infinite one-dimensional arrangements. To our knowledge, this 1-D chain structures constituted by mono-Ln
sandwiched POM units and transition-metal complex cations are very rare.
Graphical Abstract Two novel organic–inorganic composite phosphotungstates, [H9{Ce(α-PW11O39)2}Cu(en)2] · 6H2O (1) and H7[Cu(en)2{Er(α-PW11O39)2}Cu(en)2] · 12H2O (2) (en = ethylenediamine) have been synthesized by the hydrothermal reaction of the trivacant Keggin polyoxoanion [α-A-PW9O34]9− with CeIII or ErIII ions in the presence of Cu2+ ions and en, and structurally characterized by IR spectra, elemental analysis and thermogravimetric analysis. X-ray crystallographic
analyses indicate that they are all built by sandwich-type [Ln(α-PW11O39)2]11− (Ln = CeIII, ErIII) polyoxoanions and [Cu(en)2]2+ cations generating infinite one-dimensional arrangements. To our knowledge, this 1-D chain structures constituted by mono-Ln
sandwiched POM units and transition-metal complex cations are very rare.
相似文献