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1.
Reaction of 2, 3-dihydro-1H-1. 5-benzodiazepines with dichlorocarbene generated in situ using benzyltriethylammonium chloride (TEBA) as a phase transfer catalyst in chloroform-aqueous sodium hydroxide mixture gave mainly 1,2-cycloadducts, cis and trans-1a, 3-disubstituted-1, 1-dichloro-1a, 2,3,4-tetrahydro-1H-azirino[1,2-a][1,5]benzodiazepines (2.3), and formylated 1,2-cycloadducts, trans-1a,3-disubstituted-1, 1-dichloro-4-formyl-1a, 2, 3, 4–1 H-azirino[1, 2-a][1, 5]benzodiacepines (4). The stereo-structures of cycloadducts and the mechanism are also discussed.  相似文献   

2.
Summary 11,41-Dihydroxy-11,41-diethyl-1,4-dipropylcyclohexanes, like the previously described 11,41-dihydroxy-11,41-dimethyl-1,4-diethylcyclohexanes, give a molecular compound of three molecules of cis- and one molecule of trans-form.  相似文献   

3.
Abstract— Previous work has shown that fibroblast-derived collagenase/matrix-metalloproteinase-1(MMP–1), responsible for the breakdown of dermal interstitial collagen, was dose-dependently induced in vitro and in vivo by UVA irradiation and this induction was at least partly mediated byinterleukin–6(IL–6). We here provide evidence that UVA-inducedIL–1α andIL–1β play a central role in the induction of the synthesis both ofIL–6 and collagenase/MMP–1. In contrast to the late increase ofIL–1α andIL–1β mRNA levels at 6 h postirradiation, bioactivity ofIL–1 is already detectable at 1 h postirradiation. This early peak ofIL–1 bioactivity appears to be responsible for the induction ofIL–6 synthesis and together withIL–6 lead to an increase of the steady-state mRNA level of collagenase/MMP–1 as deduced from studies usingIL–1α andIL–1β antisense oligonucleotides or neutralizing antibodies againstIL–1α andIL–1β Besides the early posttranslationally controlled release of intracellularIL–1, a latter pretranslationally controlled synthesis and release ofIL–1 perpetuates the UV response. From these data we suggest a UV-induced cytokine network consisting ofIL–1α,IL–1β andIL–6, which via interrelated autocrine loops induce collagenase/MMP–1 and thus may contribute to the loss of interstitial collagen in cutaneous photoaging.  相似文献   

4.
This study investigated vitamin K1 (VK1) distribution following intravenous vitamin K1–fat emulsion (VK1–FE) administration and compared it with that after VK1 injection. Rats were intravenously injected with VK1–FE or VK1. The organ and tissue VK1 concentrations were determined using high‐performance liquid chromatography method at 0.5, 2 and 4 h to determine distribution, equilibrium and elimination phases, respectively. In the VK1–FE group, the plasma, heart and spleen VK1 concentrations decreased over time. However, other organs like liver, lung, kidney, muscle and testis, reached peak VK1 concentrations at 2 h. In the VK1 injection group, the liver VK1 concentrations were significantly higher than those in other organs at the three time points. However, VK1 concentrations in the other organs peaked at 2 h. In addition, in VK1–FE group, the heart, spleen and lung VK1 concentrations were significantly higher than those in the VK1 injection group at the three time points, and the liver VK1 concentration was significantly higher than that in the VK1 injection group at 4 h. The VK1 amount was greatest in the liver compared with the other organs. Thus, the liver is the primary organ for VK1 distribution. The distribution of VK1 is more rapid when injected as VK1–FE than as VK1. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

5.
The melting points of anhydrous 1-O-α- -glucopyranosyl- -mannitol, 1-O-α- -glucopyranosyl- -mannitol dihydrate and a new compound, 1-O-α- -glucopyranosyl- -mannitol-ethanol (2/1) were determined using differential scanning calorimetry. The melting onset values were 169.2 (3), 104.3 (18) and 158.7 (9), respectively, and the melting peak values were 171.4 (5), 107.9 (15) and 160.1 (6), respectively. 1-O-α- -glucopyranosyl- -mannitol dihydrate and 1-O-α- -glucopyranosyl- -mannitol-ethanol (2/1) decompose to anhydrous form when heated at slow heating rates.According to TG-FTIR measurements, 1-O-α- -glucopyranosyl- -mannitol-ethanol (2/1) lost its ethanol in the 110–190°C range, and 1-O-α- -glucopyranosyl- -mannitol dihydrate lost its crystal water in the 60–210°C range. After removal of ethanol and crystal water, both decomposed in air totally as carbohydrates usually do, forming lower hydrocarbons with OH-groups, CO2 and H2O.  相似文献   

6.
Synthesis and Structure of Highly Functionalized 2, 3‐Dihydro‐1H‐1, 3, 2‐diazaboroles A series of differently substituted 2, 3‐dihydro‐1H‐1, 3, 2‐diazaboroles has been prepared by various methods. 1, 3‐Di‐tert‐butyl‐2‐trimethylsilylmethyl‐1H‐1, 3, 2‐diazaborole ( 7 ), 2‐isobutyl‐1, 3‐bis(1‐cyclohexylethyl)‐1H‐1, 3, 2‐diazaborole ( 8 ), 1, 3‐bis‐(1‐cyclohexylethyl)‐2‐trimethylsilylmethyl‐1H‐1, 3, 2‐diazaborole ( 9 ) 1, 3‐bis(1‐methyl‐1‐phenyl‐propyl)‐2‐trimethylsilylmethyl‐1H‐1, 3, 2diazaborole ( 10 ) and 2‐bromo‐1, 3‐bis(1‐methyl‐1‐phenyl‐propyl)‐1H‐1, 3, 2‐diazaborole ( 11 ) were formed by reaction of the corresponding 1, 4‐diazabutadienes with the boranes Me3SiCH2BBr2, iBuBBr2 and BBr3 followed by reduction of the resulting borolium salts [R1 = tBu, Me(cHex)CH, [Me(Et)Ph]C; R2 = Me3SiCH2, iBu, Br] with sodium amalgam. Treatment of 11 and 12 with silver cyanide afforded the 2‐cyano‐1, 3, 2‐diazaboroles 13 and 14 . An alternative route to compound 8 is based on the alkylation of 2‐bromo‐1, 3, 2‐diazaborole 12 with isobutyllithium. Equimolar amounts of 13 and isobutyllithium give rise to the formation of 15 . The new compounds were characterized by 1H‐, 13C‐, 11B‐NMR, IR and mass spectra. The molecular structures of 7 and meso ‐10 were confirmed by x‐ray structural analysis.  相似文献   

7.
A novel reaction of α-iodo ketone (α-iodocycloalkanone, α-iodo-β-alkoxy ester, and α-iodoacyclicketone) with irradiation under a high-pressure mercury lamp gave the corresponding α-hydroxyketone in good yields. In the case of α,α′-diiodo ketone, α,α′-dihydroxyketone which little has been reported until now was obtained. This reaction affords a new, clean and convenient synthetic method for α-hydroxy- and α,α′-dihydroxyketone.  相似文献   

8.
The structural characterization, the in vitro antioxidant activity, and the hypoglycemic activity of a polysaccharide (SGP-1-1) isolated from Siraitia grosvenorii (SG) were studied in this paper. SGP-1-1, whose molecular weight is 19.037 kDa, consisted of Gal:Man:Glc in the molar ratio of 1:2.56:4.90. According to the results of methylation analysis, GC–MS, and NMR, HSQC was interpreted as a glucomannan with a backbone composed of 4)-β-D-Glcp-(1→4)-, α-D-Glcp-(1→4)-, and 4)-Manp-(1 residues. α-1,6 linked an α-D-Galp branch, and α-1,6 linked an α-D-Glcp branch. The study indirectly showed that SGP-1-1 has good in vitro hypoglycemic and antioxidant activities and that these activities may be related to the fact that the SGP-1-1’s monosaccharide composition (a higher proportion of Gal and Man) is the glycosidic-bond type (α- and β-glycosidic bonds). SGP-1-1 could be used as a potential antioxidant and hypoglycemic candidate for functional and nutritional food applications.  相似文献   

9.
We demonstrate a rational template carbonization method to produce nitrogen-containing nanoporous carbons at 800 °C, using 1, 10-phenanthroline (or benzimidazole) as carbon/nitrogen source and magnesium citrate as template. The mass ratio of 1, 10-phenanthroline (or benzimidazole) and magnesium citrate has exerted the vital role in the determination of pore structures and the resulting electrochemical performances. It reveals that the carbon-P:Mg-1:1 (obtained by heating 1, 10-phenanthroline and magnesium citrate at 800 °C with the mass ratio of 1:1) and carbon-B:Mg-1:1 (obtained by heating benzimidazole and magnesium citrate at 800 °C with the mass ratio of 1:1) samples both are amorphous, nitrogen-containing, and highly nanoporous in nature. The carbon-P:Mg-1:1 sample has a large BET surface area of 1,657.4 m2 g?1 and high pore volume of 1.83 cm3 g?1, and those of carbon-B:Mg-1:1 sample are of 1,105.4 m2 g?1 and 1.67 cm3 g?1, respectively. Based on a three-electrode system using a 6-mol L?1 KOH aqueous solution as electrolyte, the carbon-P:Mg-1:1 and carbon-B:Mg-1:1 samples can deliver large specific capacitances of 289.0 and 255.6 F g?1 at a current density of 0.5 A g?1. They can also exhibit high energy densities of 40.1 and 35.5 Wh kg?1 when designated the power density as 0.25 kW kg?1 as well as highly long-term cycling durabilities.  相似文献   

10.
Copper in different organs of Egyptian camels was successfully determined spectrophotometrically using Fast Grey RA. Its values amounted to: 200.8 ± 11.4, 155.8 ± 16.1, 142 ± 6.8, 128.3 ± 6.9, 117.6 ± 5.1, 113.0 ± 5.3, 86.3 ± 3.2, 79.0 ± 5.2, 76.3 ± 3.7, 66.3 ± 4.3, 59.8 ± 1.7, 57.6 ± 3.0, 53.0 ± 2.2, 36.3 ± 2.3 and 3.03 ± 0.32 μg/g dry matter of hair, liver, spleen, lung, heart, integument, muscle, brain, lymph gland, small intestine, large intestine, kidney, adrenal, fourth stomach, and hump, respectively, while 1 ml citrated blood contained 6.97 ± 0.64 μg. Of 16 elements mentioned, only vanadium interferes with the determination of copper in hair by the present method.  相似文献   

11.
The anisotropic electrocatalytic properties of gold nanobelts and nanoplates enclosed by either {1 1 0} or {1 1 1} facets were studied. Different strategies were used to synthesize these materials. It was found that the {1 1 0} surface of gold does not necessarily show a higher electrocatalytic activity than the {1 1 1} surface. The {1 1 0} surface of gold is more active than the {1 1 1} surface for glucose oxidation in both, neutral and alkaline media. However, for methanol oxidation in alkaline solution, the {1 1 0} surface shows a lower activity than the {1 1 1} surface, which is contrary to the general belief that {1 1 0} facet is the most active surface among the three basal planes. The possible mechanisms are discussed.  相似文献   

12.
Under the agency of the potent lithiating agent, n-butyllithium in TMEDA, an array of organosilanes was found to undergo 1, n-silyl rearrangements via carbanionic intermediates. Unambiguous 1, 2-, 1, 3- and 1, 4-silyl shifts were uncovered in 1-trimethylsilyl-1, 1, 2-triphenylethane, 1, 1-bis(trimethylsilyl)-1-phenylalkanes and 1, 2-bis(trimethylsilyl)-1, 2-diphenylethane, respectively. Cross-over and competition experiments established that these rearrangements generally are intramolecular and occur with decreasing ease in the order, 1, 2 > 1, 3 > 1, 4. In other compounds, such as 1, 1-bis(trimethylsilyl)-1, 2-diphenylethane, 1, n-bis(trimethylsilyl)benzenes and triphenyl(trimethylsilyl)methane, competing 1, n-silyl shifts occurred. Attack of the organolithium intermediates on solvent and silicon—lithium exchange were significant side reactions in some instances. 1-Trimethylgermyl-1, 1, 2-triphenylgermane underwent no discernible rearrangement but rather gave the product expected from germanium—lithium exchange. By conducting time and competition studies, it was shown that lithiation is the product-determining step in these rearrangements and that dual pathways, namely 1, 3-versus consecutive 1, 2- 1, 4-pathways, are operative in certain rearrangements.  相似文献   

13.
14.
The aim of this study was to investigate the effects of microwave ultrasonic-assisted extraction (MUAE) on the content, structure, and biological functions of Brassica rapa L. polysaccharide (BRP). Response surface methodology (RSM) was used to optimize the parameters of MUAE, and it obtained a polysaccharide with yield of 21.802%. Then, a neutral polysaccharide named BRP-1-1 with a molecular weight of 31.378 kDa was isolated and purified from BRP using DEAE-650 M and Sephadex G-100. The structures of the BRP-1-1 were elucidated through a combination of FT-IR, GC-MS, NMR, and methylation analysis. The results showed that BRP-1 consisted of mannose (Man) and glucose (Glu) in a molar ratio of 7.62:1. The backbone of BRP-1-1 mainly consisted of →6)-α-D-Glup-(1→4-β-D-Glup-(1→2)-α-D-Manp-(1→2)-α-D-Glup-(1→, the branch was [T-α-D-Manp-(1]n→. BRP-1-1 intervention significantly inhibited α-glucosidase activity; an inhibition rate of 44.623% was achieved at a concentration of 0.5 mg/mL. The results of the in vitro biological activity showed that BRP-1-1 has good antioxidant and hypoglycemic activity, suggesting that BRP-1-1 could be developed as a functional medicine.  相似文献   

15.
《Thermochimica Acta》1987,122(1):143-152
Enthalpies and temperatures of fusion have been measured by differential scanning calorimetry for urea and a number of its mono- and di-alkyl derivatives. Enthalpies obtained are: urea, 14.79 kj mol−1; monomethylurea, 15.75 kJ mol−1 ; monoethylurea, 13.94 kJ mol−1 ; monopropylurea, 14.63 kJ mol−1 ; monoisopropylurea, 17.40 kJ mol−1 ; monobutylurea, 14.55 kJ mol−1 ; monotertbutylurea, 33.13 kJ mol−1 ; dimethyl-1,1 urea, 29.61 kJ mol−1 ; dimethyl-1,3 urea, 13.62 kJ mol−1; diethyl-1,1 urea, 16/78 kJ mol−1 ; diethyl-1,3 urea, 12.46 kJ mol−1 ; dibutyl-1,3 urea, 14.87 kJ mol−1; trimethyl-1,1,3 urea, 14.30 kJ mol−1. Entropies of fusion have been derived from the experimental results.By temperature scanning starting from r.t. some solid-to-solid transitions for four alkylureas have also been detected, all hitherto unreported. Temperatures and enthalpies of transition are: for monoisopropylurea, 375.5 K and 2.31 kJ mol −1 ; for monobutylurea (two transitions), 313.1 K and 7.02 kJ mol−1 , 344.9 K and 0.88 kJ mol−1 ; for diethyl-1,3 urea, 339.4 K and 1.87 kJ mol−1 ; for dibutyl-1,3 urea, 311.5 K and 11.10 kJ mol−1.  相似文献   

16.
New synthetic routes to 1-methyl-1-silaindane (1b) and 1-methyl-1-germaindane (1b) were developed and the desired products were obtained in good isolated yield. Compounds 1a and 1b were fully characterized by mass spectroscopy, 1H and 13C{1H} NMR, and infrared spectroscopy.  相似文献   

17.
Photoelectron angular distributions have been measured for the three-photon resonant one-photon ionization, (3+1), of Xe via the 7s[1 1/2]0 1 and 8s[1 1/2]0 1 states. The results are in good agreement with the theoretical predictions of Tang and Lambropoulos [13] for the 8s[1 1/2]0 1, but not for the 7s[1 1/2]0 1 state. Furthermore, the results are compared to those which have been obtained by Blazewicz et al. [1] for the three-photon resonant two-photon ionization, (3+2), of Xe via the 6s[1 1/2]0 1 state.  相似文献   

18.
Expression and purification of β-galactosidases derived from Bifidobacterium provide a new resource for efficient lactose hydrolysis and lactose intolerance alleviation. Here, we cloned and expressed two β-galactosidases derived from Bifidobacterium. The optimal pH for BLGLB1 was 5.5, and the optimal temperature was 45 °C, at which the enzyme activity of BLGLB1 was higher than that of commercial enzyme E (300 ± 3.6 U/mg) under its optimal conditions, reaching 2200 ± 15 U/mg. The optimal pH and temperature for BPGLB1 were 6.0 and 45 °C, respectively, and the enzyme activity (0.58 ± 0.03 U/mg) under optimum conditions was significantly lower than that of BLGLB1. The structures of the two β-galactosidase were similar, with all known key sites conserved. When o-nitrophenyl-β-D-galactoside (oNPG) was used as an enzyme reaction substrate, the maximum reaction velocity (Vmax) for BLGLB1 and BPGLB1 was 3700 ± 100 U/mg and 1.1 ± 0.1 U/mg, respectively. The kinetic constant (Km) of BLGLB1 and BPGLB1 was 1.9 ± 0.1 and 1.3 ± 0.3 mmol/L, respectively. The respective catalytic constant (kcat) of BLGLB1 and BPGLB1 was 1700 ± 40 s−1 and 0.5 ± 0.02 s−1, respectively; the respective kcat/Km value of BLGLB1 and BPGLB1 was 870 L/(mmol∙s) and 0.36 L/(mmol∙s), respectively. The Km, kcat and Vmax values of BLGLB1 were superior to those of earlier reported β-galactosidase derived from Bifidobacterium. Overall, BLGLB1 has potential application in the food industry.  相似文献   

19.
LiNi1/3Co1/3Mn1/3O2 was prepared by a modified sol–gel method, selecting ethylene diamine tetraacetic acid and citric acid as the co-chelating agent. The mole ratios of ethylene diamine tetraacetic acid (EDTA) to metal ion (Mn+) were 0:1, 1:1 and 2:1. The obtained samples were characterized by XRD, BET and SEM. The XRD showed that LiNi1/3Co1/3Mn1/3O2 had good crystallinity and well-ordered layered structure. After calcined at 850 °C, the LiNi1/3Co1/3Mn1/3O2 particles exhibited a three-dimensional space network structure, which was greatly correlated with the ratio of EDTA to metal ion. The LiNi1/3Co1/3Mn1/3O2 obtained from a mole ratio of 1:1 (EDTA:Mn+) had the best electrochemical performance. The reversible capacities were reached 168 and 100 mAh/g at 1C and 10C discharge rate, respectively. The result of the cycling performance showed a high capacity maintenance ratio of 89.3 % at 1C and 25 °C after 50 cycles. The further electrochemical performance was evaluated by electrochemical impedance spectroscopy and cyclic voltammetry.  相似文献   

20.
Medium-resolution spectra of the N2 b1Πu-X1Σg+ band system were recorded by 1 + 1 multiphoton ionization. In the spectra we found different linewidths for transitions to different vibrational levels in the b 1Πu state: Δν0 = 0.50 ± 0.05 cm−1, Δν1 = 0.28 ± 0.02 cm−1, Δν2 = 0.65 ± 0.06 cm−1, Δν3 = 3.2 ± 0.5 cm−1, Δν4 = 0.60 ± 0.07 cm−1, and Δν5 = 0.28 ± 0.02 cm−1. From these linewidths, predissociation lifetimes τν were obtained: τ0 = 16 ± 3 ps, τ1 > 150 ps, τ2 = 10 ± 2 ps, τ3 = 1.6 ± 0.3 ps, τ4 = 9 ± 2 ps, and τ5 > 150 ps. Band origins and rotational constants for the b 1Πuν = 0 and 1 levels were determined for the 14N2 and 14N15N molecules.  相似文献   

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