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Pure rotational transitions of the ClSO radical have been observed by Fourier-transform microwave spectroscopy. a-type and b-type transitions, for both 35Cl and 37Cl isotopologues, were detected, and the observed very complicated fine and hyperfine components were assigned well. The intensities of the observed spectra of the two isotopologues correspond to the ratio of the isotope abundances of 35Cl and 37Cl. A total of 21 molecular constants were determined precisely for both 35ClSO and 37ClSO, including the rotational constants, centrifugal distortion constants, electronic spin-rotation constants, nuclear spin-rotation constants, magnetic hyperfine constants, and quadrupole coupling constants of chlorine. The molecular constants show ClSO to have the 2A′′ electronic ground state with an out-of-plane unpaired electron. The spin density of the chlorine atom is about 10.6%, which is similar to that of the fluorine atom for FSO, about 8%. Results of the ClSO radical are compared with those of other triatomic radicals with similar structures, the XSS, XSO, and XOO radicals with X = H, F, and Cl, leading to a conclusion that the ClSO radical is more like FSO, but fairly different from the FOO and ClOO radicals. [ABSTRACT FROM AUTHOR]

Pure rotational transitions of two conformers of the CH2CHCO radical have been observed by Fourier-transform microwave spectroscopy, where one conformer is called the s-trans-3-propenalyl radical and the other the 3-propenolyl radical. The observed two conformers have different electronic states. The former, the s-trans-3-propenalyl radical, has the 2A′ electronic state and can be written as CH2CHĊO, where the unpaired electron resides mainly on the terminal CO carbon. On the other hand, the latter, 3-propenolyl radical has the 2A′′ electronic state and can be written as ĊH2CHCO. We were able to observe pure rotational transitions of the two conformers. Since both of the species have an unpaired electron, there exist spin–rotation interactions due to the unpaired electron and the magnetic hyperfine interactions due to the three coupling protons. The observed very complicated spectra, caused by these interactions, were assigned, leading to detailed molecular constants including the fine and hyperfine coupling constants for both of the species. The determined molecular constants support the electronic structures of the two conformers. There exists a controversy as to which of the two conformers is the lowest energy one. Our present observation led to the conclusion that s-trans-3-propenalyl is the lowest energy conformer. [ABSTRACT FROM AUTHOR]

A Fourier-transform microwave spectrum of the cis-β-cyanovinyl radical is re-measured for the Ka = 0 ladder of the a-type transitions up to 30 GHz and the 212–111 transition at 19.85 GHz. Four b-type transitions are also observed using a MW–MW double-resonance technique. Fine and hyperfine components observed for each rotational transition are fully assigned in the present study, and the precise molecular constants are determined for the radical. From the comparisons of the hyperfine coupling constants with those of the vinyl radicals, it is concluded that the substitution of one of the β-hydrogens by the cyano group has little effect on the electronic structure of the vinyl radical. [ABSTRACT FROM AUTHOR]

Five variable dimensional cadmium(ii) coordination polymers, {[Cd2(bpy)2(NO3)4·H2O]}n (1), [Cd(2,3-Pydc)]n (2), {[Cd2(2,3-Pydc)(bpy)2(NO3)(H2O)2]·(NO3)·3H2O}n (3), [Cd2(2,3-Pydc)2(H2O)]n (4) and {[Cd(NA)(NO3)(H2O)2]}n (5), have been synthesized by hydrothermal reaction of pyridine-2,3-dicarboxylic acid (2,3-H2Pydc) and 4,4′-bipyridine (bpy) with cadmium nitrate under different temperatures. At 80 °C, the mixture A of a 1-D compound 1 containing only a ligand of 4,4′-bpy and 2-D 36·46·53 topological compound 2 with a single ligand of 2,3-Pydc2− were obtained. At 120 °C or so, the 3-D 64·102 topological compound 3 containing mixed ligands of 2,3-Pydc2− and 4,4′-bpy was assembled. However, as the temperature increased to 170 °C, partial 2,3-H2Pydc in situ decarboxylated into nicotinic acid (HNA) and consequently another mixture B of 3-D 316·423·53·63 topological compound 4 reported previously and 1-D chain-like compound 5 containing NA− were constructed. Meanwhile, the complexes 1–3 and 5 exhibited good luminescent properties. [ABSTRACT FROM AUTHOR]

At low temperature, the reactions of quinoline-2,3-dicarboxylic acid (2,3-H2qldc) with ZnCl2 in three different solvents gave three 0-D mononuclear compounds respectively, namely Zn(2,3-Hqldc)2(H2O)2 (1), Zn(2,3-Hqldc)2(DMSO)2 (2) and Zn(2,3-Hqldc)2(H2O)2·C6H6 (3). At high temperature, the three corresponding reactions always produced 2-D 44 topological layer [Zn(2,3-Hqldc)2]n (4). Interestingly, compound 4 may also be constructed through the temperature-driven irreversible change in solution from 1, 2 and 3. Supramolecular structure analyses reveal that through hydrogen bonding interactions, such as O–H…O/C–H…O)/C–H…π/π…π, the mononuclear units Zn(2,3-Hqldc)2(H2O)2 (1), Zn(2,3-Hqldc)2(DMSO)2 (2) and Zn(2,3-Hqldc)2(H2O)2·C6H6 (3) as well as the 2-D layer [Zn(2,3-Hqldc)2]n (4) were further assembled into 3-D 412·63 (in 1 and 4) and 3-D 424·64 (in 2 and 3) supramolecular networks, respectively. Obviously, these results show that the reaction temperature and solvent play critical roles in directing the molecular structures and supramolecular assemblies of these low-dimensional zinc(ii) compounds. [ABSTRACT FROM AUTHOR]

Pure rotational transitions of two conformers of the CH 2 CHCO radical have been observed by Fourier-transform microwave spectroscopy, where one conformer is called the s- trans -3-propenalyl radical and the other the 3-propenolyl radical. The observed two conformers have different electronic states. The former, the s- trans -3-propenalyl radical, has the 2 A' electronic state and can be written as CH 2 CHĊO, where the unpaired electron resides mainly on the terminal CO carbon. On the other hand, the latter, 3-propenolyl radical has the 2 A'' electronic state and can be written as ĊH 2 CHCO. We were able to observe pure rotational transitions of the two conformers. Since both of the species have an unpaired electron, there exist spin-rotation interactions due to the unpaired electron and the magnetic hyperfine interactions due to the three coupling protons. The observed very complicated spectra, caused by these interactions, were assigned, leading to detailed molecular constants including the fine and hyperfine coupling constants for both of the species. The determined molecular constants support the electronic structures of the two conformers. There exists a controversy as to which of the two conformers is the lowest energy one. Our present observation led to the conclusion that s- trans -3-propenalyl is the lowest energy conformer.

Two different crystal forms, namely {[Dy2(mpda)3(H2O)2]·H2O}n (1) and [Dy2(mpda)3(H2O)4]n (2), were obtained from the reaction of multidentate 2,6-dimethylpyridine-3,5-dicarboxylic acid (H2mpda) with Dy2O3 at different temperatures. Structural analysis reveals that compound 1 is a 2-D triple-stranded meso-helical layer, and 2 a 3-D chain-layer framework. The fluorescent measure shows that compound 1 is a promising luminescent probe for various metals with a remarkable “on–off” switch of emission, mainly deriving from many pairs of inversely arranged 4-aza bowl-like crown ethers distributed in the 2-D helical plane. Moreover, compound 1 presents noticeable hydrogen-sorption at medium pressure.

A series of 0-D, 1-D, and 2-D metal-organic compounds through reactions of quinoline-2,3-dicarboxylic acid (2,3-H(2)qldc) with transition metal salts MCl(2), namely, M(2,3-Hqldc)(2)(H(2)O)(2) (M = Co(1), Zn(4) and Cd(7)), [M(3-qlc)(2)(H(2)O)(2)](n) (M = Co(2), Zn(5) and Cd(8)), M(2-qldc-3-OCH(3))(2)(CH(3)OH)(2) (M = Co(3) and Zn(6)) and [Cd(2,3-qldc-OCH(3))(μ(2)-Cl)](2n) (9) (where, 3-Hqlc = quinoline-3-carboxylic acid and 2-qldc-3-OCH(3) = 3-(methoxycarbonyl)quinoline-2-carboxylic acid), were synthesized and characterized by elemental analysis, IR, thermogravimetric analysis (TG), and single-crystal X-ray diffraction. When the temperature ranged from room temperature to 70 °C, three isomorphous mononuclear complexes 1, 4 and 7 were obtained in H(2)O/H(2)O + CH(3)OH. As the temperature rose further to above 90 °C, due to the decomposition of 2-position carboxyl group in ligand 2,3-H(2)qldc, the same reactions, respectively, produced three isomorphous 2-D layer-like structures 2, 5 and 8 with 4(4) topology in water. By contrast, when the mixed solvent of H(2)O + CH(3)OH at a 1 : 1 ratio (v/v) was applied, the three above-mentioned reactions respectively gave compounds 3, 6 and 9 with the 3-position esterification of 2,3-H(2)qldc. Compounds 3 and 6 are mononuclear and isomorphous, while complex 9 has a 1-D double-stranded chain-like structure connected by two μ(2)-Cl bridges. Obviously, these results reveal that the reaction temperature and solvent play a critical role in structural direction of these low-dimensional compounds. Meanwhile, the photoluminescent property of the selected compounds is also investigated.

Our previous studies identified two 2-benzoylaminobenzoate derivatives 1, which potently inhibited superoxide (O(2)˙(-)) generation induced by formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP) in human neutrophils. In an attempt to improve their activities, a series of anthranilic acid derivatives were synthesized and their anti-inflammatory effects and underlying mechanisms were investigated in human neutrophils. Of these, compounds 17, 18, 46, 49, and 50 showed the most potent inhibitory effect on FMLP-induced release of O(2)˙(-) in human neutrophils with IC(50) values of 0.20, 0.16, 0.15, 0.06, and 0.29 μM, respectively. SAR analysis showed that the activities of most compounds were dependent on the ester chain length in the A ring. Conversely, a change in the linker between the A and B ring from amide to sulfonamide or N-methyl amide, as well as exchanges in the benzene rings (A or B rings) by isosteric replacements were unfavorable. Further studies indicated that inhibition of O(2)˙(-) production in human neutrophils by these anthranilic acids was associated with an elevation in cellular cAMP levels through the selective inhibition of phosphodiesterase 4. Compound 49 could be approved as a lead for the development of new drugs in the treatment of neutrophilic inflammatory diseases.

Quercetin, rich in fruits and vegetables, has been used as a nutritional supplement because of its anti-inflammatory and antioxidative properties. Its positive effects on anti-hepatic fibrosis have also been suggested. However the anti-hepatofibrotic mechanisms upon which quercetin acts have yet to be well characterized. In the present study, we investigated the anti-proliferative effect of quercetin on activated hepatic stellate cells (aHSCs), the central role of hepatofibrosis, and evaluated the proteins involved in growth inhibition by a 2D gel electrophoretic analysis. Activated HSCs were isolated from Sprague Dawley rats and were spontaneously activated in vitro. Quercetin restrained the proliferation of aHSCs rather than quiescent HSCs and heptotcytes by inducing a G(1) arrest as examined by cell cycle analysis and evidenced by increased levels of p53, p21(CIP1/WAF1), as well as p27(KIP1), and decreased abundance of cyclins (D(1), D(2), A, E). An apoptosis through extrinsic pathway as demonstrated by elevated expression of Fas/Fas ligand (FasL), annexin V labeling, chromatin condensation, sub-G(1) fraction (7.39%), caspase-3 activity, was also observed. The 2D electrophoresis analysis revealed that quercetin negatively regulated protein molecules associated with metabolism (α-enolase, phosphoglycerate kinase), survival, cytokinesis (tubulin), and protein folding (protein disulfide isomerase A3) leading to cell growth retardation. Furthermore, quercetin might restrain HSC activation through reducing the levels of inflammatory cytokines (CXCL10, Midkine). Taken together, quercetin exerted diverse mechanisms to inhibit the growth of aHSCs. Proper consumption of quercetin could be beneficial to control the progression of heptofibrosis.