Objective: To figure out the effect of somatostatin analogue Octreotide on proliferation and invasion of human hepatocellular carcinoma cell MHCC97-H and the underlying mechanism in vitro and in vivo. Methods: MHCC97-...Objective: To figure out the effect of somatostatin analogue Octreotide on proliferation and invasion of human hepatocellular carcinoma cell MHCC97-H and the underlying mechanism in vitro and in vivo. Methods: MHCC97-H cells were treated with Octreotide at the concentration of 0.2 ug/mL in vitro, proliferation related to time was evaluated. After treated with Octreotide at the concentration of 0.2 ug/mL for 48 h, MHCC97-H cells were observed by transmission electron microscope. Cell proliferation was detected by MTT assay after MHCC97-H cells were treated with Octreotide at different concentrations including 0.05, 0.1, 0.2, 0.4, 0.6 and 0.8 ug/mL for 36 h in vitro. 27 nude mice, in which MHCC97-H tumor mass was planted orthotopically, were divided into 3 groups randomly including control group (intraperitoneal injection with equal volume normal saline; n=8), low dose treated group (intraperitoneal injection with Octreotide at 50 ug/kg?d; n=9) and large dose treated group (intraperitoneal injection with Octreotide at 200 ug/kg?d; n=10). All mice were raised for 35 d and sacrificed. The information about survival time, the weight at death point and the pathology change of liver and lung was collected. The expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinases-2 (MMP-2) in mouse HCC tissues were detected by immunohistochemistry finally. Results: MTT assays showed that Octreotide inhibited the proliferation of MHCC97-H cells significantly. Apoptosis cells were found by transmission electron microscope after treatment with Octreotide at 0.2 ug/mL for 48 h in vitro. The proliferation was inhibited significantly by Octreotide in a dose-dependant manner (r=0.86, P<0.01). Compared with control group, the treated group had the heavier weight at death point and lower intrahepatic metastasis ratio (P<0.05), meanwhile, there was not significant difference in treated groups (P>0.05). The positive expression ratios of VEGF and MMP-2 in treated groups were lower than those in control group (P<0.05), while there was no apparent difference in treated groups (P>0.05). Conclusion: Octreotide could inhibit the proliferation of MHCC97-H cells in vitro via inducing apoptosis and the inhibitory function acts in a dose-dependant manner. Octreotide could improve survival of mice with MHCC97-H cells and inhibit the metastasis of MHCC97-H cells in vivo. Regulation of VEGF and MMP-2 expression by Octreotide would be involved in its inhibition in vivo.展开更多
Lanthanide methoxides supported by carbon-bridged bis(phenolate) ligands 2,2′-methylene-bis(6-tert- butyl-4-methylphenoxo) (MBMP2-) [(MBMP)Ln( μ-OMe)(THF)2]2 (Ln = Nd (1), Yb (2)) were synthesized in high yields by ...Lanthanide methoxides supported by carbon-bridged bis(phenolate) ligands 2,2′-methylene-bis(6-tert- butyl-4-methylphenoxo) (MBMP2-) [(MBMP)Ln( μ-OMe)(THF)2]2 (Ln = Nd (1), Yb (2)) were synthesized in high yields by the protolysis reaction using (C5H5)3Ln(THF) as starting materials, and complex 1 was structurally characterized. The coordination geometry around the center metal can be best described as a distorted octahedron. Complexes 1 and 2 were shown to be efficient initiators for the ring-opening polymerization of 2,2-dimethyltrimethylene carbonate (DTC) and L-lactide. The mechanism of DTC polymerization was explored by the end group analysis of the oligomer.展开更多
Four divalent lanthanide complexes Sm(ArO)2 -(THF)4) Yb(ArO)2(THF)3, Eu(ArO)2(THF)3 (ArO=2,6-di-tert-butyl-4-methylphenolate) and (ButCp)2Sm(THF)2 were synthesized. Their catalytic activities on the polymerization of ...Four divalent lanthanide complexes Sm(ArO)2 -(THF)4) Yb(ArO)2(THF)3, Eu(ArO)2(THF)3 (ArO=2,6-di-tert-butyl-4-methylphenolate) and (ButCp)2Sm(THF)2 were synthesized. Their catalytic activities on the polymerization of acrylonitrile were studied. The catalytic activities were influenced by the central metal ions involved. The catalytic activities of these divalent lanthanide complexes can be greatly increased by adding NaOC6H2-2,6-But2-4-Me, NaOC6H4-4-But, or NaOC10H6-2-Me. The amount of additive has apparent effect on the catalytic activity, but the additive has no effect on the tacticity of the resulting polyacryloni-trile.展开更多
A series of neutral bimetallic lanthanide aryloxides p-C6H4[OLnL(THF)n]2 [Ln = Y(1), Yb(2), Sm(3)(n = 1) and La(4)(n = 2), L = Me2NCH2CH2N{CH2-(2-O–C6H2–tBu2-3,5)}2] and alkoxides p-C6H4CH2[OLnL(THF)]2 [Ln = Y(5), Y...A series of neutral bimetallic lanthanide aryloxides p-C6H4[OLnL(THF)n]2 [Ln = Y(1), Yb(2), Sm(3)(n = 1) and La(4)(n = 2), L = Me2NCH2CH2N{CH2-(2-O–C6H2–tBu2-3,5)}2] and alkoxides p-C6H4CH2[OLnL(THF)]2 [Ln = Y(5), Yb(6)] supported by an amine-bridged bis(phenolate) ligand have been synthesized through one-pot reactions of Ln(C5H5)3(THF), LH2 with p-benzenediol and 1,4-benzenedimethanol, respectively. All complexes have been fully characterized by elemental analyses, single-crystal X-ray diffraction analysis, and IR and multi-nuclear NMR spectroscopy(in the cases of 1, 4 and 5). Study of their catalytic behavior revealed that, in general, all complexes are efficient initiators for the polymerization of rac-lactide(LA) and rac-β-butyrolactone(BBL), except for 3 and 4 in the case of BBL. The influence imposed by lanthanides of different ionic radii and initiating groups of different structures on the activity, controllability, and stereoselectivity of polymerization were systematically studied and compared. Highly heterotactic PLA(Pr up to 0.99) and syndiotactic PHB(Pr ≈ 0.81) with high molecular weight and narrow polydispersity formed and were automatically capped with hydroxyl functionality at both ends.展开更多
Polymerization of acrylonitrile was carried out using,for the first time,the lanthanide-sodium alkoxide clusters Ln2(OCH2CH2NMe2)12(OH)2Na8 [Ln=Yb (1),Nd (2) and Sm (3)] as single component catalysts.These heterobimet...Polymerization of acrylonitrile was carried out using,for the first time,the lanthanide-sodium alkoxide clusters Ln2(OCH2CH2NMe2)12(OH)2Na8 [Ln=Yb (1),Nd (2) and Sm (3)] as single component catalysts.These heterobimetallic complexes exhibit high activity and give atactic polyacrylonitriles with high molecular weight.The polymerization temperature can be varied over the range ?78 to 50°C.The solvent has a substantial effect on the polymerization activity.The order of activity for solvents is DMF>DME≈toluene≈THF>hexane.展开更多
An unexpected carbon-oxygen bond cleavage of THF (THF = tetrahydrofuran) promoted by guanidinate titanium complex was described. Guanidinate lithium [Pr2iNC(NCy)2]Li (Cy = cyclohexyl) formed in situ reacted with TiCl4...An unexpected carbon-oxygen bond cleavage of THF (THF = tetrahydrofuran) promoted by guanidinate titanium complex was described. Guanidinate lithium [Pr2iNC(NCy)2]Li (Cy = cyclohexyl) formed in situ reacted with TiCl4(THF)2 in a 2:1 molar ratio to produce the gua- nidinate titanium chloride [Pr2iNC(NCy)2]2TiCl2 (1) in good yield. The reaction of [Pr2iNC(NCy)2]2TiCl2 with lithium diisopropylamide in THF afforded an unexpected [Pr2iNC(NCy)2]2Ti(OBun)2 (2), which was formed by the cleavage of carbon-oxygen bond of THF. Complexes 1 and 2 were fully characterized by elemental analysis, NMR and IR spectroscopies, and X-ray crystal structure determination for complex 2.展开更多
The synthesis,characterization and luminescent properties of aluminum complexes containing a dianionic N-aryloxo functionalized β-ketoiminate ligand are presented.4-(2-Hydroxy-5-R-phenyl)imino-2-pentanone (R=Me,L 1 H...The synthesis,characterization and luminescent properties of aluminum complexes containing a dianionic N-aryloxo functionalized β-ketoiminate ligand are presented.4-(2-Hydroxy-5-R-phenyl)imino-2-pentanone (R=Me,L 1 H 2;R=tert-butyl,L 2 H 2) ligands reacted with AlEt 3 in tetrahydrofuran to give the aluminum complexes (L 1 AlEt) 2 (1) and (L 2 AlEt) 2 (2) in reasonable isolated yields.X-ray diffraction revealed that complexes 1 and 2 have solvent-free centrosymmetric dimeric structures,and each aluminum center has distorted trigonal bipyramidal geometry.At room temperature,complexes 1 and 2 exhibit blue photoluminescence in acetonitrile with maximum emission wavelengths of 419 and 413 nm,respectively.展开更多
Four lanthanum alkoxides stabilized by a carbon-bridged bis(phenolate) ligand were synthesized and their catalytic behavior for the ring-opening polymerization of L-lactide was explored. Reactions of [(MBMP)LaCp(THF) ...Four lanthanum alkoxides stabilized by a carbon-bridged bis(phenolate) ligand were synthesized and their catalytic behavior for the ring-opening polymerization of L-lactide was explored. Reactions of [(MBMP)LaCp(THF) 2 ] (MBMP 2 = 2,2′-methylene-bis(6-tert-butyl-4-methyl phenoxo)) with HOCH 2 Ph, HOCH 2 CF 3 , HOCH(CH 3 ) 2 , and HOCH 2 CH 2 N(CH 3 ) 2 , respectively, in a 1:1 molar ratio in THF gave the dimeric lanthanum alkoxo complexes [(MBMP)Ln(μ-OR)(THF) 2 ] 2 (OR = OCH 2 Ph(1), OCH 2 CF 3 (2), OCH(CH 3 ) 2 (3), OCH 2 CH 2 N(CH 3 ) 2 (4)]. These complexes were well characterized, and the definitive molecular structure of complex 1 was determined. It was found that complexes 1 to 4 are efficient initiators for the ring-opening polymerization of L-lactide. The structure of the alkoxo groups has a significant effect on the catalytic behavior, and complex 2 can initiate L-lactide polymerization in a controlled manner.展开更多
The lanthanide coordination polymers bearing a 13-membered macrocycle, [(13-EDTA-pnOH)H2] were synthesized. The products [Ln(13-EDTA-pnOH)(H2O)2·NO3]n (Ln = Eu(1), Tb(2), Dy(3)) have been obtained by MS, IR and e...The lanthanide coordination polymers bearing a 13-membered macrocycle, [(13-EDTA-pnOH)H2] were synthesized. The products [Ln(13-EDTA-pnOH)(H2O)2·NO3]n (Ln = Eu(1), Tb(2), Dy(3)) have been obtained by MS, IR and element analyses. The solid-state structure of 1 was established by single-crystal X-ray analysis. The coordination geometry around the central metal atom in complex 1 is a nine-coor-dinated, tricapped-trigonal prism having six donor atoms (two amine nitrogen atoms, two amide oxygen atoms and two carboxymethyl oxygen atoms) from one ligand, one oxygen atom from a neighboring ligand, and two more oxygen atoms from two water molecules. The europium atoms are linked by―Eu―O―C―O―Eu―bridges to form an infinite chain.展开更多
文摘Objective: To figure out the effect of somatostatin analogue Octreotide on proliferation and invasion of human hepatocellular carcinoma cell MHCC97-H and the underlying mechanism in vitro and in vivo. Methods: MHCC97-H cells were treated with Octreotide at the concentration of 0.2 ug/mL in vitro, proliferation related to time was evaluated. After treated with Octreotide at the concentration of 0.2 ug/mL for 48 h, MHCC97-H cells were observed by transmission electron microscope. Cell proliferation was detected by MTT assay after MHCC97-H cells were treated with Octreotide at different concentrations including 0.05, 0.1, 0.2, 0.4, 0.6 and 0.8 ug/mL for 36 h in vitro. 27 nude mice, in which MHCC97-H tumor mass was planted orthotopically, were divided into 3 groups randomly including control group (intraperitoneal injection with equal volume normal saline; n=8), low dose treated group (intraperitoneal injection with Octreotide at 50 ug/kg?d; n=9) and large dose treated group (intraperitoneal injection with Octreotide at 200 ug/kg?d; n=10). All mice were raised for 35 d and sacrificed. The information about survival time, the weight at death point and the pathology change of liver and lung was collected. The expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinases-2 (MMP-2) in mouse HCC tissues were detected by immunohistochemistry finally. Results: MTT assays showed that Octreotide inhibited the proliferation of MHCC97-H cells significantly. Apoptosis cells were found by transmission electron microscope after treatment with Octreotide at 0.2 ug/mL for 48 h in vitro. The proliferation was inhibited significantly by Octreotide in a dose-dependant manner (r=0.86, P<0.01). Compared with control group, the treated group had the heavier weight at death point and lower intrahepatic metastasis ratio (P<0.05), meanwhile, there was not significant difference in treated groups (P>0.05). The positive expression ratios of VEGF and MMP-2 in treated groups were lower than those in control group (P<0.05), while there was no apparent difference in treated groups (P>0.05). Conclusion: Octreotide could inhibit the proliferation of MHCC97-H cells in vitro via inducing apoptosis and the inhibitory function acts in a dose-dependant manner. Octreotide could improve survival of mice with MHCC97-H cells and inhibit the metastasis of MHCC97-H cells in vivo. Regulation of VEGF and MMP-2 expression by Octreotide would be involved in its inhibition in vivo.
基金Supported by the National Natural Science Foundation of China (Grant No. 20472063)the Innovation Project of Graduate Education of Jiangsu Province+1 种基金the State Key Laboratory of Polymer Physics and Chemistrythe Key Laboratory of Organic Synthesis of Jiangsu Province
文摘Lanthanide methoxides supported by carbon-bridged bis(phenolate) ligands 2,2′-methylene-bis(6-tert- butyl-4-methylphenoxo) (MBMP2-) [(MBMP)Ln( μ-OMe)(THF)2]2 (Ln = Nd (1), Yb (2)) were synthesized in high yields by the protolysis reaction using (C5H5)3Ln(THF) as starting materials, and complex 1 was structurally characterized. The coordination geometry around the center metal can be best described as a distorted octahedron. Complexes 1 and 2 were shown to be efficient initiators for the ring-opening polymerization of 2,2-dimethyltrimethylene carbonate (DTC) and L-lactide. The mechanism of DTC polymerization was explored by the end group analysis of the oligomer.
基金the National Natural Science Foundation of China (Grant No. 20072027).
文摘Four divalent lanthanide complexes Sm(ArO)2 -(THF)4) Yb(ArO)2(THF)3, Eu(ArO)2(THF)3 (ArO=2,6-di-tert-butyl-4-methylphenolate) and (ButCp)2Sm(THF)2 were synthesized. Their catalytic activities on the polymerization of acrylonitrile were studied. The catalytic activities were influenced by the central metal ions involved. The catalytic activities of these divalent lanthanide complexes can be greatly increased by adding NaOC6H2-2,6-But2-4-Me, NaOC6H4-4-But, or NaOC10H6-2-Me. The amount of additive has apparent effect on the catalytic activity, but the additive has no effect on the tacticity of the resulting polyacryloni-trile.
基金financial supported by the National Natural Science Foundation of China (20972108, 21174095, 21132002)a project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)the Qing Lan Project is gratefully acknowledged
文摘A series of neutral bimetallic lanthanide aryloxides p-C6H4[OLnL(THF)n]2 [Ln = Y(1), Yb(2), Sm(3)(n = 1) and La(4)(n = 2), L = Me2NCH2CH2N{CH2-(2-O–C6H2–tBu2-3,5)}2] and alkoxides p-C6H4CH2[OLnL(THF)]2 [Ln = Y(5), Yb(6)] supported by an amine-bridged bis(phenolate) ligand have been synthesized through one-pot reactions of Ln(C5H5)3(THF), LH2 with p-benzenediol and 1,4-benzenedimethanol, respectively. All complexes have been fully characterized by elemental analyses, single-crystal X-ray diffraction analysis, and IR and multi-nuclear NMR spectroscopy(in the cases of 1, 4 and 5). Study of their catalytic behavior revealed that, in general, all complexes are efficient initiators for the polymerization of rac-lactide(LA) and rac-β-butyrolactone(BBL), except for 3 and 4 in the case of BBL. The influence imposed by lanthanides of different ionic radii and initiating groups of different structures on the activity, controllability, and stereoselectivity of polymerization were systematically studied and compared. Highly heterotactic PLA(Pr up to 0.99) and syndiotactic PHB(Pr ≈ 0.81) with high molecular weight and narrow polydispersity formed and were automatically capped with hydroxyl functionality at both ends.
基金supported by the National Natural Science Foundation of China (20972107 and 21072146)
文摘Polymerization of acrylonitrile was carried out using,for the first time,the lanthanide-sodium alkoxide clusters Ln2(OCH2CH2NMe2)12(OH)2Na8 [Ln=Yb (1),Nd (2) and Sm (3)] as single component catalysts.These heterobimetallic complexes exhibit high activity and give atactic polyacrylonitriles with high molecular weight.The polymerization temperature can be varied over the range ?78 to 50°C.The solvent has a substantial effect on the polymerization activity.The order of activity for solvents is DMF>DME≈toluene≈THF>hexane.
基金supported by the National Natural Science Foundation of China(Grant No.20472063).
文摘An unexpected carbon-oxygen bond cleavage of THF (THF = tetrahydrofuran) promoted by guanidinate titanium complex was described. Guanidinate lithium [Pr2iNC(NCy)2]Li (Cy = cyclohexyl) formed in situ reacted with TiCl4(THF)2 in a 2:1 molar ratio to produce the gua- nidinate titanium chloride [Pr2iNC(NCy)2]2TiCl2 (1) in good yield. The reaction of [Pr2iNC(NCy)2]2TiCl2 with lithium diisopropylamide in THF afforded an unexpected [Pr2iNC(NCy)2]2Ti(OBun)2 (2), which was formed by the cleavage of carbon-oxygen bond of THF. Complexes 1 and 2 were fully characterized by elemental analysis, NMR and IR spectroscopies, and X-ray crystal structure determination for complex 2.
基金supported by the National Natural Science Foundation of China (20771078 and 20972108)the Major Basic Research Project of the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (07KJA15014)the Qing Lan Project
文摘The synthesis,characterization and luminescent properties of aluminum complexes containing a dianionic N-aryloxo functionalized β-ketoiminate ligand are presented.4-(2-Hydroxy-5-R-phenyl)imino-2-pentanone (R=Me,L 1 H 2;R=tert-butyl,L 2 H 2) ligands reacted with AlEt 3 in tetrahydrofuran to give the aluminum complexes (L 1 AlEt) 2 (1) and (L 2 AlEt) 2 (2) in reasonable isolated yields.X-ray diffraction revealed that complexes 1 and 2 have solvent-free centrosymmetric dimeric structures,and each aluminum center has distorted trigonal bipyramidal geometry.At room temperature,complexes 1 and 2 exhibit blue photoluminescence in acetonitrile with maximum emission wavelengths of 419 and 413 nm,respectively.
基金supported by the National Natural Science Foundation of China (20972108, 21174095 and 21132002)the Priority Academic Program Developement of Jiangsu Higher Education Institutions, and the Qing Lan Project
文摘Four lanthanum alkoxides stabilized by a carbon-bridged bis(phenolate) ligand were synthesized and their catalytic behavior for the ring-opening polymerization of L-lactide was explored. Reactions of [(MBMP)LaCp(THF) 2 ] (MBMP 2 = 2,2′-methylene-bis(6-tert-butyl-4-methyl phenoxo)) with HOCH 2 Ph, HOCH 2 CF 3 , HOCH(CH 3 ) 2 , and HOCH 2 CH 2 N(CH 3 ) 2 , respectively, in a 1:1 molar ratio in THF gave the dimeric lanthanum alkoxo complexes [(MBMP)Ln(μ-OR)(THF) 2 ] 2 (OR = OCH 2 Ph(1), OCH 2 CF 3 (2), OCH(CH 3 ) 2 (3), OCH 2 CH 2 N(CH 3 ) 2 (4)]. These complexes were well characterized, and the definitive molecular structure of complex 1 was determined. It was found that complexes 1 to 4 are efficient initiators for the ring-opening polymerization of L-lactide. The structure of the alkoxo groups has a significant effect on the catalytic behavior, and complex 2 can initiate L-lactide polymerization in a controlled manner.
基金Supported by the National Natural Science Foundation of China (Grant No. 20472063)the University of Hong Kong (WTW)
文摘The lanthanide coordination polymers bearing a 13-membered macrocycle, [(13-EDTA-pnOH)H2] were synthesized. The products [Ln(13-EDTA-pnOH)(H2O)2·NO3]n (Ln = Eu(1), Tb(2), Dy(3)) have been obtained by MS, IR and element analyses. The solid-state structure of 1 was established by single-crystal X-ray analysis. The coordination geometry around the central metal atom in complex 1 is a nine-coor-dinated, tricapped-trigonal prism having six donor atoms (two amine nitrogen atoms, two amide oxygen atoms and two carboxymethyl oxygen atoms) from one ligand, one oxygen atom from a neighboring ligand, and two more oxygen atoms from two water molecules. The europium atoms are linked by―Eu―O―C―O―Eu―bridges to form an infinite chain.
