Water-soluble b-alanine C60 adducts were synthesized, and the scavenging ability to superoxygen anion radical O2- and hydroxyl radical.OH were studied by autoxidation of pyrogallol and chemiluminescence, respectively....Water-soluble b-alanine C60 adducts were synthesized, and the scavenging ability to superoxygen anion radical O2- and hydroxyl radical.OH were studied by autoxidation of pyrogallol and chemiluminescence, respectively. It was found thatβ-alanine C60 adducts showed an excellent efficiency in eliminating superoxygen anion radical and hydroxyl radical. The 50% inhibition concentration (IC50) for superoxygen anion radical and hydroxyl radical were 0.15 mg/mL and 0.048 mg/mL, respectively. The difference should be mainly attributed to the different scavenging mechanisms.展开更多
New podand compound 1,2 bis (8′ quinolyloxy ethoxy) benzene (BQEB) was prepared. A lanthanum adduct with BQEB was synthesized and its structure was characterized by X ray crystal analysis using Mo Kα radiation ( λ ...New podand compound 1,2 bis (8′ quinolyloxy ethoxy) benzene (BQEB) was prepared. A lanthanum adduct with BQEB was synthesized and its structure was characterized by X ray crystal analysis using Mo Kα radiation ( λ =0 071073 nm). Crystal data: space group C2/c, Z=4, a =1 8636(3) nm, b =2 0036(3) nm, c =1 5186(3) nm, α =90 00°, β =91 452(14)°, γ =90 00°, R f=0 0373 for 6520 observed data. In the crystal structure the La 3+ is ten coordinated by three NO - 3 and four H 2O. Two podand molecules link to the coordination core via O—H…N (average O…N=0 2766(3) nm) hydrogen bonds. The adduct has a one dimensional chain sandwich structure consisting of every two podand molecules with a [La(NO 3) 3·4H 2O] as a bridge. The whole crystal is packed in a manner of…LLMLLMLL….展开更多
Strong room-temperature photoluminescence from the adducts of C60 reacting with five different aliphatic amines, namely propylethylamine (PPA), n-butyl amine (BTA), n-heptylamine (HPA) and dodecylamine (DDA) and dieth...Strong room-temperature photoluminescence from the adducts of C60 reacting with five different aliphatic amines, namely propylethylamine (PPA), n-butyl amine (BTA), n-heptylamine (HPA) and dodecylamine (DDA) and diethylamine (DEA), was firstly found from their toluene solution at relatively shorter wavelength around 519 nm.The fluorescence intensity has a good correlation with the length of n-alkyl group chain, the steric position and concentration of different amines and setting of solution as well as the UV-radiation. Their fluorescence quenching by concentration and by aromatic electron-donor N,N-dimethylaniline (DMA) were first investigated and determined.展开更多
A new dinuclcar copper (II) complex containing 3-ferrocenyl-2-crotomic acid salt (FCA)and phen has been synthesized. Its structure was charactcrized by X-ray crystal analysis. The molecular is a pentametallic compound.
Objective This paper aims to elucidate the combined toxicity of magnetite nanoparticles/Chromium [MNPs/Cr(Ⅵ)] adducts. Methods The HEK293 cell was exposed to either Cr(Ⅵ) or MNPs, or their adducts MNPs/Cr(Ⅵ). The c...Objective This paper aims to elucidate the combined toxicity of magnetite nanoparticles/Chromium [MNPs/Cr(Ⅵ)] adducts. Methods The HEK293 cell was exposed to either Cr(Ⅵ) or MNPs, or their adducts MNPs/Cr(Ⅵ). The cytotoxicity was evaluated by assessing the cell viability, apoptosis, oxidative stress induction, and cellular uptake. Results The toxicity of formed adducts is significantly reduced when compared to Cr(Ⅵ) anions. We found that the cellular uptake of MNPs/Cr(Ⅵ) adduct was rare, only few particles were endocytosed from the extracellular fluid and not accumulated in the cell nucleus. On the other hand, the Cr(Ⅵ) anions entered cells, generated oxidative stress, induced cell apoptosis, and caused cytotoxicity. Conclusion The results showed minor effects of the nanoadducts on the tested cells and supported that magnetite nanoparticles could be implemented in the wastewater treatment process in which advantageous properties outweigh the risks.展开更多
A new podand compound o-Bis(8’-quinolyloxy) ethylenoxyl benzene (BQEB) was prepared. A lanthanum adduct with BQEB was spothesized and its structure was characterized by X-ray crystal analysis. The La(III) is ten-coor...A new podand compound o-Bis(8’-quinolyloxy) ethylenoxyl benzene (BQEB) was prepared. A lanthanum adduct with BQEB was spothesized and its structure was characterized by X-ray crystal analysis. The La(III) is ten-coordinated to the three No3- and four H2O. Two podand molecules are linked to the coordination core by four hydrogen bonds. The crystal is packed in the manner of .LLMLLMLL.展开更多
Hemoglobin styrene oxide adducts in blood have been studied as a molecular biomarker of worker exposed to styrene. Determination of protein styrene oxide adducts in different biological samples with modified Raney Ni ...Hemoglobin styrene oxide adducts in blood have been studied as a molecular biomarker of worker exposed to styrene. Determination of protein styrene oxide adducts in different biological samples with modified Raney Ni procedure is described in this paper. The following biological samples have been investigated: fresh rat blood reacted with styrene oxide in vitro; rat blood reacted with styrene or styrene oxide in vivo; vein blood from workers exposed to styrene in two factories. The data showed that there was a good linear dose response relationship between reacting dose of styrene oxide or styrene and amount of protein styrene oxide adducts in both in vitro and in vivo experiments. For human samples, a dose response relationship between protein adducts and styrene exposure can be found in glass fiber factory, but not in piano manufacture plant.展开更多
Mulberry Diels-Alder-type adducts(MDAAs)are unique phenolic natural products biosynthetically derived from the intermolecular[4+2]-cycloaddition of dienophiles(mainly chalcones)and dehydroprenylphenol dienes,which are...Mulberry Diels-Alder-type adducts(MDAAs)are unique phenolic natural products biosynthetically derived from the intermolecular[4+2]-cycloaddition of dienophiles(mainly chalcones)and dehydroprenylphenol dienes,which are exclusively distributed in moraceous plants.A total of 166 MDAAs with diverse skeletons have been isolated and identified since 1980.Structurally,the classic MDAAs characterized by the chalcone-skeleton dienophiles can be divided into eight groups(Types A−H),while others with non-chalcone dienophiles or some variations of classic MDAAs are non-classic MDAAs(Type I).These compounds have attracted significant attention of natural products and synthetic chemists due to their complex architectures,remarkable biological activities,and synthetic challenges.The present review provides a comprehensive summary of the structural properties,bioactivities,and syntheses of MDAAs.Cited references were collected between 1980 and 2021 from the SciFinder,Web of Science,and China National Knowledge Internet(CNKI).展开更多
The title of this little assay coins three new words: Pre-Chelates, Post-Adducts and Implexes. These, very daring new excursions into the scientific English language, come from the developments of Quelamycin and Sodiu...The title of this little assay coins three new words: Pre-Chelates, Post-Adducts and Implexes. These, very daring new excursions into the scientific English language, come from the developments of Quelamycin and Sodium L-Thioproline, through our different group studies arriving to cancer reversal by a dual strategy. It is enough to read all our published materials, cites and related papers, dealing more or less with the chemistry and possible mechanism of action of these compounds, to gather somewhat what signified our monomeric-triferric-doxorubicine, as possibly one of the first Pre-Chelates and our Sodium L-Thioproline, probably as one of the first Post-Adducts. Both molecules come to the human patients with cancer blood from the exterior. After this indication, it will be proposed a seed concept of a new type of molecules, the “Implexes” in which the metals will be embraced instead of being linked.展开更多
Synthesis of bicyclic systems containing chlorine atoms, and/or ether groups in aromatic rings can be con- sidered as an important method for building bicyclic system and production of new adducts. One of the most imp...Synthesis of bicyclic systems containing chlorine atoms, and/or ether groups in aromatic rings can be con- sidered as an important method for building bicyclic system and production of new adducts. One of the most important types in the cycloaddition reaction is the Diels-Alder reaction (1,4 cycloaddition). In the present investigation a new ether of allylic type (dienophile) p-allyl bromo phenol was prepared and its structure was confirmed by molecular weight determination, refractive index, infrared spectra, and density. A new adduct was obtained by means of 1,4 cycloaddition reaction of hexachlorocyclopentadiene (HCP) and the new pre- pared dienophile. The reaction takes place without using solvent, catalysts, or elimination of any compound. The effect of variations in temperature, initial molar ratio and reaction duration were studied to determine the optimum conditions of the reaction. The optimum conditions reached were reaction temperature recorded 140?C, initial molar ratio diene: dienophile was 3:1 and the reaction duration time reached 6 h. Under these optimum conditions the maximum yield was 78%. The new adduct revealed very high biological effect as sulfate-reducing bacteria (SRB).展开更多
Myrcauones A-D(1-4),four new phloroglucinol-terpene adducts were isolated from the leaves of Myrciaria cauliflora.Their structures with absolute configurations were elucidated by combination of spectroscopic analysis,...Myrcauones A-D(1-4),four new phloroglucinol-terpene adducts were isolated from the leaves of Myrciaria cauliflora.Their structures with absolute configurations were elucidated by combination of spectroscopic analysis,single crystal X-ray diffraction,and electronic circular dichroism(ECD)calculations.Compound 1 was a rearranged isobutylphloroglucinol-pinene adduct featuring an unusual 2,3,4,4a,10,11-hexahydro-1H-3,11a-methanodibenzo[b,f]oxepin backbone.Compound 4 showed moderate antibacterial activity against Gram-positive bacteria including multiresistant strains.展开更多
Complexes of the general formula [MBr2(TMTU)n] (where M is Mn, Fe, Co, Ni, Cu, Zn or Cd;TMTU is Tetramethylthiourea;n is 0.75, 2 or 3) were obtained by the reaction of salts and ligand in solution. The bromides were s...Complexes of the general formula [MBr2(TMTU)n] (where M is Mn, Fe, Co, Ni, Cu, Zn or Cd;TMTU is Tetramethylthiourea;n is 0.75, 2 or 3) were obtained by the reaction of salts and ligand in solution. The bromides were selected among several other salts because they had thermochemical data in the literature. Properties as capillary melting points;C, H, N, Br and metal contents;TG/DTG and DSC curves;and IR and electronic spectra were determined. The values of several thermodynamic parameters for the complexes were found by solution calorimetry. From them, the standard enthalpies of the metal-sulphur coordinated bonds were calculated. The standard enthalpies of the formation of the gaseous phase adducts also were estimated.展开更多
The word “clusters” in scientific terminology as aggregated molecules or atoms appeared in chemistry relatively recently. The terms clusters have been used intensively since the discovery of fullerenes. The term clu...The word “clusters” in scientific terminology as aggregated molecules or atoms appeared in chemistry relatively recently. The terms clusters have been used intensively since the discovery of fullerenes. The term cluster is not a new one for other branches of science such as astrophysics-star cluster, globular cluster, galaxy cluster, in biology and medicine-cancer cluster, genetic cluster, or in computing-data cluster. Adducts in chemistry were known significantly earlier. Both clusters and adducts are assemblies of atoms or molecules that are held together by weak van der Waals or London dispersion forces. Clusters are homogeneous and usually consist of one sort of atom or molecule. Clusters can also be a host for other types of atoms or molecules. Adducts usually consist of two different types of molecules, one of which is the host molecule. Both clusters and adducts are well defined by IUPAC. The present short review describes some important phenomena of these intriguing associations, which have interest for chemical extraction, separation, analysis, and for nature in general.展开更多
Thiols play vital roles in cellular metabolism knowledge of which may be important in the design of future anticancer drugs. Previous work on the composition of the thiols present in human cancer cell lines has shown ...Thiols play vital roles in cellular metabolism knowledge of which may be important in the design of future anticancer drugs. Previous work on the composition of the thiols present in human cancer cell lines has shown the presence of an unknown low molecular weight species, deemed to be a “Conthiol”, which could be important in this respect. This was prepared and isolated from a human prostate cancer cell line (LNCaP) in the form of an adduct of 2-mercuri-4-nitrophenol;it accounts for 56.5% of the total cellular thiols present in this cell line. Initial LC-MS analysis of this adduct had indicated that the possible molecular weight of the thiol was in the region of 467 daltons. In further analytical studies to identify the thiol, attempts were made to release it from the adduct by passage through a Thiopropyl Sepharose6B column. LC-MS analysis of the column eluate revealed two components yielding negative ion fragments of 427 m/z and 449 m/z. Only the former component contained thiol, indicating that a breakdown and/or possible rearrangement of the Conthiol had occurred. Further investigations of the column thiol eluate using ICP-MS analysis showed that the sulfur content agreed with the spectrophotometric analysis result (Ellman assay) and that the molecule did not contain phosphate. Amino acid analyses of the eluate were negative. In an attempt to prevent the breakdown of the thiol released by the Thiopropyl Sepharose 6B column, the adduct was treated with 5% v/v bromine water prior to applying to the column. In this instance the thiol containing eluate obtained from the column was treated with an equimolar quantity of mercuric chloride forming a fresh adduct, RS-Hg-SR. LC-MS analysis of this mercurial adduct detected a negative ion fragment of 782 m/z which on further ionization gave a ladder like pattern showing loss of mass units of 58 in each rung. This would seem to suggest the presence of a repeat polymer like structure containing 5 monomers, which, plus the thiol atom, gives a possible formula weight of 322;probably revealing only a part of the unknown Conthiol molecule whose properties and formula weight do not correlate with any known cellular thiol. Further analysis of the thiol released from the adduct on the Thiopropyl Sepharose 6B column by Infra-red (FTIR) provided little information except to confirm the presence of the thiol group and C=O stretch bands together with the possibility of a lactam ring at 1651 and 1634 cm·s<sup>-</sup><sup>1</sup>.展开更多
Two novel acid-base adducts,[H_2L_1^(2+)](Hpbda)_2(1,L_1 = l,4-di(lH-imidazol-4-yl)benzene,H_2pbda = 1,4-benzenedicarboxylic acid) and[H_2L_2^(2+)](NO_3)_2(2,L_2 = l,4-di(l-carboxymethyl-imidazol-4-yl)benzene),have be...Two novel acid-base adducts,[H_2L_1^(2+)](Hpbda)_2(1,L_1 = l,4-di(lH-imidazol-4-yl)benzene,H_2pbda = 1,4-benzenedicarboxylic acid) and[H_2L_2^(2+)](NO_3)_2(2,L_2 = l,4-di(l-carboxymethyl-imidazol-4-yl)benzene),have been prepared and characterized by single-crystal X-ray diffraction,IR spectroscopy and elemental analysis.Compound 1 crystallizes in monoclinic,space group P2_1/n with a = 5.3525(11),b = 9.1471(19),c = 19.314(4) ?,β = 92.342(3)°,V= 944.8(3) ?~3,Z = 2,C_(16)H_(16)N_6O_(10),M_r = 452.35,D_c = 1.590 g/cm^3,μ = 0.135 mm^(-1),S = 1.058,F(000) = 468,the final R = 0.0661 and wR = 0.1887 for 2298 observed reflections(I> 2σ(I)).Compound 2 crystallizes in monoclinic,space group P2_1/c with a = 9.6923(10),b = 17.2950(17),c = 7.1880(7) ?,β =94.801(2)°,V= 1200.7(2) ?~3,Z = 2,C_(28)H_(22)N_4O_8,M_r = 542.50,D_c = 1.501 g/cm^3,μ = 0.112 mm^(-1),S= 1.060,F(000) = 564,the final R = 0.0394 and wR = 0.1017 for 2768 observed reflections(I >2σ(I)).In the title compounds,both of L_1 and L_2 ligands act as weak base to accept protons to exhibit diprotonated H_2L_1^(2+) and H_2L_2^(2+) form,which can effectively employ as hydrogen bonding donors to combine anion moieties to form binary adducts respectively.In the crystal packing diagram of two polymers,there exist extensive noncovalent interactions including charge-transfer interactions,C(N)-H…π and N-H…O,C-H…O,O-H…O hydrogen bonding interactions between co-crystal moieties which consolidate the structures of supramolecular polymers,thus generating three-dimensional(3D) frameworks.展开更多
文摘Water-soluble b-alanine C60 adducts were synthesized, and the scavenging ability to superoxygen anion radical O2- and hydroxyl radical.OH were studied by autoxidation of pyrogallol and chemiluminescence, respectively. It was found thatβ-alanine C60 adducts showed an excellent efficiency in eliminating superoxygen anion radical and hydroxyl radical. The 50% inhibition concentration (IC50) for superoxygen anion radical and hydroxyl radical were 0.15 mg/mL and 0.048 mg/mL, respectively. The difference should be mainly attributed to the different scavenging mechanisms.
文摘New podand compound 1,2 bis (8′ quinolyloxy ethoxy) benzene (BQEB) was prepared. A lanthanum adduct with BQEB was synthesized and its structure was characterized by X ray crystal analysis using Mo Kα radiation ( λ =0 071073 nm). Crystal data: space group C2/c, Z=4, a =1 8636(3) nm, b =2 0036(3) nm, c =1 5186(3) nm, α =90 00°, β =91 452(14)°, γ =90 00°, R f=0 0373 for 6520 observed data. In the crystal structure the La 3+ is ten coordinated by three NO - 3 and four H 2O. Two podand molecules link to the coordination core via O—H…N (average O…N=0 2766(3) nm) hydrogen bonds. The adduct has a one dimensional chain sandwich structure consisting of every two podand molecules with a [La(NO 3) 3·4H 2O] as a bridge. The whole crystal is packed in a manner of…LLMLLMLL….
文摘Strong room-temperature photoluminescence from the adducts of C60 reacting with five different aliphatic amines, namely propylethylamine (PPA), n-butyl amine (BTA), n-heptylamine (HPA) and dodecylamine (DDA) and diethylamine (DEA), was firstly found from their toluene solution at relatively shorter wavelength around 519 nm.The fluorescence intensity has a good correlation with the length of n-alkyl group chain, the steric position and concentration of different amines and setting of solution as well as the UV-radiation. Their fluorescence quenching by concentration and by aromatic electron-donor N,N-dimethylaniline (DMA) were first investigated and determined.
文摘A new dinuclcar copper (II) complex containing 3-ferrocenyl-2-crotomic acid salt (FCA)and phen has been synthesized. Its structure was charactcrized by X-ray crystal analysis. The molecular is a pentametallic compound.
文摘Objective This paper aims to elucidate the combined toxicity of magnetite nanoparticles/Chromium [MNPs/Cr(Ⅵ)] adducts. Methods The HEK293 cell was exposed to either Cr(Ⅵ) or MNPs, or their adducts MNPs/Cr(Ⅵ). The cytotoxicity was evaluated by assessing the cell viability, apoptosis, oxidative stress induction, and cellular uptake. Results The toxicity of formed adducts is significantly reduced when compared to Cr(Ⅵ) anions. We found that the cellular uptake of MNPs/Cr(Ⅵ) adduct was rare, only few particles were endocytosed from the extracellular fluid and not accumulated in the cell nucleus. On the other hand, the Cr(Ⅵ) anions entered cells, generated oxidative stress, induced cell apoptosis, and caused cytotoxicity. Conclusion The results showed minor effects of the nanoadducts on the tested cells and supported that magnetite nanoparticles could be implemented in the wastewater treatment process in which advantageous properties outweigh the risks.
文摘A new podand compound o-Bis(8’-quinolyloxy) ethylenoxyl benzene (BQEB) was prepared. A lanthanum adduct with BQEB was spothesized and its structure was characterized by X-ray crystal analysis. The La(III) is ten-coordinated to the three No3- and four H2O. Two podand molecules are linked to the coordination core by four hydrogen bonds. The crystal is packed in the manner of .LLMLLMLL.
基金TheNationalNaturalScienceFoundationofChina (No .5 98730 2 8)
文摘Hemoglobin styrene oxide adducts in blood have been studied as a molecular biomarker of worker exposed to styrene. Determination of protein styrene oxide adducts in different biological samples with modified Raney Ni procedure is described in this paper. The following biological samples have been investigated: fresh rat blood reacted with styrene oxide in vitro; rat blood reacted with styrene or styrene oxide in vivo; vein blood from workers exposed to styrene in two factories. The data showed that there was a good linear dose response relationship between reacting dose of styrene oxide or styrene and amount of protein styrene oxide adducts in both in vitro and in vivo experiments. For human samples, a dose response relationship between protein adducts and styrene exposure can be found in glass fiber factory, but not in piano manufacture plant.
基金supported by the National Natural Science Foundation of China (Nos.81973203 and 81973195)the Guangdong Basic and Applied Basic Research Foundation,China (No.2020A1515010841)+2 种基金the Open Program of Shenzhen Bay Laboratory (No.SZBL2021080601007)the Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) (No.SML2021SP301)the Key-Area Research and Development Program of Guangdong Province,China (No.2020B1111110003).
文摘Mulberry Diels-Alder-type adducts(MDAAs)are unique phenolic natural products biosynthetically derived from the intermolecular[4+2]-cycloaddition of dienophiles(mainly chalcones)and dehydroprenylphenol dienes,which are exclusively distributed in moraceous plants.A total of 166 MDAAs with diverse skeletons have been isolated and identified since 1980.Structurally,the classic MDAAs characterized by the chalcone-skeleton dienophiles can be divided into eight groups(Types A−H),while others with non-chalcone dienophiles or some variations of classic MDAAs are non-classic MDAAs(Type I).These compounds have attracted significant attention of natural products and synthetic chemists due to their complex architectures,remarkable biological activities,and synthetic challenges.The present review provides a comprehensive summary of the structural properties,bioactivities,and syntheses of MDAAs.Cited references were collected between 1980 and 2021 from the SciFinder,Web of Science,and China National Knowledge Internet(CNKI).
文摘The title of this little assay coins three new words: Pre-Chelates, Post-Adducts and Implexes. These, very daring new excursions into the scientific English language, come from the developments of Quelamycin and Sodium L-Thioproline, through our different group studies arriving to cancer reversal by a dual strategy. It is enough to read all our published materials, cites and related papers, dealing more or less with the chemistry and possible mechanism of action of these compounds, to gather somewhat what signified our monomeric-triferric-doxorubicine, as possibly one of the first Pre-Chelates and our Sodium L-Thioproline, probably as one of the first Post-Adducts. Both molecules come to the human patients with cancer blood from the exterior. After this indication, it will be proposed a seed concept of a new type of molecules, the “Implexes” in which the metals will be embraced instead of being linked.
文摘Synthesis of bicyclic systems containing chlorine atoms, and/or ether groups in aromatic rings can be con- sidered as an important method for building bicyclic system and production of new adducts. One of the most important types in the cycloaddition reaction is the Diels-Alder reaction (1,4 cycloaddition). In the present investigation a new ether of allylic type (dienophile) p-allyl bromo phenol was prepared and its structure was confirmed by molecular weight determination, refractive index, infrared spectra, and density. A new adduct was obtained by means of 1,4 cycloaddition reaction of hexachlorocyclopentadiene (HCP) and the new pre- pared dienophile. The reaction takes place without using solvent, catalysts, or elimination of any compound. The effect of variations in temperature, initial molar ratio and reaction duration were studied to determine the optimum conditions of the reaction. The optimum conditions reached were reaction temperature recorded 140?C, initial molar ratio diene: dienophile was 3:1 and the reaction duration time reached 6 h. Under these optimum conditions the maximum yield was 78%. The new adduct revealed very high biological effect as sulfate-reducing bacteria (SRB).
基金supported by the National Key R&D Program of China(No.2017YFC1703800)the Program for the National Natural Science Foundation of China(Nos.81822042,81630095)+2 种基金the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01Y036)Key-Area Research and Development Program of Guangdong Province(2020B1111110004)the High-performance Computing Platform of Jinan University.
文摘Myrcauones A-D(1-4),four new phloroglucinol-terpene adducts were isolated from the leaves of Myrciaria cauliflora.Their structures with absolute configurations were elucidated by combination of spectroscopic analysis,single crystal X-ray diffraction,and electronic circular dichroism(ECD)calculations.Compound 1 was a rearranged isobutylphloroglucinol-pinene adduct featuring an unusual 2,3,4,4a,10,11-hexahydro-1H-3,11a-methanodibenzo[b,f]oxepin backbone.Compound 4 showed moderate antibacterial activity against Gram-positive bacteria including multiresistant strains.
文摘Complexes of the general formula [MBr2(TMTU)n] (where M is Mn, Fe, Co, Ni, Cu, Zn or Cd;TMTU is Tetramethylthiourea;n is 0.75, 2 or 3) were obtained by the reaction of salts and ligand in solution. The bromides were selected among several other salts because they had thermochemical data in the literature. Properties as capillary melting points;C, H, N, Br and metal contents;TG/DTG and DSC curves;and IR and electronic spectra were determined. The values of several thermodynamic parameters for the complexes were found by solution calorimetry. From them, the standard enthalpies of the metal-sulphur coordinated bonds were calculated. The standard enthalpies of the formation of the gaseous phase adducts also were estimated.
文摘The word “clusters” in scientific terminology as aggregated molecules or atoms appeared in chemistry relatively recently. The terms clusters have been used intensively since the discovery of fullerenes. The term cluster is not a new one for other branches of science such as astrophysics-star cluster, globular cluster, galaxy cluster, in biology and medicine-cancer cluster, genetic cluster, or in computing-data cluster. Adducts in chemistry were known significantly earlier. Both clusters and adducts are assemblies of atoms or molecules that are held together by weak van der Waals or London dispersion forces. Clusters are homogeneous and usually consist of one sort of atom or molecule. Clusters can also be a host for other types of atoms or molecules. Adducts usually consist of two different types of molecules, one of which is the host molecule. Both clusters and adducts are well defined by IUPAC. The present short review describes some important phenomena of these intriguing associations, which have interest for chemical extraction, separation, analysis, and for nature in general.
文摘Thiols play vital roles in cellular metabolism knowledge of which may be important in the design of future anticancer drugs. Previous work on the composition of the thiols present in human cancer cell lines has shown the presence of an unknown low molecular weight species, deemed to be a “Conthiol”, which could be important in this respect. This was prepared and isolated from a human prostate cancer cell line (LNCaP) in the form of an adduct of 2-mercuri-4-nitrophenol;it accounts for 56.5% of the total cellular thiols present in this cell line. Initial LC-MS analysis of this adduct had indicated that the possible molecular weight of the thiol was in the region of 467 daltons. In further analytical studies to identify the thiol, attempts were made to release it from the adduct by passage through a Thiopropyl Sepharose6B column. LC-MS analysis of the column eluate revealed two components yielding negative ion fragments of 427 m/z and 449 m/z. Only the former component contained thiol, indicating that a breakdown and/or possible rearrangement of the Conthiol had occurred. Further investigations of the column thiol eluate using ICP-MS analysis showed that the sulfur content agreed with the spectrophotometric analysis result (Ellman assay) and that the molecule did not contain phosphate. Amino acid analyses of the eluate were negative. In an attempt to prevent the breakdown of the thiol released by the Thiopropyl Sepharose 6B column, the adduct was treated with 5% v/v bromine water prior to applying to the column. In this instance the thiol containing eluate obtained from the column was treated with an equimolar quantity of mercuric chloride forming a fresh adduct, RS-Hg-SR. LC-MS analysis of this mercurial adduct detected a negative ion fragment of 782 m/z which on further ionization gave a ladder like pattern showing loss of mass units of 58 in each rung. This would seem to suggest the presence of a repeat polymer like structure containing 5 monomers, which, plus the thiol atom, gives a possible formula weight of 322;probably revealing only a part of the unknown Conthiol molecule whose properties and formula weight do not correlate with any known cellular thiol. Further analysis of the thiol released from the adduct on the Thiopropyl Sepharose 6B column by Infra-red (FTIR) provided little information except to confirm the presence of the thiol group and C=O stretch bands together with the possibility of a lactam ring at 1651 and 1634 cm·s<sup>-</sup><sup>1</sup>.
基金supported by the National Natural Science Foundation of China(No.21171040 and 21302019)the disguished organic project(2013JCJS01)
文摘Two novel acid-base adducts,[H_2L_1^(2+)](Hpbda)_2(1,L_1 = l,4-di(lH-imidazol-4-yl)benzene,H_2pbda = 1,4-benzenedicarboxylic acid) and[H_2L_2^(2+)](NO_3)_2(2,L_2 = l,4-di(l-carboxymethyl-imidazol-4-yl)benzene),have been prepared and characterized by single-crystal X-ray diffraction,IR spectroscopy and elemental analysis.Compound 1 crystallizes in monoclinic,space group P2_1/n with a = 5.3525(11),b = 9.1471(19),c = 19.314(4) ?,β = 92.342(3)°,V= 944.8(3) ?~3,Z = 2,C_(16)H_(16)N_6O_(10),M_r = 452.35,D_c = 1.590 g/cm^3,μ = 0.135 mm^(-1),S = 1.058,F(000) = 468,the final R = 0.0661 and wR = 0.1887 for 2298 observed reflections(I> 2σ(I)).Compound 2 crystallizes in monoclinic,space group P2_1/c with a = 9.6923(10),b = 17.2950(17),c = 7.1880(7) ?,β =94.801(2)°,V= 1200.7(2) ?~3,Z = 2,C_(28)H_(22)N_4O_8,M_r = 542.50,D_c = 1.501 g/cm^3,μ = 0.112 mm^(-1),S= 1.060,F(000) = 564,the final R = 0.0394 and wR = 0.1017 for 2768 observed reflections(I >2σ(I)).In the title compounds,both of L_1 and L_2 ligands act as weak base to accept protons to exhibit diprotonated H_2L_1^(2+) and H_2L_2^(2+) form,which can effectively employ as hydrogen bonding donors to combine anion moieties to form binary adducts respectively.In the crystal packing diagram of two polymers,there exist extensive noncovalent interactions including charge-transfer interactions,C(N)-H…π and N-H…O,C-H…O,O-H…O hydrogen bonding interactions between co-crystal moieties which consolidate the structures of supramolecular polymers,thus generating three-dimensional(3D) frameworks.
