Comments on the ring-opening polymerization of morpholine-2,5-dione derivatives by various metal catalysts and characterization of the products formed in the reactions involving R2SnX2, where X = OPr(i) and NMe2 and R = Bu(n), Ph and p-Me2NC6H4

(3S,6S)-3-Isopropyl-6-methyl-morpholine-2,5-dione (1), and (3S,6S)-3,6-dimethyl-morpholine-2,5-dione (2), do not enter into ring-opening polymerization reactions with metal catalyst precursors commonly employed for lactides, and with Sn(II) octanoate, only low molecular weight oligomers are obtained. Reactions with R2SnX2 compounds, where R = Ph, Bu(n) and p-Me2NC6H4 and X = OPr(i) or NMe2, reveal that ring-opening of the morpholine-2,5-diones does occur, but that polymerization is terminated by the formation of kinetically-inert products such as {Ph2Sn[mu,eta(3)-OCH(Me)CONCH(Pr(i))COOPr(i)]}2 (3), and {[Bu(n))2Sn[mu,eta(3)-OCH(Me)CONCH(Me)CONMe2]}2 (4), with elimination of HX. Ph3SnOPr(i) is seen to react reversibly with morpholine-2,5-diones in toluene-d8 by 1H NMR spectroscopy while (Bu(n))3SnNMe2 reacts by ring opening to give (Bu(n))3SnOCH(Me)C(O)NHCHMeC(O)NMe2. The new organotin compounds have been characterized by 1H, 13C{1H} and 118Sn NMR spectroscopy and compounds 1, 2, 3 and 4 by single crystal X-ray crystallography.     

Synthesis and cytotoxic evaluation of novel brominated N-alkyl pyrano[3,2-c]quinolinones

A novel series of 6-alkyl-4-bromopyrano[3,2-c]quinoline-2,5-diones ( 2a–c ), 6-alkyl-3,4-dibromopyrano[3,2-c]quinoline-2,5-diones ( 4a–c ), and 6-alkyl-3-amino-bromopyrano[3,2-c]quinoline-2,5-diones ( 6a–c ) were synthesized via appropriate conventional methods and in good yields. The structures of target compounds were approved by elemental analysis, IR, ¹H NMR, ¹³C NMR, and mass spectrometry. The antitumor inhibitory activities of the new compounds were evaluated on several cancer cell lines, A-549 (human lung cancer), HCT-116 (human colon cancer), MCF-7 (breast cancer), and HePG-2 (human liver cancer). Moreover, 50% inhibitory concentrations, IC₅₀, were established. 5-Fluorouracil was used as a positive control in the viability assay. The screening results showed that most of the examined compounds exposed powerful inhibition activity toward various cell lines. Particularly, Compound 4c exhibited higher cytotoxic activity against four tumor cell lines than the reference drug, 5-fluorouracil, with significantly lower IC₅₀ values. Accordingly, most of the synthesized compounds would be a better prospective growth in the anticancer drug discovery.     

Isolation of sesquiterpenoids from sponge Dysidea avara and chemical modification of avarol as potential antitumor agents

The marine sponge Dysidea avara contained avarol (1) and avarone (2). Avarol on acylation yielded 2',5'-O-dibenzoylavarol (3); 2,5'-O-(4-chlorobenzoyl)avarol (4); 2,5'-O-dicinnamoylavarol (5); 2,5'-O-(4-bromobenzoyl)avarol(6); 2',5'-O-dioctanoylavarol (7); 2',5'-O-(4-fluorobenzoyl)avarol (8) and diacetylavarol (9). The structural elucidation of all the compounds 1-9 have been done by spectral analysis. The cytotoxicity of these compounds were also determined and evaluated. Compounds 6 and 9 showed selective cytotoxicity against Hepa (human hepatoma) and KB cell lines respectively.     

Cobalt-lanthanide coordination polymers constructed with metalloligands: a ferromagnetic coupled quasi-1D Dy3+ chain showing slow relaxation

Four types of cobalt-lanthanide heterometallic compounds based on metalloligand Co(2,5-pydc)(3) (3-) (2,5-H(2)pydc=pyridine-2,5-dicarboxylate acid), [Ln(2)Co(2)(2,5-pydc)(6)(H(2)O)(4)](n) 2n H(2)O (1) (Ln=Tb, Dy for 1 a, 1 b respectively), [Tb(2)Co(2)(2,5-pydc)(6)(H(2)O)(4)](n)3n H(2)O (2), [Tb(2)Co(2)(2,5-pydc)(6)(H(2)O)(9)](n)4n H(2)O (3), and [LaCo(2,5-pydc)(3)(H(2)O)(2)](n)2n H(2)O (4) have been synthesized. Compound 1 has a layer structure with well-isolated carboxylate-bridged Ln(3+) chains, compound 2 is a three-dimensional (3D) porous network with Tb(3+) chains that are also well isolated and carboxylate bridged, 3 is a layer structure based on dinuclear units, and 4 is a 3D network with boron nitride (BN) topology. DC magnetic studies reveal ferromagnetic coupling in all the carboxylate-bridged Ln(3+) chains in 1 a, 1 b, and 2. Compared to the silence of the out-of-phase ac susceptibility of 2, above 1.9 K the magnetic relaxation behavior of both 1 a and 1 b is slow like that of a single-chain magnet.     

Gold(III) complexes with imidazole,benzoxazole, purine and pyrimidine derivatives

Summary The synthesis and characterization of Au^III complexes with several heterocyclic ligands are reported. The compounds have general formula [AuX₃(L)], where L =N-methylimidazole (N-MeIz),N-ethylimidazole (N-EtIz),N-propylimidazole (N-PrIz), benzoxazole (BO), 2-methylbenzoxazole (2-MeBO), 2,5-dimethylbenzoxazole (2,5-diMeBO), 2-amino-pyrimidine (2-APm), 4(6) -hydroxy-pyrimidine [4(6)-hydrPm] or hypoxanthine (Hypox) and X = Cl or Br. Elemental analysis, conductivity measurements and spectral studies were used for the characterization of the complexes. A square-planar geometry withN-bonded heterocyclic ligands is suggested.     

Dynamic NMR study and theoretical calculations on the conformational exchange of valsartan and related compounds

Valsartan (1), an antihypertensive drug of the sartan family, and three related compounds, 3-methyl-2-((2'-(1-methyl-1H-tetrazol-5-yl)biphenyl-4-ylmethyl) pentanoylamino)butyric acid (2), 3-isopropyl-6-propyl-4-(2'-(1H-tetrazol-5-yl)biphenyl-4-ylmethyl) morpholine-2,5-dione (3), and 3-isopropyl-6-propyl-4-(4'-(1H-tetrazol-5-yl)biphenyl4-ylmethyl) morpholine-2,5-dione (4), were studied by nuclear magnetic resonance (NMR) spectroscopy. Assignment of (1)H and (13)C NMR resonances for the compounds were completed using COSY, HSQC and HMBC techniques. It was found that each of the compounds 1, 2, and 4 had two sets of (1)H and (13)C resonances, suggesting the presence of two conformers in solution. Based on NOESY experiments at different temperatures, thermodynamic parameters of the conformational exchange process were deduced for these compounds. The exchange barrier was found to be 17.9 +/- 0.7, 18.5 +/- 0.8, and 17.7 +/- 0.6 kcal mol(-1) with the corresponding free energy difference (DeltaG) of 0.32 +/- 0.04, 0.23 +/- 0.01, and 0.13 +/- 0.04 kcal mol(-1) for 1, 2, and 4, respectively, at 298 K. Two conformations of valsartan were elucidated by NMR spectroscopy and quantum chemistry calculation. The results showed that two conformers of valsartan interchange via rotation about the C(O)--N bond.     

巴戟天内生真菌Trichoderma spirale A725中两个新的聚酮类化合物(英文)

综合运用硅胶柱色谱、反相硅胶柱色谱、Sephadex LH-20凝胶柱色谱以及制备型高效液相色谱技术对药用植物巴戟天内生真菌Trichoderma spirale A725的次生代谢产物进行分离纯化,得到6个聚酮类化合物,采用多种现代波谱技术确定其结构,分别为:6-羟基-4-异丙基-1,8-二甲基螺环[4.5]癸-1,8-二烯-7-酮(1),2-羟基-2,5-二甲基-7-氧代-5,7-二氢-2H-呋喃[3,4-b]吡喃-4-羧酸(2), 3-乙基-4-羟基-6-甲基-二氢-吡喃-2-酮(3),苯乙内酯A (4), 3-羟基-5-(4-羟基苄基)二氢呋喃-2(3H)-酮(5), 4-乙酰-3-羟基-6-甲基吡喃-2-酮(6).其中化合物1和2为新化合物,化合物3为新天然产物.此外,利用四株肿瘤细胞株(Hep G-2、MCF-7、SF-268及A549)对化合物1~6细胞毒活性进行评估,结果表明化合物1~6对上述肿瘤细胞均无明显的细胞毒活性.     

Lignans and anthraquinones from the fruits of Morinda citrifolia

Two new anthraquinones, 1,6-dihydroxy-5-methoxy-2-methoxymethylanthraquinone (1) and 1,5,7-trihydroxy-6-methoxy-2-methoxymethylanthraquinone (2), and one new lignan isoamericanoic acid A (3) were isolated from the fruits of Morinda citrifolia along with 11 known compounds scopoletin, luteolin, americanin A, americanin D, 3,3'-bisdemethylpinoresinol, p-cresol, p-hydroxybenzoic acid, p-hydroxybenzaldehyde, 4-hydroxy-3-methoxybenzaldehyde, 4-hydroxy-3-methoxycinnamaldehyde, and 2,5-dihydroxy-4-methoxybenzaldehyde. The structures of all compounds were elucidated by spectroscopic analysis.     

Synthesis of acyclic nucleoside analogs of 6-substituted 2-aminopurines and 2-amino-8-azapurines

Several new acyclonucleoside purine and 8-azapurine analogs have been prepared from 2-amino-4,6-dichloropyrimidine ( 1 ) and 3-amino-1,2-propanediol ( 2a ) and 4-amino-1-butanol ( 2b ), respectively, as the starting materials. The new target compounds are: 2-amino-6-chloro-9-(2,3-dihydroxypropyl)purine ( 6a ), 2-amino-6-chloro-9-(4-hydroxybutyl)purine ( 6b ), 2-amino-6-chloro-9-(2,3-dihydroxypropyl)-8-azapurine ( 7a ), 2-amino-6-chloro-9-(4-hydroxybutyl)-8-azapurine ( 7b ), 9-(2,3-dihydroxypropyl)-8-azaguanine ( 8a ), 9-(4-hydroxybutyl)-8-azaguanine ( 8b ), 9-(2,3-dihydroxypropyl)-8-azathioguanine ( 9a ), and 9-(4-hydroxybutyl)-8-azathioguanine ( 9b ). Also, the requisite intermediate pyrimidine derivatives, 2,5-diamino-4-(2,3-dihydroxypropylamino)-6-chloropyrimidine ( 5a ) and 2,5-diamino-4-(4-hydroxybutylamino)-6-chloropyrimidine ( 5b ) are novel.     

Bioactive Components from the Mycelium of Antrodia Salmonea

Three new compounds, 2,4‐dimethoxy‐6‐methylbenzene‐1,3‐diol ( 1 ), salmoquinone ( 2 ), and 3‐(4‐hydroxyphenyl)‐4‐isobutyl‐1H‐pyrrole‐2,5‐dione ( 3 ), together with six known compounds, 2‐methoxy‐6‐methyl‐p‐benzoquinone ( 4 ), 2,3‐dimethoxy‐5‐methyl‐p‐benzoquinone ( 5 ), 2‐hydroxy‐5‐methoxy‐3‐methyl‐p‐benzoquinone ( 6 ), eburcoic acid ( 7 ), fomefficinic acid C ( 8 ), and a pyrroledione ( 9 ), were isolated from the mycelium of Antrodia salmonea. The structures of these compounds were elucidated by spectrometric analyses including IR, NMR, and MS. Among these compounds, 4 and 5 exhibited cytotoxicity against KB, HepG2, and H2058 cell lines.     

海洋放线菌Streptomyces sp.124092中的细胞毒活性成分

对海洋放线菌Streptomyces sp.发酵液的提取物进行柱层析分离, 得到5个化合物. 经MS, NMR, 1H-1H COSY, HSQC和HMBC等数据鉴定, 其结构分别为3-氨基-丙酸对甲苯酯(1)、6-Amino-3-(4-hydroxybenzyl)-1,4-diazonane-2,5-dione(2)、正丁基-α-D-吡喃甘露糖苷(3)、大豆苷元(4)和1H-3-吲哚甲酸(5). 其中化合物1和2为新化合物, 细胞毒活性测试结果表明, 化合物1~4对人肝癌细胞(SMMC-7721)具有不同程度的生长抑制活性.     

Chemical constituents and biological studies of the leaves of Grevillea robusta

Three new compounds: Graviquinone (1), cis-3-hydroxy-5-pentadecylcyclohexanone (2), and methyl 5-ethoxy-2-hydroxycinnamate (3), and thirty-eight known compounds were isolated and identified from the leaves of Grevillea robusta. The structures of these compounds were determined by spectroscopic and chemical transformation methods. Graviquinone (1) showed the strongest cytotoxicity against MCF-7, NCI-H460, and SF-268 cell lines. Methyl 2,5-dihydroxycinnamate (4), graviphane (13), and dehydrograviphane (14) exhibited very potent DPPH scavenging activity compared with α-tocopherol. Methyl 2,5-dihydroxycinnamate (4) and bis-norstriatol (17) demonstrated strong inhibition of L-DOPA oxidation by mushroom tyrosinase compared with kojic acid.     

Indole Alkaloids from Alocasia macrorrhiza

Five new indole alkaloids, alocasins A-E (3-7), together with known hyrtiosin B (1) and hyrtiosulawesin (2) were isolated from Alocasia macrorrhiza (L.) SCHOTT; their structures were elucidated on the basis of spectroscopic data. Compounds 1-7 were in vitro tested for cytostatic activity on human throat cancer (Hep-2), human hepatocarcinoma (Hep-G2), and human nasopharyngeal carcinoma epithelial (CNE) cell lines by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method; compounds 2, 3, 6 and 7 showed mild antiproliferative activity against Hep-2 and Hep-G2 whereas compounds 2 and 4 showed gentle antiproliferative activity against CNE.     

2,3,5,8(1)-Tetrahydroimidazo[1,2-a]pyrimidine-2,5-dione derivatives

The corresponding ylidene, azomethine, and azo derivatives of 2,3,5,8(1)-tetrahydroimidazo [1,2-a]pyrimidine-2,5-dione were synthesized by reaction of 7-methyl-and 6-bromo-7-methyl-2,3,5,8(1)-tetrahydroimidazo[1,2-a]pyrimidine-2,5-diones with aldehydes, insatin, aromatic nitroso compounds, and arenediazonium salts. Ylidene derivatives of 7-methyl-2,3,5,8(1)-tetrahydroimidazo[1,2-a]pyrimidine-2,5-dione were also obtained by reaction of 2-amino-4-methyl-6-oxo-1,6-dihydro-1-pyrimidylacetic acid with carbonyl compounds.     

Synthesis,Structures, and Thermal Properties of Cobalt(II) Thiocyanate Coordination Compounds with 2,5‐Dimethylpyrazine

Reactions of Co(NCS)₂ with 2,5‐dimethylpyrazine lead to the formation of five compounds of compositions Co(NCS)₂(H₂O)₄ · 4(2,5‐dimethylpyrazine) ( 1 ), Co(NCS)₂(H₂O)₄ · 3(2,5‐dimethylpyrazine) ( 2 ), Co(NCS)₂(2,5‐dimethylpyrazine)(H₂O)₂ · 3(2,5‐dimethylpyrazine) ( 3 ), [Co(NCS)₂]₂(H₂O)₆ · 4(2,5‐dimethylpyrazine) · 4H₂O ( 4 ), and Co(NCS)₂(2,5‐dimethylpyrazine)(MeOH)₂ ( 5 ). 1 and 2 are simple aqua complexes, in which the Co cations are octahedrally coordinated by two thiocyanate anions and four water molecules, whereas in 3 the Co cations are linked by the 2,5‐dimethylpyrazine ligands into chains. In compound 4 Co(NCS)₂](H₂O)₆ dimers are observed, which are linked by bridging water molecules. In compound 5 the Co cations are connected into chains by the 2,5‐dimethylpyrazine co‐ligand and are additionally coordinated by terminal anionic ligands and methanol molecules. Thermogravimetric measurements of compounds 1 – 4 show several mass steps, in which the water and the co‐ligands and the water molecules are stepwise removed. Elemental analysis, XRPD investigations, and IR spectroscopic investigations indicate that all of these compounds decompose into new phases of composition Co(NCS)₂(2,5‐dimethylpyrazine)₂ ( 6 ) that on further heating decompose into [Co(NCS)₂]₃(2,5‐dimethylpyrazine) ( 8 ) via Co(NCS)₂(2,5‐dimethylpyrazine) ( 7 ) as intermediate. Compound 7 can be directly obtained by thermal removal of methanol from compound 5 .     

Dioxo-2,5 pipérazines. 1. La synthèse des carboxythiazolo dioxo-2,5 pipérazines

A new and general synthesis of 2,5-dioxopiperazine condensed with the thiazolidine ring is described. The synthesis involves the use of N-ethoxy carbonyl-2-ethoxy-1-2-dihydroquinoleine (EEDQ) as activating agent to form the 2,5-diketopiperazine (EEDQ) as activating agent to form the 2,5-diketopiperazine ring. By this method 9-carbobutoxy-7,7-dimethyl-2,5-dioxo-8-this-1,4-diazabicyclo[4.3.0] nonane (6) and 9-carboxy-8,8 dimethyl-2,5-dioxo-7-thia-1,4-diazabicy clo [4.3.0] nonane (8) were obtained, with near quantitative yield, from 4-carboxy-2-carbobutoxy-5,5 dimethylthiazolidine (4). The former was transformed into acid 7 by hydrolysis with barium bydroxyde and the latter was esterified with diazornethane thus producing a methylester 9. The use of the ethy lester of N-(2-cabobutoxy-4-carboxy-5,5-dimethyl-thiazolidine)glycine (10) for synthesis of 6 was also successful. The spectromethric data were interpreted and confirm the proposed structure of the new compounds.     

Preparation of a family of hexanuclear rhenium cluster complexes containing 5-(phenyl)tetrazol-2-yl ligands and alkylation of 5-substituted tetrazolate ligands

The preparation of two new families of hexanuclear rhenium cluster complexes containing benzonitrile and phenyl-substituted tetrazolate ligands is described. Specifically, we report the preparation of a series of cluster complexes with the formula [Re(6)Se(8)(PEt(3))(5)L](2+) where L = benzonitrile, p-aminobenzonitrile, p-methoxybenzonitrile, p-acetylbenzonitrile, or p-nitrobenzonitrile. All of these complexes undergo a [2 + 3] cycloaddition with N(3)(-) to generate the corresponding [Re(6)Se(8)(PEt(3))(5)(5-(p-X-phenyl)tetrazol-2-yl)](+) (or [Re(6)Se(8)(PEt(3))(5)(2,5-p-X-phenyltetrazolate)](+)) cluster complexes, where X = NH(2), OMe, H, COCH(3), or NO(2). Crystal structure data are reported for three compounds: [Re(6)Se(8)(PEt(3))(5)(p-acetylbenzonitrile)](BF(4))(2)?MeCN, [Re(6)Se(8)(PEt(3))(5)(2,5-phenyltetrazolate)](BF(4))?CH(2)Cl(2), and [Re(6)Se(8)(PEt(3))(5)(2,5-p-aminophenyltetrazolate)](BF(4)). Treatment of [Re(6)Se(8)(PEt(3))(5)(2,5-phenyltetrazolate)](BF(4)) with HBF(4) in CD(3)CN at 100 °C leads to protonation of the tetrazolate ring and formation of [Re(6)Se(8)(PEt(3))(5)(CD(3)CN)](2+). Surprisingly, alkylation of the phenyl and methyl tetrazolate complexes ([Re(6)Se(8)(PEt(3))(5)(2,5-N(4)CPh)](BF(4)) and [Re(6)Se(8)(PEt(3))(5)(1,5-N(4)CMe)](BF(4))) with methyl iodide and benzyl bromide, leads to the formation of mixtures of 1,5- and 2,5-disubstituted tetrazoles.     

The Preparation of Dicompartmental Multifunctional Group Ligands

A convenient method for the preparation of the phenol-based ligands 1,6-bis(2-thiophenyl)-2,5-bis(2-hydroxy-3-hydroxymethyl-5-methylbenzyl)-2,5-diazahexane and 1,6-bis(5-methyl-2-thiophenyl)-2,5-bis(2-hydroxy-3-hydroxymethyl-5-methyl-benzyl)-2,5-diazahexane possessing two dissimilar compartments having multifunctional groups is reported. To synthesize these ligands, an equivalent of 1,6-bis(2-thiophene)-2,5-diazahexane or 1,6-bis(5-methyl-2-thiophene)-2,5-diazahexane and two equivalents of 2,2-dimethyl-6-methyl-8-(chloromethyl)benzo-1,3-dioxin were reacted in the presence of Na₂CO₃ in 1,4-dioxane, followed by acid hydrolysis of an acetonide-protecting group. Characterization data for the new compounds is reported.     

Lanthanide-thiophene-2,5-dicarboxylate frameworks: ionothermal synthesis, helical structures, photoluminescent properties, and single-crystal-to-single-crystal guest exchange

Eight three-dimensional lanthanide-thiophene-2,5-dicarboxylate frameworks, [Ln(TDC)(2)]·(choline) (1-6; Ln = Gd, Nd, Eu, Er, Tb, Dy; TDC = thiophene-2,5-dicarboxylate), [Yb(TDC)(2)(e-urea)]·(choline)·H(2)O (7; e-urea = ethyleneurea), [Nd(2)(TDC)(3)(e-urea)(4)]·3(e-urea) (8) have been successfully prepared in deep eutectic solvents (choline chloride/e-urea), respectively. Compounds 1-7 are anionic frameworks with 8-connected bcu topology, while compound 8 features a neutral 6-connected rob-type framework with guest e-urea molecules. In these structures, lanthanide ions show dicapped trigonal prism, pentagonal bipyramid, and tricapped trigonal prism coordination configurations, respectively, and the TDC ligands exhibit different coordination modes. Versatile helical substructures are presented in these compounds. The photoluminescent properties of compounds 3 (Eu) and 8 (Nd) were studied. Moreover, compound 8 can perform single-crystal-to-single-crystal guest exchange. The ethanol-exchange mechanism of 8 can be ascribed to the kinetically controlled flexibility (KCF).     

醌型木素模型物的光学特性

为探索醌型木素化学结构与颜色的关系,以五种醌型木素模型物2-甲氧基-1,4-苯醌(I)、1,2-苯醌(II)、4-亚烯丙基-2-甲氧基-2,5-环己二烯酮(亚甲基醌)(III)、5-甲氧基-1,4-苯醌-2-氧负离子(IV)和5-甲基-1,4-苯醌-2-氧负离子(V)作为纸浆中醌型木素发色体的代表,在B3LYP/6-311++G(2d,p)水平上获得了它们在乙醇中的稳定基态构型,采用含时密度泛函理论(TD-DFT)在同等水平上计算了其在乙醇溶液中的电子光谱,并分析了它们在可见光范围内的吸收.结果发现:五种模型物在可见光范围内的吸收均源于电子的π→π*跃迁,它们的最大吸收波长顺序依次为IIIIIIIVV,吸光系数顺序依次为IVIVIIIII;漂白过程中生成的醌氧负离子以及邻醌类模型物具有中等大小的吸光系数(ε=1978-3197),吸收波长较长(445.47-552.36 nm),是漂白后纸浆具有颜色的重要原因.对醌类模型物吸收波长较小(414.91 nm),吸光系数大小为中等(ε=2094),亚甲基醌类模型物虽然吸光系数大(ε=31935),但吸收波长较小(407.90 nm),二者对漂白后纸浆的颜色影响较小.