烯二炔类抗肿瘤抗生素的合成进展

综述了四个天然产和的中分离的烯二炔类抗肿瘤抗生素的合成进展.它们是:Calicheamicin,Esperamicin,Neocarcinostatin chromophore和dynemicin,此外还综述了若干人工设计的烯二炔类结构化合物的合成进展     

从溶胀平衡研究玻璃态高聚物的凝聚缠结网络

在13~15℃室温条件下对聚苯乙烯(PS)颗粒在二氧六环/水混合溶剂中的溶胀情况进行目视观察,可以看到,当减小混合溶剂二氧六环/水中的水含量时,PS颗粒从玻璃态到溶胀的玻璃态、溶胀的高弹态、流体态的转变,与PS颗粒升温时从玻璃态到高弹态、流体态的转变相对应.选定混合溶剂二氧六环/水(水6·8wt%)对一个单分散PS试样(Mw=1·68×105)在30℃进行分相平衡和溶胀平衡的测定.分相平衡是先将PS/二氧六环/水(混合溶剂水含量6·8wt%)体系加热到130℃使PS溶解成一均相溶液,然后在冷却过程中分相,在30℃达分相平衡(30天)时,浓相高分子体积浓度p″=0·304,稀相几乎为纯溶剂.从Flory-Huggins相平衡理论得出此体系的高分子-溶剂相互作用参数χ=0·63.本工作使用的单分散PS试样在选定的混合溶剂,即二氧六环/水(水6·8wt%)中,30℃时不能溶解只能溶胀,单分散PS颗粒淬冷试样(密度ρp=1·0451g/mL)到达溶胀平衡(80天)时浓相高分子体积浓度p″=0·308.而此淬冷试样经在80℃热处理100h后的老化试样(ρp=1·0470g/mL)达溶胀平衡(70天)时p″=0·312.从溶胀过程中浓相体积变化曲线可知试样经在80℃热处理过程中凝聚网络趋向于更均一,更接近热处理温度下的平衡态,试样密度增大,网络产生了新的链间凝聚,物理交联密度增大(凝聚点间分子量减小).从溶胀平衡理论并取χ=0·63(分相平衡)可得到淬冷试样的物理交联点间分子量Mc=11·6×104,老化试样的物理交联点间分子量Mc=6·9×104.实验结果说明溶胀过程及溶胀平衡的测定可以反映玻璃态高聚物中的凝聚网络结构的细节,而且非常敏感.     

Strukturen aus AIB2− und BaAl4−analogen Einheiten. I Die Verbindungen Sr4Pd5P5 und Sr2Pd3P3

Structures with AIB₂? and BaAl₄?type Units. I The Compounds Sr₄Pd₅P₅ and Sr₂Pd₃P₃ Sr₄Pd₅P₅ (Cmcm, a = 4.177(1) Å, b = 31.377(5) Å, c = 8.581(2) Å, Z = 4) und Sr₂ Pd₃P₃(Pmmm, a = 4.199(1) Å, b = 4.212(1) Å, c = 34.227(4) Å, Z = 4) have been prepared by heating the elements. Both structures contain exclusively units characteristic for the AIB_2? and BaAl₄?type. The ratio between isolated P-atoms and P₂?pairs is interpreted with an ionic splitting of the formulas.     

Changes in the composition of volatile monoterpenes and sesquiterpenes of Pinus armandi, P. tabulaeformis, and P. bungeana in Northwest China

The volatile mono-and sesquiterpenes obtained from the needles and resin of Pinus armandi, P. tabulaeformis, and P. bungeana growing in the Qinling, Taibai, and Huanglong Mountain forest ecosystem were analyzed by means of GC-MS. Forty-eight constituents were identified, and α-pinene, β-pinene, 1R-α-pinene, β-caryophyllene, cadindiene, α-caryophyllene, D-limonene, and 1S-β-pinene were the major components of the mono-and sesquiterpenes in the needles and resin. The components of the volatile mono-and sesquiterpenes from the needles and resin at Qinling, Taibai, and Huanglong Mountains had remarkable differences in three pine species, whereas the monopertene content such as α-pinene, β-pinene, D-limonene, and camphene were mostly changed in the growing stage. The intraspecies variation in the different ecosystems can be attributed to the species’ geography and genetic variation, and even the adaptation of the pine species to different ecological environments. Moreover, monoterpenes and sesquiterpenes can be induced by the attack of bark beetles, of which the α-pinene, β-pinene, 1R-α-pinene, 1S-α-pinene, b-myrecene, and β-caryophyllene contents had positive relations with the attacking Dendroctonus armandi and D. valens. Published in Khimiya Prirodnykh Soedinenii, No. 5, pp. 430–433, September–October, 2006.     

{[Cu4(nip)4(4，4′-bipy)4(DMF)4]·CH3OH}n配合物的合成与晶体结构

A coordination polymer, {[Cu₄(nip)₄(4，4′-bipy)₄(DMF)₄]·CH₃OH}_n, have been synthesized by the layer method using 5-nitroisophthalic acid (H₂nip), Cu(CH₃COOH)₂ and 4,4′-bipyridine(4,4′-bipy) with three solutions in a marrow tube and structurally characterized by X-ray single-crystal structure analysis. The results indicated that the nip ligand has a μ₂ mono-atomic bridging-monodentate coordination mode and the structure is a two-dimensional network. CCDC: 623420.     

Small-volume radial flow cell for all-solid-state ion-selective electrodes

A flow cell with a radial distribution of four all-solid-state ion selective electrodes (ISEs), or alternatively three ISEs and one reference electrode, was designed and optimized for mass production. The radial distribution of the electrodes reduces the cell volume and is expected to minimize cross-contamination between different electrodes. Two different cell prototypes were developed and tested for all-solid-state K⁺-ISEs based on a solvent polymeric ion-selective membrane (ISM) and a conducting polymer, poly(3,4-ethylenedioxythiophene), as solid internal contact. In the first prototype, PEDOT was electropolymerized from an aqueous solution of the monomer and the doping ion salt, sodium polystyrenesulfonate (NaPSS). The second prototype employed an aqueous dispersion of PEDOT(PSS) that is commercially available (Baytron P, Bayer AG). Compared to electrochemical synthesis, solution casting of the polymer dispersion was found to be a more advantageous method to deposit the conducting polymer layer aiming at mass production. The resulting prototypes of the flow cell had a small volume (ca. 17-37 μl), which makes them suitable for application in clinical analysis.     

藉时间分辨荧光技术研究氢苊、荧蒽与环糊精的络合过程

用时间分辨荧光技术研究二氢苊、荧蒽与β-环糊精的络合过程以及乙醇分子对络合过程的影响, 观察到它们在环糊精水溶液中有长寿命组份存在. 证明这些分子与环糊精分子发生了络合作用, 并根据荧光衰减曲线的指前因子计算出了它们的络合平衡常数.     

A preliminary 3D model for cytochrome P450 2D6 constructed by homology model building

Summary A homology model building study of cytochrome P450 2D6 has been carried out based on the crystal structure of cytochrome P450 101. The primary sequences of P450 101 and P450 2D6 were aligned by making use of an automated alignment procedure. This alignment was adjusted manually by matching -helices (C, D, G, I, J, K and L) and -sheets (3/4) of P450 101 that are proposed to be conserved in membrane-bound P450s (Ouzounis and Melvin [Eur. J. Biochem., 198 (1991) 307]) to the corresponding regions in the primary amino acid sequence of P450 2D6. Furthermore, -helices B, B and F were found to be conserved in P450 2D6. No significant homology between the remaining regions of P450 101 and P450 2D6 could be found and these regions were therefore deleted. A 3D model of P450 2D6 was constructed by copying the coordinates of the residues from the crystal structure of P450 101 to the corresponding residues in P450 2D6. The regions without a significant homology with P450 101 were not incorporated into the model. After energy-minimization of the resulting 3D model of P450 2D6, possible active site residues were identified by fitting the substrates debrisoquine and dextrometorphan into the proposed active site. Both substrates could be positioned into a planar pocket near the heme region formed by residues Val³⁷⁰, Pro³⁷¹, Leu³⁷², Trp³¹⁶, and part of the oxygen binding site of P450 2D6. Furthermore, the carboxylate group of either Asp¹⁰⁰ or Asp³⁰¹ was identified as a possible candidate for the proposed interaction with basic nitrogen atom(s) of the substrates. These findings are in accordance with a recently published predictive model for substrates of P450 2D6 [Koymans et al., Chem. Res. Toxicol., 5 (1992) 211].     

Synthesis and Characterization of Pyrrolthiosemicarbazone Complexes of Palladium(II). Crystal Structures of [{Pd[C4H4NC(H)=NNC(S)NHMe](Cl)}2{μ‐Ph2P(CH2)3PPh2}] and [Pd{C4H4NC(H)=NNC(S)NHMe}{Ph2P(CH2)2PPh2‐P,P}](Cl)

Reaction of the thiosemicarbazone ligands C₄H₄NC(H)=NN(H)C(S)NHR (R = Me, a ; Et, b ) with Li₂[PdCl₄] gave the dinuclear complexes [Pd{C₄H₄NC(H)=NNC(S)NHR}(μ‐Cl)]₂ (R = Me, 1a ; Et, 1b ) with a central Pd₂Cl₂ core and with deprotonation of the thiosemicarbazones at the hydrazinic nitrogen atom. Treatment of 1a and 1b with triphenylphosphine gave the mononuclear compounds [Pd{C₄H₄C(H)=NNC(S)NHR}(Cl)(PPh₃)] (R = Me, 2a ; Et, 2b ), whereas reaction of 1a and 1b with tertiary diphosphines gave mono‐ and dinuclear compounds, as appropriate, with the corresponding diphosphine acting as a monodentate ( 6b ), chelating ( 3a ) and bridging ligand ( 4a, 5a , 4b, 5b ). Treatment of 1a and 1b with (Ph₂PCH₂CH₂PPh₂)W(CO)₅ gave the new heterobimetallic complexes 7a and 7b . The crystal structures of complexes 3a and 4a are described.