Novel aromatic carboxamides from dehydroabietylamine as potential fungicides: Design,synthesis and antifungal evaluation

The present study was carried out to design and synthesize a number of novel aromatic carboxamide derivatives of dehydroabietylamine. The preliminary antifungal assay indicated that most of title compounds displayed moderate to good antifungal activity toward the six fungal strains in vitro. Compounds 3i, 3q, 4b and 4d showed significant antifungal activity against Sclerotinia sclerotiorum, with EC₅₀ values ranging from 0.067 ～ 0.393 mg/L. Compounds 3i, 4b and 4d also showed pronounced mycelial growth inhibition activities against B. cinerea and A. solani. Furthermore, in the in vivo assay, compound 4b exhibited brilliant protective activity against S. sclerotiorum-infected rape leaves. Meanwhile, the in vivo bioassay on tomato plants infected by B. cinerea showed that compound 3i and 4d displayed excellent protective activity at 200 mg/L, which were near to boscalid. Primary mechanistic study revealed that 4b could inhibit sclerotia formation as well as reduce the exopolysaccharide level. SEM and TEM analysis indicated that 4b possessed a strong ability to destroy the surface morphology of mycelia, cell structure and seriously interfere with the growth of the fungal pathogen. In addition, 4b exhibited good inhibitory activity (IC₅₀ = 23.3 ± 1.6 μM) toward succinate dehydrogenase (SDH). Molecular modeling study confirmed the binding modes between compound 4b and SDH. The above antifungal results and fungicidal mechanism study revealed that this class of dehydroabietylamine derivatives could be potential SDH inhibitors and lead compounds for novel fungicides development.     

Separation of helium and hydrocarbon mixtures by a two-membrane column

The permeabilities to pure gases can be directly used in the calculation of mixed gas permeation through a rubbery membrane (silicone rubber), but the permeabilities of cellulose acetate membranes to mixed gases are considerably affected by the presence of hydrocarbons. The efficiency of separation increases with decreasing pressure ratio and reaches a maximum when the pressure ratio becomes zero. The enrichment of the less permeable gas can be easily achieved in a stripper. Combining two strippers made out of two different membranes, highly concentrated products (99%) are continuously obtained at both ends of the column. As a result, the overall separation factors are greatly increased.     

基于富勒烯和噻吩聚合物的本体异质结太阳电池

随着全球能源需求量的逐年增加,对可再生能源的有效利用成为亟待解决的问题。现在使用的能源多来自矿物燃料的开采,其中包括石油、天然气和煤等,而这些资源是非常有限的。因此,发展新能源和新能源材料是我国进入21世纪必须解决的重大课题,其中太阳能被认为是清洁可再生新能源的代表之一。基于噻吩跟富勒烯的异质结太阳能电池是目前太阳能电池的重要发展方向之一。该种太阳能电池因其制备简单、成本低廉、重量轻和可制成柔性器件等优点近年来受到多方的广泛重视。经过努力,该种太阳能电池的光电转化性能已经得到了一定提高,最高光电转化效率已达到7%左右,但是跟无机半导体硅和染料敏化太阳能电池相比还有一定差距。因此,这方面的研究任重而道远,研究空间也非常大。本文从材料合成的角度,简要综述了近年来国内外在基于富勒烯和噻吩的异质结太阳能电池方面所取得的最新研究进展,并对下一步需要研究的热点问题作了展望。     

Discrete variational Xα calculations for Sc2 and Ti2

The electronic structures of the Se₂ and Ti₂ molecules have been calculated by the DV Xα method. For these molecules ¹∑_g⁺ ground states are obtained which correspond to triple and quadruple bonding in Se₂ and Ti₂ respectively. Both the calculated ionization potentials and optical transition energies are in good agreement with experimental data. Equilibrium bond lengths of 2.21 and 1.96 À have been obtained for Se₂ and Ti₂ respectively.     

Laser double-resonance studies of Rydberg states of HgAr

The first Rydberg states of the HgAr van der Waals molecule have been characterized by a laser double-resonance technique. Two states have been observed, which correlate to Hg(7s³S₁)+Ar(¹S₀), a strongly bound state, C, in accord with theoretical expectations and a very weakly bound state, D, which is unexplained.     

On the dissociation of diatomic molecules at metal surfaces

The role of activation barriers in the process of dissociative adsorption of diatomic molecules on metal surfaces is considered in terms of the topology of the diabatic potential energy surfaces of the interacting system. The location of possible barriers on the potential energy surface determines the dependence of the dissociative threshold on either the normal translational or total energy content of the incident molecules.     

Transient electron spin resonance spectroscopy of the carotenoid triplet state in Rhodopseudomonas Sphaeroides wild type

We have determined the triplet state spin sublevel dynamics of spheroidene contained within the photosynthetic bacterium Rhodopseudonionas sphaeroides wild type. The triplet state decay dynamics were measured using direct-detection, rapid-transient, high-field, electron spin resonance spectroscopy on chromatophores isolated from the bacterium. The transient signals were analyzed as a function of microwave power to obtain the individual triplet state spin sublevel decay rate constants and the spin—lattice relaxation time. The individual triplet state spin sublevel decay constants yielded a value of 4.2±0.3 μs for the overall triplet state lifetime, which agrees with the lifetime measured previously by other workers using optical spectroscopic methods.     

纺锤体驱动蛋白抑制剂的设计、合成与生物活性研究

纺锤体驱动蛋白(kinesin spindle protein, KSP/Eg5)作为潜在的肿瘤治疗靶点, 使发现KSP抑制剂成为热点. 设计并合成了4-氧基-β-四氢咔啉衍生物作为新型的KSP抑制剂, 并测定了其对KSP的抑制活性, 均优于阳性对照物. 其中化合物9c抑制KSP的IC50＝0.065 μmol•L－1, 优于阳性对照物Monastro l100多倍. 生物活性研究表明为抗肿瘤药物提供了新结构类型的候选化合物.     

Triplet state of 4-biphenylcarbonyl and 2-naphthylcarbonyl chromophores in homopolymers,copolymers and model compounds

The triplet state of poly(1-(4-biphenyl)-2-propen-1-one), poly(1-(2-naphthyl)-2-propen-1-one), copolymers of the above carbonyl monomers with methyl methacrylate and respective model compounds was sought in solution at room temperature by emission spectroscopy and microsecond flash photolysis. Although 4-biphenylcarbonyl and 2-naphthylcarbonyl yield an intense phosphorescence at 77 K, no emission was observed in solution at room temperature. The intense transient spectrum observed in benzene solution for 1-(4-biphenyl)-3-chloropropan-1-one and 1-(2-naphthyl)-3-chloropropan-1-one was ascribed to the triplet state. Self-quenching was found to decrease the intensity of the transient spectrum and the life-time when building up both chromophores in a macromolecule. More efficient self-quenching was observed for 2-naphthylcarbonyl than for the 4-biphenylcarbonyl chromophore which was suggested as a suitable triplet probe. The limiting triplet life-time of 4-biphenylcarbonyl built up in a copolymer with methyl methacrylate at low concentration in a thermodynamically good solvent is about 0·3 ms.