GC-MS Chemical Profiling,Biological Investigation of Three Salvia Species Growing in Uzbekistan

Salvia is a potentially valuable aromatic herb that has been used since ancient times. The present work studied the chemical profile of three Salvia species essential oils (EO): S. officinalis, S. virgata and S. sclarea, as well as assessing their antioxidant and enzyme inhibitory activities. A total of 144 compounds were detected by GC-MS analysis, representing 91.1, 84.7 and 78.1% in S. officinalis, S. virgata and S. sclarea EOs, respectively. The major constituents were cis-thujone, 2,4-hexadienal and 9-octadecenoic acid, respectively. The principal component analysis (PCA) score plot revealed significant discrimination between the three species. The antioxidant activity of the EOs was evaluated using in vitro assays. Only S. virgata EO showed antioxidant activity in the 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay (26.6 ± 1.60 mg Trolox equivalent (TE)/g oil). Moreover, this oil exhibited the highest antioxidant activity in 2,2-azino bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), cupric-reducing antioxidant capacity (CUPRAC) and ferric-reducing power (FRAP) assays in comparison with the other two EOs (190.1 ± 2.04 vs. 275.2 ± 8.50 and 155.9 ± 1.33 mg TE/g oil, respectively). However, S. virgata oil did not show any effect in the chelating ability assay, while in the PBD assay, S. officinalis had the best antioxidant activity (26.4 ± 0.16 mmol TE/g oil). Enzyme inhibitory effect of the EOs was assessed against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), tyrosinase, α-glucosidase and α-amylase. AChE enzyme was more sensitive to S. officinalis EO (4.2 ± 0.01 mg galantamine equivalent (GALAE)/g oil), rather than S. virgata EO, which was ineffective. However, S. virgata had the highest BChE effect (12.1 ± 0.16 mg GALAE/g oil). All studied oils showed good tyrosinase inhibitory activity, ranging between 66.1 ± 0.61 and 128.4 ± 4.35 mg kojic acid equivalent (KAE)/g oil). Moreover, the EOs did not exhibit any glucosidase inhibition and were weak or inefficient on amylase enzyme. Partial least squares regression (PLS-R) models showed that there is an excellent correlation between the antioxidant activity and the volatile profile when being compared to that of enzyme inhibitory activity. Thus, the studied Salvia essential oils are interesting candidates that could be used in drug discovery for the management of Alzheimer’s and hyperpigmentation conditions.     

Medicinal Applications of Metal Complexes Binding to Biological Macromolecules

Biological macromolecules present in living organisms, like proteins, DNA, have many metal-binding sites. As a consequence, coordination compounds can react with such cellular components, displaying possible toxic effects, or they also may have beneficial applications. So metal ions and compounds not only are essential for life in e.g. dioxygen transport, or biocatalysis, but they can also be used for controlled toxicity in medicinal applications. Well-known examples are the application of gold compounds in arthritis treatment, bismuth compounds for ulcer healing, and silver compounds for open skin protection. However, only in a few cases details of the mechanist are known, and if so, the biological macromolecules play a key role. Transition-metal coordination compounds that have metal-ligand exchange rates comparable to cell-division processes, i.e. in particular Pt and Ru, often appear to be highly active in killing cancers, as seen from the study of several cancer cell lines. Classical examples, like cisplatin, and new examples of Pt and Ru compounds will be discussed in some detail, with a focus on their binding to the DNA biomacromolecule. The classical compound cis-diamminedichloridoplatinum(II), often abbreviated as cisplatin, and its first-generation derivatives are known to bind to several biomacromolecules in a specific way, and eventually bind at DNA. Four important examples are shown in the figure. However, on its way to DNA other cellular components, like proteins and peptides might be intermediates before the final target is reached. Other metal-containing drugs, like Ru compounds, that show anti-cancer activity have a less well-known mode of action. Molecular-based mechanistic studies may result in improved clinical administration protocols.     

Macromolecules in ordered media. II. A fluorescence study of the polymer-liposome association

The interactions of poly (4-vinyl pyridine) with dimyristoylphosphatidic acid-based liposomes were studied in heterogeneous solution systems. The polymer was dispersed in aqueous buffer solutions of small unilamellar vesicles and after a suitable period of incubation to raise the equilibrium, the experiments has been conducted as a function of polymer concentration and temperature. According to the measurements of the steady-state fluorescence spectra, changes in the intensities as well as shifts in the emission peak wavelength, has served as raw data to accounting for the polymer-vesicle interactions. Quantitative evaluation of the interaction has been done using a simple associating model with some approximations. The key parameters evaluated were the amount of polymer bound and the number of charged lipids on a membrane site as well as the number of effective charges of poly (4-vinyl pyridine) chains at the liposome interface.     

无机小分子与细胞中生物大分子的相互作用

细胞是生命体的基本组成单元,是一个复杂的、能真实反映生物体系的活体.以细胞为研究对象,开展无机小分子与大分子相互作用的研究,有可能真正理解生命过程中一些问题的化学本质.无机小分子与细胞生物大分子相互作用的研究内容非常丰富,目前应着重研究那些对人类有严重威胁的一些疾病如糖尿病、心血管病、肿瘤、神经退行性病变等有关的细胞无机化学中无机小分子与生物大分子相互作用的问题.这对于了解生物大分子的结构、功能,对于疾病预防和治疗,了解小分子对生命过程的调控机制,对于药物作用新靶点的发现、药物的分子设计、作用机理和药物的研究与开发,均具有十分重要的科学意义和应用价值.论文还就开展无机小分子与细胞中生物大分子的相互作用研究的目标和内容提出了具体的建议.     

疏水膜色谱法对生物大分子的快速纯化

首次采用自制的分别级合了辛基、丁基、苯基及聚乙二醇-4000的4种常用疏水基团的纤维素疏水膜色谱柱,以键合了辛基、苯基的SepharoseCL－4B凝胶柱为对照,考察了疏水膜色谱柱对牛血清白蛋白（BSA）的动态吸附容量及流速对吸附容量的影响。疏水膜色谱柱对蛋白及酶具有较好的疏水吸附及纯化作用,但吸附容量比相应的琼脂糖凝胶柱低得多。增大流速及降低蛋白溶液质量浓度对疏水膜色谱柱的吸附容量影响较小,这些性能使膜色谱柱非常适合于大体积低质量浓度蛋白溶液（如基团工程培养液）的分离纯化。     

Chemical Paradigm vs. Biological Paradigm in the Biological Clock Controversy

Examples of biological rhythmicity mounted in the first half of the twentieth century, but the nature of biological rhythms – whether they were direct responses to rhythmic environmental stimuli or generated internally by biological clocks or oscillators – remained sharply disputed. When Frank A. Brown Jr. observed precise twenty-four-hour rhythms in the colour changes of fiddler crabs that were isolated from changes in environmental lighting that could synchronise them with the daily cycle, he rejected the internal clock as an explanation, owing to his belief that such a biological mechanism must operate chemically and consequently run faster at higher temperatures (Van’t Hoff’s rule), which was not borne out by his experiments. Colin Pittendrigh was committed to the idea that the rhythms were generated by unknown, temperature-compensated mechanisms, without offering any explanation for how this might be accomplished. At the core of their dispute, which was aired publicly from 1954 until Brown’s death in 1983, was a difference in belief: Brown’s fundamental reductionism, which required biological processes to conform to the laws of chemistry, vs. Pittendrigh’s trust in the power of evolution to select for such a temperature compensated biological clock, for which no plausible chemical model then existed.     

生物大分子分析研究领域的重大突破——2002年诺贝尔化学奖(质谱部分)简介

2002年10月9日,瑞典皇家科学院宣布,将2002年诺贝尔化学奖授予在生物大分子分析领域作出重大贡献的3位科学家.     

Iodination with Silver Sulfate and Iodine. II. Uridines

Iodination of uridines with iodine and silver sulfate at room temperature gives iodinated uridines in excellent yield.     

Chemical Composition and Biological Activity of Argentinian Propolis of Four Species of Stingless Bees

The chemical composition of propolis of four species of stingless bees (SLBs) from Argentina was determined, and its antibacterial and anticancer activity was evaluated on selected types of microbes and cancer cell lines. Volatile secretions of all propolis samples are formed by 174 C₂–C₁₅ organic compounds, mainly mono- and sesquiterpenes and their derivatives. The chromatograms of ether extracts showed 287 peaks, of which 210 were identified. The most representative groups in the extracts of various propolis samples were diterpenoids (mainly resin acids), triterpenoids and phenolic compounds: long-chain alkenyl phenols, resorcinols and salicylates. The composition of both volatile and extractive compounds turned out to be species-specific; however, in both cases, the pairwise similarity of the propolis of Scaptotrigona postica and Tetragonisca fiebrigi versus that of Tetragona clavipes and Melipona quadrifasciata quadrifasciata was observed, which indicated the similarity of the preferences of the respective species when choosing plant sources of resin. The composition of the studied extracts completely lacked flavonoids and phenolcarboxylic acids, which are usually associated with the biological activity and medicinal properties of propolis. However, tests on selected microbial species and cancer cell lines showed such activity. All propolis samples tested against Paenibacillus larvae, two species of Bacillus and E. coli showed biofilm inhibition unrelated to the inhibition of bacterial growth, leading to a decrease in their pathogenicity. Testing the anticancer activity of ether extracts using five types of cell cultures showed that all four types of propolis studied inhibit the growth of cancer cells in a dose- and time-dependent manner. Propolis harvested by T. clavipes demonstrated the highest cytotoxicity on all tested cell lines.     

纳米材料对生物凝聚态的调控

生物大分子的凝聚态及其动态变化过程涉及许多重要的生理及病理过程,如凝血现象与阿尔茨海默病。对上述生物凝聚态过程进行研究,发展对这些凝聚态过程的调控方法,进而发展相应的疾病诊断治疗新策略,具有非常重大的意义。纳米技术基于原子或分子组装可构建出新型的纳米功能器件或具有新颖生物效应的纳米材料,为解决生物医学领域的重大问题提供了强有力的研究手段。利用一系列的纳米材料可以发展对生物凝聚态的调控新方法,通过控制肿瘤血管凝血和制备纳米抗凝剂等实现对于凝血过程的调控,通过识别、结合、调控淀粉样蛋白及其聚集状态,实现阿尔茨海默病的诊断与治疗。对于生物凝聚态及其调控进行详细的研究,有望为开发新一代纳米药物提供新思路与新途径。     

Organized Monolayers of Biological Macromolecules on Au(111) Surfaces

Single-crystal electrochemistry and scanning tunneling microscopy directly in aqueous electrolyte solution (in situ STM) are established in physical electrochemistry but new in studies of adsorption and interfacial electrochemistry of biological macromolecules. These high-resolution techniques have now been applied comprehensively to proteins and other biomolecules in recent studies, discussed in this report. Focus is on three systems. The first one is a pair of amino acids, cysteine and cystine. These are strongly adsorbed via thiolate and disulfide, respectively, with identical reductive desorption and in situ STM patterns. Long-range lateral order can be imaged to molecular resolution. The amino acids are also reference molecules for the blue single-copper protein Pseudomonas aeruginosa azurin. This protein assembles in two well-defined orientations. One applies on bare Au(111) to which the protein is linked via its surface disulfide group. This orients the copper center away from the electrode surface. The other mode is by hydrophobic interactions with variable-length alkanethiols self-assembled on Au(111). In this mode the copper center is directed towards the surface. Adsorption and long-range electron tunneling in both modes have been characterized in detail using different electrochemical and spectroscopic techniques, as well as STM. Other data show that penta-(A–T) oligonucleotide adsorbed via a covalently bound thiol linker also displays reductive desorption and in situ STM to molecular resolution. The three systems thus appear to open new perspectives for broader use of high-resolution electrochemical techniques in comprehensive investigations of large biological molecules.     

分子印迹聚合物研究:从小分子到生物大分子

分子印迹技术是一项制备功能聚合物材料的方法,其对印迹分子的专一性选择识别能力引起了人们的广泛关注。随着方法的基本确立和技术的逐渐成熟,其应用领域和范围不断扩大。本文在总结以往研究结果的基础上,对迄今为止进展相对缓慢的生物大分子印迹研究予以了特别关注,对相关的水环境下的分子识别问题进行了仔细的讨论,认真的分析了生物大分子印迹研究工作的难点和不利因素,对分子印迹技术的未来发展和应用前景进行了展望。     

实验准备工作上的一些改进

在做实验准备时,不仅要考虑到实验效果,而且要考虑到实验准备的工作效率和自身的保护;诸如我们常会碰到的挥发性有毒液体药品的分瓶,一个实验滴加几种溶液时滴管的处理,以及制取甲烷原料的处理等等的问题。     

Synthesis of Some New Dihydropyrimidines by Iodine as a Catalyst at Ambient Temperature and Evaluation of Their Biological Activity

An improved method for the synthesis of some new dihydropyrimidines from aromatic aldehydes, 1,3‐dicarbonyl compounds, and thiourea with significant enhancement in reaction rates, short reaction time (4–6 h), good to excellent yields (70–93%), and ambient temperature using molecular iodine as catalyst is described. The biological evaluation revealed that the newly synthesized compounds 4a , 4b , 4c , 4d , 4e , 4f , 4g , 4h , 4i , 4j and 7a , 7b , 7c , 7d , 7e , 7f , 7g , 7h , 7i , 7j exhibited good antimicrobial activity and moderate antimycobacterial activity against Mycobacterium tuberculosis H₃₇RV.     

Chemical Kinetics Database and Predictive Schemes for Nonthermal Humid Air Plasma Chemistry. Part II. Neutral Species Reactions

Reliable kinetics data are necessary input for models describing the decomposition of gases in electric discharge or electron-beam devices. In this second part of a continuing series, we provide a core database describing the dominant reactions of neutral species in nonthermal low temperature (300–700K) pulsed plasmas containing humid air. Recommended rate constants and extrapolation methods are provided in a manner to facilitate prediction of reactivities as a function of temperature and pressure.