化學

本實驗在探討，當金奈米粒子和植物中的葉綠素產生鍵結作用力時，能量轉移的結果是否能幫助葉綠素激發電子。經由兩者混合後光譜的變化,發現兩者之間發生能量轉移。為探討此轉移現象和濃度的關係，我們將大小不同的金奈米和不同毫升數的葉綠素作用，並將其結果和金奈米與葉綠素的吸收強度和作比較，使用正規化的計算方法算出比值，由此看出兩者之間能量轉移的效率。當金顆粒約大於30nm時，正規化的數值隨的葉綠素濃度的增加而變大；而當金奈米顆粒約小於30nm時，則隨著葉綠素的增加而變小。Much attention is currently focused on chromophoric molecules because they can not only mimic natural antenna systems but also exhibit unique optical and physical properties. Chlorophyll , produced by extracting from green leaves, has electrostatic interactions with Au nanoparticles through carboxyl groups. Herein, we report the charge transfer between chlorophyll and Au nanoparticles using UV-vis electronic absorption spectroscopy. The efficiency of charge transfer from chlorophyll to Au nanoparticles was estimated by the normalization of Q-ban absorption intensity. From the observation of absorption intensity versus concentration of chlorophyll curves, we find that the efficiency of charge transfer is increased while the size of Au-particle is larger than 30nm, but decreased while the size smaller than 30nm.

Phosphodiestarase of subtype PDE IVb inhibitors are considered as perspective drugs for the treatment of the central nervous system disorders (depression, Alzheimer’s disease, Parkinson’s disease). Pyrrolizidinone Glaxo-1, proposed by GlaxoSmithKline, is a highly potent PDE IVb inhibitor (IC50 = 63 nM), then conventional phosphodiesterase inhibitors Ro-20-1724, Rolipram and Cilomilast. However the activity of the Glaxo-1 was studied on a racemic sample, since the asymmetric approach to its synthesis has not been developed. Therefore the purpose of this research was the development of an efficient synthetic scheme enabling enantioselective excess to both (-)- and (+)-Glaxo-1, which can be than subjected to biological studies. \r The key stage in proposed asymmetric synthesis (-)- and (+)-Glaxo-1 is stereoselective [4+2]-cycloaddition of the nitroolefin to an optically activity vinyl ethers, derived from (-)- or (+)-trans-2-phenylcyclohexanols. The resulting chiral cyclic nitronates are transformed into a functionalized cyclic oxime ethers using tandem sylilation-nucleophilic substitution procedure. Reduction and decarboxylation of these products lead to optically pure Glaxo-1 and the regeneration of chiral 2-phenylcyclohexanols (91%). \r Thus both enantiomers (+) and (-)-Glaxo-1 were obtained selectively in average yield 12% from isovaniline and nitroethane. The study of biological profiles of each enantiomer of Glaxo-1 will be conducted in near future.

本實驗以薄膜色層層析（TLC）、高效能液相層析（HPLC）分析等化學方法，進行金銀花品種差異的鑑識；此外，配合生藥學的顯微鏡檢視，如中藥材組織鏡檢、藥材粉末鏡檢等比對，以期找出辨別金銀花品種的方法。研究至目前為止，由金銀花之薄膜色層分析的Rf值（0.225、0.425、0.7、0.85、0.95）可確認出金銀花藥材，並得知金銀花藥材中皆含有綠原酸的成分；以高效能液相層析的圖譜與成分峰的積分面積可用來判別金銀花的品種，並從質譜分析瞭解成分含量；進行生藥學的藥材粉末組織鏡檢，發現無法作為金銀花藥材的分類憑藉。未來將持續延伸實驗，朝向中藥奈米化與一般粉末在藥效、成分上差異的比較，並進行金銀花萃取液的抗菌作用試驗，瞭解不同品種之金銀花藥材在藥理作用的異同，接續著奈米化藥材的應用與實踐。Using thin layer chromatograph (TLC) and high performance liquid chromatography (HPLC), we can study how to differentiate the species variation of honeysuckle; beside, based on the observation of biopharmaceutical microscope, such as comparing the histology of Chinese herbs and its powder, we suggest that we could differentiate the species of honeysuckle. From the present, firstly, we could distinguish the honeysuckle from other herbs by the Rf value of TLC(0.225, 0.425, 0.7, 0.85, 0.95), from which we find that all honeysuckles contain the component of Chlorogenic acid. Secondly, we could tell the species of honeysuckle according to the map of HPLC and the peak area after integration, as well as the integrants of honeysuckle by way of LC-Mass analysis. Thirdly, while studying the histological analysis based on the observation of biopharmaceutical microscope, we found that it shows no difference between all the honeysuckles; thus, it fails to be a scientific method used to distinguish the herb honeysuckle. However, in the biochemical experiments of honeysuckles, we found honeysuckles from different sources and the place of origin shows difference in their antibiotic effect, showing the importance of local medicine. When it comes to my future work, in order to extend my experiments on honeysuckles, I would compare the nano-scale honeysuckle powder with normal-sized one in their clinical effects and components.

This chemistry project was designed to measure the vitamin C levels within liquid cold and flu remedies, and see if they had been accurately stated on the package. A range of Cold and flu drinks was selected, including one made with only cold water (Lemsip Original, Lemsip Max, Effer-C-Cold Water, Relief and Lemting) .The procedure used to carry out the experiment was a redox titration, each trial required two titrations, with the first being a blank titration to determine a sodium thiosulfate concentration in the absence of vitamin C. The following Drinks had more Vitamin C than stated on the packaging – Lemsip Original (19.4%), Lemsip Max (22.1%), Effer-C (17%) and Relief (8.8%). Lemting was the only drink made to directions that had less Vitamin C than stated by 31.8%. Two conclusions can be drawn from these results, the first being that Lemting has the most inaccurately recorded mass of vitamin C and is also the only drink with less vitamin C than stated. The other interesting result is that Effer-C (the only drink made with cold water) had 170mg of extra vitamin C. Of the other drinks that had more vitamin C, Lemsip Max was next with an extra 22.8mg. Early research had showed that Vitamin C was affected by high temperatures (above approximately 70oC) and, as cold and flu drinks are commonly made with hot water the Vitamin C levels might change when they were made up. This poses a further possible research question which is, in making cold and flu remedies with hot water is some of the available Vitamin C being destroyed?

鹼性電池使用的電解液均為強鹼，電池中的鋅極會與其發生腐蝕反應，使得電池放電壽命降低，並產生氫氣，而大量氫氣使得電池有爆裂的危險，為了改善上述問題，我們自行設計了氣體觀測儀器，用來檢測銀鋅電池充放電與靜置時之氣體產生量，更藉由探討影響變因的過程找出銀鋅電池較合適之使用條件，其中包含電解液種類及濃度之選擇、電極面積與充電電流對使用效果之影響，並改善電池腐蝕程度；我們將鋅極以浸鍍處理(Sn:Pb ＝1:1 )並搭配電解液添加物(KOH:Zn(OH)42 －＝ 2:1) 可效率地抑制氣體產生；更用氯化銀粉末取代傳統氧化銀極片為正極，發現氯化銀可代替氧化銀電極，且有不錯的放電效果。;As we know, the electrolyte solution used in an alkalinebattery is a concentrated alkaline solution, which corrodes the zinc electrode in a battery of this kind. The corrosive reaction not only reduces the lifespan of the battery but also produces hydrogen, causing the battery to explode. This study is intended to help us design a device to measure the quantity of hydrogen gas generated in the charging of a zinc-silver battery. We have studied several factors affecting zinc-silver battery, including the variety of electrolyte, the concentration of alkaline solution, the surface of electrode, and the density of charging current, etc. To reduce the corrosion of zinc electrode, we plate the zinc electrode by the immersion electroless plating method, using several kinds of low-polluting anti-corrosive additives (metallic compounds such as lead and tin). We also add zincate ion into electrolyte solution to further reduce the quantity of hydrogen produced. The experiments show a zinc-silver alkaline battery works most efficiently, if the powder of silver chloride is used instead of silver oxide.

近年來重金屬污染問題日益嚴重，因此檢測地下水、工業廢水中的重金屬含量為一重要課題。本實驗即是利用錄音機中的零件－石英振盪器作為電化學分析偵測的工作電極，在0.1 M KNO3（pH = 3）溶液中利用循環伏安法以50 mV/s 的掃描速度從 – 100 到 – 700 mV 持續掃描 10 圈，來穩定電極表面。 以方波陽極剝除伏安法（SWASV）模式設定預濃縮電位– 700 mV、預濃縮時間60 秒偵測重金屬的鉛離子。掃描電位範圍由 – 700 到 – 100 mV vs. Ag/AgCl 往氧化方向掃描。偵測鉛離子濃度範圍為200－600 ppb，之後可針對各種條件作最佳化的條件探討可降低偵測濃度及實際運用於地下水及工業廢水的檢測。 Heavy metal pollution becomes very serious. Lead (Pb) determination is a continuous research interest in clinical, environmental, and industrial application. The main causes for living biological media are mutagenic, carcinogenic, and teratogenic activity. The determination of trace metal in the ground and industrial waste water will be a important project. Here, we report a simple system which using quartz crystal microbalance (QCM) (use in radio machine) for working electrode. The QCM was first equilibrated in 0.1 M KNO3（pH = 3）base electrolyte for about 1 min before electrochemical experiments. It was then pretreated by continuous scans in the window from – 100 to – 700 mV at a scan rate of 50 mV/s until a stable background current obtained. The amount of Pb2+ was detected quantitatively using square-wave anodic stripping voltammetry（SWASV）. The potential range was set from – 100 to – 700 mV in the cathodic direction for most cases. The standard addition method concentration range is from 200 to 600 ppb. Analytical conditions were systematically optimized and extended to practical applications aslo.

The purpose of this project was to create a detection device for alcoholic drunk condition in human by using the principle of vapor pressure difference between breath samplings from normal and alcoholic-drunk men. The work comprises of three major steps. The first task was an experiment to determine an average air volume that can be fully blown out from the lungs of non-drunk people as a control. Twenty adult Thai volunteers weighing between 50 - 80 kg (average 59 kg) were used. The average blown out air volume was found to be 369.9 mL, with the range in values from 340-400 mL (sample size N = 20, SD = 15.47). The second task was an experiment to measure relationship between the blown air volume (100-700 mL, both from alcoholic-drunk and control groups of people) and the resulted vapor pressure by using manometer. The vapor pressure of normal breath increased from 400 to 1,600 newton/m2 with increasing blown air volume, whereas that of the alcoholic-drunk was found to be 600 to 1,800 newton/m2. The last task was to create a detection device prototype to gauge the alcoholic content in the human body from the breath. Air volume of 300 mL was arbitrary chosen to trigger lighting up of indicator lamps. The breath samples of low vapor pressure (low amount of alcohol, 21.12-44.00 mL, equivalent to 14.00-29.17 mg%) would trigger a green lamp to light up. A moderate vapor pressure range (medium amount of alcohol, 88-132 mL, equivalent to 58.33-87.57 mg%) would trigger green and yellow lamps to light up while a high vapor pressure (high amount of alcohol, 250 mL, equivalent to 165.72 mg%) would trigger green, yellow and red lamps to all light up. None of the three lamps would light up from (non-alcoholic) breath of control people. This device has also been tested to external group of volunteers. The work in this project has successfully demonstrated a useful application of simple principle in chemistry on partial vapor pressure.

In the last two decades, there has been increased interest in the utility of quantum scale semiconductors. These fluorescent single crystals can be as small as 1 nm in diameter, and their size and shape has been shown to be controlled by the duration, temperature, and ligand molecules used in their synthesis. Quantum dots, provide clear benefits over the organic dyes currently used for tracking biological processes. Yet, as the production of quantum dots is often very costly, the search continues for finding an industry-ready synthesis for a quantum scale semiconductor which would have high yield, optimal durability, high luminescence, and a broad absorbance range. Silicon, in particular, has been of great interest as it is the second most abundant element on the Earth’s crust and is generally a bioinert and electrochemically stable element. We report the synthesis of water-soluble, luminescent silicon nanoparticles with potential applications to bioimaging. Through a solution state top-down approach, the synthesis of hydrogen capped silicon nanoparticles was achieved in various organic solvents. The surface of the nanoparticles was capped with the functional organic molecules rendering the Si-QDs both air and water stable. Cell studies performed with our silicon nanoparticles and human monocytes show the direct applications these particles could have for tracking biological processes and the progression of cancer in the human body. In attempt to shift the luminescence of these particles, alterations of experimental methodology was also explored in the areas of reaction solvent and heating time. Through these changes, shape control of silicon nanoparticles was achieved in the form of silicon nanorods. The synthesis of this new shape of silicon at the quantum scale was confirmed by ultraviolet spectroscopy, photoluminescence, and transmission electron microscopy. The results of this study indicate that the use of silicon nanocrystals for biomedical applications is feasible.

Nano-sized calcium phosphate was used in the synthesis of starch-based composite plastics to provide a cheap but sturdier biodegradable alternative to petroleum derived plastics used in film packaging. Nano-sized calcium phosphates were produced from the precipitation reaction of calcium nitrate tetrahydrate (Ca(NO3)2 ‧ 4H2O) and phosphoric acid (H3PO4). The nanoparticles were co-extruded and molded with thermoplastic starch (TPS) at ratios of 0%, 1%, and 5% by mass. Tensile strength and elongation percentage of the resultant composite plastics were tested in three replicates. The results show that there is a significant difference between the tensile strengths of the 0% and 5% calcium phosphate composites at a 5% level of significance. The trend between the composite’s tensile strength and percentage calcium phosphate follows a geometric progression, enabling a projection for the 10% nano-calcium phosphate to have a tensile strength of 10 MPa, the average tensile strength for low-density polyethylene (LDPE). This shows that it is feasible to synthesize a 10% nano-calcium phosphate-TPS plastic that can be a viable substitute for LDPE plastics in film packaging, paving the way for the commercialization of starch-based plastics. The use of biodegradable plastics with improved physical characteristics will lessen consumer dependence on petroleum derived plastics and solve the environmental issues brought about by the use of such plastics.

Smoothened (SMO) is a critical component of Hedgehog (HH) pathway that is essential for stem cell renewal and is dysregulated in many cancer types. SMO is a seven transmembrane domain protein with three intracellular loops. Primary structures of SMO intracellular loops are unique and very much conserved among the species, which is indicative of significant and unique roles in intermolecular or intramolecular interactions. The hypothesis was that synthetic analogs of SMO intracellular loops may function as HH pathway inhibitors. Derivatives of second intracellular loop were synthesized utilizing automated solid phase peptide synthesis based on Fmoc chemistry. Peptides were purified by HPLC and there anti-proliferative activity tested on melanoma cells by MTT assay. Targeted libraries of second loop derivatives of varying length helped to identify compounds that inhibited the growth of melanoma cells in vitro with IC50 in nanomolar range. The most potent of antagonists obtained is the palmitoyl derivative of the Nterminal half of the loop, and is 12 residues long. Lipidation proved to be critical for the activity. Remarkably, retro-inverso versions of the peptide, in which all amino acids are in D-configuration, are even more potent and have IC50 in subnanomolar range. Circular dichroism studies proved that the peptides are folded both in aqueous solutions and in the presence of lipids mimicking the membrane environment. They also suggested that retroinverso analogs have a different fold, which may contribute to higher activity. The new compounds are promising drug candidates and present convenient tools for solving the\r mechanisms of hedgehog signaling.