Imidazolium-Based Organic Structure Directing Agents for the Synthesis of Microporous Materials

The central theme of this thesis is the use of imidazolium-based organic structure directing agents (OSDAs) in microporous materials synthesis. Imidazoliums are advantageous OSDAs as they are relatively inexpensive and simple to prepare, show robust stability under microporous material synthesis conditions, have led to a wide range of products, and have many permutations in structure that can be explored. The work I present involves the use of mono-, di-, and triquaternary imidazolium-based OSDAs in a wide variety of microporous material syntheses. Much of this work was motivated by successful computational predictions (Chapter 2) that led me to continue to explore these types of OSDAs. Some of the important discoveries with these OSDAs include the following: 1) Experimental evaluation and confirmation of a computational method that predicted a new OSDA for pure-silica STW, a desired framework containing helical pores that was previously very difficult to synthesize. 2) Discovery of a number of new imidazolium OSDAs to synthesize zeolite RTH, a zeolite desired for both the methanol-to-olefins reaction as well as NOX reduction in exhaust gases. This discovery enables the use of RTH for many additional investigations as the previous OSDA used to make this framework was difficult to synthesize, such that no large scale preparations would be practical. 3) The synthesis of pure-silica RTH by topotactic condensation from a layered precursor (denoted CIT-10), that can also be pillared to make a new framework material with an expanded pore system, denoted CIT-11, that can be calcined to form a new microporous material, denoted CIT-12. CIT-10 is also interesting since it is the first layered material to contain 8 membered rings through the layers, making it potentially useful in separations if delamination methods can be developed. 4) The synthesis of a new microporous material, denoted CIT-7 (framework code CSV) that contains a 2-dimensional system of 8 and 10 membered rings with a large cage at channel intersections. This material is especially important since it can be synthesized as a pure-silica framework under low-water, fluoride-mediated synthesis conditions, and as an aluminosilicate material under hydroxide mediated conditions. 5) The synthesis of high-silica heulandite (HEU) by topotactic condensation as well as direct synthesis, demonstrating new, more hydrothermally stable compositions of a previously known framework. 6) The synthesis of germanosilicate and aluminophosphate LTA using a triquaternary OSDA. All of these materials show the diverse range of products that can be formed from OSDAs that can be prepared by straightforward syntheses and have made many of these materials accessible for the first time under facile zeolite synthesis conditions.

Perinatal hipoxic ischemic injury in the auditory pathway and the effect of several neuroprotective agents

192 p.

Pathogenicity of Aeromonas sobria to Thai silver barb (Barbodes gonionotus Bleeker) and its sensitivity to some antibiotic agents

Five isolates of Aeromonas sobria, collected from the diseased fish were selected for detection the pathogenicity following water-born infection method on silver barbs (Barbodes gonionotus) at the selected exposure dose 2.5x10⁸ CFU/ml which was standardized by preliminary test. In the experimental condition lesion and mortality were found in fishes. Among the isolate, Ass17 Ass19, Ass31 and Ass36 were successfully infected 20-60% fishes. Another isolate Ass20 was found non-pathogenic. Drug sensitivity test was performed by six antibiotics viz. Oxytetracycline, Oxolinic acid, Chloramphenicol, Stilphamethozazole, Streptomycin, Erythromycin. All the isolates showed variable reaction patterns to antibiotics. Most of the isolates were found sensitive to Oxytetracycline (OT), Oxolinic acid (OA) and Chloramphenicol (C) but resistance to Erythromycin and Sulphamethoxazole (SXT). Isolate Ass31 found resistant to Oxolinic acid.

Studies on phenolase enzyme in prawns. II. The inhibitory action on the enzyme by certain chemical agents

The effect of certain chemical agents on dopa oxidation by phenolases has been examined. Sulphur containing amino carboxylic acids are inhibitory agents for dopa oxidation. Tyrosine, a substrate for the enzyme also acts as an inhibitor for dopa oxidation by the enzyme. The possible mode of action has been discussed. The function of diethyl dithiocarbamate in suppressing the display of enzyme activity has been detailed and its behaviour has been compared to the other chemical agents studied.

Effects of 2-phenoxy ethanol and MS-222 on milkfish fingerlings (Chanos chanos) as anaesthetic agents

An experiment was undertaken in order to determine an adequate anaesthetic and optimum concentrations for use in the handling of fingerling milkfish (Chanos chanos). The compounds 2-phenoxy ethanol and MS-222 were investigated. Results show the latter to be adequate with optimum concentrations between 100 and 200 ppm.

Synthesis of analogues of flazin, in particular, flazinamide, as promising Anti-HIV agents

Flazin isolated from the fruiting bodies of Suillus granulatus was found to possess weak anti-HIV activity (EC50=2.36 mu m, TI= 12.1). To establish a SAR study, 46 flazin analogues were synthesized, and their anti-HIV activities were evaluated in vitro. A

A comparative study on the induced breeding and in vitro fertilization performance by various inducing agents in catfish, Heteropneustes fossilis (Bloch)

Brood catfish, Heteropneustes fossilis were collected from Tamirabarani river basin of Tamil Nadu, India and kept in cement tanks. Three inducing hormones viz, Ovaprim, Ovatide and WOVA-FH were injected at the rate of 0.5, 1.0, 1.5 and 2.0 ml/kg body weight in order to induce oocyte maturation and ovulation. After 10-13h of injection at a water temperature of 27±-0.5°C, stripping of eggs and in vitro fertilization was done. Ovaprim gave maximum (94.67%) hatching rate followed by Ovatide (90.33%) and WOVA-FH (77.33%).

Anti Human Immunodeficiency Virus-1 (HIV-1) Agents 3. Synthesis and in Vitro Anti-HIV-1 Activity of Some N-Arylsulfonylindoles

In order to find compounds with superior anti human immunodeficiency virus type 1 (HIV-1) activity, twelve simple N-arylsulfonylindoles (3a-1) were synthesized and preliminarily evaluated as HIV-1 inhibitors in vitro for the first time. Several compounds

Anti HIV-1 Agents 2. Discovery of Dibenzofurans as New HIV-1 Inhibitors In Vitro

Ten dibenzofurans were synthesized and evaluated as human immunodeficiency virus (HIV)-1 inhibitors in vitro for the first time. Among these compounds, compounds 1, 6, 7 and 8 demonstrated significant anti-HIV-1 activity. Especially compound 1 showed the

Anti Human Immunodeficiency Virus-1 (HIV-1) Agents 1. Discovery of Benzyl Phenyl Ethers as New HIV-1 Inhibitors in Vitro

Ten single benzyl phenyl ethers were synthesized and evaluated as human immunodeficiency virus-1 (HIV-1) inhibitors in vitro for the first time. Among these compounds, especially 4-nitrobenzyl phenyl ether (3h) exhibited the highest anti-HIV-1 activity wi

Anti Human Immunodeficiency Virus Type 1 (HIV-1) Agents 4. Discovery of 5,5 '-(p-Phenylenebisazo)-8-hydroxyquinoline Sulfonates as New HIV-1 Inhibitors in Vitro

To search for compounds with superior anti-human immunodeficiency virus type 1 (HIV-1) activity, ten 5,5'-(p-phenylenebisazo)-8-hydroxyquinoline sulfonates (4a-j) were synthesized and preliminarily evaluated as HIV-1 inhibitors in vitro for the first time. Some compounds demonstrated anti-HIV-1 activity, especially 5,5'-(p-phenylenebisazo)-8-hydroxyquinoline p-ethylbenzenesulfonate (4g) and 5,5'-(p-phenylenebisazo)-8-hydroxyquinoline p-chlorobenzenesulfonate (41) showed the more potent anti-HIV-1 activity with 50% effective concentration (EC50) values of 2.59 and 4.01 mu g/ml, and therapeutic index (TI) values of 31.77 and 24.51, respectively.

Anti HIV-1 agents 5: Synthesis and anti-HIV-1 activity of some N-arylsulfonyl-3-acetylindoles in vitro

In continuation of our program aimed at the discovery and development of compounds with superior anti-human immunodeficiency virus type 1 (HIV-1) activity, 21N-arylsulfonyl-3-acetylindole analogs (2a-u) were synthesized and preliminarily evaluated as HIV-1 inhibitors in vitro. Among of all the analogs, several compounds exhibited significant anti-HIV-1 activity, especially N-phenylsulfonyl-3-acetyl-6-methylindole (2j) and N-(p-ethyl)phenylsulfonyl-3-acetyl-6-methylindole (2n) showed the most potent anti-HIV-1 activity with EC50 values of 0.36 and 0.13 mu g/mL, and TI values of >555.55 and 791.85, respectively. It demonstrated that introduction of the acetyl group at the 3-position of N-arylsulfonyl-6-methylindoles could generally lead to the more potent analogs. (C) 2010 Elsevier Ltd. All rights reserved.