Aims of Study

With the aim of studying the formation of the 2.5-helix in water as well as to introduce side chain diversity, Gellman and his group synthesized / -peptides from a variety of / -amino acid building blocks (34-39) constrained with five-membered rings (Fig. 2.21). 

Ridd and Yoshida explored the At-nitration of aromatic nitroanilines with nitronium hex-afluorophosphate in nitromethane with the aim of studying the Bamberger rearrangement (Chapter 4, Section 4.5). In was found that amines of low basicity essentially undergo complete A -substitution if the amine is in excess 2,4-dinitroaniline and 2,3-dinitroaniline form A, 2,4-trinitroaniline and At,2,3-trinitroaniline, respectively, as the sole products. More basic nitroanilines give mixtures of C-substituted, At-substituted and poly-substimted materials. The use of nitronium salts for At-nitration has been extensively reviewed. ... 

With the aim of studying the glycosphingolipid metabolism, thiolactosylcera-mide (39c) (Scheme 12) was obtained. The corresponding free disaccharide has been shown to be totally resistant to the action of a mixture of GMi- -galacto-sidase and glucocerebrosidase [38]. 

The Photochemical Activity and solar Ultraviolet Radiation (PAUR I) and Photochemical Activity and solar Ultraviolet Radiation Modulation Factors (PAUR II) projects had the aim of studying various aspects of ultraviolet radiation and photochemistry interrelationships. PAUR I aimed at studying the interrelationships between total ozone, UV-B radiation, aerosol load, air pollutants, photodissociation rates of N02 and 03 and tropospheric ozone. PAUR II has the aim of studying the interactions between UV-B, total ozone, tropospheric ozone and photochemical activity in the presence of alternating maritime and Saharan aerosols. The present paper presents the main concepts underlying the two projects, the approach followed and a brief overview of some of the results obtained so far. Further, the main results of PAUR I that are relevant to tropospheric ozone chemistry over the Eastern Mediterranean are presented. 

Complexes of type 38 have been realized with several metal centres. Representative examples are collected in Figure 5. Most of these complexes have been synthesized with the aim of studying the interaction between the two metal centres since the silicon retains these centres in close proximity. Limited rotational freedom in this class of compounds leads to preferred conformations in the solid and presumably also in solution. As portrayed in Figure 6, three conformations are possible exolexo, exolendo and endo/endo. 

The aims of studies on the first three groups have been broadly similar - principally elucidation of the origins of metal ion selectivity and investigation of the conformational variability. All of the studies were reasonably successful in reproducing observed structures or in rationalizing the differences predicted on the basis of gas phase calculations and those determined in the solid state or solution. 

One of the aims of studies involving solid components is to reduce the rate of back-reaction. The charge-recombination reaction expected in the absence of a solution-based redox couple is shown as follows ... 

Presently, some information is available on the structure of the active site of PAL and its mechanism of action. This knowledge was advanced with an aim of studies on PAL mutants obtained by site-directed mutagenesis, 100-102 comparison of its structure with the recently determined three-dimensional structure of histidine ammonia-lyase io3,i°4 as wejj as (fog detailed analysis of structure-activity relationship found for its inhibitors.105-108 Despite a recent knowledge of PAL three-dimensional structure, 109 110 the detailed mechanism of this particular enzyme action remains unresolved. 

DNA biosensors are also of great interest for the future development of microelectronic sensors for the detection of biological compounds and antigens. DNA would act as a promoter between the electrode and the biological molecule under study. Recently, some electrochemical research has been done in this direction with the aim of studying the interaction of DNA immobilized on the electrode surface with substances in solution. 

Bluish green photoluminescence in solution is displayed by bismole polymer 27 <2006PSA4857>. This compound has been prepared with the aim of studying the contribution of the bismuth atom to the conjugated main chain, but mainly for application as an X-ray contrast material <2006PSA4857>. 

In this research the kinetic resolution of 1-phenylethanol catalyzed by commercially available immobilized lipase from CALB was assayed in non-aqueous conditions in SC-CO2 and IL/SC-CO2 systems with the aim of studying the enan-tioselectivity of Novozym 435. The influence of different reaction parameters, such as pressure, the acyl donor/alcohol molar ratio and different ILs, on the enantio-merically pure compound (R)-l-phenylethyl acetate formation via kinetic resolution of 1-phenylethanol was investigated. 

These ions show close similarity with the corresponding parent ones both experimentally and theoretically. With the aim of studying rearrangements of the methylcyclopentyl cation type Saunders and Rosenfeld (1970) prepared a cation [113] from 1-methylcyclobutyl chloride in SbFj-... 

With the aim of studying a geometrically well-defined cyclopropylcarbinyl cation Baldwin and Foglesong (1968a) prepared the 8,9-dehydro-2-adamantyl 3,5-dinitrobenzoates [125 X = H, D or T]. The solvolysis of [125] in 60% aqueous acetone proceeded with considerable rate enhancement in comparison with 2-adamantyl tosylate. Scrambling of the label to the 8 and 9 positions in the solvolysis of [125 X = D] and [125 X = T] revealed a degenerate rearrangement (90) of the intermediate 8,9-dehydro-2-adamantyl cation [126]. 

The transfer of the information described in the preceding sections of this chapter to the in vivo situation is a matter where opinions are sharply divided, even if more than 20 years have elapsed since the discovery by Vasington and Murphy [4]. One key problem, naturally, is the impossibility of reproducing the composition and the conditions of the cytosol in in vitro experiments. The above mentioned effect of Mg on the rate of Ca influx into mitochondria is but one striking example of the difficulties inherent to the extrapolation to the in situ conditions. Of interest in this respect are recent experiments [124,125] in which methods have been devised to estimate simultaneously the membrane potential across the plasma membrane and the mitochondria of nerve endings in situ. The conclusion of this work has been that the concentration of free Ca in the cytosol correlates directly to the membrane potential across the mitochondrial membrane, and is maintained at a steady-state level below 1 jaM. Simulation of the in situ conditions has also been the aim of studies [126] in which isolated liver endoplasmic reticulum has been added to media in which isolated liver mitochondria were made to take up Ca, or in which liver cells have been treated with digitonin to abolish the permeability barrier of the plasma membrane. It was found that respiring mitochondria lower the external Ca " concentration to about 0.5 /iM. The addition of endoplasmic reticulum vesicles produces a further decrease of the external Ca " to about 0.2 jaM. Thus, mitochondria... 

These detailed studies of the interactions and structure of mixtures of ionic liquids with aromatic organic compounds have not been yet extended to other families of molecular solutes. In the case of mixtures of ionic liquids with water or acetonitrile, although different experimental data were published with the aim of studying the limit of the low concentration of ionic liquid [48, 49], or the effect on the solubility of a third molecular species [50], no complete picture of the structure of the ionic liquid as a function of concentration has been established (Fig. 12). 

Thus far, different model substances have been used in the open sea to simulate biogenic sea slicks with the aim of studying their influence on various remote sensing signals (Alpers and Hiihnerfuss 1989, Hiihnerfuss 1986, Hiihnerfuss and Garrett 1981, Hiihnerfuss et al. 1982, 1984, 1987). The choice of these chemicals was largely based on their physico-chemical... 

The 1H chemical shifts of the side-chain protons of these compounds are listed in Tables 2-4. The data are taken from the review by Foris,5 which covers NMR data on azo dyestuffs published before 1977 newer papers are collected in the article by Fedorov.6 Fedorov et al recently published an extensive set of 1H NMR data on compounds 3-40 in DMSO-rf6 with the aim of studying the electronic effects of substituents, rotational isomerism and hydrogen bonding. The values in Table 5 are typical of azo dyes and are complementary to those of side-chain protons (Tables 2-4). 

With the aim of studying their structure-antibacterial activity relationships, a series of new 7-substituted 6-fluoro-4-oxo-l,4-dihydro-l,8-naphthyridine-3-carboxylic acids... 

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