Interconversion Pathways

The mimicking of the iron-sulfur clusters by synthetic chemistry has been quite successful over the years. One of the last synthetic clusters to be obtained was the [3Fe-4S] cluster (109, 110). This new synthetic compound was useful for the demonstration of interconversion pathways, as well as for the formation of different heterometal clusters beyond those produced in proteins (111). The [3Fe-4S] core... 

FIGURE 4.3.3 Interconversion pathways of various forms of anthocyanins in acidic aqueous medium. 

Malloy, T. B., Jr., Conformational Barriers and Interconversion Pathways in some Small-Ring Molecules, 11, 97. 

For bicyclic and polycychc systems, fewer conformations and interconversion pathways need to be considered than is the usual case for monocyclic systems. For example, placing a CHj bridge on a... 

Barriers, Conformational, and Interconversion Pathways in Some Small... 

In summary, failure to detect a rigidly achiral presentation does not mean that such a presentation cannot be found among the infinitely many presentations of a knot failure to interconvert enantiomorphous presentations by ambient isotopy does not exclude the possibility that an interconversion pathway can be found among the infinitely many pathways that are available and a palindromic knot polynomial does not necessarily mean that the knot is amphicheiral. Consequently, it may be impossible in certain cases to determine with complete certainty whether a knot is topologically chiral or not. The fundamental task of the theory of knots was stated over a hundred years ago by its foremost pioneer Given the number of its double points, to find all the essentially different forms which a closed curve can assume. 15 Yet to find invariants that will definitively determine whether or not a knot is chiral remains an unsolved problem to this day.63a Vassiliev invariants have been conjectured to be such perfect invariants.63b... 

B. Ion-Molecule Reactions of R3 xSiHx+ as Probes of Ion Structures and Interconversion Pathways... 

When several sp3-hydridized substituents are attached to a planar framework, their mutual interactions lead to conformational states and interconversion pathways that complicate the simple pictures given in... 

TABLE 8 Classification of Some of the Different Interconversion Pathway Possibilities That Can Influence the Retention Behavior of Polypeptides or Proteins in Adsorption HPLC... 

Reiter, W. D. and Vanzin, G. F., Molecular genetics of nucleotide sugar interconversion pathways in plants. Plant Mol Biol 2001, 47 (1-2), 95-113. 

As mentioned above, polymorphism may also arise for compounds formed by isomers whose structures are related by low-energy interconversion pathways, e.g. cluster carbonyls with different distributions of bridging and terminal ligands, or substituted metallo-arenes and metallo-cyclopentadienyl complexes [60]. In such cases, the structural isomers correspond to different energetic minima along the interconversion pathway and the cohesion of the respective crystals may stabilize the less thermodynamically stable isomers. Crystals of structural isomers may (or may not) interconvert via a phase transition. 

The pentoses, such as xylose (Xyl), that result from the hydrolysis of lignocel-lulose (see above) resist fermentation by Saccharomyces, because it lacks an efficient mechanism to convert Xyl into xylulose (Xlu). The isomerization redox interconversion pathway of Xyl and Xlu, via xylitol, that is native to Saccharomyces, is inefficient due to a cofactor incompatibility (see Fig. 8.5) and results in a redox imbalance and the accumulation of xylitol [24]. Many bacteria, in contrast,... 

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