Conformational characterization procedure

Our protocol and the adiabatic mapping procedure described by Ha et al (8) have two features in common. They are both based on molecular mechanics approach, and they both start with several structures scattered at regular intervals over the (( ), j ) space. But the objectives of the approaches are fundamentally different. Whereas the adiabatic mapping procedure is intended to fully characterize the conformational energy surface of disaccharides, our... 

The absolute configuration of 41 at the stereogenic centers at C-2, C-7, C-8 and C-9 was determined following the same procedure as for compound 40. The tri-/>-bromobenzoate 41c, whose ten-membered ring conformation ( mmx = 67.34 kcal/mol) resembled those of 40, 41A, 40a and 41a showed a typical split CD and this established the chirality of the 7-OBrBz/8-OBrBz as being positive. Therefore, herbarumin II (41) was characterized as (2i , IS, 85, 9i )-2,7,8-trihydroxy-9-propyl-5-nonen-9-olide (41). 

In essence, we wish to follow the Gibbs entropy maximization procedure of Section 5.2 backward in time. Specifically, we seek to characterize the final stage of equilibration when effective local equilibrium has been achieved in each small cell n, but cell intensities are not yet equalized throughout the system. To make direct contact with Section 5.2, we shall temporarily revert to the entropy representation (Section 5.3), which generates a scalar product and metric geometry that is conformally equivalent to the (/-based metric... 

The computational investigation of 37-R and 37-S shows that, even if these molecules are characterized by steric constraints due to the spiro linkage of the two five-member rings, up to four slightly different conformers featuring similar energy were located by the MM/MD procedure. The comparison of the... 

Many different approaches to QSAR have been developed since Hansch s seminal work. As briefly discussed above, the major differences between these methods can be analyzed from two viewpoints (1) the types of structural parameters that are used to characterize molecular identities, starting from different representation of molecules, from simple chemical formulas to three-dimensional conformations and (2) the mathematical procedure that is employed to obtain the quantitative relationship between these structural parameters and biological activity. 

Work on the isolation and characterization of the membrane-bound FeS-A/B protein was renewed more than twenty years later by Oh-oka, Takahashi, Kuriyama, Saeki and Matsubara using n-butanol in the isolation procedure and by Wynn and Malkin using acetone. Both groups found partially degraded FeS-clusters, as indicated by the FeS composition, Oh-oka et al finding 4.1Fe -i- 3.2S and Wynn and Malkin 7.9 Fe -i- 6.4 S. Eater, Oh-oka et al used acetone for protein isolation and carried out extended spectroscopic measurements. It was found that only when strictly anaerobic conditions were maintained during the isolation and purification process could the native protein be isolated with intact [4Fe 4S] clusters, conforming strictly to the (8Fe-i-8S) stoichiometry ... 

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