Structural information variations

If structural information of the protein target is available, e.g., a crystal structure, in silico screening of huge virtual compound libraries can be conducted by the use of docking simulations. Based on identified primary hits, structural variations of the ligand can be evaluated by computational modeling of the ligand-protein complex. 

In this review, structural information on sulfoxides and sulfones is presented with emphasis on recent results and on structural variations. It is our intention that the discussion reflect the characteristic patterns of this area rather than provide an encyclopedic coverage. However, for the simplest, most fundamental, substances we are aiming at complete coverage as well. 

While under negative CID conditions, no structural information could be obtained by CID from NPE0-S04 compounds on a MS-MS instrument despite the variation of CID parameters, although the behaviour of the homologue ion mlz 590 (equivalent to the negative ion 667) under positive CID conditions was comparable with NPEO product ion spectra because of the destructive ionisation process of the precursor NPE0-S04 [15]. 

The number of satellite peaks will depend on the shape of the interface between the units. It is convenient to think of the diffraction pattern in the kinematic approximation as the Fourier transform of the structure. If the layers in the units were graded so that the overall structure factor variation were sinusoidal, this would have ordy one Fourier component and thus only one pair of satellites. If the interface is abrapt, this is equivalent to the Fourier transform of a square wave, which consists of an infinite number of odd harmonics the corresponding diffraction pattern is also an infinite number of odd satellites. The intensities of the satellites therefore contain information about the interface sharpness and grading. 

Phenolic acids are often found in plant tissue, and have been implicated in many cases of allelopathy (4). Figure 6 shows a separation of three free phenolic acids and Figure 7 shows mass spectra obtained from these compounds. These spectra give both molecular weight and structural information. Phenolic acids can easily be thermally decarboxylated. The height of the molecular ion peak varies owing to ion source temperature. The variation depends also to some extent on the composition of the LC eluent, and this will be further examined. 

For oxirane rings an IR absorption around 890 cm-1 is characteristic. This is also observed in the case of K-region epoxides and can be used for diagnostic purposes, but it is not sensitive enough to provide detailed structural information. The oxepins ordinarily do not show this band. Ultraviolet spectroscopy has been invaluable in studying the dynamic equilibrium between the arene oxides and oxepins. The solvent variation of UV spectra has also been exploited very effectively.8... 

Variation ofX Ligand. Most of the rate, spectroscopic, and structural information available on Co(III) compounds has been obtained for neutral LCo(DH)2X compounds. In reviewing this chemistry, we will consider first variations in the X ligand and then variations in the L ligand. 

---