Molecular cleavage

Apply disconnective transforms which do not alter stereocenters but which separate stereocenters by molecular cleavage. 

The full biological activity of C2 toxin, a mixture of components I and II, is obtained by activation of the toxin with trypsin (Miyake and Ohi-shi, 1987 Ohishi et al., 1980 Ohishi et al., 1980 Ohishi, 1987). As described in Section 9.2 (Assay method for the toxin), the full activity of the toxin is produced by a mixture of untrypsinized component I and trypsinized component II. This indicates that activation of the toxin is brought about by the molecular cleavage of component II, but not of component I, by trypsin. Therefore, to study the biological activity of botulinum C2 toxin and the effect of ADP-ribosylation of cytoplasmic actin by C2 toxin on whole cells, it is essential to prepare activated component II (trypsinized component II). 

The answer may be in discovering more specific mechanism-based P-lactamase inhibitors. It is curious that the best drugs developed so far are also P-lactam compounds (Fig. 6-14). One very interesting inhibitor is penicillanic acid sulfone (sulbactam, Fig. 6-14). This drug acts as a substrate (becomes hydrolyzed) and as an irreversible inactivator of TEM-type P-lactamase (covalently binding to it via molecular cleavage). 

Thus for each original reaction with oxygen there can be numerous propagation reaction. The peroxides may also cleave to give aldehydes, ketones, acids, or alcohols. Due to this type of molecular cleavage, the product becomes soft with lower average molecular weight. 

Potential risks of these substances include low molecular cleavage products from the crosslinking reaction, longer cycle times and recycling. Following comminution, these materials can only be used as such and only as added filler material in the... 

PDMS-hydrophobed silica antifoams, after storage in soda ash, revealed no change in molecular weight. This suggests that molecular cleavage at the Si-O bond in PDMS to produce lower molecular weight fragments of lower viscosity cannot provide an explanation for the phenomenon [79],... 

H3C)Si group, which is released by molecular cleavage. The mass 157 may be assigned to an ion (H3C)3Si—C( = CH2)—Si (CH3)2, which results from the loss of a methyl group from the original molecule. 

Investigations on (ClgSi—CCl2)2SiCl2 show that reaction with ZnF at 20 °C will produce (F3 Si—0012)2 SiF yield, while at 100 ""O molecular cleavage occurs... 

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