Single-point modifications

Multiple single-point modification of both halves of the bisindole framework provided vinepidine (144), a bisindole alkaloid that exhibited experimental antitumor activity similar to vincristine without demonstrating the acute neuronal toxicity of this alkaloid. Ultimately, the vinepidine experience was both educational and an exercise in humility, since the compound showed promise in preclinical neurotoxicology models yet demonstrated considerable neurotoxicity in clinical trials. Nevertheless, vinepidine brings a rich example of the combined effects of ring D conformation (with its associated effect on N-6 basicity) and the presence of an N-1 formyl group. 

The Ml test equipment is easy to operate, provides repeatable results, and low cost to operate. It is widely used for quality control and for distinguishing between members of a single family of plastics. Specifically, this MI makes a single-point test that provides information on resistance to flow at only a single shear rate. Because variations in branching or MWD can alter the shape of the viscosity curve, the MI may give a false ranking of plastics in terms of their shear rate resistance to flow. To overcome this problem, extrusion rates are sometimes measured for two loads, or other modifications are made. 

The Dewar-Golden-Harris approach (DGH), also called FMMF method (i.e. Field, Mesomeric and Mesomeric-Field method) [Dewar et al, 1971a] is a modification of the Dewar-Grisdale approach, where the substituent X is approximated by a finite dipole (represented by two point charges along the /-X bond) and the reaction site at position i as a single point charge. This approach is based on the equation ... 

Alternative Methods of PL Modification with DTP A and DTPA-PL Coupling to an Antibody. Alternatively, to ensure a single-point attachment of DTPA-PL to an antibody, DTPA-PL bearing a PDP on its N-terminal is synthesized (22), see the scheme in Fig. 3A. For this purpose,... 

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