Substituents basic groups

This group has been best investigated theoretically, and is the most used in large-scale production. The basic members are ethylene and its derivatives. According to the type of substituent, the group contains two subgroups, alkenes (olefins) and polar vinyl monomers. 

Recent work on the non-competitive inhibition of both porcine and fungal aminoacy-lase by a- and (3-fluoro- and -hydroxy acids indicated that the active site of the fungal enzyme should interact with the a-substituent of a substrate via an acidic group while the porcine enzyme has a basic group in the corresponding position with which to recognize substrates 721. 

In spite of the different categories in the scheme, the diversity of structures of acydonucleosides led to other categories that do not fit exactly with those in Scheme 2. However, they were correlated with those in the scheme by considering one of the structures in Scheme 2 as a basic skeleton and the extra groups or chains as substituents. Functional groups other than the hydroxyl can be considered as substituents. The first category in each disconnection represents the most important member. 

Amino acids can be classified according to their substituent R groups (Fig. 1.2 to Fig. 1.8) in basic amino acids, R contains a further amino group, whereas in acidic amino acids, R contains a further carboxyl group. In addition, there are aliphatic, aromatic, hydroxyl containing and sulfur containing amino acids according to the nature of the substituent, as well as a secondary amino acid. 

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