- C6H5−NH2C6H5−NH2C_{6} H_{5}-N H_{2}
- CH3NH2C H_{3} N H_{2}.
- NH2−CH2−COOHN H_{2}-C H_{2}-C O O H
- NH2−CH(CH3)−COOHN H_{2}-C H\left(C H_{3}\right)-C O O H.