text: * Acetonyl group
  * Acyl group (e.g. acetyl group, benzoyl group) 
  * Alkyl group (e.g., methyl group, ethyl group) 
  * Alkenyl group (e.g., vinyl group, allyl group) 
  * Alkynyl group (propargyl group)
  * Benzyloxycarbonyl group (Cbz)
  * tert-butoxycarbonyl group (Boc) 
  * Carboxyl group