“…Among these, it is worth mentioning the amino acids proline, hydroxyproline (Davankov and Kurganov, 1983;Yamskov et al, 1981), cysteine (Natalini et al, , 2008b(Natalini et al, , 2008c, histidine Watanabe, 1983), phenylalanine (Wan et al, 1997;Wernicke, 1995), alanine (Tsvetkov and Mingelgrin, 1987), lysine (Tsvetkov and Mingelgrin, 1987), isoleucine (Huang et al, 2005), and penicillamine (Ôi et al, 1995), and few amino alcohols carrying a phenylglycinol (Hyun et al, 2003(Hyun et al, , 2004, leucinol (Hyun and Ryoo, 1996;Hyun et al, 2002), or pyrrolidinemethanol (Natalini et al, 2007) residual as the basic scaffold.…”