U.S. Pat. No. 5,326,396 of Abdelrazig et al. disclosed a composition having the formula R1???NH2 or R1???X???NHCO???R2 wherein R1 represents a C4-C6 alkyl group, X represents an oxygen atom or secondary nitrogen group (NH), and R2 represents hydrogen atom or C1-C3 alkyl group when X is a secondary amine and R2 represents a primary amino group or ???CH2 C(O)CH3 when X represents oxygen atom.