containing the desired product were collected and lyophylized the resulting powder was ice cooled and washed with acetonitrile to obtain 0 33 g of 6 o 2 tetradecylhexadecanoyl n acetylmuramyl l alanyl d isoglutamine 5 norbornene 2 3 dicarboxyimidyl ester as a white powder elementary analysis for str4 calculated c 63 62 h 9 01 n 6 18 found c 63 44 h 8 81 n 6 12 100 mg of 6 o butyryl n acetylmuramyl l alanyl d isoglutamine and 27 2 mg of p nitrophenol were dissolved in 3 ml of acetonitrile and 1 ml of an acetonitrile solution containing 40 3 mg of dicyclohexylcarbodiimide was added thereto under ice cooling and stirring after 30 minutes the reaction temperature was allowed to warm to room temperature the stirring was continued overnight followed by filtration to remove the precipitated dicyclohexylurea the filtrate was concentrated under reduced pressure and to the resulting syrup was added diethyl ether the precipitated powder was taken out by filtration recrystallization of the powder from tetrahydrofuran diethyl ether gave 70 5 mg of 6 o butyryl n acetylmuramyl l alanyl d isoglutamine p nitrophenyl ester as a white powder ir kbr 3350 2960 2930 1760 1720 1650 1520 1345 1200 860 745 cm 1 elementary analysis for c 29 h 41 n 5 o 14 1 2h 2 o calculated c 50 28 h 6 11 n 10 11 found c 50 33 h 6 25 n 10 01 the biological activities of the compounds i according to the present invention were confirmed by the following test examples 1 to 6 the compounds of the invention used in these test examples are as follows group a c57bl 6.