FIELD: organic chemistry, medicine, oncology, pharmacy. SUBSTANCE: invention relates to novel derivatives of substituted purinyl showing immunomodulating, in part, immunostimulating activity both in vivo and in vitro without toxicity, a pharmaceutical composition and a method of inhibition of the tumor growth. Derivatives of substituted purinyl or its pharmaceutically acceptable derivatives correspond to the formula (I) 
where R1 means substituted amino-group presented by the formula NR5R6 where R5 and R6 are taken independently among the group consisting of hydrogen atom, C1-4-alkyl, cyclopropyl, 1-methyl-2-acetoxyethyl and unsubstituted amino-group; or R5 R6 taken in common with nitrogen atom to which they are bound form azethidine or methylaziridine under condition that R5 and R6 both do not mean hydrogen atom and that R5 and R6 both do not mean amino-group; R2 and R3 are taken independently among the group consisting of hydrogen atom, C1-4-alkyl, amino-group, mercapto- group, thiol substituted with C1-4-alkyl and halogen atom; R4 means the formula -(CH2)-L-O-CO-X12, where L is taken among the group consisting of (CH2)n-,-(CH2)m-Q-(CH2)m- and -(CH2)m-C≡C-(CH2)m- where Q means O, S, NH or CH2 where X12 means lower aminoalkyl group, amino acid taken among isoleucine, leucine, proline, arginine, glycine, alanine, glutamic acid, valine, ornithine or citrulline bound by its α-amino-group or peptide comprising 2-5 indicated amino acids; n is a whole number from 1 to 6; m is a whole number from 1 to 3 under condition that if R1 means NH2 and R4 means pentyloxycarbonyl-L-arginine then R2 does not mean hydrogen atom. Invention relates to also a pharmaceutical composition that comprises effective amount of compounds of the formula (I) and a pharmaceutically acceptable carrier. Invention relates to also a method of the growth inhibition by administration to mammal a compound of the formula (I). EFFECT: new compounds indicated above, valuable antitumor property. 14 cl, 10 tbl, 7 dwg
