ИСТИНА

At present work, new derivatives of betulinic acid 2 and 3 were synthesized and characterized. Initially, interaction of betulininc acid 1 with propargyl bromide followed by introduction of oxalic acid fragment were carried out. Subsequent conjugation of acetylenic moieties in 2 with 1-azido-N-acetylgalactosamine led to selective formation of new triterpenoid based glycoconjugate 3. Residues of specific «GalNAc» monosaccharides is known to provide selective binding of conjugates with ASGP-receptor in hepatocytes and thus is known to conduct targeted delivery of drugs to liver. Compound 3 exhibited a high level of cytotoxicity against the target HepG2 cell line. Affinity study of 3 by SPR-spectroscopy showed the Kd values, comparable to the conventional branched ASGPr-ligands. Therefore, the synthesized glycoconjugate is promising for a detailed study on the subject of targeted antitumor properties against hepatocarcinoma in vitro. Also, the proposed approach is planned to be used for other pentacyclic triterpenoids.