Conjugate of podophyllotoxin with chlorambucil: synthesis, biological testing and molecular modeling

In the present work we have studied a novel conjugate of the DNA alkylating agent chlorambucil with podophyllotoxin, a ligand of the colchicine binding site in tubulin. The target compound was obtained by Steglich esterification of podophyllotoxin with the percentage yield of 41%. Results of biotesting carried out on the carcinoma A549 cell line revealed that at a concentration of 2 μM the conjugate caused full depolymerization of microtubules without any other effect on free tubulin. The conjugate inhibited proliferation (IC50=135±30 nM) and growth (EC50=240±30 nM) of A549 cells. The data of computer molecular docking of the novel compound into the 3D model of the colchicine binding site in α,β-tubulin and molecular dynamics modelling allowed to explain the observed difference in effects of chlorambucil-podophyllotoxin and chlorambucil-colchicine conjugates on microtubules.Izuchen kon"iugat DNK-alkiliruiushchego agenta khlorambutsila s podofillotoksinom — ligandom kolkhitsinovogo saĭta tubulina. Tselevoe soedinenie polucheno éterifikatsieĭ po Steglikhu s vykhodom 41%. Rezul'taty biotestirovaniia na kletkakh kartsinomy A549 vyiavili ego sposobnost' v kontsentratsii 2 mkM vyzvat' polnuiu depolimerizatsiiu seti mikrotrubochek bez kakogo-libo drugogo deĭstviia na svobodnyĭ tubulin. Poluchennyĭ kon"iugat ingibiruet proliferatsiiu (IC50=135±30 nM) i rost (EC50=240±30 nM) kletok A549 v nanomoliarnom intervale kontsentratsiĭ. Rezul'taty komp'iuternogo molekuliarnogo dokinga novogo soedineniia v trekhmernuiu model' kolkhitsinovogo saĭta α,β-tubulina i modelirovaniia molekuliarnoĭ dinamiki pozvoliaiut ob"iasnit' razlichie v deĭstvii kon"iugatov podofillotoksina s khlorambutsilom i kolkhitsina s khlorambutsilom na set' mikrotrubochek.