LAUSR

ABSTRACT Lipophilicity was investigated for 20 2′‐deoxyribonucleoside derivatives modified with electron‐neutral 1,2‐dicarba‐closo‐dodecaborane, 1,12‐dicarba‐closo‐dodecaborane, 7,8‐dicarba‐nido‐undecaborate anion, and metallacarborane containing Co, Fe, or Cr. The partition coefficient (P) for neutral conjugates and the distribution coefficient (D7.4) for ionic compounds were determined as a lipophilicity descriptor using a shake‐flask method. All modified nucleosides had P/D7.4 values higher than those of an appropriate unmodified 2′‐closo‐dodecaborane and metallacarborane was found to be three orders of magnitude higher than that of its unmodified counterpart. The lowest impact on the P/D7.4 values of the conjugates was observed for the 7,8‐dicarba‐nido‐undecaborate anion. A preliminary molecular modeling study of a thymidine‐carborane conjugate with &bgr;‐cyclodextrin confirmed the ability of the components to form an inclusion complex. Graphical abstract Figure. No Caption available.