STRUCTURE-ACTIVITY-RELATIONSHIPS OF 2-CHLORO-2'-ARABINO-FLUORO-2'-DEOXYADENOSINE AND RELATED ANALOGS - PROTEIN-BINDING, LIPOPHILICITY, AND RETENTION IN REVERSED-PHASE LC
V. Reichelova et al., STRUCTURE-ACTIVITY-RELATIONSHIPS OF 2-CHLORO-2'-ARABINO-FLUORO-2'-DEOXYADENOSINE AND RELATED ANALOGS - PROTEIN-BINDING, LIPOPHILICITY, AND RETENTION IN REVERSED-PHASE LC, Journal of liquid chromatography, 18(6), 1995, pp. 1123-1135
Plasma protein binding of 2-chloro-2'-arabino-fluoro-2'-deoxyadenosine
(CAFDA), 2-chloro-2'-deoxyadenosine (CdA), 2-fluoro-1-beta-D-arabinof
uranosyladenine (F-araA) and structurally related analogues 2-chloro-a
denosine (2-Cl-Ado), 5'-chloro-5'-deoxyadenosine (5'-Cl-5'-dAdo), as w
ell as parent nucleosides 2'-deoxyadenosine (dAdo), 1-beta-D-arabinofu
ranosyladenine (araA) and adenosine (Ado) was determined and correlate
d with lipophilicity expressed as the logarithm of partition coefficie
nt in n-octanol/water system (log P-o/w). Drug binding to human serum
albumin (HSA) was utilized since it is considered to exemplify nonspec
ific binding of small molecules to other macromolecules. Percentage of
drugs bound to HSA increased from 3.5% to 27% following the order of
increase in lipophilicity (log P-o/w increased from -0.970 to 0.498).
A similar correlation was observed when protein binding was correlated
with retention in reversed-phase liquid chromatography (RP-LC) (capac
ity ratios, k', increased from 0.36 to 1.15), but the elution order of
some compounds did not follow the parallel increase in either protein
binding or lipophilicity. The introduction of a fluorine at the 2'-ar
abino position of CdA not only increased the acid stability of CAFDA,
but also resulted in a higher binding to HSA (27.0% for CAFDA versus 2
4.3% for CdA) and much higher lipophilicity (log P of 0.498 for CAFDA
compared to 0.025 for CdA).