Chemistry Reference
In-Depth Information
TABLE 5.19 (
Continued
)
QCARs That Used Only the Pearson and Mawby (1967) Softness Parameter
(
σ
p
) to Predict Cation Toxicity
Reference
QCAR
r
2
Cations
Tatara et al.
(1997)
Log EC50 = −10.47 +
83.49(σ
p
)
0.50
Ca
2+
, Cd
2+
, Cu
2+
, Hg
2+
, Mg
2+
, Mn
2+
, Ni
2+
, Pb
2+
,
Zn
2+
Tatara et al.
(1998)
Log EC50 = −1.23 +
16.72(σ
p
)
0.50
Ca
2+
, Cd
2+
, Co
2+
, Cr
3+
, Cs
+
, Cu
2+
, Fe
3+
, K
+
, La
3+
,
Li
+
, Mg
2+
, Mn
2+
, Na
+
, Ni
2+
, Pb
2+
, Sr
2+
, Zn
2+
.
Enache et al.
(1999)
−(log EC
50
) = 3.59
− 14.4(σ
p
)
0.83
Ba
2+
, Ca
2+
, Cd
2+
, Co
2+
, Cu
2+
, Mg
2+
, Mn
2+
, Ni
2+
,
Pb
2+
, Zn
2+
Mendes et al.
(2010)
Log EC
50
= −0.77 +
17.52(σ
p
)
0.799
Ag
1+
, Ba
2+
, Ca
2+
, Cd
2+
, Co
2+
, Cs
1+
, Cu
2+
, Fe
2+
,
Hg
2+
, K
1+
, Li
1+
, Mg
2+
, Mn
2+
, Na
1+
, Ni
2+
, Pb
2+
,
Sr
2+
, Zn
2+
[NRI] assay, Coomassie blue [CB] assay, and cellular growth rate [CGR] assay)
to develop QSARs to predict IC
50
values, that is, the concentration that inhibited
50% of the L-929 cell line of murine fibroblasts (
Table 5.20
)
. In addition, Sauvant
et al.
(1997) developed a QSAR to predict the IC
50
values for the ciliated protozoa,
Tetrahymena pyriformis
GL, using the doubling time from a
T. pyriformis
GL popu-
lation assay or DTP (Table 5.20).
Enache et al.
(2003) determined the concentration at which there is a 50% decrease in
the rate of callus development in the sunflower (
Helianthus annuus
F.1.
Sunspot) and
found a large number of correlations with relevant physical and chemical descriptors
for 16 of their QSARs (Table 5.20).
Hickey (2005) developed linear solvation energy relationships (LSERs) for neu-
tral inorganic species based on LSER equations developed for neutral organic com-
pounds. The general LSER equation was log(Property) = mVi/100
i
/100 + sπ* + bβ
m
+ aα
m
,
where V
i
was the intrinsic (van der Waals) molecular volume, π* was the solute ability
to stabilize a neighboring charge or dipole by nonspecific dielectric interactions, and
β
m
and α
m
were the solute ability to accept or donate a hydrogen in a hydrogen bond.
The coefficients m, s, b, and a were constants for a particular set of conditions, deter-
mined by multiple linear regression of the LSER variable values for a series of chemi-
(2005) LSERs to predict the water solubility and toxicity of cations are referred
Newman and McCloskey (1996), and deZwart and Sloof (1983) to predict the toxicity
of 40 cations to
Vibrio fischeri
in the Microtox
®
test (Table 5.4). Hickey (2005) used
data reported by Bringmann and Kuhn (1977, 1982), Khangarot and Ray (1989), and
LeBlanc (1984) to predict the toxicity of 53 cations to
Daphnia magna
and data from
Junhke and Ludemann (1978) to predict the toxicity of 32 cations to the Golden orfe
Leuciscus idus melanotus
(Table 5.4). The LSERs/QSARs from Hickey (2005) are
listed after those of Walker et al.
(2007) in Table 5.20, so that the r
2
adj. values could
be used without interruption from Enache et al.
(2000) to Walker et al.
(2007).
