3 Results and discussion
Our study deals with 28 p-substituted phenols of the set of Selassieet al. [2] despite five to seven of them
with electron withdrawing substituents (-NO2,
-NH2, -CN, -Cl, -Br, -CONH2, -CHO,
-NHCOCH3 -SO2NH2) were
omitted from their analyses. We suppose that the phenols cannot be
investigated as a whole. Therefore we have classified the whole group
into three datasets as follows (Table 1):
- Dataset A contains electron donating substituents such as R = H or
alkyl. The iodine atom can be assigned to this dataset due to its low
electronegativity as well. Surprisingly, also the phenoxyl substituent
behaves as the remaining ones of this dataset probably due to
neutralization of opposite electron withdrawing properties by its
bonded aromatic ring (resonance effect). Therefore this dataset
contains 12 molecules.
- Dataset B contains electron withdrawing substituents such as R =
alkoxyls and hydroxyl, halogens (except I), cyano- , nitro- and amino-
groups, altogether 12 molecules (some of them were omitted by Selassieet al .[2])
- Dataset C contains four molecules (omitted by Selassie et
al. [2]) with substituents containing C=O or S=O
bonds which might affect the toxicity by different mechanisms than
phenols. This dataset is too small to be treated by regression
analyses.