np7b00570_si_001.pdf (1.23 MB)
Synthesis and Bioactivity of Reduced Chalcones Containing Sulfonamide Side Chains
journal contribution
posted on 2018-01-08, 18:07 authored by Anwar
E. M. Noreljaleel, A. Wilhelm, S. L. Bonnet, J. H. van der WesthuizenThe effect on the bioactivity of
antibacterial sulfonamide drugs
against malaria and tuberculosis via an increase of the lipid solubility
groups by condensation with a reduced chalcone was investigated. Sulfonamide
derivatives (8a–8d) were obtained
via a 1,3-diarylpropane scaffold, prepared by reduction of the relevant
chalcones, followed by the addition of a sulfonamide moiety via the
Mannich and the Mannich exchange reactions. The ClogP values indicated
that the lipophilicities of 8a–8d and intermediate reduced chalcones and N-alkylated reduced chalcones
(5a–7a) were much higher than those
of the sulfonamides (1a–1c). The
N-alkylated reduced chalcone derivatives 6 and 7 exhibited the highest antimalarial (Plasmodium falciparum (NF54 strain)) activity. Addition of the sulfonamide group weakened
the activity, even though some ClogP values were higher, while 1a–1c showed no activity. The reduced
chalcones 5a and 5 showed potent growth
inhibition of Mycobacterium tuberculosis (H37Rv strain),
but the sulfonamide derivatives 8a and 8d showed no or insignificant activity (0 and 14%, respectively) against M. tuberculosis, despite high ClogP values. Thus, the possible
increase in bioactivity expected from an increase in ClogP values
(lipophilicity) might be counteracted by the higher molecular weight
of the studied analogues.