Synthesis and characterization of novel bioactive 1,2,4-oxadiazole natural product analogs bearing the N-phenylmaleimide and N-phenylsuccinimide moieties

Abstract

SummaryTaking into consideration the biological activity of the only natural products containing a 1,2,4-oxadiazole ring in their structure (quisqualic acid and phidianidines A and B), the natural product analogs 1-(4-(3-tert-butyl-1,2,4-oxadiazol-5-yl)phenyl)pyrrolidine-2,5-dione (4) and 1-(4-(3-tert-butyl-1,2,4-oxadiazol-5-yl)phenyl)-1H-pyrrole-2,5-dione (7) were synthesized starting from 4-(3-tert-butyl-1,2,4-oxadiazol-5-yl)aniline (1) in two steps by isolating the intermediates 4-(4-(3-tert-butyl-1,2,4-oxadiazol-5-yl)phenylamino)-4-oxobutanoic acid (3) and (Z)-4-(4-(3-tert-butyl-1,2,4-oxadiazol-5-yl)phenylamino)-4-oxobut-2-enoic acid (6). The two natural product analogs 4 and 7 were then tested for antitumor activity toward a panel of 11 cell lines in vitro by using a monolayer cell-survival and proliferation assay. Compound 7 was the most potent and exhibited a mean IC50 value of approximately 9.4 µM. Aniline 1 was synthesized by two routes in one-pot reactions starting from tert-butylamidoxime and 4-aminobenzoic acid or 4-nitrobenzonitrile. The structures of compounds 1, 2, 4, 5 and 6 were confirmed by X-ray crystallography.

Synthesis of moxifloxacin–Au (III) and Ag (I) metal complexes and their biological activities

“…The IR spectra of moxifloxacin ligand and its Au (III) and Ag(I) metal complexes were recorded by FTIR spectrophotometer (Kunze et al 2002;Maftei et al 2013;Neda et al 1993b;Plinta et al 1994). The FTIR spectra of the silver and gold complexes of moxifloxacin ligand exhibited major changes as compared to the free ligand.…”

The crystal structure of (5-methyl-1,2,4-oxadiazol-3-yl)ferrocene, C13H12FeN2O

“…Furthermore, the inring angles are all near the value expected for a regular pentagon (108°). Yet, they can be divided into two distinct groups: three angles at the heteroatoms that are more acute than the ideal value [C13-N14-C15 102.65(13)°< O11-N12-C13 103.14(15)°< N12-O11-C15 106.17 (13) [11], and 5-chloromethyl-3-(4-methylphenyl)-1,2,4-oxadiazole [12].…”

N -heterocyclic carbenes (NHC) with 1,2,4-oxadiazole-substituents related to natural products: Synthesis, structure and potential antitumor activity of some corresponding gold(I) and silver(I) complexes

“…1-(4-(3-tert-Butyl-1,2,4-oxadiazol-5-yl)phenyl)-1H-pyrrole-2,5-dione D was tested in vitro for antitumor activity toward a panel of 11 cell lines by using a monolayer cell survival and proliferation assay and was found to be moderately active [31].…”