Novel 2,6-bis(4-methoxyphenyl)-1-methylpiperidin-4-one oxime esters: synthesis and a new insight into their antioxidant and antimicrobial potential

Abstract

A simple and efficient protocol for the synthesis of novel 2,6-bis(4-methoxyphenyl)-1-methylpiperidin-4-one oxime esters 4(a-q) is described. Initially, p-anisaldehyde 1 was condensed (Mannich reaction) with acetone and ammonium acetate trihydrate afforded 2,6-bis(4-methoxyphenyl)piperidin-4-one 2. Then, methylation followed by oximation with hydroxylamine hydrochloride (NH 2 OH•HCl) furnished a key scaffold 4. Further, to explore the enhanced biological properties of the piperidin-4-one core i.e. the key scaffold 4 was conjugated with substituted benzoyl chlorides in the presence of anhydrous K 2 CO 3 as base to obtain novel 2,6-bis(4-methoxyphenyl)-1-methylpiperidin-4-one oxime esters 4(a-q) in excellent yields. The newly synthesized compounds were characterized by elemental analysis, IR, 1 H NMR, 13C NMR and mass spectroscopic techniques, and screened for their in vitro antioxidant and antimicrobial activities. Most of the compounds exerted positive efficacy towards the biological assays performed. Among the synthesized analogues, compounds 4l and 4m exhibited promising antioxidant activity and on the other hand compounds 4b and 4d manifested persuasive antibacterial activity, whereas compound 4b displayed stupendous antifungal activity against A. flavus strain.

Protective effect of aqueous seed extract of Vitis Vinifera against oxidative stress, inflammation and apoptosis in the pancreas of adult male rats with diabetes mellitus

“…However, biological effects of guanidine N,N-dimethyl has never been reported. Meanwhile, oxime methoxy-phenyl and seychellene have been suggested to play a role as anti-oxidant [35,36]. Benzene 3-methylcyclopentyl was proposed to display anti-inflammatory properties [37] and 9-octadecenamide, phenol was reported to display anti-oxidant properties [37].…”

Rumex nervosus leaves meal improves body weight gain, duodenal morphology, serum thyroid hormones, and cecal microflora of broiler chickens during the starter period

“…Feeding a diet with 1,000 mg/kg RN resulted in greater duodenal villus height, villus width, and villus surface area and lower count of cecal salmonella and E. coli . Oxime-, methoxy-phenyl-, and hexadecanoic acid, methyl ester was identified in the RN extract, which has an antimicrobial activity ( Hema et al., 2011 ; Harini et al., 2014 ). Recently, it has been found that a mixture of Potentilla anserine , Polygonum aviculare , and Rumex crispus extracts decreased the count of cecal E. coli ( Kupczyński et al., 2019 ).…”

Antioxidant Potential of Piperidine Containing Compounds-a Short Review

“…Results showed that antioxidant activity was (DPPH assay, ABTS radical scavenging assay, FRAP assay, and cupric ion reducing antioxidant capacity assay) enhanced when the hydroxy group was introduced on the phenyl ring. Among the synthesized compounds, compounds with electronegative fluoro or chloro or bromo group on benzoyl ester moiety showed excellent antibacterial activity whereas compound with the fluoro group exhibited significant antifungal activity [36].…”