H. Vijay Kumar

Synthesis and antioxidant properties of some novel 5H-dibenz[b,f]azepine derivatives in different in vitro model systems.

A series of 5H-dibenz[b,f]azepine containing different aminophenols and substituted aminophenols were synthesized. 3-chloro-1-(5H-dibenz[b,f]azepine-5yl)propan-1-one (2) was obtained by N-acylation of 5H-dibenz[b,f]azepine (1) with 3-chloro propionyl chloride. Further base condensation with different aminophenols and substituted aminophenols to produce series of 5H-dibenz[b,f]azepine containing aminophenol and substituted aminophenol (2a-e). The structures of newly synthesized compounds were characterized by spectral and elemental analysis. Their antioxidant properties were evaluated by using several methods: scavenging effects on 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical, inhibition of lipid peroxidation using beta-carotene linoleate system, inhibition of human low-density lipoprotein (LDL) oxidation and reducing power. Butylated Hydroxy Anisole (BHA) and Ascorbic acid (AA) were used as the reference antioxidant compounds and also the comparative study with the synthesized compounds was done. Under our experimental conditions, Compound (2) showed negligible activity over all the antioxidant assays but 5H-dibenz[b,f]azepine containing different aminophenols and substituted aminophenols (2a-e) showed good antioxidant activities over all the methods and compounds containing substituted aminophenols 2e and 2d showed predominant antioxidant activities among the synthesized analogues.

In Vitro Antioxidant Activity of Dibenz[b,f]azepine and its Analogues

Dibenz[b,f]azepine and its five derivatives bearing different functional groups were synthesized by known methods. The compounds thus synthesized were evaluated for antioxidant potential through different in vitro models such as (DPPH) free radical scavenging activity, s-carotene-linoleic acid model system, reducing power assay and phosphomolybdenum method. Under our experimental condition among the synthesized compounds dibenz[b,f]azepine (a) and 10-methoxy-5H-dibenz[b,f]azepine (d) exhibited potent antioxidant activity in concentration dependent manner in all the above four methods. Butylated hydroxyl anisole (BHA) and ascorbic acid (AA) were used as the reference antioxidant compounds. The most active compounds like dibenz[b,f]azepine and its methoxy group substituent have shown more promising antioxidant and radical scavengers compared to the standards like BHA and ascorbic acid. It is conceivable from the studies that the tricyclic amines, i.e. dibenz[b, f]azepine and some of its derivatives are effective in their antioxidant activity properties.

Synthesis of Amino Acid Analogues of 5H-Dibenz[b,f]azepine and Evaluation of their Radical Scavenging Activity

A method for the synthesis of tyrosine, phenyl alanine, hydroxy proline and threonine free amino acid analogues of 5H-dibenz[b,f]azepine is proposed. 5H-dibenz[b,f]azepine was prepared by known method. The key intermediate 3-chloro-1-(5H-dibenz[b,f]azepine-5-yl)propan-1-one was obtained by N-acylation of 5H-dibenz[b,f]azepine with 3-chloro propionyl chloride. Further coupling of respective free amino acid to produce 2-(3-(5H-dibenz[b,f]azepine-5-yl)-3-oxopropylamino)3-(4 hydroxyphenyl) propanoic acid, 2-(3-(5H-dibenz[b,f]azepine-5-yl)-3-oxopropylamino)-3-phenyl propanoicacid,1-(3-(5H-dibenz[b,f]azepine-5-yl)-3-oxopropyl)-3-hydroxypyrolidine-2-carboxylic acid and 2-(3-(5H-dibenz[b,f] azepine-yl)-3-oxopropyl amino)-3-hydroxy butanoic acid. The synthesized compounds were evaluated for their potential over 1,1-diphenyl-2-picryl hydrazyl (DPPH) free radical scavenging activity. Butylated hydroxy anisole (BHA) and ascorbic acid (AA) were used as the reference antioxidant compounds and also the comparative study with synthesized compounds was done. Under our experimental conditions tyrosine, hydroxy proline and threonine analogues possess a direct scavenging effect on trapping the stable free radical DPPH. Hydroxy proline analogues showed a significant radical scavenging activity among the synthesized analogues

Synthesis of N-Methyl-6-heterocyclic-1-oxoisoindoline Derivatives by Microwave Assisted Buchwald-Hartwig Amination

An rapid and efficient microwave assisted Pd(II) catalyzed protocol for the preparation of N-methyl-6-heterocyclic-1-oxoisoindoline derivatives by Buchwald-Hartwig amination with an overall yield 68-85% has been described.