Shikha Agarwal

Antioxidant and Antimicrobial Assessment of Synthesized and Spectrally Characterized New Nitrophenothiazines and their Sulfone Analogues

GRAPHICAL ABSTRACT Abstract A series of new nitrophenothiazines and their sulfones were synthesized and their in vitro antimicrobial assessment was carried out against a representative panel of gram positive and gram negative bacterial strains and selected fungi species. The synthesized compounds were screened for antioxidant activity by 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay and 2,2-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•+) radical cation decolorization assay. Structural determination was carried out by spectral and elemental investigations.

Synthesis, characterization and evaluation of novel benzothiazole clubbed chromene derivatives for their anti-inflammatory potential

Abstract A series of chromene derivatives (5a–f) were prepared by multistep synthesis process using 2-[3-phenyl prop-2-ene nitrile] 1,3-benzothiazole and dimedone using piperidine as catalyst in ethanol. The reaction was found to proceed via Knoevenagel condensation of aldehydes with benzothiazole, followed by the elimination to afford the 2-(benzo[d]thiazol-2-yl)-3-(aryl)acrylonitrile, which then undergoes Michael addition with 5,5-dimethyl-1,3-cyclohexanedione, followed by intramolecular O-cyclization to give the products. The structures of all novel constructed derivatives were corroborated by elemental analysis and spectral data (FT-IR, 1H-NMR, 13C-NMR and Mass). Subsequently, the compounds were tested for their in-vivo anti-inflammatory activity. This study revealed that these synthesized derivatives tend to have significantly anti inflammatory activity and shall prove as structural templates in the design and development of new anti inflammatory drugs. Graphical Abstract

Diversity Oriented Synthesis of 4H-Pyrimido[2,1-b]benzothiazole Derivatives via Biginellis Reaction: A Review

BACKGROUNDnHeterocycles have extended into widespread use for generating large collection of molecules in multi-component reactions. The development of new strategies for fused pyrimidobenzothiazole system has remained a highly attractive but challenging proposition for scientists working all around.nnnOBJECTIVEnThe main objective of this work is to explore the utility of different catalysts as an ecofriendly reaction medium for green Biginellis reaction.nnnMETHODnA detailed study of Biginellis reactions using various catalysts was done using different research tools. The methods involved reaction of equimolar mixture of benzothiazole, 1,3-diketone and aldehyde as reactants by conventional and greener pathways via Knoevenagal condensation.nnnRESULTSnThe present review has several significant advantages for the scientists regarding green synthesis viz. green conditions, short reaction times, high yields, clean reaction conditions, easy isolation of products, simple work-up procedure and mild reaction conditions.nnnCONCLUSIONnOur report gives an overview of the combinatorial libraries for fused benzothiazole entities using metal catalyst, acid catalyst, ionic liquids, phase transfer catalyst, nano catalyst, etc.

Thiazole containing Heterocycles with CNS activity

BACKGROUNDnThiazoles are promising scaffolds in the area of medicinal and pharmaceutical chemistry and have accounted to show different pharmacophoric properties. For the last years, thiazole derivatives have focused too much attention to develop different new CNS active agents. It has been broadly used to generate diverse therapeutic agents against various CNS targets. Histamine H3 receptors are seriously involved in the pathophysiology of numerous disorders of the central nervous system.nnnMETHODnThe literature survey has been done using different database from peerreviewed journals. The quality of repossessed papers was evaluated using standard tools. The details of important papers were described to focus on the potency of thiazole containing heterocycles with CNS activity.nnnRESULTnEighty nine papers were included in the review indicating thiazole containing heterocycles with CNS activity. (1) to (30) papers included different thiazole derivatives impregnated withCNS activity. Different CNS agents have been shown in references (37) to (56). The remaining papers have been searched for anticonvulsant agents (57) to (78) and other miscellaneous activities from (79) to (89).nnnCONCLUSIONnA detailed investigation has been carried out on thiazoles and its derivatives to judge its efficacy to overcome several CNS disorders. This article covers the recent updates of thiazole and its derivative with CNS activity already present in literature and will definitely provide a better platform for the production and development of potent thiazole based CNS vigorous drugs in near future.