The current study presents the synthesis of thiophene-appended pyrazoles through 3+2 annulations of chalcones 3(a-g)with aryl hydrazine hydrochlorides 4(a-d) in acetic acid (30%) under reflux conditions produced the thiophene-pyrazole hybrids 5(a-g) in good yields. Structures of synthesized new pyrazoles were confirmed by spectral studies, and elemental analysis. Further, preliminary biological evaluation studies show that compounds 5b and 5f having chloro substitution only in the thiophene ring exhibited excellent inhibition (12.5-25.0 µg/mL) against all the tested organisms in comparison with that of the standard. Compounds, 5a, 5c and 5g having electronegative chloro substitutions each in the aromatic and thiophene rings showed excellent (12.423-31.213 µg mL^-1) DPPH radical scavenging potencies. The synthesis of pyrazoline derivatives and the efficacy of some of the synthesized molecules as antimicrobial and antioxidant agents validate the significance of this study.

An effective and expeditious method of the synthesis of a highly functionalized piperidines, catalyzed by nontoxic, recyclable and environment friendly sodium lauryl sulfate (SLS), via one-pot multi-component condensation of aldehydes, amines and β-ketoesters in water at room temperature, has been developed. This new protocol has advantages such as moderate to high yields of products obtained after simple post reaction workup. Structure of the synthesized compounds 4a–4j have been elucidated based on the 1H NMR, 13C NMR, FT-IR spectroscopy and elemental analysis.

Novel fragrant starch-based films with limonene were successfully prepared. Biodegradable materials of natural origin were used and the process was relatively simple and inexpensive. The effect of limonene on physicochemical properties of starch-based films (moisture absorption, solubility in water, wettability, mechanical properties) were compared to glycerol plasticized system. Taking into consideration that the obtained materials could also exhibit bactericidal and fungicidal properties, the studies with Escherichia coli, Candida albicans and Aspergillus niger were performed. Such a material could potentially find application in food packaging (e.g. masking unpleasant odors, hydrophilic starch film would prevent food drying), or in agriculture (e.g. for seed encapsulated tapes).

A series of semicarbazones, thiosemicarbazones, 1,3,4-oxadiazoles/thiadiazoles bearing pyrazole scaffold were designed and synthesized. All the synthesized new compounds were characterized by 1H NMR, 13C NMR, MS and elemental analysis. The synthesized compounds were screened to probe their in vitro antimicrobial activity against bacteria and fungi species. The structure-activity relationship of the synthesized compounds was studied. The compounds displayed good to excellent potency against tested microorganisms. The in vitro antioxidant activities of the 1,3,4-oxadiazoles/thiadiazoles were evaluated by DPPH, hydroxyl and nitric oxide radical scavenging assay. Among the tested compounds, compound with chloro substitution showed good antioxidant potential.