: The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields

Thiazole-containing compounds as therapeutic targets for cancer therapy.

In past decades, interdisciplinary research has been of great interest for scholars. Thiazolidine motifs behave as a bridge between organic synthesis and medicinal chemistry and compel researchers to explore new drug candidates. Thiazolidine motifs are very intriguing heterocyclic five-membered moieties present in diverse natural and bioactive compounds having sulfur at the first position and nitrogen at the third position. The presence of sulfur enhances their pharmacological properties, and, therefore, they are used as vehicles in the synthesis of valuable organic combinations. They show varied biological properties viz. anticancer, anticonvulsant, antimicrobial, anti-inflammatory, neuroprotective, antioxidant activity and so on. This diversity in the biological response makes it a highly prized moiety. Based on literature studies, various synthetic approaches like multicomponent reaction, click reaction, nano-catalysis and green chemistry have been employed to improve their selectivity, purity, product yield and pharmacokinetic activity. In this review article, we have summarized systematic approaches for the synthesis of thiazolidine and its derivatives, along with their pharmacological activity, including advantages of green synthesis, atom economy, cleaner reaction profile and catalyst recovery which will help scientists to probe and stimulate the study of these scaffolds.

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Saturated Five-Membered Thiazolidines and Their Derivatives: From Synthesis to Biological Applications

Quantitative structure-activity relationship (QSAR) modelling of 55 focal adhesion kinase (FAK) (EC 2.7.10.2) inhibitors of triazinic nature was performed using the Monte Carlo method. The ...

Design and development of novel focal adhesion kinase (FAK) inhibitors using Monte Carlo method with index of ideality of correlation to validate QSAR.

Design, synthesis, DNA binding, modeling, anticancer studies and DFT calculations of Schiff bases tethering benzothiazole-1,2,3-triazole conjugates

Postprandial hyperglycemia can be controlled by delaying the absorption of glucose resulting from carbohydrate digestion α-Amylase is the initiator of the hydrolysis of polysaccharides, and therefore developing α-amylase inhibitors can lead to development of new treatments for metabolic disorders like diabetes mellitus In the present work, we set out to rationally develop α-amylase inhibitors based on the thiazolidine-4-one scaffold The structures of all these newly synthesized hybrids were confirmed by spectroscopic analysis (IR, 1H-NMR, MS) The appearance of two sets of signals for some protons in 1H NMR revealed the existence of a mixture of 2E,5Z (371–420%) and 2Z,5Z isomers (584–628%), which was further supported by DFT studies All the newly synthesized compounds have potential inhibitory properties as revealed through in vitro α-amylase inhibition activity Compound 5a at 100 μg mL−1 concentration showed a remarkable inhibition of 9004% In vitro α-amylase inhibition was further supported by docking studies of compound 5a against the active site of human pancreatic α-amylase (PDB ID: 2QV4) The docking studies revealed that the bonding interactions found between 5a and human pancreatic α-amylase are similar to those responsible for α-amylase inhibition by acarbose

Synthesis of novel inhibitors of α-amylase based on the thiazolidine-4-one skeleton containing a pyrazole moiety and their configurational studies

Acyl hydrazones are an important class of heterocyclic compounds promising pharmacological characteristics. Malaria is a life-threatening mosquito-borne blood disease caused by a plasmodium parasite. In some places, malaria can be treated and controlled with early diagnosis. However, some countries lack the resources to do this effectively. The present work involves the design and synthesis of some novel acyl hydrazone based molecular hybrids of 1,4-dihydropyridine and pyrazole (5a–g). These molecular hybrids were synthesised by condensation of 1,4-dihydropyridin-4-yl-phenoxyacetohydrazides with differently substituted pyrazole carbaldehyde. The final compound (5) showed two conformations (the major, E, s-cis and the minor, E, s-trans) as revealed by NMR spectral data and further supported by the energy calculations (MOPAC2016 using PM7 method). All the synthesised compounds were screened for their in vitro antimalarial activities against chloroquine-sensitive malaria parasite Plasmodium falciparum (3D7) and antimicrobial activity against Gram positive bacteria i.e. Bacillus cereus, Gram negative bacteria i.e. Escherichia coli and antifungal activity against one fungus i.e. Aspergillus niger. All these compounds were found more potent than chloroquine and clotrimazole, the standard drugs. In vitro antiplasmodial IC50 value of the most potent compound 5d was found to be 4.40 nM which is even less than all the three reference drugs chloroquine (18.7 nM), pyrimethamine (11 nM) and artimisinin (6 nM). In silico binding study of compound 5d with plasmodial cysteine protease falcipain-2 indicated the inhibition of falcipain-2 as the probable reason for the antimalarial potency of compound 5d. All the compounds had shown good to excellent antimicrobial and antifungal activities.

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Design, synthesis, conformational and molecular docking study of some novel acyl hydrazone based molecular hybrids as antimalarial and antimicrobial agents

Thiazolidine‐4‐one clubbed pyrazoles hybrids: Potent α‐amylase and α‐glucosidase inhibitors with NLO properties

The present study describes a multicomponent synthesis of molecular hybrid containing pyrazole, thiazole moiety using hydrazone as a linker, which have been synthesized by condensation of 1-phenyl-3-(aryl)-1H-pyrazole-4-carbaldehydes 1A-B: , thiosemicarbazide and α-bromoketones 2A-C: .The target hybrid compounds, 1-((1-phenyl-3-aryl-1H-pyrazole-4-yl)methylene)-2-(4-arylthiazole-2-yl)hydrazine 3A-F: are characterized by 1H-NMR, 13C NMR, FT-IR and mass. Apoptosis inducing ability and cytotoxic nature of all the hybrid compounds having thiazole, pyrazole and hydrazone were assessed by using biological assays viz morphological, fluorescence and tunel assays on granulosa cells of ovarian antral follicles of goat (Capra hircus) in vitro. Apoptosis was recognized and quantified using differential staining of ethidium bromide and acridine orange where apoptotic cells exhibited red fluorescence and live normal cells with intact cell membrane and normal nucleus displayed bright green fluorescence. Among the tested compounds, compound 3E: and 3B: showed the maximum potency to induce apoptosis with percentage of apoptosis 25.61±2.95and 23.45±1.46 respectively followed by 3F: (20.95±0.40) and 3D: (20.44±1.60) in comparison with control (5.14±0.44).

Multicomponent Synthesis of Some Molecular Hybrid Containing Thiazole Pyrazole as Apoptosis Inducer.

An efficient and environmentally benign methodology for the oxidative aromatization of 1,4-dihydropyridines to their corresponding pyridine derivatives is developed. The oxidative aromatization of 1,4-dihydropyridines was explored using silica-supported ceric ammonium nitrate as catalyst in CH3CN with or without sonication at room temperature. This supported catalyst acts as a more efficient oxidising reagent and offers several advantages over other reported reagents in terms of reaction time and yields. The supported reagent is found to be more efficient and selective when compared with its unsupported form. The Belousov–Zhabotinskii reaction was not observed in present reaction. The dealkylation observed in case of 4-n-alkyl/n-alkenyl with other oxidising agents is also not observed in the present case.

Silica-supported ceric ammonium nitrate (CAN): a simple, mild and solid-supported reagent for quickest oxidative aromatization of Hantzsch 1,4-dihydropyridines

Kulbir Kadyan

Papers

Synthesis of novel inhibitors of α-amylase based on the thiazolidine-4-one skeleton containing a pyrazole moiety and their configurational studies

Design, synthesis, conformational and molecular docking study of some novel acyl hydrazone based molecular hybrids as antimalarial and antimicrobial agents

Thiazolidine‐4‐one clubbed pyrazoles hybrids: Potent α‐amylase and α‐glucosidase inhibitors with NLO properties

Multicomponent Synthesis of Some Molecular Hybrid Containing Thiazole Pyrazole as Apoptosis Inducer.

Silica-supported ceric ammonium nitrate (CAN): a simple, mild and solid-supported reagent for quickest oxidative aromatization of Hantzsch 1,4-dihydropyridines