Synthesis and in vitro cholinesterase inhibitory potential of dihydropyridine derivatives.

Twelve derivatives of dihydropyridine derivatives (6-17) were synthesized and evaluated for in-vitro cholinesterases (AChE, BChE) inhibitory activity. All compounds showed potent activity with IC50 values between 0.21±0.003 to 147.14±0.12µM for AChE and among them five compounds showed potent activity with IC50 values 17.16±0.02 to 231.6±0.12µM for BChE when compared with standard Eserine (IC50 = 0.85±0.0001 µM (AChE) & 0.04±0.0001µM (BChE). The most potent compound 11 can be considered as potential lead compound showed an inhibition of 95.35±0.11 and IC50= 0.21±0.003 while compound 7 showed an inhibition of 83.45±0.13 and IC50= 17.16±0.02. It is concluded from structural activity relationship that the presence of nitro group at C-2 and C-4 position of dihydropyridine ring increase the acetyl cholinesterase and butyrylcholinesterase activities of these compounds while presence of -Br and -Cl also enhances the activities.

Biologically active scaffolds: Synthesis, characterization and studies of oxino bis-pyrazoles by environmental friendly method.

In the present communication, synthesis of bis-pyrazolones containing aryl motifs (4-14) and their α-glucosidase inhibitory activity, hemolytic and antihemolytic activities were reported. The newly synthesized compounds were characterized by analytical techniques such 1H-NMR, 13C-NMR, IR, mass spectrometry and compound No 4 additionally by X-ray crystallography. Compounds 4, 12, 14 were obtained in more than 85% yield. In comparison to typical acarbose (IC50 = 37.38±0.12µM), all synthesized compounds showed potent activity with IC50 values between 31.26±0.11 to 396.25±0.18µM. The most potent compounds 6, 8 and 11 showed IC50 values within the range of 31.26±0.11 to 37.48±0.12µM. Compounds 7, 10, 12 and 13 showed IC50 values within the range of 65.23±0.12 to 154.87±0.16µM, while compounds 4, 5 and 9 showed moderate inhibition with IC50 values 286.56±0.16 to 396.25±0.18µM. Structure-activity relationship (SAR) studies, suggests that electron withdrawing groups played a crucial role in enhancing α-glucosidase inhibitory effects of title compounds. In addition, results of the hemolytic and antihemolytic activity studies indicated that compound 13 possessed moderate levels of hemolytic and highest anti- hemolytic activity while 8 showed low anti- hemolytic and high hemolytic activity.

Microwave and conventional synthesis of Co (II), Cu (II) and Ni (II) metal complexes of some acid hydrazones with their spectral characterization and biological evaluation.

The transition metal complexes of Co(II), Ni(II), and Cu(II) derived from N'-((5-(2,5-dichlorophenyl)furan-2-yl)methylene)-2-hydroxybenzohydrazide (L24) and N'-((5-(2, 5-dichlorophenyl)furan-2-yl)methylene)benzohydrazide (L21) have been synthesized by conventional as well as microwave method being shorter time consuming, solvent less and gives improved yields as compared to the traditional conventional technique. These compounds were characterized by melting point, TLC, FTIR, 1H-NMR, elemental analysis, potentiometric titration, ICP-OES and EIMS. From this analytical data it is confirmed that complexes are in octahedral structure with coordination number 6 which revealed 1:2 (metal:ligand). FTIR data shows that these synthesized hydrazone ligands have ONO donor sites and coordinate with transition metal ions in a tridentate monobasic manner. All these synthesized compounds were tested for evaluation of antibacterial activity by agar disc diffusion assay and total antioxidant activity by Phosphomolybdenum method.

A library-screening approach for developing a fluorescence sensing array for the detection of metal ions.

Detection of individual metal ions is of importance across a range of fields of chemistry including environmental monitoring, and health and disease. Fluorescence is a highly sensitive technique and small fluorescent molecules are widely used for the detection and quantification of metal ions in various applications. Achieving specificity for a single metal from a single sensor is always a challenge. An alternative to selective sensing is the use of a number of non-specific sensors, in an array, which together respond in a unique pattern to each analyte. Here we show that screening a library of compounds can give a small sensor set that can be used to identify a range of metal ions following PCA and LDA. We explore a method for screening the initial compounds to identify the best performing sensors. We then present our method for reducing the size of the sensor array, resulting in a four-membered system, which is capable of identifying nine distinct metal ion species in lake water.

Ethyl 2-(pyridine-4-carboxamido)-4,5,6,7-tetra-hydro-1-benzothio-phene-3-carboxyl-ate.

In the title compound, C(17)H(18)N(2)O(3)S, the dihedral angles between the thio-phene ring and the ethyl ester group and the pyridine-4-carboxamide unit are 7.1 (2) and 9.47 (11)°, respectively. An intra-molecular N-H⋯O hydrogen bond generates an S(6) ring. In the crystal, inversion dimers linked by pairs of C-H⋯O hydrogen bonds between the tetra-hydro-1-benzothio-phene and the pyridine-4-carboxamide residues generate R(2) (2)(16) loops. There exists positional disorder in three methelene groups of the cyclo-hexane ring and the terminal C atom of the ethyl ester side chain in a 0.691 (14):0.309 (14) occupancy ratio.