Classical and advanced chemical sciences
One pot four component, environmentally benign synthesis of 1H-indol-2-yl-5,10-dioxo-5,10-dihydro-1H-pyrazolo[1,2-b]phthalazine-2- carbonitrile derivatives was achieved in the presence of ionic liquid [bmim][OH]. The multi component reaction occurs with an initial formation of pthalazine followed by its reaction with the Knoevenagel cyclocondensation product of indole aldehyde and malononitrile/ethyl cyanoacetate in the presence of [bmim][OH] as ionic liquid at 70-75 oC for 30-45 min. All the synthesized pthalazine indolyl analogues have been tested for their anti-cancer activity on breast and lung carcinoma cell lines. Among the tested derivatives, 5b, 5c, 5e, and 5f found to be active against the cancer cell lines. Further, molecular modeling studies were performed to understand binding pattern of the top active molecules with the target protein.
Keywords: [bmim][OH]; environmentally benign synthesis; one-pot reaction; indol derivatives
A novel series of substituted chalcones containing benzyloxy moiety (3a-3h) was synthesized by microwave induced Claisen-Schmidt condensation of 2-acetyl-1-naphthol and its halo derivatives with different substituted aromatic aldehydes. All the synthesized chalcones were characterized by spectral analysis and screened for their antibacterial and antifungal effectiveness by using standard methods. It is found that the microwave irradiation technique is superior in terms of considerable increase in the reaction rate, yields and shortening the reaction time. The investigation of antimicrobial screening revealed that compounds (3a-3d) containing benzyloxy group at para position of aldehyde ring of chalcones possessing more potent antimicrobial activity.
Keywords: Chalcones; Claisen-Schmidt condensation; microwave irradiation; antibacterial activity; antifungal activity
In the investigation, a series of new pyridyl and thiazolyl clubbed hydrazone derivatives have been synthesized. The newly synthesized compounds were evaluated for their in vitro antimicrobial and antioxidant activities. Some among the compounds have shown excellent antimicrobial activity against both bacterial and fungal pathogens. Two compounds among the series have exhibited excellent antioxidant activity. Furthermore, a molecular docking study has been performed against DNA gyrase to know the binding modes of these molecules and recorded good binding affinity. The ADME study has also been performed for predicting the pharmacokinetic profile, which expressed good oral drug-like behaviour.
Keywords: Antimicrobial activity, antioxidant activity, thiazole, hydrazone, molecular docking study
The synthesis, X-ray crystal structure, and variable temperature magnetic properties of [(3-NH2-2-Clpy)2CuBr2] (3-NH2-2-Clpy = 3-chloro-2-aminopyridine) (1) are presented. The compound was characterized using combustion analysis, X-ray powder diffraction, single crystal X-ray diffraction, and temperature- dependent magnetic susceptibility measurements. Compound 1 crystallizes in the monoclinic space group P21/n. Inversion related molecules form a dimeric unit via short Cu…Br contacts. The dimers are linked into a step-like chain via short Br…Br contacts. Surprisingly, magnetic susceptibility measurements (1.8-325 K), which indicate weak antiferromagnetic interactions, are best fit by a uniform chain model suggesting that the exchange within and between dimers is nearly identical. Fitting the data with the S = ½ uniform chain model gave J = -3.38(2) K with C = 0.407(1).
Keywords: Copper(II); antiferromagnetism; crystal structure; 3-amino-2-chloropyridine
Chemical and biological aspects of life
The study sought to determine the phytochemical components, antioxidant and antimicrobial activities of n-hexane, ethyl acetate and methanolic extracts of Amaranthus hybridus L. leaf. Three extracts of A. hybridus were examined for antimicrobial activity using disc diffusion assay. The different extracts demonstrated varied concentration-dependent antimicrobial activities against the test organisms. All extracts studied in this work were active against E. coli, S. aureus, B. cereus, T. mentagrophyte and A. niger. The methanol extract showed potent inhibitory activity against T. mentagrophyte when compared to a standard antifungal agent, fluconazole. In vitro antioxidant activities were studied spectrophotometrically using vitamin C as standard. There were significant correlations between the methanolic extract and vitamin C for 2,2-diphenyl-1- picrylhydrazyl (DPPH) scavenging, reducing ability, hydroxyl radical inhibitory and phosphomolybdate scavenging. The results of this study have shown that leaves of A. hybridus possess bioactive compounds which contributed to its antimicrobial and antioxidant properties.
Keywords: Maceration; Amaranthus hybridus; phytochemical constituents; antimicrobial; antioxidant; stigmasterol; quinazoline; capsaicin; methyl commate B.
Theoretical and computational chemistry
Based on the results of a quantum chemical calculation using two variants of the DFT method, the possibility of the existence of a zinc heteroligand complex with trans-dibenzoporphyrazine and fluoride ion where oxidation degree of zinc is +3 that is unusual for the given chemical element, have been shown. The data on the key structural parameters and multiplicity of the ground state of this complex have been presented, too.
Keywords: zinc(III), fluoride ligand, di[benzo]porphyrazine, DFT method