QSAR study of inibition by coumarins of IQ induced mutation in S. typhimurium TA98

In silico prediction of the mutagenicity of nitroaromatic compounds using correlation weights of fragments of local symmetry

Most quantitative structure-property/activity relationships (QSPRs/QSARs) techniques involve using different programs separately for generating molecular descriptors and separately for building models based on available descriptors. Here, the capabilities of the CORAL program are evaluated. A user of the program should apply as the basis for models the representation of the molecular structure by means of the simplified molecular input-line entry system (SMILES) as well as experimental data on the endpoint of interest. The local symmetry of SMILES is a novel composition of symmetrically represented symbols, which are three 'xyx', four 'xyyx', or five symbols 'xyzyx'. We updated our CORAL software using this optimal, new flexible descriptor, sensitive to the symmetric composition of a specific part of the molecule. Computational experiments have shown that taking account of these attributes of SMILES can improve the predictive potential of models for the mutagenicity of nitroaromatic compounds. In addition, the above computational experiments have confirmed the advantage of using the index of ideality of correlation (IIC) and the correlation intensity index (CII) for Monte Carlo optimization of the correlation weights for various attributes of SMILES, including the local symmetry. The average value of the coefficient of determination for the validation set (five different models) without fragments of local symmetry is 0.8589 ± 0.025, whereas using fragments of local symmetry improves this criterion of the predictive potential up to 0.9055 ± 0.010.

Facile synthesis of pyrazole derivatives using reusable Fe3O4@MCM-41-SO3H

In this research, Fe3O4-MCM-41-SO3H was synthesized as a magnetically reusable Lewis acid catalyst and used in the cyclization reaction of 3-acylcoumarins or 3-chromonecarboxylic acid with arylhydrazine derivatives for the synthesis of pyrazoles in high yields under solvent-free conditions and with a simple work-up process. Fe3O4-MCM-41-SO3H was characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analyses.

Synthesis of 3-[(coumarinyl)carbonyl]-3a,8b-dihyroindeno[1,2-b]pyrrole-4(1H)-ones and their conversion to coumarin bearing spiro[isobenzofuran-1,2′-pyrrole] moiety compounds via oxidative cleavage reaction

The synthesis of substituted coumarin derivatives bearing indenopyrrole and spiro[isobenzofuran-1,2′-pyrrole] in a four-component sequential reaction and following oxidative cleavage reaction.

FT-IR, FT-Raman and UV-Vis spectra and DFT calculations of 3-cyano-4-methylcoumarin

The vibrational and electronic spectra of 3-cyano-4-methylcoumarin (3C4MC) are reported and discussed. In this work the structural properties, vibrational frequencies and electronic spectra of 3C4MC have been investigated extensively using density functional theory (DFT) employing B3LYP exchange correlation with the normal basis level 6-31G(d,p). NBO and HOMO, LUMO analysis has been carried out. The geometries and normal modes of vibrations obtained from B3LYP calculations are in good agreement with the experimentally observed data.

Antitumor agents 292. Design, synthesis and pharmacological study of S- and O-substituted 7-mercapto- or hydroxy-coumarins and chromones as potent cytotoxic agents

Thirty-five S- and O-substituted 7-mercaptocoumarin (9-23) and 7-hydroxy- or 7-mercapto-chromone (24-43) analogs were designed, synthesized and evaluated in vitro against four human tumor cell lines [KB (nasopharyngeal), KB-vin (vincristine-resistant subline), A549 (lung) and DU145 (prostate)] with paclitaxel as the positive control. Many of the synthesized compounds exhibited potent cytotoxic activity. Among them, compounds 10 and 18 showed broad spectrum activity with GI(50) values ranging from 0.92 to 2.11 μM and 2.06-14.07 μM, respectively. However, 33, a 3-brominated compound, displayed significant and selective inhibition against MDR KB-vin with a GI(50) of 5.84 μM. Regardless of the size of the 7-alkoxy group, 2-α-bromoethyl-8-bromomethyl compounds (40-43) exhibited increased cytotoxicity compared with 2-ethyl-8-bromomethyl compounds (36-39). Moreover, in a preliminary pharmacological study, 10 not only remarkably increased cellular apoptosis in a concentration-dependent manner, but also clearly induced A549 cell cycle arrest at the G2/M phase. Thus, these coumarin derivatives merit investigation as novel potential antitumor agents with further structural modification to produce an optimal lead compound and elucidate the detailed pharmacological mechanism(s).

Design of novel 4-hydroxy-chromene-2-one derivatives as antimicrobial agents

This paper presents the design of novel 4-hydroxy-chromene-2 one derivatives, based on previously obtained minimal inhibitory concentration values (MICs), against twenty four microorganism cultures, gram positive and negative bacteria and fungi. Two of our compounds, 3b (MIC range 130-500 microg/mL) and 9c (31.25-62.5 microg/mL), presented high potential antimicrobial activity. The compound 9c had equal activity to the standard ketoconazole (31.25 microg/mL) against M. mucedo. Enlarged resistance of S. aureus, E. coli and C. albicans on the effect of potential drugs and known toxicity of coumarin antibiotics, motivated us to establish SAR and QSAR models of activity against these cultures and correlate biological activity, molecular descriptors and partial charges of functional groups to explain activity and use for the design of new compounds. The QSAR study presents essential relation of antimicrobial activity and dominant substituents, 4-hydroxy, 3-acetyl and thiazole functional groups, also confirmed through molecular docking. The result was ten new designed compounds with much improved predicted inhibition constants and average biological activity.