Chamarthi Naga Raju

A series of new urea 3a–3d and thiourea derivatives 5a–5f have been synthesized in high yields (77–88%) by the reaction of substituted aryl isocyanates 2a–2d and substituted aryl isothiocynates 4a–4f with 4-aminobenzoic hydrazide 1. The structures of all the synthesized compounds were characterized by IR, NMR (¹H and ¹³C), mass and elemental analyses. The synthesized compounds were screened for their anti-microbial activity. The present study revealed that Gram-negative and positive bacteria such as Escherichia coli and Streptococcus aureus were more susceptible to the solvent extracts. The methanol and acetone extracts of the newly synthesized compounds were evaluated for in vitro antibacterial activity against human pathogenic bacteria Escherichia coli and Streptococcus aureus and antifungal activity against Aspergillus niger and Aspergillus oryzae. Compound 5e have exhibited good antibacterial and antifungal activity.

Functionalized ionic liquids (FILs) are efficient ILs for the protection of various functionalities such as aldehydes, phenol, and alcohols with acetic anhydride under neat conditions. The attracted rising interest and the subject of active research in the field of catalysis is the variety of expanded applications and yet reports on ILs are still quickly increasing. This work reports a sulfonic acid functionalized ionic liquid is an environmentally friendly, easy handling, and reusable ionic liquid catalyst for the protection of aldehydes and phenols. The catalyst was characterized with different spectroscopic techniques which indicates the fabricated IL is matching with the reported methods. The catalyst can be recycled up to eight times without substantial loss in activity. Furthermore, no chromatographic separations were needed to obtain the desired products.

A novel class of carbamoyl phosphonates derivatives of dimethyl, ethyl, and aryl phosphonates were prepared by one-pot synthesis through treatment with 4-methyl benzene sulfonyl isocyanates. The synthesized carbamoyl phosphonates were studied their antimicrobial activity and docking studies. The attained results displayed that, most of the products have significant antibacterial activity against both Gram-positive (Staphylococcus aureus, Bacillus subtilis) and Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli). The compound 3d shown good antifungal activity against Aspergillus niger, Trichoderma viride. In addition, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and minimum fungicidal concentration (MFC) was also calculated. Although molecular docking studies provide the bonding interaction between the product and DNA Gyrase binding pocket it shows the stability of the drug. The compound 3d (Diphenyl (tosylcarbamoyl) phosphonate) is found to be a potential antimicrobial agent against Pseudomonas aeruginosa and Trichoderma viride and 3d also showed hydrophobic interaction with 3LPX.

A series of new phosphorylated derivatives of didanosine were designed, synthesized and evaluated their anticancer effects on human breast cancer cells. Their binding affinities were evaluated against aromatase enzyme and the molecular docking studies demonstrated that 9a, 9h and 9i exhibited high binding interactions than the parent molecule (ddI) and other derivatives; evaluated the aromatase enzyme inhibition. The cell viability, cell proliferation, lactate dehydrogenase showed potential anti-proliferative in dose dependent manner, these results were well correlated with hoesch stain and DNA fragmentation on MDA-MB-231 breast cancer cell lines. Cytotoxicity results disclosed that tryptophan amino acid ester substituted derivative 9i showed potential cell death against MDA-MB-231 cancer cell lines. Furthermore, compound 9i has great potential significance for further investigations (in vivo).

A series of new carbamates and sulfonamide derivatives of cis-tramadol 5(a-e) and 7(a-e) have been synthesized in high yields by the reaction of cis-tramadol with various chloroformates 4(a-e) and sulfonyl chlorides 6(a-e). All the newly synthesized compounds were characterized by IR, NMR (1H and 13C), mass and elemental analyses. The synthesized compounds were evaluated for their antibacterial and antifungal activities. Compounds 5a, 5b, 7a and 7c exhibited potent antibacterial and antifungal activity.

Synthesis of a series of new urea and thiourea derivatives of 2-pyridyl piperazine was accomplished by reacting various isocyanates and isothiocyanates in the presence of triethylamine (TEA) at 50 °C. All the title compounds were obtained in high yields and their structures were characterized by IR, ¹H, ¹³C NMR, Mass spectral, and Elemental analysis. The synthesized compounds were screened for in vitro and in silico antioxidant and antimicrobial activities. All the title compounds exhibited potent antioxidant and antimicrobial activities. Out of all, 2c and 2f against DPPH, H₂O₂ and Nitro oxide have exhibited significant activity and the levels of activity were higher than the reference compounds, ascorbic acid and BHT. Whereas 2a, 2c, 2f and 2j have shown prominent activity in terms of zone of inhibition against all the microbial strains tested than the standards such as levofloxacin and nystatin. In addition in silico studies also conveyed the same that is 2a, 2c, 2f and 2j have displayed the highest binding energies against peroxiredoxins and DNA gyrase protein than the standards akin to the rest of the compounds. In overall, 2c and 2f have exhibited most promising antioxidant and antimicrobial activity than the rest of the title compounds in vitro and in silico. Hence, 2c and 2f will stand as a lead and promising antioxidant and antimicrobial drug candidates in future. Graphical Abstract Communicated by Ramaswamy H. Sarma

A series of new 1,1′-(1,4-phenylene)diurea derivatives were synthesized by reacting 1,4-diiso­cyanato­benzene with various biologically relevant primary and secondary amines with high yields. The struc­tures of the synthesized compounds were characterized by IR, ¹H and ¹³C NMR, and mass spectra and elemental analyses. Most of the synthesized compounds showed good activities against some bacterial and fungal strains.

Silica-supported lanthanum (III) chloride (SiO2–LaCl3·7H2O) was prepared and characterized by infrared spectroscopy, X-ray diffraction analysis,

A pioneering class of urea/thiourea derivatives of naphthalene-1,5-diamine was synthesized in excellent yields (89-96%) by one-pot procedure via treatments with phenyl isocyanates or phenyl isothiocyanates. All the constructed derivatives were evaluated for antimicrobial activity using in vitro and in silico methods. The obtained results showed that, all the titled compounds displayed the most significant antibacterial activity against gram-positive and gram-negative bacteria namely B. substilis, B. sphaerius, S. aureus, P. aeruginosa, K. aerogenes, C. violaceum and antifungal activity against A. Niger, C. tropicum, R. oryzae, F. moniliforme and C. lunata when compared with the standard drugs such as ciproflaxacin and clotrimazole. Among all, the compounds 2c, 2e and 3d, 3e displayed higher content of antimicrobial activity akin to the rest of the compounds due to the presence of fluoro substitution on aromatic ring. Furthermore, molecular docking studies provided support to the in vitro studies. Four of the synthesized compounds, 4-fluorophenyl, 3-trifluoromethylphenyl, 4-chlorophenyl exhibited significant binding modes and were the best target ligands as they fitted more stably into the DNA gyrase binding pocket. Henceforth, it is suggested that, the fabricated urea/thiourea derivatives of naphthalene-1,5-diamine would stand as the prosperous antimicrobial drug candidates for further studies.

The porous poly(2-naphthol) was made-up by combining the 2-naphthol, dimethoxymethane as an cross linker in presence of FeCl3. Furthermore the polymer was functionalized with ClSO3H to get a dense acid catalyst. The reagent is active for benzylation of arenes with benzylic alcohols irrespective of the nature of substituted arenes. This catalyst is good active compared with other acid catalyst used for Friedel−Crafts benzylation.