1,4-Benzothiazine-2-carboxylic acid 1-oxides as analogues of antibacterial quinolones

Synthesis of 7-amino-6-halogeno-3-phenylquinoxaline-2-carbonitrile 1,4-dioxides: a way forward for targeting hypoxia and drug resistance of cancer cells

New water-soluble hypoxia activated 7-aminoquinoxaline 1,4-dioxides, prepared by the regioselective Beirut reaction, acted as HIF-1α suppressors and induced apoptosis in hypoxic and MDR cancer cells.

Synthesis, characterization, antimicrobial activities and QSAR studies of some 10a-phenylbenzo[b]indeno[1,2-e][1,4]thiazin-11(10aH)-ones

A series of 10a-phenylbenzo[b]indeno[1,2-e][1,4]thiazin-11(10aH)-ones (3) has been synthesized and tested for their antimicrobial activity. The antimicrobial evaluation data indicated that compounds, 3b, 3d, 3k and 3m exhibited very promising antibacterial activity and the compounds 3b and 3k exhibited notable activity, almost comparable to penicillin for Staphylococcus aureus and Bacillus subtilis respectively. The derivatives 3g and 3l exhibited high antifungal activity. Moreover, antibacterial activities were more prolific than antifungal activity. The QSAR studies indicated the importance of topological parameters, Kiers second order molecular index (κα(2)) and molecular connectivity index (χ) in describing the antibacterial activity and electronic parameters, the energy of highest occupied molecular orbital (HOMO) and the dipole moment (μ) in describing the antifungal activity.

A Synthesis of 4H-1, 4-Benzothiazines

A convenient synthesis of 4H-1, 4-benzothiazines is described. The key step is the coupling between 2-amino-5-chlorophenyl disulfide (3) and ethyl acetylenecarboxylate (4) in the presence of CuI as a catalyst or by microwave irradiation in moderate yield.

Design and synthesis of modified quinolones as antitumoral acridones

The bacterial topoisomerase II (DNA gyrase) and the mammalian topoisomerase II represent the cellular targets for quinolone antibacterials and a wide variety of anticancer drugs, respectively. In view of the mechanistic similarities and sequence homologies exhibited by the two enzymes, tentative efforts to selectively shift from an antibacterial to an antitumoral activity was made by synthesizing a series of modified tricyclic quinolones, in which the essential 3-carboxylic function is surrogated by phenolic OH and the classic C-6 fluorine atom is replaced by a NH2 group. The resulting 7-amino-9-acridone derivatives were assayed for their antibacterial as well as cytotoxic activities. No antibacterial activity was found. On the other hand, many derivatives showed significant cytotoxic activity against both HL-60 and P388 leukemias and a wide panel of human and rodent solid tumor cells, derivatives 25 and 26 displaying the best overall antiproliferative activity. Against the LoVo cell line, derivative 25 exhibited higher cytotoxic effects than etoposide.