A 2-(benzothiazol-2-yl)-phenolato platinum(II) complex as potential photosensitizer for combating bacterial infections in lung cancer chemotherapy†.

Cancer and antibiotic resistance are two global health threats that usually hamper clinical chemotherapeutic efficacy. Particularly for lung cancer, bacterial infections frequently arise thereby complicating the course of cancer treatment. In this sense, three new neutral luminescent cycloplatinated(II) photosensitizers of the type [Pt(dmba)(L)] (dmba = N,N-dimethylbenzylamine-κN,κC; L = 2-(benzo[d]oxazol-2-yl)-phenolato-κN,κO1, 2-(benzo[d]thiazol-2-yl)-phenolato-κN,κO2, and 2-(1-methyl-1H-benzo[d]imidazole-2-yl)phenolato-κN,κO3) have been characterized and developed to potentially eliminate both resistant bacteria and lung cancer cells. The phototherapeutic effects of complex 2 have been evaluated using low doses of blue light irradiation. Complex 2 exerted promising photoactivity against pathogenic Gram-positive bacteria strains of clinical interest, displaying a phototoxic index (PI) of 15 for methicillin-resistant Staphylococcus aureus, one of the major microorganisms predominating lung infections. Likewise, the anticancer activity of 2 was also increased upon light irradiation in human lung A549 cancer cells (PI = 36). Further in vitro experiments with this platinum(II) complex suggest that ROS-generating photodynamic reactions were involved upon light irradiation, thus providing a reasonable mechanism for its dual anticancer and antibacterial activities.

Synthesis and Evaluation of Thymol-Based Synthetic Derivatives as Dual-Action Inhibitors against Different Strains of H. pylori and AGS Cell Line.

Following a similar approach on carvacrol-based derivatives, we investigated the synthesis and the microbiological screening against eight strains of H. pylori, and the cytotoxic activity against human gastric adenocarcinoma (AGS) cells of a new series of ether compounds based on the structure of thymol. Structural analysis comprehended elemental analysis and 1H/13C/19F NMR spectra. The analysis of structure-activity relationships within this molecular library of 38 structurally-related compounds reported that some chemical modifications of the OH group of thymol led to broad-spectrum growth inhibition on all isolates. Preferred substitutions were benzyl groups compared to alkyl chains, and the specific presence of functional groups at para position of the benzyl moiety such as 4-CN and 4-Ph endowed the most anti-H. pylori activity toward all the strains with minimum inhibitory concentration (MIC) values up to 4 µg/mL. Poly-substitution on the benzyl ring was not essential. Moreover, several compounds characterized by the lowest minimum inhibitory concentration/minimum bactericidal concentration (MIC/MBC) values against H. pylori were also tested in order to verify a cytotoxic effect against AGS cells with respect to 5-fluorouracil and carvacrol. Three derivatives can be considered as new lead compounds alternative to current therapy to manage H. pylori infection, preventing the occurrence of severe gastric diseases. The present work confirms the possibility to use natural compounds as templates for the medicinal semi-synthesis.