New dithiocarbamate cycloaurated complexes have been synthesized and their physicochemical and in vitro antitumor properties have been evaluated. All the performed studies highlighted good transport through the blood and biodistribution, according to the balance between the properties of hydrophilicity/lipophilicity and the binding of moderate strength to the BSA protein. Furthermore, none of the complexes exhibited reduction or decomposition reactions, presenting excellent physiological stability. The in vitro cytotoxic effect was evaluated on human colon cancer cell line Caco-2/TC7, and the complexes showed great antiproliferative activity and excellent selectivity, as much less effect was detected on normal Caco-2/TC7 cells. Most of the complexes exhibit antiproliferative activity that was better than or similar to auranofin, and at least nine times better than that of cisplatin. Its action mechanism is still under discussion since no evidence of cell cycle arrest was found, but an antioxidant role was shown for some of the selective complexes. All complexes were also tested as antimicrobial drugs, exhibiting good activity towards S. aureus and E. coli. bacteria and C. albicans and C. neoformans fungi.
One of the major problems of the present era is air pollution, not only for its impact on climate change but also for the diseases provoked by this scourge. Among the most concerning air pollutants is particulate matter, since it can travel long distances and affect the entire globe. Antarctica is extremely sensitive to climate change and essential for regulating temperature and permitting life on Earth. Therefore, air quality studies in this region are extremely important. The aim of this review is to present the work conducted on the identification and detection of aerosols and particulate matter in the Antarctic region in the last 20 years. These studies revealed a large number of organic and inorganic species. Organochlorine pesticides or polychlorinated biphenyls represent almost 50% of the organic fraction detected in Antarctica. Furthermore, heavy metals such as Hg and Pb were also found in the region related to anthropogenic activities. To summarize, this work detailed different analytical techniques and data processing to help characterize Antarctic aerosols and their potential sources.
Air quality is a global concerning topic because of its great impact on the environment and health. Because of that, the study of atmospheric aerosols looking for harmful pollutants is rising, as well as the interest in the origin of the contaminants. Depending on the nature and size of the aerosols, some elements can be detected at a great distance from the emission source, even in Antarctica, where this study is conducted. Several samples of PM filters from 2018 to 2019 (Deception Island) and 2019-2020 (Livingston Island) campaigns have been analyzed by three powerful spectroscopic techniques: FESEM (Field Emission Scanning Electron Microscopy), LIBS (Laser Induced Breakdown Spectroscopy), and ICP-MS (Inductively Coupled Plasma Mass Spectrometry). These techniques have allowed us to find some heavy metals in the air of the Antarctic region (Al, Fe, Ti, Ni, Cr, and Mn). Deeper studies on ICP-MS results have confirmed those results and have also provided information on their potential sources. Thus, while Al, Fe, Ti and Mn concentrations can be explained by crustal origin, Ni and Cr presented high values only coherent with important human contribution. The results point out that the Antarctic region is no longer a clean and isolated environment from human pollution.
New cyclometalated gold(III) complexes with a general structure [Au(C^N)(SR)2] or [Au(C^N)Cl(SR)], where C^N is a biphenyl ligand such as 2-(p-tolyl)pyridinate (tpy), 2-phenylpyridinate (ppy) and 2-benzylpyridinate (bzp) (SR = Spym, S(Me)2pym, 2-thiouracil (2-TU) and thiourea), and also with ethynyl moieties of the type [Au(C^N)(C≡C-Ar)2] (Ar = p-toluene and 2-pyridine) have been synthesized. All of them have been characterized, including X-ray studies of complex [Au(bzp)Cl(Spym)], and these studies have permitted to elucidate that leaving chloride ligand is trans located to CAr atom. After the full characterization, physicochemical properties were measured by evaluating drug-like water solubility and cell permeability (partition coefficient). All these experiments pointed that our complexes present adequate properties to be used as anticancer drugs. Although not all the complexes showed antiproliferative effects on Caco-2 cells, those that did were more cytotoxic than cisplatin; and complex [Au(tpy)Cl(2-TU)] is even more active than auranofin. In addition to this effectiveness, no evidence of cytotoxic effects was observed on considered normal cells (with the exception of [Au(bzp)Cl(2-TU)]. Further action mechanisms studies were performed using these selective complexes, showing cell cycle arrest on the G2/M phase, a proapoptotic behaviour and also the modification of some genes involved in tumorigenesis. Thus, as a result of this investigation, we present a new family of 17 cyclometalated complexes, 6 of them being selective and possible candidates to be used against colon cancer.