A Broad Spectrum Antiparasitic Activity of Organotin (IV) Derivatives and Its Untargeted Proteomic Profiling Using Leishmania donovani

Metals have been used in medicine since ancient times for the treatment of different ailments with various elements such as iron, gold and arsenic. Metal complexes have also been reported to show antibiotic and antiparasitic activity. In this context, we tested the antiparasitic potential of 10 organotin (IV) derivatives from 4-(4-methoxyphenylamino)-4 oxobutanoic acid (MS26) against seven eukaryotic pathogens of medical importance: Leishmania donovani, Trypanosoma cruzi, Trypanosoma brucei, Entamoeba histolytica, Giardia lamblia, Naegleria fowleri and Schistosoma mansoni. Among the compounds with and without antiparasitic activity, compound MS26Et3 stood out with a 50% effective concentration (EC₅₀) of 0.21 and 0.19 µM against promastigotes and intracellular amastigotes of L. donovani, respectively, 0.24 µM against intracellular amastigotes of T. cruzi, 0.09 µM against T. brucei, 1.4 µM against N. fowleri and impaired adult S. mansoni viability at 1.25 µM. In terms of host/pathogen selectivity, MS26Et3 demonstrated relatively mild cytotoxicity toward host cells with a 50% viability concentration of 4.87 µM against B10R cells (mouse monocyte cell line), 2.79 µM against C2C12 cells (mouse myoblast cell line) and 1.24 µM against HEK923 cells (human embryonic kidney cell line). The selectivity index supports this molecule as a therapeutic starting point for a broad spectrum antiparasitic alternative. Proteomic analysis of host cells infected with L. donovani after exposure to MS26Et3 showed a reduced expression of Rab7, which may affect the fusion of the endosome with the lysosome, and, consequently, impairing the differentiation of L. donovani to the amastigote form. Future studies to investigate the molecular target(s) and mechanism of action of MS26Et3 will support its chemical optimization.

Review of 13carbon nuclear magnetic resonance characterizations of dimethyltin carboxylates

Diorganotin carboxylates have received much interest in past decades due to their rich structural chemistry and wide range of applications in various fields. This review study provides an in-depth analysis of carbon NMR data of dimethyltin complexes. The absorptions shown by the carbonyl carbon, methyl groups attached to tin and the other carbons present in the complexes were presented in this study. The effects of nature and the number of substituents attached are also described in this report.

Air and moisture stable covalently-bonded tin(ii) coordination polymers

Compounds (1)–(4) display 1D, 2D or 3D coordination networks, in which the Sn(ii) cations exhibit distorted disphenoidal geometries due to the stereochemically active electron lone pairs.

Main-Group Medicinal Chemistry Including Li and Bi*

Main-group element compounds were among the first developed in the modern era as pharmaceutical preparations for the treatment of a wide variety of human ailments; it is now recognized that many of these elements exist in traditional medicine of many societies, for example, arsenic. The use of main-group element compounds in contemporary medicine continues for the treatment of, for example, depression (Li), stomach ulcers (Bi), cancer (As and Ga), and leishmaniasis (Sb). Not surprisingly, new compounds of these elements, and other main-group elements, continue to be investigated for their potential use in new therapies. In this chapter, the use of main-group elements as therapeutic agents is outlined and also, where understood, comments on biological targets and mechanisms of action. Further, key advances in new potential applications of main-group element compounds in medicine are evaluated.

Mechanisms by which the antitumor compound di-n-butyl-di-(4-chlorobenzohydroxamato)tin(IV) induces apoptosis and the mitochondrial-mediated signaling pathway in human cancer SGC-7901 cells

The mechanisms by which the strong antitumor diorganotin(IV) compound di-n-butyl-di-(4-chlorobenzohydroxamato)tin(IV) (DBDCT) induces apoptosis of SGC-7901 cells were first investigated. Inhibition of proliferation of four cancer cell lines compared with normal human hepatic L-O2 cells, cancer cell apoptosis, and expression of related mRNA and protein were detected using the methyl thiazolyl tetrazolium (MTT), flow cytometry, reverse transcription polymerase chain reaction (RT-PCR), Western blot, and DNA ladder assays, and electron microscopy and immunocytochemistry. DBDCT decreased cancer cell proliferation rates in a dose- and time-dependent manner and changed the cycle distribution of SGC-7901 cells; the proportion of cells in G(0)-G(1) phase was increased, whereas the numbers in S and G(2)-M phases were decreased. Blockade of the cell cycle was perhaps associated with increased levels of p21, p27, p53 and the decreased level of proliferating cell nuclear antigen (PCNA). Apoptosis was characterized by DNA fragmentation, chromosomal condensation, apoptotic bodies, sub-G(1) peaks, and an increased apoptotic rate, as shown using the annexin V-FITC method. Pretreatment of cells with N-acetylcysteine and caspase-9 inhibitor could reduce growth inhibition and DBDCT-induced apoptosis. The results showed that DBDCT-mediated cell-cycle arrest might occur through the induction of p21 in a p53-dependent manner and that DBDCT induction of the mitochondrial apoptotic signaling pathway is perhaps mediated by increasing Bax/Bcl-2 ratios, which result in the loss of DeltaPsi(m), release of cytochrome c into the cytoplasm, activation of caspase-3 and -9, and increased reactive oxygen species (ROS) generation.