Synthesis of 1,3-thiazine-2,4-diones with potential anticancer activity

Green Synthetic Strategies and Pharmaceutical Applications of Thiazine and its Derivatives: An Updated Review

Thiazines are a sizable class of organic heterocycles that are notable for their skeletal versatility and relative chemical simplicity, making them among the most flexible sources of biologically active compounds. The term "green synthesis" refers to implementing energy-efficient procedures for the nature-friendly production of materials and chemicals using green solvents, catalysts, and suitable reaction conditions. Considering the importance of green chemistry and the outstanding therapeutic profile of thiazines, the present work was designed to review the recent advances in green chemistry-based synthetic strategies of thiazine and its derivatives. The green synthetic approaches, including microwave-assisted, ultrasound-assisted, and various other synthetic methods for thiazine and its derivatives, were discussed and generalized. In addition, applications of thiazine and its derivatives in pharmaceutical sciences were explained with examples of marketed drugs.The discussed sustainable synthetic methods for thiazines and their derivatives could be useful in developing other medicinally important lead molecules. They could also aid in developing new synthetic schemes and apparatuses that may simplify chemical manufacturing processes and enable novel reactions with minimal by-products while questing for optimal, green solvents. This review can help anyone interested in this fascinating class of heterocycles to make decisions about selecting targets and tasks for future research.

Synthesis of imidazo[4,5-e][1,3]thiazino[2,3-c][1,2,4]triazines via a base-induced rearrangement of functionalized imidazo[4,5-e]thiazolo[2,3-c][1,2,4]triazines

A series of imidazo[4,5-e][1,3]thiazino[2,3-c][1,2,4]triazines was synthesized via a cascade sequence of hydrolysis and skeletal rearrangement of imidazo[4,5-e]thiazolo[2,3-c][1,2,4]triazin-7(8H)-ylidene)acetic acid esters in methanol upon treatment with excess KOH. Imidazo[4,5-e]thiazolo[3,2-b][1,2,4]triazin-6(7H)-ylidene)acetic acid esters are also suitable substrates for the reaction. In this case hydrolysis and thiazole ring expansion were accompanied with the change of the thiazolotriazine junction type from thiazolo[3,2-b][1,2,4]triazine to thiazino[2,3-c][1,2,4]triazine.

Influence of ligand lipophilicity in Pt(II) complexes on their antiproliferative and apoptotic activities in tumour cell lines

One of the most widely used strategies for drug development is the coordination of bioactive ligands to transition metals, which could improve biological activity. Moreover, the incorporation of aromatic groups to ligands may allow an enhanced lipophilicity that can influence the cellular uptake and accumulation of the metallodrugs, thus increasing their activity. Herein, we have reported the synthesis and characterization of four Pt(II) complexes [PtCl₂(L)], where L = 2-(1-pyrazolyl)-2-thiazoline (PzTn), 2-(1-pyrazolyl)-1,3-thiazine (PzTz), 2-(3,5-diphenyl-1-pyrazolyl)-2-thiazoline (DPhPzTn) or 2-(3,5-diphenyl-1-pyrazolyl)-1,3-thiazine (DPhPzTz). The study was aimed at analysing their potential anticarcinogenic ability in epithelial cervix carcinoma HeLa, human promyelocytic leukemia HL-60 and human histiocytic lymphoma U-937 tumour cell lines as well as checking whether the structural factors of the organic ligand may influence their biological activity. Our findings showed that PtDPhPzTn and PtDPhPzTz were far more effective in terms of cytotoxicity than their less lipophilic counterparts (PtPzTn and PtPzTz), especially in cells derived from solid cervical tumours, thereby suggesting that modulating the lipophilicity of the ligands can help improve the cytotoxic effect of the metal complexes.

Chemistry of Substituted Thiazinanes and Their Derivatives

Thiazinanes and its isomeric forms represent one of the most important heterocyclic compounds, and their derivatives represented a highly potent drug in disease treatment such as, 1,1-dioxido-1,2-thiazinan-1,6-naphthyridine, which has been shown to have anti-HIV activity by a mechanism that should work as anti-AIDS treatment, while (Z)-methyl 3-(naphthalen-1-ylimino)- 2-thia-4-azaspiro[5 5]undecane-4-carbodithioate showed analgesic activity, cephradine was used as antibiotic and chlormezanone was utilized as anticoagulants. All publications were interested in the chemistry of thiazine (partially or fully unsaturated heterocyclic six-membered ring containing nitrogen and sulfur), but no one was dealing with thiazinane itself which encouraged us to shed new light on these interesting heterocycles. This review was focused on the synthetic approaches of thiazinane derivatives and their chemical reactivity.

Carbodiimide-based synthesis of N-heterocycles: moving from two classical reactive sites to chemical bond breaking/forming reaction

Carbodiimides are a unique class of heterocumulene compounds that display distinctive chemical properties. The rich chemistry of carbodiimides has drawn increasing attention from chemists in recent years and has made them exceedingly useful compounds in modern organic chemistry, especially in the synthesis of N-heterocycles. This review has outlined the extensive application of carbodiimides in the synthesis of N-heterocycles from the 1980s to today. A wide range of reactions for the synthesis of various types of N-heterocyclic systems (three-, four-, five-, six-, seven-, larger-membered and fused heterocycles) have been developed on the basis of carbodiimides and their derivatives.

Assessment of the Antitumor Potentiality of Newly Designed Steroid Derivatives: Pre-Clinical Study

Cancer is recognized as one of the most prevalent contributors to mortality in several nations and it remains one of the common health issues globally. In particular, hepatocellular carcinoma (HCC) has become a public health problem along with the increase of hepatitis B (HBV) and hepatitis C (HCV) virus infections. Based on this fact, our study goaled to synthesize newly hybrid drugs containing heterocyclic rings incorporated to steroid moiety and to examine the potential antitumor activity of the newly designed heterosteroid derivatives against HCC induced in animal model. Several heterocyclic steroids were synthesized 2-7 and confirmed via the analytical and spectral data (IR, ¹H NMR¹³C NMR and Mass spectroscopy). Compounds 3, 4, and 5 were chosen to be investigated as anticancer agents in HCC rat model by means of validated biomarkers (alfa –fetoprotein, endoglin, lipocali-2 and heat shock protein-70). Following administration of compounds 3, 4 or 5, availability of the active tumor marker molecules was significantly dropped and a substantial decrease of the angiogenic and inflammatory mediators was also evident. These findings were supported by the histological examination of liver tissue. Taken together, this study indicates the potential anticancer activity of the newly synthesized heterosteroid derivatives against HCC in vivo. The antitumor activity of these compounds was likely attributable to modulating some signal transduction pathways involved in tumorigenesis, angiogenesis and inflammation.

Design, synthesis, and nematicidal activities of novel 1,3-thiazin(thiazol)-4-one derivatives against Meloidogyne incognita

Four series of novel 1,3-thiazin(thiazol)-4-one derivatives were synthesized by Suzuki coupling. Preliminary bioassays showed that most of the synthesized compounds exhibited good inhibitory activity in vivo against root-knot nematodes, Meloidogyne spp. at 20 mg L−1. Among the tested compounds, we found that two compounds displayed 46.4% and 41.4% inhibitory activity even at 1 mg L−1, respectively.

Antitumor activity of methyl (Z)-2-(isothioureidomethyl)-2-pentenoate hydrobromide against leukemia cell lines via mitotic arrest and apoptotic pathways

In a previous study, we described a series of 28 aryl- and alkyl-substituted isothiouronium salts with antitumor activity and selectivity toward a leukemia cell line. Among the synthesized compounds, methyl (Z)-2-(isothioureidomethyl)-2-pentenoate hydrobromide (IS-MF08) showed conspicuous activity. In the present study, we investigated the mechanism of action of IS-MF08. Our results showed that its mechanism most likely is related with the membrane receptor Fas and subsequent activation of the extrinsic cell death pathway, triggered by a decrease in the levels of the anti-apoptotic protein Bcl-2 and caspase-8 and -3 cascade activation, causing DNA damage and mitotic arrest. IS-MF08 also caused an increase in intracellular ROS, endoplasmic reticulum (ER) stress, and mitochondrial membrane permeabilization, resulting in organelle degradation as an attempt to reestablish cell homeostasis. Furthermore, cells exposed to IS-MF08 combined to an autophagy inhibitor were less susceptible to compound's cytotoxicity, suggesting that autophagy makes part of its mechanism of action. These data support the hypothesis that IS-MF08 acts by the apoptosis extrinsic pathway and possibly by autophagy as mechanisms of cell death.

Bioactive Thiazine and Benzothiazine Derivatives: Green Synthesis Methods and Their Medicinal Importance

Thiazines are a group of heterocyclic organic compounds that are still largely unexplored for their pharmacological activities. There are different available methods for the synthesis of thiazine derivatives in the literature. In this review, we discuss available methods of thiazine preparation through green synthesis methods. Beside their synthesis, many thiazine derivatives are biologically active and play an important role in the treatment of various diseases and show promising results of varying degrees, where they act as antibacterial, antifungal, antitumor, antimalarial, antineoplastic, antiviral, anti-inflammatory, analgesic and anticancer agents and thus they represent an interesting class of heterocyclic medicinal compounds worthy of further exploration.

New derivative of 2-(2,4-dihydroxyphenyl)thieno-1,3-thiazin-4-one (BChTT) elicits antiproliferative effect via p38-mediated cell cycle arrest in cancer cells

2-(2,4-Dihydroxyphenyl)thieno-1,3-thiazin-4-ones are a group of new compounds with potential anticancer activity. This type of derivatives was poorly investigated in the area of synthesis and biological activities. In the present study the antiproliferative action of the most active derivative BChTT was described. The aim of biological evaluation was to investigate the ability of the compound to inhibit cancer cell proliferation and identify mechanism involved in its action on the molecular level. BChTT inhibited the proliferation of lung cancer A549, colon cancer HT-29 and glioma C6 cells in the concentration-dependent manner. It was not toxic to normal cells including skin fibroblasts, hepatocytes and oligodendrocytes in the antiproliferative concentrations. BChTT decreased the DNA synthesis in the treated cancer cells and induced cell cycle arrest in the G0/G1 phase. Moreover, the ability of the compound to activate p38 kinase and decrease cyclin D1 expression was estimated. Participation of p38 kinase in the antiproliferative action of the compound was confirmed by the analysis of BChTT activity in the cells with the p38 silenced gene. The obtained results may suggest the ability of the tested derivative to inhibit cancer cells proliferation by induction of p38-mediated cyclin D1 downregulation.

Piperine promotes ultraviolet (UV)-B-induced cell death in B16F10 mouse melanoma cells through modulation of major regulators of cell survival

Piperine elevates intracellular ROS formation and impairs calcium homeostasis. It acts as a potent UVB photosensitizer, causing cell death and attenuation of major regulators of survival signalling pathways, offering a possible, practical therapeutic strategy for melanoma.