From Antibacterial to Antitumour Agents: A Brief Review on The Chemical and Medicinal Aspects of Sulfonamides

Sulfonamides have been in clinical use for many years, and the development of bioactive substances containing the sulfonamide subunit has grown steadily in view of their important biological properties such as antibacterial, antifungal, antiparasitic, antioxidant, and antitumour properties. This review addresses the medicinal chemistry aspects of sulfonamides; covering their discovery, the structure- activity relationship and the mechanism of action of the antibacterial sulfonamide class, as well as the physico-chemical and pharmacological properties associated with this class. It also provides an overview of the various biological activities inherent to sulfonamides, reporting research that emphasises the importance of this group in the planning and development of bioactive substances, with a special focus on potential antitumour properties. The synthesis of sulfonamides is considered to be simple and provides a diversity of derivatives from a wide variety of amines and sulfonyl chlorides. The sulfonamide group is a non-classical bioisostere of carboxyl groups, phenolic hydroxyl groups and amide groups. This review highlights that most of the bioactive substances have the sulfonamide group, or a related group such as sulfonylurea, in an orientation towards other functional groups. This structural characteristic was observed in molecules with distinct antibacterial activities, demonstrating a clear structure-activity relationship of sulfonamides. This short review sought to contextualise the discovery of classic antibacterial sulfonamides and their physico-chemical and pharmacological properties. The importance of the sulfonamide subunit in Medicinal Chemistry has been highlighted and emphasised, in order to promote its inclusion in the planning and synthesis of future drugs.

Phenylpropanoid-based sulfonamide promotes cyclin D1 and cyclin E down-regulation and induces cell cycle arrest at G1/S transition in estrogen positive MCF-7 cell line

Cancer is one of the most critical problems of public health in the world and one of the main challenges for medicine. Different biological effects have been reported for sulfonamide-based compounds including antibacterial, antifungal, and antitumor activities. Herein, a series of phenylpropanoid-based sulfonamides (4a, 4a', 4b, 4b', 5a, 5a', 5b and 5b') were synthesized and their cytotoxic activity was evaluated against four cell lines derived from human tumours (A549 - lung, MCF-7 - breast, Hep G2 - hepatocellular carcinoma, and HT-144-melanoma). Cell viability was significantly reduced in the MCF-7 cell line when compounds 4b, 4b' and 5a were used; IC₅₀ values were lower than those found for their precursors (eugenol and dihydroeugenol) and sulfanilamide. We observed that 4b induced cell cycle arrest at G1/S transition. This is probably due to its ability to reduce cyclin D1 and cyclin E expression. Moreover, 4b also induced apoptosis in MCF-7 cells as demonstrated by an increase in the cell population positive for annexin V in treated cultures in comparison to the control group. Taken together, the data showed that 4b is a promising antitumor agent and it should be considered for further in vivo studies.

Diverse structural assemblies of U-shaped hydrazinyl-sulfonamides: experimental and theoretical analysis of non-covalent interactions stabilizing solid state conformations

The preparation and structures of five new U-shaped hydrazinyl-sulfonamides are reported.

Novel sulfamides as potential carbonic anhydrase isoenzymes inhibitors

Sulfamides represent an important class of biologically active compounds. A series of novel sulfamides were synthesized from 1-aminoindanes, 1-aminotetralin, 2-aminoindanes and 2-aminotetralin via the reactions of free amines, benzyl alcohol and chlorosulfonyl isocyanate (CSI) followed by hydrogenolysis of the obtained sulfamoylcarbamates. Carbonic anhydrase (CA, EC 4.2.1.1) inhibitory effects of the new sulfamides have been investigated. The human (h) isozymes hCA I and hCA II have been investigated in this study by using an esterase assay with 4-nitrophenyl acetate as substrate. The new sulfamides showed inhibition constants in the micro-submicromolar range, with one compound (N-(indane-1-yl)sulfamide) showing a Ki of 0.45μM against hCA I and of 1.07μM against hCA II.

Novel LDL-oriented pharmacotherapeutical strategies

Elevated levels of low-density cholesterol (LDL-C) are highly correlated with increased risk of cardiovascular diseases (CVD). Thus, current guidelines have recommended progressively lower LDL-C for cholesterol treatment and CVD prevention as the primary goal of therapy. Even so, some patients in the high risk category fail to achieve recommended LDL-C targets with currently available medications. Thereby, additional pharmaceutical strategies are urgently required. In the review, we aim to provide an overview of both current and emerging LDL-C lowering drugs. As for current available LDL-C lowering agents, attentions are mainly focused on statins, niacin, bile acid sequestrants, ezetimibe, fibrates and omega-3 fatty acids. On the other hand, the emerging drugs differ from mechanisms are including: intervention of cholesterol biosynthesis downstream enzyme (squalene synthase inhibitors), inhibition of lipoprotein assembly (antisense mRNA inhibitors of apolipoprotein B and microsomal transfer protein inhibitors), enhanced lipoprotein clearance (proprotein convertase subtilisin kexin type 9, thyroid hormone analogues), inhibition of intestinal cholesterol absorption (Niemann-Pick C1-like 1 protein and acyl coenzyme A:cholesterol acyltransferase inhibitors) and interrupting enterohepatic circulation (apical sodium-dependent bile acid transporter inhibitors). Several ongoing agents are in their different stages of clinical trials, in expectation of promising antihyperlipidemic drugs. Therefore, alternative drugs monotherapy or in combination with statins will be sufficient to reduce LDL-C concentrations to optimal levels, and a new era for better LDL-C managements is plausible.