First Examples of H2S-Releasing Glycoconjugates: Stereoselective Synthesis and Anticancer Activities.

H2S donors are currently emerging as promising therapeutic agents in a wide variety of pathologies, including tumors. Cancer cells are characterized by an enhanced uptake of sugars, such as glucose. Therefore, novel glycoconjugated H2S donors were synthesized so that high concentrations of H2S can be selectively achieved therein. Dithiolethione portions or isothiocyanate portions were selected for their well-known H2S-releasing properties in the presence of biological substrates. A synthetic procedure employing trichloroacetimidate glycosyl donors was applied to produce, in a stereoselective fashion, C1-glycoconjugates, whereas C6-glycoconjugates were obtained by a Mitsunobu-based transformation. The resulting molecules were then tested for their anticancer effects on human pancreas adenocarcinoma ascites metastasis cell line AsPC-1. The most potent inhibitors of cell viability (6aß and 7b) proved to release H2S inside the AsPC-1 cells and to alter the basal cell cycle.

An Update on Patents Covering Agents That Interfere with the Cancer Glycolytic Cascade.

Many tumors exhibit altered metabolic characteristics relative to normal and healthy tissues. Their metabolic profile highlights a strong prevalence of glycolysis over oxidative phosphorylation, regardless of their exposure to different oxygen levels (the Warburg effect). This condition originates from a set of gene regulations, consisting of the overexpression of some enzymes or transporters involved in the glycolytic pathway. Therefore, these effectors may constitute appealing targets for the implementation of selective therapeutic interventions against cancer. Recently, significant progress has been made in the discovery of molecules that act at various levels of the glycolytic pathway of tumor cells. So far, some of the most widely explored targets of the glycolytic cascade are represented by glucose transporters, hexokinase, 6-phosphofructokinase, enolase, pyruvate kinase, lactate dehydrogenase, and monocarboxylate transporters. The purpose of this minireview is to provide an update on some of the most recently patented bioactive molecules that are able to interfere with cancer glycolysis, and on their use in specific combination therapies.

Discovery of long-chain salicylketoxime derivatives as monoacylglycerol lipase (MAGL) inhibitors.

Monoacylglycerol lipase (MAGL) is the enzyme hydrolyzing the endocannabinoid 2-arachidonoylglycerol (2-AG) to free arachidonic acid and glycerol. Therefore, MAGL is implicated in many physiological processes involving the regulation of the endocannabinoid system and eicosanoid network. MAGL inhibition represents a potential therapeutic target for many diseases, including cancer. Nowadays, most MAGL inhibitors inhibit this enzyme by an irreversible mechanism of action, potentially leading to unwanted side effects from chronic treatment. Herein, we report the discovery of long-chain salicylketoxime derivatives as potent and reversible MAGL inhibitors. The compounds herein described are characterized by a good target selectivity for MAGL and by antiproliferative activities against a series of cancer cell lines. Finally, modeling studies suggest a reasonable hypothetical binding mode for this class of compounds.

Characterization of the Saffron Derivative Crocetin as an Inhibitor of Human Lactate Dehydrogenase 5 in the Antiglycolytic Approach against Cancer.

Inhibition of lactate dehydrogenase (LDH) represents an innovative approach to tackle cancer because this peculiar glycolytic metabolism is characteristic of most invasive tumor cells. An investigation into the biological properties of saffron extracts led to the discover of their LDH-inhibition properties. In particular, the most important saffron components, crocetin, was found to inhibit LDH (IC50 = 54.9 ± 4.7 µM). This carotenoid was independently produced by chemical synthesis, and its LDH-inhibition properties manifested via its antiproliferative activity against two glycolytic cancer cell lines (A549 and HeLa, IC50 = 114.0 ± 8.0 and 113.0 ± 11.1 µM, respectively). The results described in this article suggest that saffron may be a helpful alimentary component in the prevention of cancer that potentially contributes to the efficacy of approved cancer therapies.