Enzymatic Desymmetrisation of Prochiral meso-1,2-Disubstituted-1,2-Diaminoethane for the Synthesis of Key Enantioenriched (-)-Nutlin-3 Precursor.

Herein we present the biocatalysed preparation of a mono-N-carbamate-protected precursor of antitumoral Nutlin-3a through enantioselective alkoxycarbonylation of meso-1,2-disubstituted-1,2-diaminoethane using enzyme lipases and dialkyl carbonates as acylating agents. A series of supported or free lipase enzymes were screened in combination with commercially available diallyl, diethyl and dimethyl carbonates. The reactions were conducted at different temperatures, for different reaction times and with variable co-solvent systems to evaluate the effects on the enzyme catalytic activity. The best results in terms of conversion, enantiomeric excess and yield were obtained when lipase from Candida antarctica B (CAL-B) was used with diallyl carbonate (DAC) when conducting the reaction solventless at 75 °C.

Synthesis of 2,6-Dimethyltyrosine-Like Amino Acids through Pinacolinamide-Enabled C-H Dimethylation of 4-Dibenzylamino Phenylalanine.

The synthesis of a small library of NH-Boc- or NH-Fmoc-protected l-phenylalanines carrying methyl groups at positions 2 and 6 and diverse functionalities at position 4 has been achieved. The approach, which took advantage of a Pd-catalyzed directed C-H dimethylation of picolinamide derivatives, allowed the electronic and steric properties of the resulting amino acid derivatives to be altered by appending a variety of electron-withdrawing, electron-donating, or bulky groups.

Identification of small-molecule urea derivatives as PTPC modulators targeting the c subunit of F1/Fo-ATP synthase.

Maintaining a high percentage of living and functional cells in those pathologies in which excessive cell death occurs, such as neurodegenerative disorders and cardiovascular diseases, is one of the most intriguing challenges in the field of biochemical research for drug discovery. Here, mitochondrial permeability transition-driven regulated cell death is the main mechanism of mitochondrial impairment and cell fate; this pathway is still lacking of satisfying pharmacological treatments to counteract its becoming; for this reason, it needs continuous and intense research to find new compounds as modulator of the permeability transition pore complex (PTPC) activity. In this study, we report the identification of small-molecule urea derivatives able to inhibit PTPC opening following calcium overload and selected for future use in cytoprotection.

Synthesis and biological evaluation of novel rhodanine-based structures with antiviral activity towards HHV-6 virus.

An increased awareness of diseases associated with Human herpesvirus 6 (HHV-6) infection or reactivation has resulted in a growing interest in the evaluation of the best treatment options available for the clinical management of HHV-6 disease. However, no compound has yet been approved exclusively for HHV-6 infection treatment. For this reason, the identification of anti-HHV6 compounds provides a valuable opportunity for developing efficient antiviral therapies. A possible target for antiviral drugs is the virus-cell fusion step. In this study, we synthetized potential fusion intermediates inhibitors based on the rhodanine structure. The obtained derivatives were tested for cytotoxicity and for antiviral activity in human cells infected with HHV6. Level of infection was monitored by viral DNA quantification at different time points up to 7 days post infection. Among the synthetized derivatives, 9e showed a significative inhibitory effect on viral replication that lasted over 7 days, probably attributable to the particular combination of hydrophilic and hydrophobic substituents to the rhodanine moiety. Our results support the use of these amphipathic fusion inhibitors for the treatment of HHV-6 infections.

Xylitol as a Hydrophilization Moiety for a Biocatalytically Synthesized Ibuprofen Prodrug.

Biocatalyzed synthesis can be exploited to produce high-value products, such as prodrugs. The replacement of chemical approaches with biocatalytic processes is advantageous in terms of environmental prevention, embracing the principles of green chemistry. In this work, we propose the covalent attachment of xylitol to ibuprofen to produce an IBU-xylitol ester prodrug. Xylitol was chosen as a hydrophilizer for the final prodrug, enhancing the water solubility of ibuprofen. Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) extensively used as an analgesic, anti-inflammatory, and antipyretic. Despite being the third-most-prescribed medicine in the world, the aqueous solubility of ibuprofen is just 21 mg/L. This poor water solubility greatly limits the bioavailability of ibuprofen. We aimed to functionalize ibuprofen with xylitol using the reusable immobilized N435 biocatalyst. Instead of a biphasic media, we proposed a monophasic reaction environment. The characterization of the IBU-xylitol ester was performed by 1H, 13C-NMR, DEPT, COSY, HMQC, HMBC, FTIR, and MS spectroscopy. Preliminary in vitro tests showed that this enzymatically synthesized prodrug of ibuprofen reduced the expression of the interleukin 8 genes in human bronchial epithelial cells (IB3-1) from cystic fibrosis (CF) patients.

Synthesis and NLRP3-Inflammasome Inhibitory Activity of the Naturally Occurring Velutone F and of Its Non-Natural Regioisomeric Chalconoids.

Plant-derived remedies rich in chalcone-based compounds have been known for centuries in the treatment of specific diseases, and nowadays, the fascinating chalcone framework is considered a useful and, above all, abundant natural chemotype. Velutone F, a new chalconoid from Millettia velutina, exhibits a potent effect as an NLRP3-inflammasome inhibitor; the search for new natural/non-natural lead compounds as NLRP3 inhibitors is a current topical subject in medicinal chemistry. The details of our work toward the synthesis of velutone F and the unknown non-natural regioisomers are herein reported. We used different synthetic strategies both for the construction of the distinctive benzofuran nucleus (BF) and for the key phenylpropenone system (PhP). Importantly, we have disclosed a facile entry to the velutone F via synthetic routes that can also be useful for preparing non-natural analogs, a prerequisite for extensive SAR studies on the new flavonoid class of NLRP3-inhibitors.

In Vitro and In Vivo Pharmaco-Toxicological Characterization of 1-Cyclohexyl-x-methoxybenzene Derivatives in Mice: Comparison with Tramadol and PCP.

1-cyclohexyl-x-methoxybenzene is a novel psychoactive substance (NPS), first discovered in Europe in 2012 as unknown racemic mixture of its three stereoisomers: ortho, meta and para. Each of these has structural similarities with the analgesic tramadol and the dissociative anesthetic phencyclidine. In light of these structural analogies, and based on the fact that both tramadol and phencyclidine are substances that cause toxic effects in humans, the aim of this study was to investigate the in vitro and in vivo pharmacodynamic profile of these molecules, and to compare them with those caused by tramadol and phencyclidine. In vitro studies demonstrated that tramadol, ortho, meta and para were inactive at mu, kappa and delta opioid receptors. Systemic administration of the three stereoisomers impairs sensorimotor responses, modulates spontaneous motor activity, induces modest analgesia, and alters thermoregulation and cardiorespiratory responses in the mouse in some cases, with a similar profile to that of tramadol and phencyclidine. Naloxone partially prevents only the visual sensorimotor impairments caused by three stereoisomers, without preventing other effects. The present data show that 1-cyclohexyl-x-methoxybenzene derivatives cause pharmaco-toxicological effects by activating both opioid and non-opioid mechanisms and suggest that their use could potentially lead to abuse and bodily harm.

Glyceric Prodrug of Ursodeoxycholic Acid (UDCA): Novozym 435-Catalyzed Synthesis of UDCA-Monoglyceride.

Bile acids (BAs) are a family of steroids synthesized from cholesterol in the liver. Among bile acids, ursodeoxycholic acid (UDCA) is the drug of choice for treating primary biliary cirrhosis and dissolving cholesterol gallstones. The clinical effectiveness of UDCA includes its choleretic activity, the capability to inhibit hydrophobic bile acid absorption by the intestine under cholestatic conditions, reducing cholangiocyte injury, stimulation of impaired biliary output, and inhibition of hepatocyte apoptosis. Despite its clinical effectiveness, UDCA is poorly soluble in the gastro-duodeno-jejunal contents, and pharmacological doses of UDCA are not readily soluble in the stomach and intestine, resulting in incomplete absorption. Indeed, the solubility of 20 mg/L greatly limits the bioavailability of UDCA. Since the bioavailability of drug products plays a critical role in the design of oral administration dosages, we investigated the enzymatic esterification of UDCA as a strategy of hydrophilization. Therefore, we decided to enzymatically synthesize a glyceric ester of UDCA bile acid to produce a more water-soluble molecule. The esterification reactions between UDCA and glycerol were performed with an immobilized lipase B from Candida antarctica (Novozym 435) in solvent-free and solvent-assisted systems. The characterization of the UDCA-monoglyceride, enzymatically synthesized, has been performed by 1H-NMR, 13C-NMR, COSY, HSQC, HMBC, IR, and MS spectroscopy.

Spiropiperidine-Based Oligomycin-Analog Ligands To Counteract the Ischemia-Reperfusion Injury in a Renal Cell Model.

Finding a therapy for ischemia-reperfusion injury, which consists of cell death following restoration of blood flowing into the artery affected by ischemia, is a strong medical need. Nowadays, only the use of broad-spectrum molecular therapies has demonstrated a partial efficacy in protecting the organs following reperfusion, while randomized clinical trials focused on more specific drug targets have failed. In order to overcome this problem, we applied a combination of molecular modeling and chemical synthesis to identify novel spiropiperidine-based structures active in mitochondrial permeability transition pore opening inhibition as a key process to enhance cell survival after blood flow restoration. Our results were confirmed by biological assay on an in vitro cell model on HeLa and human renal proximal tubular epithelial cells and pave the way to further investigation on an in vivo model system.

Dihydroartemisinin-Ursodeoxycholic Bile Acid Hybrids in the Fight against SARS-CoV-2.

Here, we propose the molecular hybridization of dihydroartemisinin (DHA) and ursodeoxycholic bile acid (UDCA), approved drugs, for the preparation of antiviral agents against SARS-CoV-2. DHA and UDCA were selected on the basis of their recently demonstrated in vitro activity against SARS-CoV-2. A selection of DHA-UDCA-based hybrids obtained by varying the nature of the linkage and the bile acid conjugation point as well as unconjugated DHA and UDCA were tested in vitro for cytotoxicity and anti-SARS-CoV-2 activity on Vero E6 and Calu-3 human lung cells. The hybrid DHA-t-UDCMe, obtained by conjugation via click chemistry on a gram scale, was identified as a potential candidate for SARS-CoV-2 infection treatment due to significant reduction of viral replication, possibly involving ACE2 downregulation, no cytotoxicity, and chemical stability.