Silperisone: a centrally acting muscle relaxant

Ligand-modulated nickel-catalyzed regioselective silylalkylation of alkenes

Organosilicon compounds have shown tremendous potential in drug discovery and their synthesis stimulates wide interest. Multicomponent cross-coupling of alkenes with silicon reagents is used to yield complex silicon-containing compounds from readily accessible feedstock chemicals but the reaction with simple alkenes remains challenging. Here, we report a regioselective silylalkylation of simple alkenes, which is enabled by using a stable Ni(II) salt and an inexpensive trans-1,2-diaminocyclohexane ligand as a catalyst. Remarkably, this reaction can tolerate a broad range of olefins bearing various functional groups, including alcohol, ester, amides and ethers, thus it allows for the efficient and selective assembly of a diverse range of bifunctional organosilicon building blocks from terminal alkenes, alkyl halides and the Suginome reagent. Moreover, an expedient synthetic route toward alpha-Lipoic acid has been developed by this methodology.

Iridium-Catalyzed Hydrosilylation of Unactivated Alkenes: Scope and Application to Late-Stage Functionalization

Highly efficient and general Ir-catalyzed hydrosilylation of unactivated alkenes with excellent anti-Markovnikov regioselectivity was described. A broad scope of hydrosilylated products were synthesized economically and conveniently from commercially or naturally available compounds, which provides versatile valuable precursors for organic and medicinal studies.

Harnessing the β-Silicon Effect for Regioselective and Stereoselective Rhodium(II)-Catalyzed C-H Functionalization by Donor/Acceptor Carbenes Derived from 1-Sulfonyl-1,2,3-triazoles

The regioselective and enantioselective intermolecular sp3 C-H functionalization of silicon-substituted alkanes was accomplished using Rh2( S-NTTL)4 with readily available 1-sulfonyl-1,2,3-triazoles as carbene precursors. These reactions generate a diverse array of stereodefined substituted silaalkanes.

Study of the Cytotoxic and Bactericidal Effects of Sila-substituted Thioalkyne and Mercapto-thione Compounds based on 1,2,3-Triazole Scaffold

A series of sila-organosulphur compounds containing 1,2,3-triazole cores were screened for their cytotoxic activity on human breast cancer cell line MCF-7. Most of the tested compounds exhibited moderate-to-good activity against the cancer cells. Especially, the compound 4-((2-(trimethylsilyl)ethynylthio)methyl)-1-benzyl-1H-1,2,3-triazole (3a) from series of sila-substituted thioalkyne 1,2,3-triazoles (STATs) and the compounds 3-(1-benzyl-1H-1,2,3-triazol-4-yl)-1-mercapto-1,1-bis(trimethylsilyl)propane-2-thione (4a) and 1-mercapto-1,1-bis(trimethylsilyl)-3-(1-phenethyl-1H-1,2,3-triazol-4-yl)propane-2-thione (4e) from series of sila-substituted mercapto-thione 1,2,3-triazoles (SMTTs) exhibited promising cytotoxicity against MCF-7 with IC₅₀ values of 35.17, 32.63 and 30.3 μg/mL, respectively. In addition, the possible mechanisms for inhibition of cell growth and induction of apoptotic cell death were explored by DAPI staining, cell cycle analysis and qRT-PCR. The synthetic compounds were evaluated for their in vitro antibacterial activities, and as a result, the most prominent effects were observed for 3e and 4e. Especially, 3e was found to be quite active against all the tested strains with the MIC values ranging from 15 to 62 μg/mL, except P. aeruginosa. The results of the time-kill assay suggested that the compound of 3e completely inhibited the growth of both gram-negative bacteria, A. baumannii, and gram-positive bacteria, S. aureus. In addition, SEM analysis confirmed morphostructural damage of the bacteria. Our findings could be applicable for developing dual-targeting anticancer/antibacterial therapeutics.

Photoinduced HBr-catalyzed C–Si bond cleavage of benzylsilanes and their subsequent oxidation into benzoic acids with air as the terminal oxidant

A photoinduced highly efficient C–Si bond cleavage reaction of benzylsilanes under the catalysis of HBr was developed. The in situ generated benzyl radical intermediates were aerobically oxidized into benzoic acids highly chemoselectively.

Antiallergic activity profile in vitro RBL-2H3 and in vivo passive cutaneous anaphylaxis mouse model of new sila-substituted 1,3,4-oxadiazoles

A new class of sila-substituted 1,3,4-oxadiazoles was synthesized and evaluated for antiallergic activity using RBL-2H3 as the in vitro model and the in vivo anaphylactic mouse model. We observed that compound 5c effectively suppressed DNP-HSA-induced mast cell degranulation, compared to carbon analogue 9, and also suppressed the expression of TNF-α mRNA and Akt phosphorylation in antigen-stimulated RBL-2H3 cells. We also studied the effect of 5c in an in vivo passive cutaneous anaphylaxis (PCA) mouse model. The suppression by 5c was more effective than that by diphenylhydramine (DPH), a typical anti-histamine drug.

Classification of drugs based on properties of sodium channel inhibition: a comparative automated patch-clamp study

Background

There is only one established drug binding site on sodium channels. However, drug binding of sodium channels shows extreme promiscuity: ∼25% of investigated drugs have been found to potently inhibit sodium channels. The structural diversity of these molecules suggests that they may not share the binding site, and/or the mode of action. Our goal was to attempt classification of sodium channel inhibitors by measuring multiple properties of inhibition in electrophysiology experiments. We also aimed to investigate if different properties of inhibition correlate with specific chemical properties of the compounds.

Methodology/Principal Findings

A comparative electrophysiological study of 35 compounds, including classic sodium channel inhibitors (anticonvulsants, antiarrhythmics and local anesthetics), as well as antidepressants, antipsychotics and neuroprotective agents, was carried out using rNav1.2 expressing HEK-293 cells and the QPatch automatic patch-clamp instrument. In the multi-dimensional space defined by the eight properties of inhibition (resting and inactivated affinity, potency, reversibility, time constants of onset and offset, use-dependence and state-dependence), at least three distinct types of inhibition could be identified; these probably reflect distinct modes of action. The compounds were clustered similarly in the multi-dimensional space defined by relevant chemical properties, including measures of lipophilicity, aromaticity, molecular size, polarity and electric charge. Drugs of the same therapeutic indication typically belonged to the same type. We identified chemical properties, which were important in determining specific properties of inhibition. State-dependence correlated with lipophilicity, the ratio of the neutral form of molecules, and aromaticity: We noticed that the highly state dependent inhibitors had at least two aromatic rings, logP>4.0, and pKa<8.0.

Conclusions/Significance

The correlations of inhibition properties both with chemical properties and therapeutic profiles would not have been evident through the sole determination of IC₅₀; therefore, recording multiple properties of inhibition may allow improved prediction of therapeutic usefulness.

Open experience with a new myorelaxant agent for low back pain

INTRODUCTION

Eperisone hydrochloride has been recently proposed as a muscle relaxant for the treatment of muscle contracture and chronic low back pain (LBP) as it is devoid of clinically relevant sedative effects on the central nervous system (CNS). We tested this hypothesis by performing a study of patients with LBP and muscle contracture who were treated with full-dose eperisone.

METHODS

Patients with moderate to severe, acute, or relapsing LBP received eperisone 100 mg three times daily for 10 consecutive days. Assessments included: spontaneous pain, pain on movement, resistance to passive movement, antalgic rigidity, and tolerability.

RESULTS

In total, 100 patients were enrolled into the study. The treatment achieved a consistent analgesic and muscle relaxant activity across all patients. Both spontaneous pain and pain on movement were significantly decreased, as was resistance encountered by the investigator to passive movements, antalgic rigidity, and muscle contracture. As a consequence, treatment with eperisone resulted in a lower rigidity of the lower back and an improved motility for patients. Only seven adverse reactions were reported, including light-headedness (1), occasional vertigo and/or loss of equilibrium (3), mild somnolence (2), and epigastric pain (1). In almost all cases, there was no need to interrupt the treatment and the adverse reaction resolved spontaneously.

CONCLUSIONS

Eperisone had an analgesic and muscle relaxant effect in patients with LBP. It should be noted that while it is common practice in rheumatology to combine a pain killer with a muscle relaxant in order to achieve a satisfactory result on both symptoms, the present results with eperisone were achieved with a single drug. With an improved tolerability profile compared with nonsteroidal anti-inflammatory drugs, and a lack of significant adverse effects on the CNS, eperisone hydrochloride represents a valuable alternative to traditional analgesics and muscle relaxants for the treatment of LBP.

Tolperisone: a typical representative of a class of centrally acting muscle relaxants with less sedative side effects

Tolperisone, a piperidine derivative, is assigned to the group of centrally acting muscle relaxants and has been in clinical use now for decades. The review summarizes the known pharmacokinetics, pharmacodynamics, toxicology and side effects in humans and the clinical use of tolperisone. A future perspective for further exploration of this drug is given.