TPN672: A Novel Serotonin-Dopamine Receptor Modulator for the Treatment of Schizophrenia.

TPN672 [7-(2-(4-(benzothiophen-4-yl) piperazin-1-yl)ethyl)quinolin-2(1H)-one maleate] is a novel antipsychotic candidate with high affinity for serotonin and dopamine receptors that is currently in clinical trial for the treatment of psychiatric disorders. In vitro binding study showed that TPN672 exhibited extremely high affinity for serotonin 1A receptor (5-HT1AR) (K i = 0.23 nM) and 5-HT2AR (K i = 2.58 nM) as well as moderate affinity for D3R (K i = 11.55 nM) and D2R (K i = 17.91 nM). In vitro functional assays demonstrated that TPN672 acted as a potent 5-HT1AR agonist, D2R/D3R partial agonist, and 5-HT2AR antagonist. TPN672 displayed robust antipsychotic efficacy in rodent models (e.g., blocking phencyclidine-induced hyperactivity), significantly better than aripiprazole, and ameliorated negative symptoms and cognitive deficits in the sociability test, dark avoidance response, Morris water maze test, and novel object recognition test. The results of electrophysiological experiments showed that TPN672 might inhibit the excitability of the glutamate system through activating 5-HT1AR in medial prefrontal cortex, thereby improving cognitive and negative symptoms. Moreover, the safety margin (the ratio of minimum catalepsy-inducing dose to minimum effective dose) of TPN672 was about 10-fold, which was superior to aripiprazole. In conclusion, TPN672 is a promising new drug candidate for the treatment of schizophrenia and has been shown to be more effective in attenuating negative symptoms and cognitive deficits while having lower risk of extrapyramidal symptoms and hyperprolactinemia. SIGNIFICANCE STATEMENT: TPN672 is a promising new drug candidate for the treatment of schizophrenia and has been shown to be more effective in attenuating negative symptoms and cognitive deficits while having a lower risk of extrapyramidal symptoms and hyperprolactinemia. A phase I clinical trial is now under way to test its tolerance, pharmacokinetics, and pharmacodynamic effects in human volunteers. Accordingly, the present results will have significant impact on the development of new antischizophrenia drugs.

Chronic administration of synthetic cannabidiol induces antidepressant effects involving modulation of serotonin and noradrenaline levels in the hippocampus.

Cannabidiol (CBD) is a non-psychotomimetic compound derived from Cannabis sativa. Preclinical and clinical studies have shown therapeutic potential of CBD in a variety of disorders. Despite several research efforts on CBD, its antidepressant activity has been poorly investigated and the exact mechanism of action remains unclear. Thus, this study aimed to further explore the mechanism of CBD after chronic administration (7 days). First, the dose level of CBD that is enough to produce antidepressant effects after chronic administration was explored. Second, the changes in key proteins and neurotransmitters through such methods as real-time polymerase chain reaction (RT-PCR), western blotting, and high-performance liquid chromatography-electrochemical detection (HPLC-ECD) were critically studied. Furthermore, correlation between behavioral phenotypes with protein and neurotransmitters was established and the possible mechanism was herein postulated. The results showed that only the high dose CBD 100 mg/kg chronic administration induced antidepressant-like effects in mice subjected to forced swim test. Chronic CBD 100 mg/kg administration resulted in significant increases in serotonin (5-HT) and noradrenaline (NA) levels in the hippocampus (HPC). Similarly, the chronic administration of CBD 30 mg/kg and CBD 100 mg/kg significantly decreased nuclear factor kappa B (NF-κB) expression in the HPC. Moreover, none of the treatments were observed to induce locomotor effects. Thus, we concluded that chronic administration of CBD (100 mg/kg) induced antidepressant-like effects by increasing 5-HT and NA levels in the HPC. These results shed new light on further discovery of the antidepressant effect of CBD.

Synthesis of CBD and Its Derivatives Bearing Various C4'-Side Chains with a Late-Stage Diversification Method.

A novel synthetic route for making (-)-CBD and its derivatives bearing various C4'-side chains is developed by a late-stage diversification method. Starting from commercially available phloroglucinol, the key intermediate (-)-CBD-2OPiv-OTf is efficiently and regioselectively prepared and further undergoes Negishi cross-coupling to furnish (-)-CBD. This approach allowed an efficient synthesis of (-)-CBD in a five-step total 52% yield on a 10 g scale. Furthermore, diversification on the C4'-side chain with this method can be realized in a wide range.

Oxidative Aromatization of 3,4-Dihydroquinolin-2(1 H)-ones to Quinolin-2(1 H)-ones Using Transition-Metal-Activated Persulfate Salts.

Inorganic persulfate salts were identified as efficient reagents for the oxidative aromatization of 3,4-dihydroquinolin-2(1 H)-ones through the activation of readily available transition metals, such as iron and copper. The feasible protocol conforming to the requirement of green chemistry was utilized in the preparation of the key intermediate (7-(4-chlorobutoxy)quinolin-2(1 H)-one 2) of brexpiprazole in 80% isolated yield on a 100 g scale, and different quinolin-2(1 H)-one derivatives with various functional groups were demonstrated in 52-89% yields.