Synthesis and biological evaluation of a new class of multi-target heterocycle piperazine derivatives as potential antipsychotics

A Profound Insight into the Structure-activity Relationship of Ubiquitous Scaffold Piperazine: An Explicative Review

Despite extensive research in the field of drug discovery and development, still there is a need to develop novel molecular entities. Literature reveals a substantial heterocyclic nucleus named, piperazine, which shows an immense therapeutic voyage. For several decades, molecules having the piperazine nucleus have entered the market as a drug exhibiting biological potential. It was known to possess antipsychotic, antihistamine, antianginal, antidepressant, anticancer, antiviral, cardioprotective, and anti-inflammatory activity with a specific basis for structural activity relationship. Thus, it is regarded as a key structural feature in most of the already available therapeutic drugs in the market. Reports also suggest that the extensive utilization of these currently available drugs having a piperazine nucleus shows increasing tolerance significantly day by day. In addition to this, various other factors like solubility, low bioavailability, cost-effectiveness, and imbalance between pharmacokinetics and pharmacodynamics profile limit their utilization. Focusing on that issues, various structural modification studies were performed on the piperazine moiety to develop new derivatives/analogs to overcome the problems associated with available marketed drugs. Thus, this review article aims to gain insight into the number of structural modifications at the N-1 and N-4 positions of the piperazine scaffold. This SAR approach may prove to be the best way to overcome the above-discussed drawbacks and lead to the design of drug molecules with better efficacy and affinity. Hence, there is an urgent need to focus on the structural features of this scaffold which paves further work for deeper exploration and may help medicinal chemists as well as pharmaceutical industries.

Amisulpride augmentation therapy improves cognitive performance and psychopathology in clozapine-resistant treatment-refractory schizophrenia: a 12-week randomized, double-blind, placebo-controlled trial

BACKGROUND

Although clozapine is an effective option for treatment-resistant schizophrenia (TRS), there are still 1/3 to 1/2 of TRS patients who do not respond to clozapine. The main purpose of this randomized, double-blind, placebo-controlled trial was to explore the amisulpride augmentation efficacy on the psychopathological symptoms and cognitive function of clozapine-resistant treatment-refractory schizophrenia (CTRS) patients.

METHODS

A total of 80 patients were recruited and randomly assigned to receive initial clozapine plus amisulpride (amisulpride group) or clozapine plus placebo (placebo group). Positive and Negative Syndrome Scale (PANSS), Scale for the Assessment of Negative Symptoms (SANS), Clinical Global Impression (CGI) scale scores, Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), Treatment Emergent Symptom Scale (TESS), laboratory measurements, and electrocardiograms (ECG) were performed at baseline, at week 6, and week 12.

RESULTS

Compared with the placebo group, amisulpride group had a lower PANSS total score, positive subscore, and general psychopathology subscore at week 6 and week 12 (P_Bonferroni < 0.01). Furthermore, compared with the placebo group, the amisulpride group showed an improved RBANS language score at week 12 (P_Bonferroni < 0.001). Amisulpride group had a higher treatment response rate (P = 0.04), lower scores of CGI severity and CGI efficacy at week 6 and week 12 than placebo group (P_Bonferroni < 0.05). There were no differences between the groups in body mass index (BMI), corrected QT (QTc) intervals, and laboratory measurements. This study demonstrates that amisulpride augmentation therapy can safely improve the psychiatric symptoms and cognitive performance of CTRS patients.

CONCLUSION

This study indicates that amisulpride augmentation therapy has important clinical significance for treating CTRS to improve clinical symptoms and cognitive function with tolerability and safety. Trial registration Clinicaltrials.gov identifier- NCT03652974. Registered August 31, 2018, https://clinicaltrials.gov/ct2/show/NCT03652974.

Vanillin: A Promising Biosourced Building Block for the Preparation of Various Heterocycles

The preparation of heterocyclic compounds often involves the use of petroleum-based or non-renewable sources. Considering the actual societal and environmental awareness towards sustainable chemistry, new and green sources of organic carbon are sought. In this regard, vanillin is a molecular building block that can be obtained from the depolymerization of lignin. Due to its different functional groups (hydroxyl, aldehyde, and methoxy) vanillin can undergo a variety of reactions leading to various heterocycles such as pyrimidines, quinoxalines, imidazoles or thiazoles to name a few. This mini-review will focus on the preparation of accessible heterocycles building blocks from the vanillin moiety in regard to the medicinal, pharmaceutical, and material fields.