Design, synthesis, and anti-allergic activities of novel (R)(-)-1-[(4-chlorophenyl)phenyl methyl]piperazine derivatives

Identification, Isolation and Characterization of a Pharmaceutical Impurity in Levocetirizine Hydrochloride

Background:

Levocetirizine is chemically know as (R)-(-)-2-[4-(4-chlorobenzhydryl)-1- piperazinyl]-ethoxy acetic acid dihydrochloride. Many publications have reported the synthetic routes of levocetirizine. Several related substances have been detected in levocetirizine hydrochloride drug substances. In our study, a pharmaceutical impurity, at the level of >0.1% w/w, was isolated, purified and identified. It is not included in the European Pharmacopoeia (EP).

Objective:

Identification, isolation and characterization of a new pharmaceutical impurity in levocetirizine hydrochloride.

Methods:

The impurity was enriched by normal phase silica gel, and was further purified by semipreparative HPLC. It was separated from the crystallization mother liquor of levocetirizine hydrochloride for the first time. Mass spectrometry and nuclear magnetic resonance spectroscopy are the ultimate tools in structure elucidation.

Results:

The structure was identified as levocetirizine quaternary ammonium. The formation mechanisms of the impurity are also presented. The method was applied to the determination of the impurity in levocetirizine hydrochloride in real samples.

Conclusion:

The method was applied to the determination the impurity of levocetirizine hydrochloride in real samples.

New N-benzhydrylpiperazine/1,3,4-oxadiazoles conjugates inhibit the proliferation, migration, and induce apoptosis in HeLa cancer cells via oxidative stress-mediated mitochondrial pathway

N-benzhydrylpiperazine and 1,3,4-oxadiazoles are pharmacologically active scaffolds which exhibits significant inhibitory growth effects against various cancer cells, however, antiproliferation effects and the underlying mechanism for inducing apoptosis for aforementioned scaffolds addressing HeLa cancer cells remains uncertain. In this study, N-benzhydrylpiperazine clubbed with 1,3,4-oxadiazoles (4a-4h) were synthesized, subsequently characterized using high resolution spectroscopic techniques and eventually evaluated for their antiproliferation potential by inducing apoptosis in HeLa cancer cells. The MTT assay screening results revealed that among all, compound 4d ( N-benzhydryl-4-((5-(4-aminophenyl)-1,3,4-oxadiazol-2-yl)methyl)piperazine) in particular, exhibited IC ₅₀ value of 28.13 ± 0.21 μg/mL and significantly inhibited the proliferation of HeLa cancer cells in concentration-dependent manner. The in vitro anticancer assays for treated HeLa cells resulted in alterations in the cell morphology, reduction in colony formation, and inhibition of cell migration in concentration-dependent treatment. Furthermore, G2/M phase arrest, variations in the nuclear morphology, degradation of chromosomal DNA confirmed the ongoing apoptosis in treated HeLa cells. Increase in the expression of cytochrome C and caspase-3 confirmed the involvement of intrinsic mitochondrial pathway regulating the cell death. Also, elevation in reactive oxygen species level and loss of mitochondrial membrane potential signified that compound 4d induced apoptosis in HeLa cells by generating the oxidative stress. Therefore, compound 4d may act as a potent chemotherapeutic agent against human cervical cancer.

Synthesis and Cytotoxicity Studies on Novel Piperazinylacetamides

Background:

In this study, nine novel compounds, bearing N-[2-(4-substituted piperazine-1-yl)acetyl]-N’-[bis-(4-fluorophenyl)methyl]piperazine structures were synthesized.

Methods:

Their cytotoxic properties were evaluated in vitro by NCI-60 Sulforhodamine B (SRB) assay against human cancer cell lines: Huh7 (hepatocellular), MCF7 (breast) and HCT116 (colorectal).

Results and Conclusion:

According to the activity data, most of the compounds are more cytotoxic than 5-fluorouracil against Huh7 and HCT116 cancer cell lines.

Antihistamine from Tragia involucrata L. leaves

BACKGROUND

Synthetic antihistamine drugs cause various adverse effects to overcome these problems with natural phytomedicine or phytoconstituents.

METHODS

Tragia involucrata leaves were extracted with soxhlet apparatus and fractionated with column chromatography the homogenized fractions were monitored with thin layer chromatography (TLC) and characterized by using UV-visible, FT-IR, 1H NMR, 13C NMR and MS spectral studies. Isolated compounds were screened their antihistamine activity on ileum preparation, bronchoconstriction and triple response on histamine-induced guinea pig.

RESULTS

Antihistamine 5-hydroxy-1-methylpiperidin-2-one has been isolated and characterized from the leaves of Tragia involucrata L. A promising muscle relaxant, bronchorelaxant and anti-allergic effect of 5-hydroxy-1-methylpiperidin-2-one was observed in histamine-induced guinea pig and found to be 55.54±2.78% protection at the dose level of 12.5 mg/kg in bronchoconstriction effect and 49.05±2.45% protection in triple response. These findings were confirmed by in silico molecular docking also against histamine H1 receptor compared with chlorpheniramine maleate and mepyramine. This shows that the 5-hydroxy-1-methylpiperidine-2-one possess good inhibitory effect on histamine-induced guinea pig. The muscle relaxant, bronchodilating and anti-allergic potency of 5-hydroxy-1-methylpiperidin-2-one has been discussed in context with its probable profile as an anti-asthmatic agent from T. involucrata L. leaves.

CONCLUSIONS

We can conclude that isolated 5-hydroxy-1-methylpiperidin-2-one from T. involucrata L. has potent antihistamine agent on histamine-induced guinea pig.