Synthesis of berberine-piperazine conjugates as potential antioxidant and cytotoxic agents

Current development and structure-activity relationship study of berberine derivatives

Berberine is a quaternary ammonium isoquinoline alkaloid derived from traditional Chinese medicines Coptis chinensis and Phellodendron chinense. It has many pharmacological activities such as hypoglycemic, hypolipidemic, anti-tumor, antimicrobial and anti-inflammatory. Through structural modifications at various sites of berberine, the introduction of different groups can change berberine's physical and chemical properties, thereby improving the biological activity and clinical efficacy, and expanding the scope of application. This paper reviews the research progress and structure-activity relationships of berberine in recent years, aiming to provide valuable insights for the exploration of novel berberine derivatives.

Novel Piperazine Derivatives of Vindoline as Anticancer Agents

A series of novel vindoline-piperazine conjugates were synthesized by coupling 6 N-substituted piperazine pharmacophores at positions 10 and 17 of Vinca alkaloid monomer vindoline through different types of linkers. The in vitro antiproliferative activity of the 17 new conjugates was investigated on 60 human tumor cell lines (NCI60). Nine compounds presented significant antiproliferative effects. The most potent derivatives showed low micromolar growth inhibition (GI50) values against most of the cell lines. Among them, conjugates containing [4-(trifluoromethyl)benzyl]piperazine (23) and 1-bis(4-fluorophenyl)methyl piperazine (25) in position 17 of vindoline were outstanding. The first one was the most effective on the breast cancer MDA-MB-468 cell line (GI50 = 1.00 μM), while the second one was the most effective on the non-small cell lung cancer cell line HOP-92 (GI50 = 1.35 μM). The CellTiter-Glo Luminescent Cell Viability Assay was performed with conjugates 20, 23, and 25 on non-tumor Chinese hamster ovary (CHO) cells to determine the selectivity of the conjugates for cancer cells. These compounds exhibited promising selectivity with estimated half-maximal inhibitory concentration (IC50) values of 2.54 μM, 10.8 μM, and 6.64 μM, respectively. The obtained results may have an impact on the design of novel vindoline-based anticancer compounds.

Recent Applications of Protoberberines as Privileged Starting Materials for the Development of Novel Broad-Spectrum Antiviral Agents: A Concise Review (2017-2023)

Berberine is a well-known phytochemical with significant antiviral activity against a wide range of viruses. Due to having a unique backbone consisting of four interconnected rings, it can be used as a platform for the design and development of novel semisynthetic antiviral agents. The question here is whether novel broad-spectrum antiviral drugs with enhanced activity and toxicity potential can be obtained by attempting to modify the structure of this privileged lead compound. The present study aims to review the results of recent studies in which berberine and its close analogues (protoberberine alkaloids) have been used as starting materials for the production of new semisynthetic antiviral structures. For this purpose, relevant studies published in high-quality journals indexed in databases such as Scopus, Web of Science, PubMed, etc. in the time frame of 2017 to 2023 were collected. Our selection criterion in the current review focuses on the studies in which protoberberines were used as starting materials for the production of semisynthetic agents with antiviral activity during the indicated time period. Correspondingly, studies were identified in which semisynthetic derivatives with significant inhibitory activity against a wide range of viruses including human immunodeficiency virus (HIV), enterovirus 71 (EV71), zika virus (ZIKV), influenza A/B, cytomegalovirus (CMV), respiratory syncytial virus (RSV), and coxsackieviruses were designed and synthesized. Our conclusion is that, despite the introduction of diverse semisynthetic derivatives of berberine with improved activity profiles compared to the parent natural leads, sufficient derivatization has not been done yet and more studies are needed.

Piperazine skeleton in the structural modification of natural products: a review

Piperazine moiety is a cyclic molecule containing two nitrogen atoms in positions 1 and 4, as well as four carbon atoms. Piperazine is one of the most sought heterocyclics for the development of new drug candidates with a wide range of applications. Over 100 molecules with a broad range of bioactivities, including antitumor, antibacterial, anti-inflammatory, antioxidant, and other activities, were reviewed. This article reviewed investigations regarding piperazine groups for the modification of natural product derivatives in the last decade, highlighting parameters that affect their biological activity.

Synthesis of hydrophobically modified berberine derivatives with high anticancer activity through modulation of the MAPK pathway

Linoleic acid-modified berberine derivative induces apoptosis of A549 cells and affects the expression of proteins associated with the MAPK pathway.

Potential cytotoxic and anti-metastatic effects of berberine on gynaecological cancers with drug-associated resistance

Gynaecological disorders, such as cervical, ovarian, and endometrial cancers are the second most prevalent cancer types in women worldwide. Therapeutic approaches for gynaecological cancers involve chemotherapy, radiation, and surgery. However, lifespan is not improved, and novel medications are required. Among various phytochemicals, berberine, a well-known natural product, has been shown to be a promising cancer chemopreventive agent. Pharmacokinetics, safety, and efficacy of berberine have been investigated in the several experiments against numerous diseases. Here, we aimed to provide a literature review from available published investigations showing the anticancer effects of berberine and its various synthetic analogues against gynaecological disorders, including cervical, ovarian, and endometrial cancers. In conclusion, berberine has been found to efficiently inhibit viability, proliferation, and migration of cancer cells, mainly, via induction of apoptosis by both mitochondrial dependent and -independent pathways. Additionally, structural modification of berberine showed that berberine analogues can improve its antitumor effects against gynaecological cancers.

Berberine-piperazine conjugates as potent influenza neuraminidase blocker

In these studies, we analyzed substituted piperazine based berberine analogs conjugated through a pentyloxy side chain for their in vitro and in silico biological effects. All the final analogs were screened for their in vitro antiviral action against a collection of different influenza virus strains using the CPE assay and SRB assay. Moreover, their cytotoxicity towards non-cancer cell lines was examined employing Madin-Darby canine kidney (MDCK) cell lines. The anti-influenza activities of berberine-piperazine derivatives (BPD) were evaluated in the range from 35.16 μg/mL to 90.25 μg/mL of the IC₅₀s along with cytotoxicity level which was observed in the range 44.8 μg/mL to 3890.6 μg/mL of CC₅₀s towards MDCK cells. In an effort to know the mechanism of action of BPD1-BPD23, results of Neuraminidase inhibition assay and Molecular docking studies carried out against neuraminidase as the target enzyme revealed that titled compounds are potential neuraminidase inhibitors that merge to the active site of neuraminidase, with moderate to high binding energy.