Synthesis and biological evaluation of substituted pyrrolidines and pyrroles as potential anticancer agents

The potential of the South African plant Tulbaghia Violacea Harv for the treatment of triple negative breast cancer

Triple-negative breast cancer (TNBC) is difficult to treat and has a low five-year survival rate. In South Africa, a large percentage of the population still relies on traditional plant-based medicine. To establish the utility of both methanol and water-soluble extracts from the leaves of Tulbaghia violacea, cytotoxicity assays were carried out to establish the IC50 values against a TNBC cell line. Cell cycle and apoptosis assays were carried out using the extracts. To identify the molecular compounds, present in water-soluble leaf extracts, NMR spectroscopy was performed. Compounds of interest were then used in computational docking studies with the anti-apoptotic protein COX-2. The IC50 values for the water- and methanol-soluble extracts were determined to be 400 and 820 µg/mL, respectively. The water-soluble extract induced apoptosis in the TNBC cell line to a greater extent than in the normal cell line. RNAseq indicated that there was an increase in the transcription of pro-apoptotic genes in the TNBC cell line. The crude extract also caused these cells to stall in the S phase. Of the 61 compounds identified in this extract, five demonstrated a high binding affinity for COX-2. Based on these findings, the compounds within the extract show significant potential for further investigation as candidates for the development of cancer therapeutics, particularly for TNBC.

Green Synthesis of Bioactive Pyrrole Derivatives via Heterogeneous Catalysts Since 2010

Pyrrole derivatives are known as building blocks for the synthesis of biological compounds and pharmaceutical drugs. Several processes were employed to synthesize pyrroles, including Hantzsch, Paal-Knorr, and cycloaddition of dicarbonyl compounds reaction. Using catalysts like nanoparticles, metal salts, and heterogeneous ones was necessary to obtain the targeted pyrrole structure. Also, to afford more active pyrrole compounds, heterocyclic molecules such as imidazole or other rings were used in the synthesis as amines. This review presents heterogeneous catalysts since 2010 for the green synthesis of bioactive pyrroles in a one-pot multi-component reaction. Additionally, each synthetic method included a demonstration of the suggested mechanisms. Diakylacetylenedicarboxylate, dicarbonyl group, amines, furans, and acetylene group are consolidated to yield biological pyrroles through the heterogeneous catalysts. Finally, various pyrrole-performed activities were displayed, such as antibacterial, anti-inflammatory, analgesic, and other significant activities.

Exploring Water-Soluble South African Tulbaghia violacea Harv Extract as a Therapeutic Approach for Triple-Negative Breast Cancer Metastasis

Triple-negative breast cancer (TNBC) accounts for approximately 20% of all breast cancer cases and is characterized by a lack of estrogen, progesterone, and human epidermal growth factor 2 receptors. Current targeted medicines have been unsuccessful due to this absence of hormone receptors. This study explored the efficacy of Tulbaghia violacea, a South African medicinal plant, for the treatment of TNBC metastasis. Extracts from T. violacea leaves were prepared using water and methanol. However, only the water-soluble extract showed anti-cancer activity and the effects of this water-soluble extract on cell adhesion, invasion, and migration, and its antioxidant activity were assessed using MCF-10A and MDA-MB-231 cells. The T. violacea extract that was soluble in water effectively decreased the movement and penetration of MDA-MB-231 cells through the basement membrane in scratch and invasion tests, while enhancing their attachment to a substance resembling an extracellular matrix. The sample showed mild-to-low antioxidant activity in the antioxidant assy. Nuclear magnetic resonance spectroscopy revealed 61 chemical components in the water-soluble extract, including DDMP, 1,2,4-triazine-3,5(2H,4H)-dione, vanillin, schisandrin, taurolidine, and α-pinene, which are known to have anti-cancer properties. An in-depth examination of the transcriptome showed alterations in genes linked to angiogenesis, metastasis, and proliferation post-treatment, with reduced activity in growth receptor signaling, angiogenesis, and cancer-related pathways, such as the Wnt, Notch, and PI3K pathways. These results indicate that T. violacea may be a beneficial source of lead chemicals for the development of potential therapeutic medicines that target TNBC metastasis. Additional studies are required to identify the precise bioactive chemical components responsible for the observed anti-cancer effects.

Pyrrole: A Decisive Scaffold for the Development of Therapeutic Agents and Structure-Activity Relationship

An overview of pyrroles as distinct scaffolds with therapeutic potential and the significance of pyrrole derivatives for drug development are provided in this article. It lists instances of naturally occurring pyrrole-containing compounds and describes the sources of pyrroles in nature, including plants and microbes. It also explains the many conventional and modern synthetic methods used to produce pyrroles. The key topics are the biological characteristics, pharmacological behavior, and functional alterations displayed by pyrrole derivatives. It also details how pyrroles are used to treat infectious diseases. It describes infectious disorders resistant to standard treatments and discusses the function of compounds containing pyrroles in combating infectious diseases. Furthermore, the review covers the uses of pyrrole derivatives in treating non-infectious diseases and resistance mechanisms in non-infectious illnesses like cancer, diabetes, and Alzheimer's and Parkinson's diseases. The important discoveries and probable avenues for pyrrole research are finally summarized, along with their significance for medicinal chemists and drug development. A reference from the last two decades is included in this review.

Involvement of Both Extrinsic and Intrinsic Apoptotic Pathways in Tridecylpyrrolidine-Diol Derivative-Induced Apoptosis In Vitro

Despite the decreasing trend in mortality from colorectal cancer, this disease still remains the third most common cause of death from cancer. In the present study, we investigated the antiproliferative and pro-apoptotic effects of (2S,3S,4R)-2-tridecylpyrrolidine-3,4-diol hydrochloride on colon cancer cells (Caco-2 and HCT116). The antiproliferative effect and IC₅₀ values were determined by the MTT and BrdU assays. Flow cytometry, qRT-PCR and Western blot were used to study the cellular and molecular mechanisms involved in the induction of apoptotic pathways. Colon cancer cell migration was monitored by the scratch assay. Concentration-dependent cytotoxic and antiproliferative effects on both cell lines, with IC₅₀ values of 3.2 ± 0.1 μmol/L (MTT) vs. 6.46 ± 2.84 μmol/L (BrdU) for HCT116 and 2.17 ± 1.5 μmol/L (MTT) vs. 1.59 ± 0.72 μmol/L (BrdU), for Caco-2 were observed. The results showed that tridecylpyrrolidine-induced apoptosis was associated with the externalization of phosphatidylserine, reduced mitochondrial membrane potential (MMP) accompanied by the activation of casp-3/7, the cleavage of PARP and casp-8, the overexpression of TNF-α and FasL and the dysregulation of Bcl-2 family proteins. Inhibition of the migration of treated cells across the wound area was detected. Taken together, our data show that the anticancer effects of tridecylpyrrolidine analogues in colon cancer cells are mediated by antiproliferative activity, the induction of both extrinsic and intrinsic apoptotic pathways and the inhibition of cell migration.

Therapeutic potential of pyrrole and pyrrolidine analogs: an update

The chemistry of nitrogen-containing heterocyclic compound pyrrole and pyrrolidine has been a versatile field of study for a long time for its diverse biological and medicinal importance. Biomolecules such as chlorophyll, hemoglobin, myoglobin, and cytochrome are naturally occurring metal complexes of pyrrole. These metal complexes play a vital role in a living system like photosynthesis, oxygen carrier, as well storage, and redox cycling reactions. Apart from this, many medicinal drugs are derived from either pyrrole, pyrrolidine, or by its fused analogs. This review mainly focuses on the therapeutic potential of pyrrole, pyrrolidine, and its fused analogs, more specifically anticancer, anti-inflammatory, antiviral, and antituberculosis. Further, this review summarizes more recent reports on the pyrrole, pyrrolidine analogs, and their biological potential.

Green Synthesis of New Pyrrolo [1,2-a] quinoxalines as Antiproliferative Agents in GPER-expressing Breast Cancer Cells

4,5-Dihydropyrrolo [1,2-a]quinoxalines are interesting druggable scaffolds, with multifaceted biological properties, including anticancer properties targeting the G protein-coupled estrogen receptor 1 (GPER). In this work, the synthesis and preliminary antiproliferative activity of a small set of new 4,5-dihydropyrrolo[1,2-a]quinoxalines (18-20) and pyrrolo[1,2-a]quinoxalines (21, 22) has been reported, inspired by known antiproliferative agents (G-1, G-15, and G-36). The synthesis of the pyrroloquinoxalinic core was employed following the Pictet–Spengler reaction, using the surfactant p-dodecylbenzene sulphonic acid (p-DBSA), as catalyst. It demonstrated efficiency in the catalysis of the 4-phenylpyrrole [1,2-a] quinoxaline type compound formation in mild solvents such as water, ethanol, and hydroalcoholic solutions. In addition, the reactions proceeded in a short time (between 15 and 120 minutes) at room temperature and with high yields. The in vitro MTT assays showed that the presence of isopropyl groups furnished promising antiproliferative compounds. Although, the acetyl group provided also antiproliferative effects, breaking down its responsibility in the GPER transactivation. Nevertheless, it is possible to conclude that the 4,5-dihydropyrrolo[1,2-a]quinoxalines remain a feasible scaffold to develop anticancer agents against GPER-expressing cells.