Water-soluble derivatives of evodiamine: Discovery of evodiamine-10-phosphate as an orally active antitumor lead compound

Development of natural product-based targeted protein degraders as anticancer agents

Targeted protein degradation (TPD) has emerged as a powerful approach for eliminating cancer-causing proteins through an "event-driven" pharmacological mode. Proteolysis-targeting chimeras (PROTACs), molecular glues (MGs), and hydrophobic tagging (HyTing) have evolved into three major classes of TPD technologies. Natural products (NPs) are a primary source of anticancer drugs and have played important roles in the development of TPD technology. NPs potentially expand the toolbox of TPD by providing a variety of E3 ligase ligands, protein of interest (POI) warheads, and hydrophobic tags (HyTs). As a promising direction in the TPD field, NP-based degraders have shown great potential for anticancer therapy. In this review, we summarize recent advances in the development of NP-based degraders (PROTACs, MGs and HyTing) with anticancer applications. Moreover, we put forward the challenges while presenting potential opportunities for the advancement of future targeted protein degraders derived from NPs.

Structure-Activity Relationship Study of Majusculamide D: Overcoming Metabolic Instability and Severe Toxicity with a Fluoro Analogue

Majusculamide D, isolated from the marine cyanobacterium Moorea producens, is an anticancer lipopentapeptide consisting of fatty acid, tripeptide, and pyrrolyl proline moieties. In this work, by utilizing a convergent synthetic approach, late-stage modification, and bioisostere strategy, 26 majusculamide D analogues were synthesized, and two (1i and 1j) demonstrated IC50 values < 1 nM against PANC-1 cancer cells. The results summarized a preliminary structure-activity relationship mainly at the C23, C4, C34, and C10 sites. A series of in vitro assays, including wound healing, transwell, clone formation, EdU, and western blot, confirmed that majusculamide D inhibited the migration, invasion, and proliferation of pancreatic cancer cells. The optimized fluorinated analogue 1n demonstrated a notable enhancement in stability during the mouse plasma assay (>50% left after 24 h), exhibited tumor-suppressive effects (51.5% at a dosage of 5 mg/kg), and successfully mitigated the severe toxicity (no mouse dead) observed in the group treated with majusculamide D (3 mice dead) in a xenografted mouse model.

Evodiamine: A Extremely Potential Drug Development Candidate of Alkaloids from Evodia rutaecarpa

Evodiamine (EVO) is a tryptamine indole alkaloid and the main active ingredient in Evodia rutaecarpa. In recent years, the antitumor, cardioprotective, anti-inflammatory, and anti-Alzheimer's disease effects of EVO have been reported. EVO exerts antitumor effects by inhibiting tumor cell activity and proliferation, blocking the cell cycle, promoting apoptosis and autophagy, and inhibiting the formation of the tumor microvasculature. However, EVO has poor solubility and low bioavailability. Several derivatives with high antitumor activity have been discovered through the structural optimization of EVO, and new drug delivery systems have been developed to improve the solubility and bioavailability of EVO. Current research found that EVO could have toxic effects, such as hepatotoxicity, nephrotoxicity, and cardiac toxicity. This article reviews the pharmacological activity, derivatives, drug delivery systems, toxicity, and pharmacokinetics of EVO and provides research ideas and references for its further in-depth development and clinical applications.

PROTAC derivatization of natural products for target identification and drug discovery: Design of evodiamine-based PROTACs as novel REXO4 degraders

INTRODUCTION

Natural products (NPs) play a crucial role in the development of therapeutic drugs. However, it is still highly challenging to identify the targets of NPs. Besides, NPs usually exert their pharmacological activities via acting on multiple targets or pathways, which also poses great difficulties for the target identification of NPs.

OBJECTIVES

Inspired by our continuous efforts in designing drug-like protein degraders, this study introduced a successful example for the target identification and drug discovery of natural products evodiamine by employing PROTAC technology.

METHODS

Taking advantages of proteolysis targeting chimera (PROTAC), herein an integrated strategy combining PROTAC derivatization, quantitative proteomic analysis and binding affinity validation was developed for target identification and drug discovery of antitumor NP evodiamine.

RESULTS

In this study, both highly potent PROTACs and negative controls were designed for quantitative proteomic analysis. Furthermore, REXO4 was confirmed as a direct target of 3-fluoro-10-hydroxylevodiamine, which induced cell death through ROS. In addition, the PROTAC 13c effectively degraded REXO4 both in vitro and in vivo, leading to potent antitumor activities and reduced toxic side effects.

CONCLUSION

In summary, we developed an integrated strategy for the target identification and drug discovery of NPs, which was successfully applied to the PROTAC derivatization and target characterization of evodiamine. This proof-of-concept study highlighted the superiority of PROTAC technology in target identification of NPs and accelerated the process of NPs-based drug discovery, exhibiting broad application in NP-based drug development.

Two-Phase Electrosynthesis of Dihydroxycoumestans: Discovery of a New Scaffold for Topoisomerase I Poison

Coumestan represents a biologically relevant structural motif distributed in a number of natural products, and the rapid construction of related derivatives as well as the characterization of targets would accelerate lead compound discovery in medicinal chemistry. In this work, a general and scalable approach to 8,9-dihydroxycoumestans via two-electrode constant current electrolysis was developed. The application of a two-phase (aqueous/organic) system plays a crucial role for success, protecting the sensitive o-benzoquinone intermediates from over-oxidation. Based on the structurally diverse products, a primary SAR study on coumestan scaffold was completed, and compound 3 r exhibited potent antiproliferative activities and a robust topoisomerase I (Top1) inhibitory activity. Further mechanism studies demonstrates that compound 3 r was a novel Top1 poison, which might open an avenue for the development of Top1-targeted antitumor agent.

Design of Evodiamine-Glucose Conjugates with Improved In Vivo Antitumor Activity

Natural product evodiamine is a multitargeting antitumor lead compound. However, clinical development of evodiamine derivatives was hampered by poor water solubility and limited in vivo antitumor potency. Herein, a series of evodiamine-glucose conjugates were designed by additional targeting glucose transporter-1 (GLUT1). Compared with the lead compound, conjugate 8 exhibited obvious enhancement in water solubility and in vivo antitumor efficacy. Furthermore, the effect of GLUT1 targeting also led to lower cytotoxicity to normal cells. Antitumor mechanism studies manifested that conjugate 8 acted by Top1/Top2 dual inhibition, apoptosis induction, and G2/M cell cycle arrest, which selectively targeted tumor cells with a high expression level of GLUT1. Thus, evodiamine-glucose conjugates showed promising features as potential antitumor agents.

Experimental and computational study on anti-gastric cancer activity and mechanism of evodiamine derivatives

Introduction: Human topoisomerase 1 (TOP1) is an important target of various anticancer compounds. The design and discovery of inhibitors targeting TOP1 are of great significance for the development of anticancer drugs. Evodiamine and thieno [2,3-d] pyridine hybrids show potential antitumor activity. Herein, the anti-gastric cancer activities of these hybrids were investigated. Methods: The inhibitory effects of different concentrations of ten evodiamine derivatives on the gastric cancer cell line SGC-7901 were assessed using a methyl thiazolyl tetrazolium assay. Compounds EVO-1 and EVO-6 strongly inhibited gastric cancer cell proliferation, with inhibition rates of 81.17% ± 5.08% and 80.92% ± 2.75%, respectively. To discover the relationship between the structure and activity of these two derivatives, density functional theory was used to investigate their optimized geometries, natural population charges, frontier molecular orbitals, and molecular electrostatic potentials. To clarify their anti-gastric cancer mechanisms, molecular docking, molecular dynamics simulations, and binding free energy calculations were performed against TOP1. Results: The results demonstrated that these compounds could intercalate into the cleaved DNA-binding site to form a TOP1-DNA-ligand ternary complex, and the ligand remained secure at the cleaved DNA-binding site to form a stable ternary complex. As the binding free energy of compound EVO-1 with TOP1 (-38.33 kcal·mol-1) was lower than that of compound EVO-6 (-33.25 kcal·mol-1), compound EVO-1 could be a more potent anti-gastric cancer agent than compound EVO-6. Discussion: Thus, compound EVO-1 could be a promising anti-gastric cancer drug candidate. This study may facilitate the design and development of novel TOP1 inhibitors.

N(14)-substituted evodiamine derivatives as dual topoisomerase 1/tubulin-Inhibiting anti-gastrointestinal tumor agents

Gastrointestinal tumor is an important factor threatening human health. Natural product-based drug discovery is a popular paradigm for expanding the chemical space and identifying new molecular entities that ameliorate human disease. Evodiamine-inspired medicinal chemistry presents therapeutic potential for treating tumors in different tissues via multi-target inhibition. Here, by focusing on the discovery of anti-gastrointestinal tumor drugs, a series of N(14) alkyl-substituted evodiamine derivatives were designed and synthesized. The structure-activity relationship studies culminated in the identification of the N(14)-propyl-substituted evodiamine analog 6b, which showed low nanomolar inhibitory activity against MGC-803 (IC₅₀ = 0.09 μM) and RKO (IC₅₀ = 0.2 μM) cell lines. Moreover, compound 6b was effective in inducing apoptosis, arresting the cell cycle in the G2/M phase, and inhibiting migration and invasion of MGC-803 and RKO cell lines in a dose-dependent manner in vitro. Further antitumor mechanism studies revealed that compound 6b significantly inhibited topoisomerase 1 (inhibition rate of 58.3% at 50 μM) and tubulin polymerization (IC₅₀ = 5.69 μM). Overall, compound 6b represents a promising dual topoisomerase 1/tubulin-targeting lead structure for the treatment of gastrointestinal tumor.

Natural product evodiamine-inspired medicinal chemistry: Anticancer activity, structural optimization and structure-activity relationship

It is a well-known phenomenon that natural products can serve as powerful drug leads to generate new molecular entities with novel therapeutic utility. Evodiamine (Evo), a major alkaloid component in traditional Chinese medicine Evodiae Fructus, is considered a desirable lead scaffold as its multifunctional pharmacological properties. Although natural Evo has suboptimal biological activity, poor pharmacokinetics, low water solubility, and chemical instability, medicinal chemists have succeeded in producing synthetic analogs that overshadow the deficiency of Evo in terms of further clinical application. Recently, several reviews on the synthesis, structural modification, mechanism pharmacological actions, structure-activity relationship (SAR) of Evo have been published, while few reviews that incorporates intensive structural basis and extensive SAR are reported. The purpose of this article is to review the structural basis, anti-cancer activities, and mechanisms of Evo and its derivatives. Emphasis will be placed on the optimizing strategies to improve the anticancer activities, such as structural modifications, pharmacophore combination and drug delivery systems. The current review would benefit further structural modifications of Evo to discover novel anticancer drugs.

Untargeted LC-MS/MS-Based Multi-Informative Molecular Networking for Targeting the Antiproliferative Ingredients in Tetradium ruticarpum Fruit

The fruit of Tetradium ruticarpum (TR) is commonly used in Chinese herbal medicine and it has known antiproliferative and antitumor activities, which can serve as a good source of functional ingredients. Although some antiproliferative compounds are reported to be present in TR fruit, most studies only focused on a limited range of metabolites. Therefore, in this study, the antiproliferative activity of different extracts of TR fruit was examined, and the potentially antiproliferative compounds were highlighted by applying an untargeted liquid chromatography–tandem mass spectrometry (LC-MS/MS)-based multi-informative molecular networking strategy. The results showed that among different extracts of TR fruit, the EtOAc fraction F2-3 possessed the most potent antiproliferative activity against HL-60, T24, and LX-2 human cell lines. Through computational tool-aided structure prediction and integrating various data (sample taxonomy, antiproliferative activity, and compound identity) into a molecular network, a total of 11 indole alkaloids and 47 types of quinolone alkaloids were successfully annotated and visualized into three targeted bioactive molecular families. Within these families, up to 25 types of quinolone alkaloids were found that were previously unreported in TR fruit. Four indole alkaloids and five types of quinolone alkaloids were targeted as potentially antiproliferative compounds in the EtOAc fraction F2-3, and three (evodiamine, dehydroevodiamine, and schinifoline) of these targeted alkaloids can serve as marker compounds of F2-3. Evodiamine was verified to be one of the major antiproliferative compounds, and its structural analogues discovered in the molecular network were found to be promising antitumor agents. These results exemplify the application of an LC-MS/MS-based multi-informative molecular networking strategy in the discovery and annotation of bioactive compounds from complex mixtures of potential functional food ingredients.

Discovery of novel bis-evodiamine derivatives with potent antitumor activity

Inspired by antitumor natural product evodiamine, a series of novel bis-evodiamine derivatives were designed and synthesized, which showed potent antitumor activity. In particular, compound 13b effectively inhibited the proliferation and migration of HCT116 cells. Further mechanism studies revealed that compound 13b acted by inducing HCT116 cell apoptosis and arresting the cell cycle at the G2/M phase. Thus, compound 13b represents a promising lead compound for the discovery of novel antitumor agents.

Design, synthesis and bioactivity evaluation of favorable evodiamine derivative scaffold for developing cancer therapy

Natural product evodiamine is one of the most privileged scaffolds in drug discovery and is suitable for derivatization, which can be conducted quickly for structure optimization and structure-activity relationship research. In this work, a comprehensive SAR study on evodiamine scaffold with N14-3'-fluorophenyl substituted was completed, and compounds with high anti-tumor activity and good inhibitory effect on Top1 and Top2 were screened out. Tested evodiamine derivatives exhibited excellent broad-spectrum anti-tumor activity. Among them, compound 8b revealed 55.15% and 55.50% inhibition for Top1 and Top2 at 25 μM, as well as 0.16 and 0.13 μM IC₅₀ value for MGC-803 and SGC-7901 cells, respectively; compound 9a revealed 70.50% and 71.81% inhibition for Top1 and Top2 at 25 μM, as well as 0.22 and 0.27 μM IC₅₀ value for MGC-803 and SGC-7901 cells, respectively. The further biological evaluation showed that they could functionally induce apoptosis, significantly arrest the cell cycle at the G2/M phase, and markedly inhibit cell proliferation, migration and invasion. In addition, compound 9a performed a tumor inhibitory rate of 36.35% and showed no apparent toxicity in vivo. Overall, these optimized protocols will advance the progression of cancer chemotherapy and can be used to expand the options for screening therapeutic cancer drugs.

Design, Synthesis, and Biological Evaluation of Novel Evodiamine Derivatives as Potential Antihepatocellular Carcinoma Agents

Evodiamine has many biological activities. Herein, we synthesize 23 disubstituted derivatives of N14-phenyl or the E-ring of evodiamine and conduct systematic structure-activity relationship studies. In vitro antiproliferative activity indicated that compounds F-3 and F-4 dramatically inhibited the proliferation of Huh7 (IC₅₀ = 0.05 or 0.04 μM, respectively) and SK-Hep-1 (IC₅₀ = 0.07 or 0.06 μM, respectively) cells. Furthermore, compounds F-3 and F-4 could double inhibit topoisomerases I and II, inhibit invasion and migration, block the cell cycle to the G2/M stage, and induce apoptosis as well. Additionally, compounds F-3 and F-4 could also inhibit the activation of HSC-T6 and reduce the secretion of collagen type I to slow down the progression of liver fibrosis. Most importantly, compound F-4 (TGI = 60.36%) inhibited tumor growth more significantly than the positive drug sorafenib. To sum up, compound F-4 has excellent potential as a strong candidate for the therapy of hepatocellular carcinoma.

Design, synthesis and bioactivity evaluation of novel N-phenyl-substituted evodiamine derivatives as potent anti-tumor agents

Natural products are important sources for the development of therapeutic medicine, among which evodia fruit has a wide range of medicinal properties in traditional Chinese medicine. Evodiamine, the main active component of evodia fruit, has various anti-cancer effects and has been proved to be a Topo inhibitor. From our previous attempts of modifying evodiamine, we found that the N14 phenyl substituted derivatives had showed great anti-tumor activity, which prompted us to further explore the novel structures and activities of these compounds. Compound 6f, as a N14 3-fluorinated phenyl substituted evodiamine derivative, showed a certain inhibitory activity against Topo I at 200 μM. By studying its anti-tumor effects in vitro, compound 6f could inhibit proliferation and induce apoptosis, as well as arrest the cell cycle of HGC-27 and HT-29 cell lines at G2/M phase in a concentration-dependent manner. Moreover, compound 6f could inhibit the migration and invasion of HGC-27 cell lines. Meanwhile, compound 6f could induce apoptosis of HGC-27 cells by inhibiting PI3K/AKT pathway. Overall, this work demonstrated that the N14 phenyl-substituted evodiamine derivatives had a good inhibitory effect on tumor cells in vitro, providing a promising strategy for developing potential anticancer agents for the treatment of gastrointestinal tumors.

Discovery of Novel Polycyclic Heterocyclic Derivatives from Evodiamine for the Potential Treatment of Triple-Negative Breast Cancer

Evodiamine (Evo) is a quinazolinocarboline alkaloid found in Evodia rutaecarpa and exhibits moderate antiproliferative activity. Herein, we report using a scaffold-hopping approach to identify a series of novel polycyclic heterocyclic derivatives based on Evo as the topoisomerase I (Top1) inhibitor for the treatment of triple-negative breast cancer (TNBC), which is an aggressive subtype of breast cancer with limited treatment options. The most potent compound 7f inhibited cell growth in a human breast carcinoma cell line (MDA-MB-231) with an IC₅₀ value of 0.36 μM. Further studies revealed that Top1 was the target of 7f, which directly induced irreversible Top1-DNA covalent complex formation or induced an oxidative DNA lesion through an indirect mechanism mediated by reactive oxygen species. More importantly, in vivo studies showed that 7f exhibited potent antitumor activity in a TNBC-patient-derived tumor xenograft model. These results suggest that compound 7f deserves further investigation as a promising candidate for the treatment of TNBC.

Design, synthesis and bioactivity evaluation of novel evodiamine derivatives with excellent potency against gastric cancer

Gastric cancer represents a significant health burden worldwide. Previously, inspired by the traditional Chinese medicine Wu-Chu-Yu to treat the spleen and stomach system for thousands of years, we identified N14-phenyl substituted evodiamine derivatives as potential antitumor agents with favorable inhibition on Top1. Herein, structural optimization and structure-activity relationship studies (SARs) led us to discovering a highly active evodiamine derivative compound 6t against gastric cancer. Further anti-tumor mechanism studies revealed that compound 6t played as the inhibition of topoisomerase 1 (Top1), effectively induced apoptosis, obviously arrested the cell cycle at the G2/M phase, and significantly inhibited the migration and invasion of SGC-7901 and MGC-803 cell lines in a dose-dependent manner. Moreover, the compound 6t was low toxicity in vivo and exhibited excellent anti-tumor activity (TGI = 70.12%) in the MGC-803 xenograft models. In summary, compound 6t represents a promising candidate as a potential chemotherapeutic agent against gastric cancer.