Product name: Seneciphyllinine
Synonym name: Acetylseneciphylline
Catalogue No.: SBP00954
Cas No.: 90341-45-0
Formula: C₂₀H₂₅NO₆
Mol Weight: 375.421
Botanical Source: Gynura segetum (Lour.)Merr.
Physical Description:
Type of Compound: Alkaloids

Purity: 95%~99%
Analysis Method: HPLC-DAD or/and HPLC-ELSD
Identification Method: Mass, NMR
Packing: Brown vial or HDPE plastic bottle

Storage: Store in a well closed container, protected from air and light. Put into refrigerate or freeze for long term storage.
Whenever possible, you should prepare and use solutions on the same day. However, if you need to make up stock solutions in advance, we recommend that you store the solution as aliquots in tightly sealed vials at -20℃. Generally, these will be useable for up to two weeks.

The product could be supplied from milligrams to grams
Inquire for bulk scale.

For Reference Standard and R&D, Not for Human Use Directly.

Storage conditions：Short-term storage at 2~8℃, long-term storage at -20 ~ -80℃

Introduction/Overview

Natural products, as an important source of drug discovery, play an indispensable role in the history of human struggle against diseases. However, while nature endows certain compounds with significant pharmacological activity, it often comes with significant toxicity that cannot be ignored. Pyrrolizidine alkaloids (PAs) are a type of natural product that combines biological activity and potential harm. They are widely distributed in the genus Senecio（Senecio）The genus Ligustrum（Ligularia）Chrysanthemum and Panax notoginseng genus（Gynura）Among various plants, it is known for its significant hepatotoxicity and is one of the main environmental factors leading to irreversible liver damage in humans and livestock, such as hepatic sinus obstruction syndrome (HSOS). However, the complex chemical structure and diverse biological activities of PAs, especially their potential anti-tumor effects, have long attracted the attention of medicinal chemists and pharmacologists.

Acetylated Seneciphylline is a prominent member of the pyrrolizidine alkaloid family. Its CAS number is 90341-45-0, and it is a traditional medicinal plant derived from chrysanthemum and Panax notoginseng（Gynura japonica Natural compounds isolated from the roots of Panax notoginseng (also known as "Tu San Qi" or "Jin Bu Huan"). Jusanqi is often used in folk medicine to treat traumatic injuries, stop bleeding and remove blood stasis, but its liver toxicity risk has also been frequently reported, which is closely related to the PAs components it contains. Acetylated camptothecin, as a representative component, is characterized by its chemical structure with acetylated side chains attached to its core pyrrolizidine nucleus. This structural modification may have a profound impact on its biological activity, toxicity, and pharmacokinetic properties.

In recent years, with the deepening of research on the anti-tumor activity of natural products, the potential medicinal value of acetylated camptothecin has gradually emerged. Preliminary studies have shown that the compound exhibits certain cytotoxicity towards multiple tumor cell lines, and its mechanism of action may involve the regulation of multiple key signaling pathways and molecular targets, including anti apoptotic proteins MCL1 and BCL2, transcription factor STAT3, matrix metalloproteinase MMP2, topoisomerase TOP1/TOP2A, hypoxia inducible factor HIF1A, mitogen activated protein kinase MAPK1, estrogen receptor ESR1, and aromatase CYP19A1. These targets are widely involved in key biological processes such as tumor cell proliferation, apoptosis, invasion, metastasis, angiogenesis, and hormone metabolism, suggesting that acetylated camptothecin may have a multi-target and multi pathway anti-tumor mode of action.

However, like all PAs, the hepatotoxicity of acetylated camptothecin is the biggest obstacle it faces from laboratory to clinical application. The double bonds and ester groups in its molecular structure are key pharmacophores that produce toxicity. After being metabolized and activated by the cytochrome P450 enzyme system in vivo, pyrrole metabolites with strong electrophilicity can be generated, which can then covalently bind with biomolecules such as proteins and DNA, leading to liver cell damage, necrosis, and even inducing liver cancer. Therefore, while exploring its anti-tumor potential, it is necessary to conduct in-depth and cautious research on its toxicity mechanism, structure-activity relationship, and possible attenuation strategies.

This article aims to provide a systematic review of the current research status of acetylated camptothecin. The article will first introduce its chemical structure and physicochemical properties, followed by an explanation of its plant origin and extraction methods. The focus will be on sorting out its pharmacological activities in anti-tumor and other aspects, and exploring its potential mechanisms of action and molecular targets in depth. On this basis, the pharmacological parameters and pharmacokinetic characteristics of this natural product will be evaluated, and finally, the clinical application prospects and challenges faced will be discussed, in order to provide comprehensive reference for the subsequent research of this natural product with "double-edged sword" characteristics.

Chemical structure and physicochemical properties

Acetylated camptothecin belongs to the macrocyclic diester pyrrolizidine alkaloid family, and its chemical structure is the basis for understanding its biological activity and toxicity. Its core skeleton is composed of a saturated or slightly unsaturated pyrrolizidine bicyclic ring (i.e. two pyrrolidine rings fused together), which is a common feature of all PAs. In acetylated camptothecin, there is a double bond between the 1st and 2nd positions of this double ring, forming an important toxic structural unit - the necine base (camptothecin type). The C7 and C9 hydroxyl groups of this base are bridged by an eleven membered macrocyclic lactone formed by a dicarboxylic acid (usually gibberellic acid or its derivatives), forming its macrocyclic diester structure. Its uniqueness lies in the fact that a hydroxyl group on the side chain of the macrocyclic lactone is replaced by an acetyl group (- COOCH3), and this acetylation modification is a key structural feature that distinguishes it from other analogues such as camptothecin.

From the perspective of physical and chemical properties, the molecular formula of acetylated camptothecin is C ₂₀ H ₂₅ NO ₇, with a molecular weight of 375.4210 g/mol. Its lipid water partition coefficient LogP is 1.0887, indicating that the compound has a certain degree of lipophilicity, but also moderate hydrophilicity, which allows it to cross biofilms to a certain extent and maintain a certain solubility in aqueous environments. Its water solubility parameter is 0.8211 mg/mL, which belongs to the slightly soluble level. The polar surface area (TPSA) is 82.1400 Å ², which is relatively high and usually indicates that the molecule has good oral bioavailability potential, but it may also affect its transmembrane transport. It is worth noting that its blood-brain barrier (BBB) penetration is predicted to be "high", indicating that the compound may enter the central nervous system, which may bring potential for treating central nervous system diseases and increase the risk of neurotoxicity. In addition, the predicted result of hERG inhibition is' no ', indicating a lower risk of inducing QT interval prolongation and arrhythmia in the heart. The Ames test result is 0.6, which is a critical value between negative and positive, indicating that it may have potential genetic toxicity and requires further experimental verification. These physicochemical parameters and predicted drug properties provide important references for subsequent pharmacological research and drug design.

Plant sources and extraction methods

The main plant source of acetylated camptothecin is the chrysanthemum and Panax notoginseng plants in the Asteraceae family - Chrysanthemum and Panax notoginseng（Gynura japonica (Thunb.) Juel.）。 This plant is widely distributed in China, Japan, and Southeast Asia. Its rhizome is known as "Tu Sanqi" or "Ju Ye Sanqi" in traditional medicine and is commonly used to treat bleeding, bruising, and pain. However, the hepatotoxicity of Jusanqi has been widely confirmed, and its toxic components mainly consist of various pyrrolizidine alkaloids contained in it, among which acetylated camptothecin is one of the components with high content and strong activity. In addition, in some other species of the Qianli genus（Senecio）The genus of Ligustrum（Ligularia）This compound may also exist in plants, but Chrysanthemum morifolium is its most recognized and primary source.

The extraction of acetylated camptothecin from the roots of Chrysanthemum morifolium usually follows the classic process of natural product chemistry, which mainly includes the following steps:

1. Raw material preparation and extraction Crush the dried chrysanthemum and Panax notoginseng roots and extract them using polar solvents. Common solvents include methanol, ethanol, or their aqueous solutions. In order to improve extraction efficiency, methods such as cold soaking, percolation, or heating reflux are usually used. Due to the higher stability of PAs under acidic conditions, a small amount of acid (such as 0.1% hydrochloric acid or tartaric acid) is sometimes added to the extraction solvent to promote their dissolution in salt form.

2. Preliminary purification After concentrating the crude extract, liquid-liquid extraction is usually used for preliminary separation. For example, first use non-polar solvents such as petroleum ether or n-hexane to remove lipophilic impurities, and then extract the target alkaloids with medium polarity solvents such as ethyl acetate or n-butanol. Due to the alkalinity of PAs, acid-base extraction can be used for enrichment: the crude extract is dissolved in a dilute acidic aqueous solution to make the alkaloids salt and dissolve in the aqueous phase, then washed with organic solvents to remove neutral impurities, and finally the aqueous phase is adjusted to alkalinity with alkali (such as ammonia water), and then back extracted with organic solvents (such as chloroform, dichloromethane) to obtain the total alkaloid extract.

3. Chromatographic Separation and Purification Total alkaloid extract is a complex mixture that requires modern chromatographic techniques for separation and purification. The most commonly used method is silica gel column chromatography, which separates PAs of different polarities by optimizing the eluent system (such as chloroform methanol ammonia gradient elution). In addition, alumina column chromatography, preparative thin-layer chromatography (PTLC), and high-performance liquid chromatography (HPLC) were also used for further purification. For PAs with similar structures, such as acetylated camptothecin and its non acetylated precursor, more efficient separation techniques may be required, such as medium pressure liquid chromatography (MPLC) or high-speed countercurrent chromatography (HSCCC). Finally, the structure of the purified compound was identified by spectroscopic methods such as nuclear magnetic resonance spectroscopy (NMR) and mass spectrometry (MS), confirming that it was acetylated camptothecin.

Pharmacological activity research

The pharmacological activity research of acetylated camptothecin is still in its early stages, but existing evidence suggests that it has multiple biological activities, among which anti-tumor activity is the most remarkable.

1. Antitumor activity

This is the most core direction in the research of acetylated camptothecin. Multiple in vitro cell experiments have shown that the compound exhibits significant proliferation inhibition and cytotoxicity against various human tumor cell lines. Its spectrum of action is wide, involving tumor types including:

• liver cancer Due to its hepatotoxicity, its effects on liver cancer cells such as HepG2 and Huh7 are a research hotspot. Research has shown that acetylated camptothecin can effectively inhibit the proliferation of liver cancer cells and induce their apoptosis.
• breast cancer: It showed activity on estrogen receptor positive (ER+) and triple negative breast cancer (TNBC) cell lines (such as MCF-7, MDA-MB-231), suggesting that its mechanism of action may be related to estrogen signaling pathway.
• Lung cancer It also has inhibitory effects on non-small cell lung cancer cells (such as A549).
• colorectal cancer It exhibits cytotoxicity towards colorectal cancer cells such as HCT116 and HT-29.
• Other It also shows certain activity against cell lines such as prostate cancer, gastric cancer, leukemia, etc.

It is worth noting that its anti-tumor activity is often closely related to its cytotoxicity, and its sensitivity varies in different cell lines. Its IC ₅₀ value is usually in the micromolar range, showing moderate activity.

2. Other pharmacological activities

Apart from its anti-tumor effect, there are relatively few reports on the other pharmacological activities of acetylated camptothecin. Given the commonality of their PAs, they may also have certain anti-inflammatory, antibacterial, or antiviral activities, but these aspects still lack systematic research. Its most significant "activity" is actually its liver toxicity, which is both an obstacle to its medicinal development and a research focus as a toxic substance.

Mechanism of action and molecular targets

The pharmacological effects of acetylated camptothecin, especially its anti-tumor activity, are achieved through multi-target and multi pathway synergistic effects. According to existing research, its mechanism of action mainly involves the following aspects:

1. Inducing cell apoptosis and regulating apoptosis related proteins

This is one of the core mechanisms of its anti-tumor effect. Acetylated camptothecin can induce tumor cell apoptosis through endogenous (mitochondrial) and exogenous (death receptor) pathways.

• Regulating BCL-2 family proteins This compound can downregulate the expression of anti apoptotic proteins MCL1 and BCL2, while upregulating the expression of pro apoptotic protein BAX. MCL1 and BCL2 are key anti apoptotic proteins on the outer membrane of mitochondria. Their downregulation leads to a decrease in mitochondrial membrane potential, the release of apoptotic factors such as cytochrome c, activation of the Caspase cascade reaction, and ultimately cell apoptosis.
• Inhibition of STAT3 signaling pathway STAT3 is an important transcription factor that is continuously activated in various tumors, promoting cell proliferation, survival, and angiogenesis. Acetylated camptothecin can inhibit the phosphorylation of STAT3 (Tyr705 site), thereby blocking its nuclear translocation and transcriptional activity, downregulating the expression of downstream target genes (such as MCL1, BCL2, Cyclin D1, VEGF, etc.), and exerting anti-tumor effects.

2. Inhibit tumor invasion and metastasis

• Inhibition of MMP2 activity Matrix metalloproteinase MMP2 is a key enzyme that degrades extracellular matrix (ECM) and plays an important role in tumor invasion and metastasis. Acetylated camptothecin can inhibit the expression and/or activity of MMP2, thereby weakening the migration and invasion ability of tumor cells.

3. Interference with DNA topology and replication

• Inhibition of TOP1 and TOP2A topoisomerases Topoisomerase is a key enzyme in DNA replication, transcription, and repair processes. Acetylated camptothecin may inhibit the activity of TOP1 and TOP2A, leading to the inability of DNA supercoiled structures to unwind normally, thereby hindering DNA replication and transcription, inducing DNA damage and cell death. This is similar to the mechanism of action of certain topoisomerase inhibitor anticancer drugs used in clinical practice, such as camptothecin and etoposide.

4. Inhibit tumor angiogenesis

• Regulating HIF1A signaling Hypoxia inducible factor 1 alpha (HIF1A) is a key transcription factor for tumor adaptation to the hypoxic microenvironment, which can upregulate the expression of angiogenic factors such as vascular endothelial growth factor (VEGF). Acetylated camptothecin may reduce VEGF secretion, inhibit tumor angiogenesis, and cut off tumor nutrient supply by inhibiting the protein expression or activity of HIF1A.

5. Affects cell proliferation and signal transduction

• Regulating the MAPK1/ERK pathway MAPK1 (ERK2) is a key member of the RAS-RAF-MEK-ERK signaling pathway, regulating cell proliferation, differentiation, and survival. Acetylated camptothecin may inhibit tumor cell proliferation by suppressing the activation of this pathway.
• Intervention in hormone signaling pathway: For hormone dependent tumors such as breast cancer, this compound may play a role by affecting the activity of estrogen receptor ESR1 and aromatase CYP19A1. ESR1 is the main receptor for estrogen action, while CYP19A1 is the key enzyme that converts androgens into estrogen. Inhibiting these two targets can reduce estrogen signaling, thereby inhibiting the growth of hormone sensitive tumors.

6. Liver toxicity mechanism

It must be emphasized that the hepatotoxicity of acetylated camptothecin is its most significant "side effect", and its mechanism overlaps with the anti-tumor mechanism mentioned above in some aspects, but more importantly, it is caused by its metabolic activation. This compound is metabolized by cytochrome P450 enzymes (mainly CYP3A4) in the liver. After hydrolysis of its diester structure, the double bonds at positions 1 and 2 of the necine base are oxidized to form highly reactive pyrrolic ester metabolites. These metabolites are strong electrophilic reagents that can covalently bind with nucleophilic substances such as proteins, DNA, and glutathione (GSH) in liver cells to form adducts. This will lead to:
- Protein functional damage Binding to key enzymes and structural proteins leads to metabolic disorders and structural damage in liver cells.
- DNA damage Forming DNA adducts may lead to gene mutations and cancer.
- Glutathione depletion Consuming important antioxidants within cells leads to oxidative stress and mitochondrial dysfunction.
- Injury of hepatic sinusoidal endothelial cells This is the pathological basis of hepatic sinus obstruction syndrome (HSOS).

Therefore, the anti-tumor activity of acetylated camptothecin is closely related to its liver toxicity, and its selectivity is the key to future research.

Evaluation of drug properties and pharmacokinetics

Based on the provided pharmacological parameters, a preliminary evaluation of the pharmacological potential of acetylated selegiline can be conducted.

• Physicochemical properties The molecular weight is 375.4 Da, which meets the requirement of Lipinski's Rule of Five for molecular weight<500. LogP is 1.09, with moderate lipophilicity, which is beneficial for oral absorption and transmembrane transport. The water solubility is 0.82 mg/mL, which is slightly soluble and may affect the bioavailability of its oral formulation, but can be improved through formulation techniques such as salt formation and cyclodextrin inclusion. The TPSA is 82.1 Å ², and compounds with TPSA<140 Å ² are generally considered to have good oral absorption potential, therefore this parameter is positive.
• Security risk This is the biggest challenge.High blood-brain barrier penetrability There is a risk of neurotoxicity and its impact on the central nervous system needs to be evaluated.Ames test result 0.6 This is a critical value, strongly indicating its potential genotoxicity and carcinogenicity, which is a major obstacle in drug development.HERG inhibition is negative It is one of the few positive safety indicators.
• pharmacokinetics Currently, there is very limited research data on the absorption, distribution, metabolism, and excretion (ADME) of acetylated camptothecin in the body. Based on the commonality of their PAs, it can be inferred that:
  • absorb After oral administration, it may be absorbed in the small intestine, but the first pass effect may be significant because the liver is the main organ for PAs metabolism.
  • distribution Due to its moderate lipophilicity, its distribution volume may be relatively large. High BBB penetration suggests its ability to enter brain tissue.
  • Metabolism Mainly metabolized in the liver through the CYP450 enzyme system (especially CYP3A4). Metabolic pathways include hydrolysis, oxidation (forming toxic pyrrole metabolites), N-oxidation, etc. Its acetyl group may be hydrolyzed by esterase.
  • excretion Metabolites are mainly excreted through urine and bile.
• Summary of Medicinal Properties Acetylated camptothecin has some pharmacological properties, but its Significant hepatotoxicity, potential genetic toxicity, and neurotoxicity risks Make it extremely low in potency as an oral medication. The 'therapeutic window' between its anti-tumor activity and toxicity is very narrow. Therefore, the future research direction should not be to directly develop it into a drug, but to:
  1. As a lead compound By structural modification, the toxic groups (such as the double bonds at positions 1 and 2) can be removed or reduced, while retaining or enhancing its anti-tumor activity.
  2. As a tool molecule Utilize its multi-target properties to study its mechanism of action in tumor biology.
  3. Develop a targeted delivery system Using nanotechnology and other techniques to deliver drugs specifically to tumor tissues, reducing exposure to normal tissues such as the liver.

Clinical application prospects and prospects

The clinical application prospects of acetylated camptothecin are both opportunities and challenges at present, and the challenges far outweigh the opportunities.

Main challenges:

1. Unacceptable toxicity The inherent and mechanistic liver toxicity and potential genetic toxicity are the "dead points" for its clinical translation. Any drug, no matter how effective it is, cannot be approved for marketing if its safety cannot be guaranteed.
2. Narrow treatment window The anti-tumor dose may be very close to the hepatotoxic dose, making it difficult to achieve safe and effective administration in clinical practice.
3. Complex pharmacokinetics Its metabolic activation process is complex, with significant individual differences, and is influenced by CYP450 enzyme gene polymorphism, making it difficult to predict and control its in vivo exposure and toxicity.
4. Lack of selectivity Although its anti-tumor mechanism involves multiple targets, it lacks specificity for tumor cells and also has a killing effect on normal cells (especially liver cells).

Future research directions and potential opportunities:

1. Structure Based Drug Design (SBDD)This is the most promising direction. By analyzing the eutectic structure of acetylated camptothecin and key targets such as TOP1 and STAT3, the active conformation was clarified. Then, using computer-aided drug design, the molecules are modified, such as:
   • Eliminate toxic functional groups Saturate the double bonds at positions 1 and 2, or replace them with other groups that are not easily metabolically activated.
   • Introduce targeting groups Connect ligands that can recognize tumor cell surface specific receptors (such as folate, RGD peptides, etc.) to achieve active targeting.
   • Prodrug strategy Design prodrugs that are activated only in the tumor microenvironment (such as low pH, high concentration of specific enzymes) to reduce toxicity to the liver.
2. Nano drug delivery system Encapsulating acetylated camptothecin or its low toxicity derivatives in liposomes, polymer nanoparticles, or micelles can alter their in vivo distribution, increase accumulation at the tumor site, and reduce exposure to the liver, thereby reducing toxicity and improving treatment efficacy.
3. Combination therapy strategy Explore the combination of acetylated camptothecin with low-dose other anticancer drugs (such as immune checkpoint inhibitors and targeted drugs) to synergistically enhance efficacy through its multi-target properties, while reducing toxicity by lowering the single drug dose.
4. As a biomarker or diagnostic probe Develop probes for detecting liver injury or liver function by utilizing its specific binding and metabolic characteristics with the liver.
5. In depth study of its anti-tumor mechanism Despite its toxicity, its unique mechanism of action involving multiple key oncogenic pathways makes it a valuable tool molecule for studying tumor biology, such as apoptosis escape, angiogenesis, and metastasis.

Conclusion

Acetylated camptothecin, as a typical pyrrolizidine alkaloid isolated from traditional Chinese medicine chrysanthemum and Panax notoginseng, vividly illustrates the dual properties of natural products as both poison and medicine. The macrocyclic diesters and 1,2-double bonds in its chemical structure are not only the structural basis for its multi-target anti-tumor activity, but also the root cause of its severe liver toxicity. Existing research has revealed its complex pharmacological mechanism of inhibiting tumor cell proliferation, inducing apoptosis, and inhibiting invasion and metastasis by regulating multiple key targets such as MCL1, BCL2, STAT3, MMP2, TOP1, etc., demonstrating its potential as an anti-tumor lead compound.

However, its significant hepatotoxicity, potential genetic toxicity, and narrow treatment window constitute an insurmountable gap in its clinical development. It is unrealistic to directly develop it as a drug candidate. The future research focus should shift towards "highlighting strengths and avoiding weaknesses": on the one hand, through advanced medicinal chemistry methods (such as structural modification, prodrug design) and nano drug delivery technology, efforts should be made to reduce its toxicity and improve its therapeutic selectivity; On the other hand, by using it as a unique molecular probe, we can further explore its regulatory network in tumor occurrence and development, providing insights for discovering new drug targets and treatment strategies. The research path of acetylated camptothecin is destined to be an exploratory journey that seeks a balance between risk and hope. Its ultimate value may not lie in becoming a new drug, but in providing a unique key for humans to understand life processes and overcome diseases.