Product name: Hematoxylin
Synonym name:
Catalogue No.: BP3180
Cas No.: 517-28-2
Formula: C₁₆H₁₄O₆
Mol Weight: 302.282
Botanical Source:
Physical Description:
Type of Compound: Flavonoids

Purity: 95%~99%
Analysis Method: HPLC-DAD or/and HPLC-ELSD
Identification Method: Mass, NMR
Packing: Brown vial or HDPE plastic bottle
The product could be supplied from milligrams to grams. Inquire for bulk scale.
We provide solution to improve the water-solubility of compounds, thereby facilitating the variety of activity tests and clinic uses.

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

HPLC of Hematoxylin

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

Introduction/Overview

Hematoxylin (CAS number: 517-28-2), also known as Natural Black 1, is a type of plant derived from the leguminous plant Hematoxylin（Caesalpinia sappan Natural flavonoid compounds extracted from heartwood. Since its introduction into the field of histology in the mid-19th century, its complex with metal ions such as aluminum and iron - hematoxylin lake - has become an irreplaceable nuclear staining agent in pathology laboratories worldwide, laying the foundation for morphological diagnosis of diseases. However, the value of hematoxylin is far more than that. In recent years, with the deepening of pharmacological research on natural products, hematoxylin has gradually demonstrated diversified biological activities beyond its staining function. Research has shown that it is not only an effective inhibitor of β - amyloid protein (A β 42) fibroblast formation (IC50 of 1.6 μ M), indicating its potential application in neurodegenerative diseases such as Alzheimer's disease, but also in the field of oncology, especially leukemia research, demonstrating its anti-cancer potential by regulating multiple key signaling pathways such as AMPK, STAT3, BCL2, etc. Its pharmacological parameters, such as clear molecular weight (302.28), appropriate lipid water partition coefficient (LogP: 1.58), and preliminary safety data (Ames test negative), provide the possibility for its transformation from a classic staining agent to a new therapeutic drug. This article aims to systematically review the chemical properties, plant sources, pharmacological activities, molecular mechanisms of action, pharmacological evaluation, and clinical application prospects of hematoxylin, in order to provide a comprehensive academic perspective for the modern research and development of this ancient natural product.

Chemical structure and physicochemical properties

The chemical name of hematoxylin is 7,11b-dihydrobenzo [b] indeno [1,2-d] pyran-3,4,6a, 9,10 (6H) - pentanol, with a molecular formula of C16H14O6 and a molecular weight of 302.28. Its structure belongs to the class of isoflavones in flavonoids, and its core skeleton is composed of three six membered rings (A, C, B) fused together, with the C ring being a pyran ring with a chiral center. Its structure contains multiple phenolic hydroxyl groups (located at positions 3, 4, 6a, 9, and 10), which are key functional groups for its antioxidant, metal chelation, and interaction with biomolecules.

In terms of physical and chemical properties, hematoxylin itself is a light yellow to light brown crystal or powder, but its oxidation product, hematoxylin, is a deep reddish brown color, which is the active form that forms colored complexes with metal ions. Its theoretical lipid water partition coefficient (LogP) is 1.58, indicating that it has a certain degree of lipophilicity, but not highly hydrophobic. The topological polar surface area (TPSA) is 110.38 Å ², reflecting the strong polarity brought by multiple hydroxyl groups in the molecule. Its water solubility is relatively low, about 0.18 mg/mL, which to some extent limits its bioavailability. In solution, hematoxylin is sensitive to light, heat, and pH value, especially under alkaline conditions, it is easily oxidized to hematoxylin by air. This redox property is not only the basis of its staining chemistry, but may also be involved in regulating its biological activity in vivo.

Plant sources and extraction methods

Sumu su mainly comes from Sumu su（Caesalpinia sappan L. The core talent. Sumu is a traditional Chinese medicinal herb, mainly produced in Southeast Asia, India, Yunnan, Guangxi and other parts of China. Its heartwood is red and has been used since ancient times to promote blood circulation, remove blood stasis, reduce swelling and relieve pain. Except for Su Mu, it belongs to the same plant species as Yang Su Mu（Haematoxylum campechianum L. The heartwood of) is also a traditional commercial source of hematoxylin, but its chemical composition is slightly different from that of hematoxylin.

The extraction method of hematoxylin has undergone development from traditional to modern. Traditional methods often use water or low concentration alcohols (such as ethanol) for reflux extraction, utilizing the solubility of hematoxylin and its related pigments for crude extraction. Modern extraction techniques place greater emphasis on efficiency and purity, often using the following steps:
1. preprocessing Crush the dried heartwood of Sumu to increase the extraction contact area.
2. Solvent extraction Commonly used solvents such as methanol, ethanol, or acetone water mixtures are used for ultrasound assisted extraction or hot reflux extraction. Research has shown that a 70% ethanol aqueous solution is a better choice that balances extraction efficiency and environmental friendliness.
3. Separation and purification After concentration, the crude extract was preliminarily enriched by column chromatography using macroporous adsorption resins (such as AB-8, D101), and gradient elution was performed using different concentrations of ethanol. Further purification can be achieved through methods such as silica gel column chromatography, preparative high-performance liquid chromatography (HPLC), or recrystallization to obtain high-purity hematoxylin monomers.
4. appraisal The purified product was structurally confirmed by melting point determination, UV Vis spectroscopy, IR spectroscopy, MS spectroscopy, and NMR spectroscopy.

Optimizing extraction processes (such as response surface methodology to optimize extraction parameters) and developing green extraction technologies (such as subcritical water extraction) are currently research hotspots for improving the yield and sustainability of hematoxylin.

Pharmacological activity research

Hematoxylin has a wide range of pharmacological activities, and its research has expanded from basic tissue chemistry to multiple therapeutic fields such as anti-tumor, neuroprotective, anti-inflammatory, antioxidant, etc.

1. Antitumor activity This is the pharmacological effect of hematoxylin that has received the most attention in recent years, especially in hematological malignancies. Research has shown that hematoxylin can significantly inhibit the proliferation of various leukemia cell lines (such as HL-60, K562, U937) and induce their apoptosis. Its effect is concentration and time-dependent. In addition, hematoxylin also showed certain growth inhibitory activity on solid tumors such as breast cancer, liver cancer, colon cancer, etc.
2. Neuroprotective and Anti Alzheimer's Disease Potential Hematoxylin can effectively inhibit the self aggregation and fibroblast formation of A β 42 peptide, with an IC50 value as low as 1.6 μ M. A β - fibrils are the main component of senile plaques in the brains of Alzheimer's disease patients, and their formation is closely related to neurotoxicity. The inhibitory effect of hematoxylin may be achieved by directly binding to A β monomers or fibers, interfering with the formation and extension of their β - lamellar structure. In addition, its antioxidant activity also helps alleviate the damage to neurons caused by oxidative stress.
3. Anti inflammatory and antioxidant activity Hematoxylin exerts anti-inflammatory effects by inhibiting the nuclear factor kappa B (NF - κ B) signaling pathway, reducing the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), and decreasing the production of pro-inflammatory factors (such as TNF - α, IL-6, IL-1 β). The phenolic hydroxyl group in its molecule can effectively scavenge free radicals (such as DPPH, ABTS free radicals), demonstrating significant antioxidant capacity.
4. Other activities The study also reported that hematoxylin has antiviral (such as anti dengue virus), antibacterial, antiplatelet aggregation, and wound healing promoting activities, demonstrating its multi-target properties.

Mechanism of action and molecular targets

The pharmacological effects of hematoxylin, especially its anti leukemia activity, are achieved by intervening in multiple key cellular signaling pathways and molecular targets, forming a multi-target, networked mode of action. According to the provided target information, its mechanism of action can be summarized as follows:

1. Energy metabolism and apoptosis regulation Hematoxylin can activate AMP activated protein kinase (AMPK, encoded by PRKAA1). AMPK is an energy sensor in cells, and its activation can inhibit the mammalian rapamycin target protein (mTOR) pathway, suppress protein synthesis and cell growth, while promoting autophagy and apoptosis.
2. Core regulation of apoptosis pathway Sumu Su downregulates the expression of anti apoptotic proteins B cell lymphoma 2 (BCL2) and myeloid leukemia 1 (MCL1), disrupts mitochondrial membrane stability, promotes cytochrome C release, activates caspase cascade reaction, and induces intrinsic apoptosis pathway. This is one of the core mechanisms of its anti leukemia effect.
3. Signal transduction and transcriptional activation inhibition Hematoxylin can inhibit the phosphorylation and activation of signal transduction and transcription activator 3 (STAT3). STAT3 is an important oncogenic transcription factor, and sustained activation can promote cell proliferation, survival, and immune escape. Sumu Su inhibits STAT3 and downregulates the expression of downstream target genes such as Cyclin D1, Survivor, BCL2.
4. Epigenetics and Differentiation Regulation Hematoxylin can inhibit the Notch1 signaling pathway. Notch1 is often mutated or abnormally activated in T-cell acute lymphoblastic leukemia (T-ALL) and is an important therapeutic target. Inhibition of Notch1 can affect cell differentiation and survival. Meanwhile, hematoxylin may have a regulatory effect on isocitrate dehydrogenase 1 (IDH1), and IDH1 mutations are associated with the occurrence of certain leukemia and glioma.
5. Oxidative stress defense regulation The effect of hematoxylin on the nuclear factor E2 related factor 2 (NFE2L2/Nrf2) pathway is bidirectional. At low concentrations, it may enhance cellular antioxidant defense by activating Nrf2; In certain tumor backgrounds, inhibiting excessive activation of Nrf2 may help reverse chemotherapy resistance.
6. The interaction between microtubules and DNA Hematoxylin may affect microtubule stability by interacting with microtubule associated protein tau (MAPT). In addition, studies suggest that it may interfere with the activity of DNA topoisomerase I (TOP1), although its direct effect may not be as strong as classical TOP1 inhibitors.
7. Protein kinase C inhibition The inhibition of protein kinase C alpha (PRKCA) by hematoxylin may affect the signal transduction of cell proliferation and differentiation.

In terms of neuroprotection, the mechanism of inhibiting A β aggregation may be related not only to direct interactions, but also to the synergistic effects of regulating the above-mentioned pathways (such as reducing oxidative stress and inhibiting inflammation).

Evaluation of drug properties and pharmacokinetics

The evaluation of drug properties is a crucial step in the conversion of natural products into drugs. Based on existing data, the pharmacological analysis of hematoxylin is as follows:

1. Preliminary assessment of drug properties The molecular weight of hematoxylin is 302.28 (<500), the LogP value is 1.58 (ideal range 1-3), and the TPSA is 110.38 Å ² (<140), which meets the three key indicators in Lipinski's "Five Rules" and suggests that it has a good drug like basis. Its low water solubility (0.18 mg/mL) is the main weakness, which may affect oral absorption and formulation development.
2. Absorption, distribution, metabolism, excretion (ADME)：
   • absorb Moderate LogP values and multiple hydrogen bond donors/acceptors suggest that it may be absorbed through passive diffusion, but low water solubility may limit its dissolution rate in the gastrointestinal tract, becoming the main limiting factor for oral bioavailability.
   • distribution Its blood-brain barrier (BBB) permeability is predicted to be "low", which poses a challenge for the treatment of central nervous system diseases such as Alzheimer's disease. It is necessary to improve its brain targeting through structural modification or drug delivery systems (such as nanoparticles).
   • Metabolism As a polyphenolic compound, hematoxylin is likely to undergo extensive phase II metabolism in the body, such as glucuronidation and sulfation, which may lead to its rapid clearance. Its oxidized product, hematoxylin, may also be involved in metabolic processes.
   • excretion Expected to be mainly excreted through the kidneys and bile.
3. Preliminary evaluation of safety：
   • Genotoxicity The Ames test result is 0.6 (usually considered negative if the number of revertant mutant colonies is less than twice that of the control), indicating that it has no mutagenicity, which is a positive signal.
   • cardiotoxicity The inhibitory prediction of hERG is' no ', reducing its potential risk of inducing QT interval prolongation and apical torsion type ventricular tachycardia.
   • Other Comprehensive preclinical safety evaluation data for acute toxicity, chronic toxicity, reproductive toxicity, etc. are still lacking and need to be systematically supplemented.

In summary, hematoxylin has the basic structural characteristics and preliminary safety to become a lead compound, but its Low water solubility and potentially poor metabolic stability This is its main drawback in pharmacokinetics. Future research needs to validate the above predictions through pharmacokinetic experiments (such as measuring oral bioavailability, half-life, tissue distribution, etc. in rats or mice), and explore prodrug strategies, eutectic technology, or novel delivery systems (such as liposomes, polymer micelles) to optimize their ADME properties.

Clinical application prospects and prospects

Hematoxylin has evolved from a century old staining agent to a therapeutic drug, with broad clinical application prospects but also facing challenges.

1. Potential application directions：

   • Leukemia adjuvant therapy/combination therapy Given its multi-target anti leukemia mechanism, hematoxylin or its derivatives optimized as lead compounds have the potential to be developed as novel anti leukemia drugs, especially for cases that are resistant or difficult to treat with existing targeted drugs. Combined use with conventional chemotherapy drugs (such as cytarabine, doxorubicin) or targeted drugs may result in synergistic effects, reducing dosage and toxicity.
   • Disease modifying therapy for Alzheimer's disease As an A β aggregation inhibitor, hematoxylin has the potential to be developed as a modified therapy for Alzheimer's disease. The current key is to overcome the blood-brain barrier, which can be achieved by designing brain targeted nano delivery systems or synthesizing derivatives with higher BBB permeability.
   • Expansion of tissue pathology assisted diagnosis Based on its specific binding potential with specific proteins such as abnormally aggregated A β and phosphorylated tau, a novel hematoxylin derivative staining agent is developed for pathological diagnosis and grading of neurodegenerative diseases.
   • Anti inflammatory and antioxidant therapy Used to treat chronic inflammation related diseases such as arthritis, colitis, etc.

2. Challenges and Prospects Faced：

   • Drug efficacy and selective optimization Further clarification is needed on the main therapeutic targets among its numerous targets, and structural modifications should be used to enhance its selectivity towards diseased cells (such as cancer cells) and reduce its potential impact on normal cells.
   • Pharmacokinetic Engineering The core task of advancing its preclinical research is to solve the problems of poor water solubility, fast metabolism, and low brain permeability in the system. Modern medicinal chemistry and pharmaceutical technology provide various tools for this purpose.
   • Deep analysis of the mechanism of action Chemical biological methods such as photoaffinity labeling and proteomics are needed to more accurately identify the direct target proteins within cells and elucidate the interrelationships between their multi-target networks.
   • Preclinical and clinical research After completing the preclinical pharmacodynamics, pharmacokinetics, and safety evaluation of the system, gradually advance clinical trials to verify its effectiveness and safety in humans.

In the future, research on hematoxylin will exhibit the characteristics of interdisciplinary integration, combining computational chemistry, structural biology, nanotechnology, and clinical medicine. It is expected to transform this ancient natural molecule into modern drugs with clear molecular mechanisms and good therapeutic indices.

Conclusion

Sumu Su, a classic staining agent that has silently served in histological laboratories for over a hundred years, is once again attracting the attention of pharmacologists with its novel and diverse biological activities. From inhibiting the neuroprotective effect of A β aggregation to exerting anti leukemia effects by regulating multiple key pathways such as AMPK, STAT3, BCL2, etc., hematoxylin has demonstrated the unique advantages of natural product multi-target and multi pathway synergistic effects. Despite facing challenges such as water solubility, metabolic stability, and blood-brain barrier permeability in drug development, its clear chemical structure, good drug like basis, preliminary safety data, and rich pharmacological activity make it a highly valuable lead compound for development. Through the rational modification of modern medicinal chemistry and the empowerment of advanced drug delivery technology, hematoxylin is expected to break through existing limitations and transform from a "staining agent" for pathological sections to a "therapeutic agent" for major diseases such as leukemia and Alzheimer's disease. The in-depth and continuous research on it is not only a modern exploration of a traditional medicinal resource, but also provides insightful examples for the development of innovative drugs derived from natural products.