 Chemical Structure.png)
Hematoxylin (also known as Hydroxybrazilin; Natural Black 1) is a natural compound that forms strongly colored complexes with certain metal ions, notably Fe(III) and Al(III) salts and a kind of stain in histology. It is extracted from the bark of the logwood tree. Metal-haematein complexes are used to stain cell nuclei prior to examination under a microscope. Structures that stain with iron- or aluminium-haematein are often called basophilic, even though the mechanism of the staining is different from that of staining with basic dyes. Haematoxylin and eosin stain is one of the most commonly used stains in histology.
Physicochemical Properties
| Molecular Formula | C16H14O6 | |
| Molecular Weight | 302.28 | |
| Exact Mass | 302.079 | |
| CAS # | 517-28-2 | |
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| PubChem CID | 442514 | |
| Appearance | Light brown to brown solid powder | |
| Density | 1.7±0.1 g/cm3 | |
| Boiling Point | 579.9±50.0 °C at 760 mmHg | |
| Melting Point | 200 °C (dec.)(lit.) | |
| Flash Point | 304.5±30.1 °C | |
| Vapour Pressure | 0.0±1.7 mmHg at 25°C | |
| Index of Refraction | 1.810 | |
| LogP | 0.51 | |
| Hydrogen Bond Donor Count | 5 | |
| Hydrogen Bond Acceptor Count | 6 | |
| Rotatable Bond Count | 0 | |
| Heavy Atom Count | 22 | |
| Complexity | 444 | |
| Defined Atom Stereocenter Count | 2 | |
| SMILES | C1C2=CC(=C(C=C2[C@H]3[C@@]1(COC4=C3C=CC(=C4O)O)O)O)O |
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| InChi Key | HLUCICHZHWJHLL-UHFFFAOYSA-N | |
| InChi Code | InChI=1S/C16H12O6/c17-10-2-1-8-13-9-4-12(19)11(18)3-7(9)5-16(13,21)6-22-15(8)14(10)20/h1-4,17,19-21H,5-6H2 | |
| Chemical Name | 3,4,6a,10-tetrahydroxy-6a,7-dihydroindeno[2,1-c]chromen-9(6H)-one | |
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| HS Tariff Code | 2934.99.9001 | |
| Storage |
Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: This product requires protection from light (avoid light exposure) during transportation and storage. |
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| Shipping Condition | Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs) |
Biological Activity
| Targets |
Amyloid β-Protein (Aβ, Aβ42) (EC50 = 12.5 μM for inhibiting Aβ42 fibrillation) [2] |
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| ln Vitro |
Hematoxylin oxidizes to reddish brown hematein when it comes into contact with air. Hematoxylin, when converted to its hematein form and mixed with a mordant (often a metal salt), gives tissue slices a stain that ranges from deep blue to black, depending on the staining technique used. Hematoxylin is also amphoteric in its hematein form on its own; it is blue at alkaline pH and red at acid pH. Nonspecific staining is eliminated by differentiation that comes after Hematoxylin staining[1]. In SH-SY5Y cells, hematoxylin treatment significantly reduces the cytotoxicity caused by Aβ42. One possible agent against Aβ fibrillogenesis and cytotoxicity is hematoxylin[2]. The foundation of anatomical pathology diagnosis is the tissue section stained with hematoxylin and eosin (H&E). To make it easy to distinguish between distinct cell components, the H&E process dyes the cytoplasm and nucleus with different colors[3]. Hematoxylin (Haematoxylin) potently inhibited Aβ42 (Amyloid β-Protein 42) fibrillation in a dose-dependent manner. At concentrations of 5-25 μM, it reduced Thioflavin T (ThT) fluorescence intensity (a marker of Aβ fibrillation) by ~35% (5 μM), ~62% (12.5 μM), and ~80% (25 μM) compared to the control group, with an EC50 of 12.5 μM [2] - It alleviated Aβ42-induced cytotoxicity in human neuroblastoma SH-SY5Y cells. Pretreatment with Hematoxylin (Haematoxylin) (5-25 μM) for 2 hours reduced Aβ42-mediated cell death: cell viability increased from ~32% (Aβ42 alone) to ~55% (5 μM), ~72% (12.5 μM), and ~85% (25 μM) as detected by MTT assay [2] - The anti-amyloid effect was associated with binding to Aβ42 monomers and preventing their aggregation into toxic fibrils, as confirmed by transmission electron microscopy (TEM) showing reduced fibril formation in the presence of 12.5 μM Hematoxylin (Haematoxylin) [2] |
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| ln Vivo | Guidelines (This is our suggested protocol; it should be adjusted based on your unique requirements as it just offers as a guideline). The H&E staining procedure[4]: 1. Staining racks should be used to hold the glass slides containing the paraffin sections. In three changes of xylene, remove the paraffin from the samples for two minutes each time. 2. Assist in hydrating the samples. I. Slides should be put through three 100% ethanol changes, lasting two minutes each. ii. For two minutes, switch to 95% ethanol. iv. Shift to a 70% ethanol for two minutes IV. 3. Rinse the slides for at least two minutes under running room temperature tap water. 4. Stain the samples for three minutes with hematoxylin solution. 5. Run some cold water over the slides under the faucet for at least five minutes. 6. Stain the samples for two minutes in a working eosin Y solution. Assemble the samples and dehydrate them. I. About 20 times, submerge the slides in 95% ethanol. ii. For two minutes, switch to 95% ethanol. iv. Go through two changes in 100% ethanol, giving each change two minutes. 7. Samples should be cleared in three xylene changes, lasting two minutes each. 8. Put a coverslip on each slide after covering the tissue with a drop of Permount. Look over the slides under a microscope. | ||
| Enzyme Assay |
Aβ42 fibrillation inhibition assay (ThT fluorescence-based): Aβ42 peptide was dissolved in buffer and incubated at 37°C to induce fibrillation. Different concentrations of Hematoxylin (Haematoxylin) (0-25 μM) were added to the Aβ42 solution, and ThT reagent was added at a final concentration of 20 μM. Fluorescence intensity was measured at excitation 485 nm and emission 515 nm every 1 hour for 48 hours to monitor fibrillation kinetics [2] - Aβ42 monomer binding assay (TEM-based): Hematoxylin (Haematoxylin) (12.5 μM) was incubated with Aβ42 monomers at 37°C for 24 hours. Samples were placed on copper grids, stained with uranyl acetate, and observed under a transmission electron microscope to analyze the morphology of Aβ aggregates [2] |
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| Cell Assay |
Aβ-induced cytotoxicity alleviation assay: Human neuroblastoma SH-SY5Y cells were seeded in 96-well plates at a density of 5×10³ cells/well and cultured for 24 hours. Cells were pretreated with Hematoxylin (Haematoxylin) (5-25 μM) for 2 hours, then exposed to 20 μM Aβ42 oligomers for another 24 hours. MTT reagent was added, and absorbance at 570 nm was measured to calculate cell viability. Annexin V-FITC/PI double staining was used to detect apoptotic cells [2] |
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| Animal Protocol |
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| Toxicity/Toxicokinetics |
In vitro, Hematoxylin (Haematoxylin) showed no significant cytotoxicity to SH-SY5Y cells at concentrations up to 25 μM, as indicated by >90% cell viability in the absence of Aβ42 [2] |
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| References |
[1]. M Titford. The long history of hematoxylin. Biotech Histochem. Mar-Apr 2005;80(2):73-8. [2]. Hematoxylin Inhibits Amyloid β-Protein Fibrillation and Alleviates Amyloid-Induced Cytotoxicity. J Phys Chem B. 2016 Nov 10;120(44):11360-11368. [3]. Tissue processing and hematoxylin and eosin staining. Methods Mol Biol. 2014;1180:31-43. [4]. Manual hematoxylin and eosin staining of mouse tissue sections. Cold Spring Harb Protoc. 2014 Jun 2;2014(6):655-8. |
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| Additional Infomation |
Hematoxylin appears as white to yellowish crystals that redden on exposure to light. (NTP, 1992) (+)-haematoxylin is a haematoxylin. It is an enantiomer of a (-)-haematoxylin. Hematoxylin has been reported in Haematoxylum campechianum and Haematoxylum brasiletto with data available. A dye obtained from the heartwood of logwood (Haematoxylon campechianum Linn., Leguminosae) used as a stain in microscopy and in the manufacture of ink. Mechanism of Action BRAZILIN, TOGETHER WITH HEMATOXYLIN, A CONSTITUENT OF HAEMATOXYLON CAMPECHIANUM WOOD, EXHIBITED ANTIINFLAMMATORY ACTIVITIES IN CARRAGEENIN-INDUCED RAT PAW EDEMA TEST & FERTILE EGG TEST. Hematoxylin (Haematoxylin) is a natural dye extracted from the heartwood of Logwood (Haematoxylum campechianum L.) [1] - It has a long history of use in histology, serving as the primary nuclear stain in hematoxylin and eosin (HE) staining, which is widely used for tissue section visualization in pathology and research [1][3][4] - Its mechanism of staining involves binding to negatively charged components of cell nuclei (e.g., DNA) via electrostatic interactions, producing a blue-purple color [3][4] - Beyond histological applications, it exhibits potential neuroprotective activity by inhibiting Aβ fibrillation and alleviating Aβ-induced cytotoxicity, suggesting potential application in Alzheimer's disease research [2] - The standard HE staining protocol involves oxidizing hematoxylin to hematein (its active form) and mordanting with aluminum salts to enhance binding to nuclear components [3][4] |
Solubility Data
| Solubility (In Vitro) |
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| Solubility (In Vivo) |
Solubility in Formulation 1: ≥ 2.5 mg/mL (8.27 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution. Solubility in Formulation 2: ≥ 2.5 mg/mL (8.27 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly. Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution. Solubility in Formulation 3: ≥ 2.5 mg/mL (8.27 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (add these co-solvents sequentially from left to right, and one by one), clear solution. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly. Solubility in Formulation 4: 4.17 mg/mL (13.80 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with ultrasonication (<60°C). (Please use freshly prepared in vivo formulations for optimal results.) |
| Preparing Stock Solutions | 1 mg | 5 mg | 10 mg | |
| 1 mM | 3.3082 mL | 16.5410 mL | 33.0819 mL | |
| 5 mM | 0.6616 mL | 3.3082 mL | 6.6164 mL | |
| 10 mM | 0.3308 mL | 1.6541 mL | 3.3082 mL |