Absorption, Distribution and Excretion
Urinary excretion of (14)C following topical application of ((14)C)naphth-1-ol indicated that about 50% was absorbed percutaneously in man.
Sixty-two workers of a carbochemical plant exposed to benzene, naphthalene, toluene, o-xylene, p-xylene, phenol and pyridine were examined. In urine samples collected before and after occupational exposure significant differences in concn values of phenol (21.7-97.6 mg/l), 1-naphthol (0.1-9.38 mg/l), hippuric acid (95.5-873.9 mg/l) and m-methylhippuric acid (29.0-93.5 mg/l) were found. There was a correlation between benzene and naphthalene in the breathing zone air and phenol and 1-naphthol in the urine of coke plant workers.
Chemical exposure of assemblers handling creosote impregnated wood and of a single worker chiselling coal tar pitch layer was assessed by measuring airborne naphthalene and various polycyclic aromatic hydrocarbons, and by measurement of urinary excretion of 1-naphthol and 1-pyrenol. The sum concn polycyclic aromatic hydrocarbon and of 4-6 aromatic ring containing polycyclic aromatic hydrocarbons were high, 440 ug/cu m and 290 ug/cu m, respectively, when chiselling. In the assemblers workplace, the polycyclic aromatic hydrocarbons concn were about 1/50 of this value. Regarding airborne naphthalene concn the situation was reversed (assemblers, 1000 ug/cu m; chiseller, 160 ug/cu m). Correspondingly, the assemblers urinary 1-naphthol concn were 15-20 times higher than those of the chiseller. The urinary 1-pyrenol concn of the chiseller was 2-4 times higher than among the assemblers. As the estimated pyrene inhalation doses among the assemblers could account only for 2%-25% of the 24 hr pyrenol excretion in the urine, the skin was presumably the main route of uptake. ...
Oral administration of 45 mg alpha-Naphthol/kg bw resulted in 95% of the administered dose being eliminated within 72 hr after treatment in male mice.

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Metabolism / Metabolites
Yields 1-napthhyl-alpha-D-glucoside ... in blowfly and in grass grub; yields 1-naphthyl phosphate in fly and in grass grub. /from table/
Yields 1-naphthyl-beta-D-glucuronide in rat, in rabbit, in fly and in mouse. /from table/
Yields 1-naphthyl sulfate in rat, rabbit, mouse, guinea pig, fly, and grass grub. /from table/
After 0.1 mmol 1-naphthol injected into intestinal loops (rat in vivo), 70-90% in intestinal venous blood was present as 1-naphthol glucuronide. For 1.0 and 2.0 mmol injections, proportion of 1-naphthol present as 1-naphthol glucuronide was 25-50%.
For more Metabolism/Metabolites (Complete) data for 1-NAPHTHOL (8 total), please visit the HSDB record page.
1-Naphthol has known human metabolites that include 1-Naphthyl glucuronide.
1-Naphthol is a known human metabolite of naphthalene.
Paraoxonase (PON1) is a key enzyme in the metabolism of organophosphates. PON1 can inactivate some organophosphates through hydrolysis. PON1 hydrolyzes the active metabolites in several organophosphates insecticides as well as, nerve agents such as soman, sarin, and VX. The presence of PON1 polymorphisms causes there to be different enzyme levels and catalytic efficiency of this esterase, which in turn suggests that different individuals may be more susceptible to the toxic effect of OP exposure.

Toxicity Summary
1-Naphthol is a cholinesterase or acetylcholinesterase (AChE) inhibitor. A cholinesterase inhibitor (or 'anticholinesterase') suppresses the action of acetylcholinesterase. Because of its essential function, chemicals that interfere with the action of acetylcholinesterase are potent neurotoxins, causing excessive salivation and eye-watering in low doses, followed by muscle spasms and ultimately death. Nerve gases and many substances used in insecticides have been shown to act by binding a serine in the active site of acetylcholine esterase, inhibiting the enzyme completely. Acetylcholine esterase breaks down the neurotransmitter acetylcholine, which is released at nerve and muscle junctions, in order to allow the muscle or organ to relax. The result of acetylcholine esterase inhibition is that acetylcholine builds up and continues to act so that any nerve impulses are continually transmitted and muscle contractions do not stop. Among the most common acetylcholinesterase inhibitors are phosphorus-based compounds, which are designed to bind to the active site of the enzyme. The structural requirements are a phosphorus atom bearing two lipophilic groups, a leaving group (such as a halide or thiocyanate), and a terminal oxygen.

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Toxicity Data
LC50 (rat) > 420 mg/m3/1h

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Interactions
... As model xenobiotics, the substituted aryl compounds aniline, 1-naphthylamine, and 1-naphthol (1-NOH) were investigated herein for their potential to react with HOCl and the transformed into genotoxic products. The compounds were first exposed to HOCl (25-150 uM) in phosphate buffer and afterward used to treat human fibroblasts or purified DNA. DNA single-strand breaks in cells and the binding of HOCl-reacted 1-[14C]NOH to purified DNA were assessed by DNA alkaline elution and scintillation spectrometry, respectively. It was found that neither HOCl nor compounds alone could break cellular DNA. But HOCl-reacted compounds produced up to 400 rad equivalents of DNA breaks. HOCl reaction products of aniline and the model bicyclic aryl compounds differed in their DNA-breaking characteristics. HOCl-reacted 1-[14C]NOH was stable and bound to DNA at up to 124 pmol/mg DNA. Sodium thiosulfate, glutathione, and taurine inhibited the transformation reactions; but only the former two blocked binding of HOCl-reacted 1-NOH to DNA. Ultraviolet spectra showed that HOCl reacted rapidly (<1 min) and equally well with 1-NOH at pH 7.2 or at an intraphagosomal pH of 5.0. Reaction concentrations of HOCl in this study were 2- to 11-fold lower than levels generated in vitro by stimulated neutrophils. These results show that certain aryl compounds can react readily with approximated physiological levels of HOCl (-OCl) to form relatively long-lived products that bind DNA and are genotoxic to human cells.

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Non-Human Toxicity Values
LD50 Rat oral 2.59 g/kg
LD50 Cat oral 134 mg/kg bw
LD50 Mouse oral 275 mg/kg bw
LD50 Rabbit dermal >10,000 mg/kg /from table/
For more Non-Human Toxicity Values (Complete) data for 1-NAPHTHOL (8 total), please visit the HSDB record page.

[1]. 1-Naphthol as an ESPT fluorescent molecular probe for sensing thermotropic microenvironmental changes of pluronic F127 in aqueous media. Phys Chem Chem Phys. 2015 Jul 14;17(26):16752-9.

1-naphthol is a naphthol carrying a hydroxy group at position 1. It has a role as a genotoxin and a human xenobiotic metabolite.
1-Naphthol has been reported in Selaginella sinensis, Juglans nigra, and Magnolia liliiflora with data available.
1-naphthol (1N) is a metabolite of carbaryl and naphthalene that is an intermediate in Metabolism of xenobiotics by cytochrome P450. It is generated by spontaneous reaction from (1R,2S)-Naphthalene epoxide then is it converted to 1,4-Dihydroxynaphthalene. Although 1-Naphthol is not persistent in the body, a single urine sample may adequately predict exposure over several months to chlorpyrifos, which is a broad-spectrum organophosphate insecticide. In adult men, TCPY and 1N were associated with reduced testosterone levels (A3198, A3199).

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Mechanism of Action
The mechanism(s) of toxicity of 1-naphthol and two of its possible metabolites, 1,2- and 1,4-naphthoquinone, to freshly isolated rat hepatocytes has been studied. 1-Naphthol and both naphthoquinones exhibited a dose-dependent toxicity to hepatocytes. [1-14C]-1-Naphthol was metabolised by hepatocytes predominantly to its glucuronic acid and sulphate ester conjugates, but small amounts of covalently bound products were also formed. Blebbing on the surface of the hepatocytes was observed following exposure to 1-naphthol and the naphthoquinones, together with a dose-dependent decrease in intracellular glutathione (GSH), which preceded the onset of cytotoxicity. The toxicity of 1-naphthol and the naphthoquinones was potentiated by dicoumarol, an inhibitor of DT-diaphorase (NAD(P)H:quinone oxidoreductase). This enhanced toxicity was accompanied by a greater amount of surface blebbing, an increased depletion of intracellular GSH, particularly in the case of 1-naphthol and 1,4-naphthoquinone, and a decreased metabolism of 1-naphthol to its conjugates with variable effects on the amount of covalently bound products formed. These results support the suggestion that the toxicity of 1-naphthol may be mediated by the formation of 1,2-naphthoquinone and/or 1,4-naphthoquinone, which may then be metabolised by one electron reduction to naphthosemiquinone radicals. These, in turn, may covalently bind to important cellular macromolecules or enter a redox cycle with molecular oxygen thereby generating active oxygen species. Both of these processes appear to play a role in producing the cytotoxic effects of 1-naphthol.

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Therapeutic Uses
1-Naphthol was selectively toxic to human colorectal tumors compared to corresponding normal colonic tissue removed at surgery and maintained in short-term organ culture. Nineteen of 24 tumors studied have shown a significant differential response. Three human colonic adenocarcinoma xenografts, in the short-term organ culture system, displayed the same response to 1-naphthol as primary tumors removed at surgery. 1-Naphthol, 1,2- and 1,4-naphthoquinone were also toxic to two human colonic adenocarcinoma cell lines, LoVo and COLO 206. The selective toxicity of 1-naphthol is mediated in part through an accumulation of 1-naphthol in the tumor tissue due to impaired conjugation by the tumor. The higher concentrations of 1-naphthol may then exert their toxicity either directly or by formation of naphthoquinones. Some indirect evidence was obtained for the possible involvement of 1,2- or 1,4-naphthoquinone in the cytotoxicity of 1-naphthol. Our studies suggest that further studies are warranted of the possible use of 1-naphthol or related compounds as antitumor agents.

C10H8O

144.1699

144.057

90-15-3

1-Naphthol-d8;207569-03-7

7005

White to off-white solid powder

1.2±0.1 g/cm3

288.0±0.0 °C at 760 mmHg

94-98ºC

144.0±10.6 °C

0.0±0.6 mmHg at 25°C

1.678

2.71

1

1

0

11

133

0

KJCVRFUGPWSIIH-UHFFFAOYSA-N

InChI=1S/C10H8O/c11-10-7-3-5-8-4-1-2-6-9(8)10/h1-7,11H

naphthalen-1-ol

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Ethanol : ~100 mg/mL (~693.63 mM)
H2O : ~1 mg/mL (~6.94 mM)

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

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Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*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.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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 (Please use freshly prepared in vivo formulations for optimal results.)