Metabolites/Metabolic Products Five metabolites were obtained by anaerobic culture of phorbol (1) from croton tiglium with human intestinal bacteria: isophorbol (2), deoxyphorbol (3), 4β,9α,20-trihydroxy-13,15-open-1,6,15-tigliatriene-3,13-dione (4), 4β,9α,20-trihydroxy-15,16,17-trinor-1,6-tigliadiene-3,13-dione (5), and 4β,9α,20-trihydroxy-14(13→12)-abeo-12αH-1,6-tigliadiene-3,13-dione (6). All these metabolites (2-6) were identified and characterized by spectroscopic methods, including two-dimensional nuclear magnetic resonance. Nine specific strains isolated from the human gut all demonstrated the ability to convert compound 1 into these metabolites.

Toxicity Summary
Identification and Uses: Phorboxol is a powder. It is used in biochemical and medical research. Human Exposure and Toxicity: Phorboxol lacks the lymphocyte activation-inducing properties found in phorboxol esters. Unlike phorboxol esters, phorboxol lacks pro-tumorigenic activity and is either ineffective or weakly responsive in inhibiting the growth of human melanoma cells and stimulating their differentiation. Animal Studies: Phorboxol (20 μg/mL) has no biological activity and no effect on the binding sites of mouse meningeal proteins. In organ cultures, phorboxol does not stimulate the synthesis of prostaglandin E2 and bone resorption in the skull of newborn mice. Phorboxol did not show erythroid differentiation activity in Friend virus-transformed proerythroid C1745 cells. Therefore, phorboxol is an inactive analogue of phorboxol esters. The term "phorboxol" is used to describe a class of naturally occurring compounds that can be referred to as phorbol diterpenoids. Porboxol esters are tetracyclic diterpenoids, commonly known for their pro-tumorigenic activity. Phlorizate mimics the action of diacylglycerol (DAG), an activator of protein kinase C that regulates various signal transduction pathways and other cellular metabolic activities. The biological activity of phorbolizate exhibits high structure specificity. Even at low concentrations, phorbolizate can be toxic in animals fed diets containing phorbolizate. This toxicity limits the use of many phorbolizate-containing nutrient plants and agricultural byproducts as animal feed. Furthermore, in addition to its antinutritional and toxic effects, some phorbolizate derivatives are also known for their antibacterial and antitumor activities. The molluscicidal and insecticidal properties of phorbolizate suggest its potential as a highly effective biopesticide and insecticide. Phlorizate itself does not induce tumors, but exposure to subcarcinogenic doses of carcinogens can promote tumor growth. TPA and its associated phorbolizate have been reported as potent stimulants for plasminogen activator synthesis. Bioassays have shown a strong correlation between TPA, phorbol 12,13-didecanoate (PDD), and TPA β-oxide (a derivative of TPA) inducing plasminogen activator and promoting tumor growth. The mechanism of action of phorbol is not covalent binding to cellular DNA, but rather mimics transformation effects, such as altering cell membrane morphology, increasing saturation density, changing cell surface fucosylated peptides, and increasing the levels of plasminogen activator and ornithine decarboxylase. (A15429) Various phorbol esters possess important biological properties, most notably their ability to exert pro-tumorigenic effects by activating protein kinase C. They are similar to diacylglycerols, glycerol derivatives in which two hydroxyl groups react with fatty acids to form esters. The most common phorbol ester is 12-O-tetradecanoylphorbol-13-acetate (TPA), also known as phorbol-12-myristate-13-acetate (PMA), which is used as a biomedical research tool in carcinogenicity models. The combination of TPA and iomycin can also stimulate T cell activation, proliferation, and cytokine production, and is used in intracellular staining protocols for these cytokines. (Wikipedia)

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Interactions
12-O-tetradecanoylphorbol-13-acetate (I) and phorbol (II) can enhance the recovery rate of ouabain-resistant mutants in V79 Chinese hamster cell cultures treated with N-methyl-N'-nitro-N-nitrosoguanidine and methylazoethanol acetate. In both cases, I was more effective than II in promoting mutant recovery.
Study on the mechanism of skin tumor promotion. In female mice, simultaneous administration of phorbol and 12-O-tetradecanoylphorbol-13-acetate after induction with 7,12-dimethylbenzo[a]anthracene (DMBA) had no effect on the promoting effect.
A single subcutaneous injection of 200 μCi of ((3)H)-thymidine into pregnant BALB/c mice, followed by intraperitoneal injection of phorbol twice weekly into offspring mice for 25 weeks, resulted in higher incidence of lung and liver tumors in male offspring than in untreated littermates, and slightly higher incidence in female offspring as well. The overall difference in tumor incidence was statistically significant, but the increase in the incidence of each type of tumor was only critically significant. Mild carcinogenic activity was also observed with ((3)H)-thymidine alone in untreated mothers and offspring. ((3)H)-thymidine can be used as a broad-spectrum carcinogen in transplacental two-stage carcinogenicity studies to determine the organ specificity of different oncogens. In female Wistar rats, a single administration of 6 mg dimethylbenzanthracene (DMBA) followed by intraperitoneal injection of 4 mg phorbol twice weekly for 10 weeks significantly increased the incidence of mammary adenocarcinoma and lymphocytic leukemia compared to administration of 6 mg DMBA alone. In female Sprague-Dawley rats, using the same doses of DMBA and phorbol, and the same injection regimen, administration of phorbol after DMBA administration did not increase the incidence of mammary adenocarcinoma or lymphocytic leukemia compared to administration of DMBA alone. In Wistar and Sprague-Dawley rats, the pro-cancer activity of phorbol was strain-dependent, particularly in cases of DMBA-treated rats receiving phorbol treatment. The effect of phorbol on the incidence of mammary adenocarcinoma and lymphocytic leukemia was investigated. Porbolbol did not promote the incidence of mammary fibroadenoma in DMBA-treated rats, mammary adenocarcinoma in procarbazine-treated rats, or mammary adenocarcinoma or fibroadenoma in X-ray-treated rats. DMBA and procarbazine (with or without phorbol) tend to induce more anterior (thoracic) breast tumors than posterior (abdominal) breast tumors. X-ray irradiation tends to induce roughly equal numbers of anterior and posterior breast tumors. The regional differences in chemically induced breast cancer are due to differences in the transport and delivery of chemical carcinogens to different regions, rather than differences in the amount of breast tissue in each region. Analysis of the number of breast tumors in Sprague-Dawley rats under DMBA, procarbazine, and X-ray irradiation indicates that the development of breast adenocarcinoma and breast fibroadenoma are independent processes. For more complete data on interactions with phorbol (7 in total), please visit the HSDB record page.

Isakov N. Protein kinase C (PKC) isoforms in cancer, tumor promotion and tumor suppression. Semin Cancer Biol. 2017 May 29. pii: S1044-579X(17)30108-6. doi: 10.1016/j.semcancer.2017.04.012. [Epub ahead of print] Review. PubMed PMID: 28571764.

Phorbol is a white solid. (NTP, 1992)
Porphyrin is a diterpenoid compound with a structure of thiocarbazone hydroxylated at C-4, -9, -12(β), -13, and -20, a carbonyl group at C-3, and unsaturated bonds at positions 1 and 6. It is a tetracyclic diterpenoid compound, and also an enone, cyclic ketone, tertiary alcohol, and tertiary α-hydroxy ketone. It is derived from the hydride of thiocarbazone.
Porphyrin has been reported in Rehmannia glutinosa, Croton tiglium, and Euphorbia pekinensis, and relevant data exist.
Porphyrin is a natural plant-derived organic compound belonging to the thiocarbazone diterpenoid family. Phorbol was first isolated in 1934 as a hydrolysis product of croton oil, which is extracted from the seeds of the laxative Croton tiglium. The structure of phorphyrin was determined in 1967. It is highly soluble in most polar organic solvents and water.

C20H28O6

364.4327

364.189

17673-25-5

17673-25-5;

442070

Off-white to light yellow solid powder

1.415 g/cm3

572ºC at 760 mmHg

250-251ºC DECOMP

313.8ºC

1.83E-15mmHg at 25°C

1.648

-0.8

5

6

1

26

753

8

C[C@@H]1[C@H]([C@@]2([C@@H](C2(C)C)[C@H]3[C@]1([C@@H]4C=C(C(=O)[C@]4(CC(=C3)CO)O)C)O)O)O

QGVLYPPODPLXMB-UBTYZVCOSA-N

InChI=1S/C20H28O6/c1-9-5-13-18(24,15(9)22)7-11(8-21)6-12-14-17(3,4)20(14,26)16(23)10(2)19(12,13)25/h5-6,10,12-14,16,21,23-26H,7-8H2,1-4H3/t10-,12+,13-,14-,16-,18-,19-,20-/m1/s1

(1S,2S,6R,10S,11R,13S,14R,15R)-1,6,13,14-tetrahydroxy-8-(hydroxymethyl)-4,12,12,15-tetramethyltetracyclo[8.5.0.02,6.011,13]pentadeca-3,8-dien-5-one

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: Please store this product in a sealed and protected environment (e.g. under nitrogen), avoid exposure to moisture.

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

DMSO : ~50 mg/mL (~137.20 mM)
H2O : ≥ 20 mg/mL (~54.88 mM)

Solubility in Formulation 1: ≥ 1.67 mg/mL (4.58 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 16.7 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.

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Solubility in Formulation 2: ≥ 1.67 mg/mL (4.58 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 16.7 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.

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Solubility in Formulation 3: ≥ 1.67 mg/mL (4.58 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 16.7 mg/mL clear DMSO stock solution to 900 μL of corn oil and mix evenly.

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Solubility in Formulation 4: 5 mg/mL (13.72 mM) in PBS (add these co-solvents sequentially from left to right, and one by one), clear solution; with ultrasonication (<60°C).

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