Sphingosine N-acyltransferase[2]

Drug compounds have included stable heavy isotopes of carbon, hydrogen, and other elements, mostly as tracers that influence measurement during the drug development process. It's possible that the pharmacokinetics and functional range of medications contribute to the concern over mutagenesis [1]. In monkey kidney cells, fumonisin B1 alters gene expression and causes problems with signal transmission [2]. In LLC-PK1 renal cells, fumonisin B1 promotes sphingolipid-promoted radical annihilation and sphingosine buildup, which results in sheathing astrocyte-type DNA damage [2].

Absorption, Distribution and Excretion
Fusarium B1 (FB1) is a major compound in the secondary metabolites of Fusarium moniliforme Sheldon and is associated with certain human and animal diseases. Following intraperitoneal injection of FB1 (7.5 mg/kg) in rats, FB1 is rapidly absorbed, reaching peak plasma concentrations within 20 minutes. Subsequently, FB1 is rapidly cleared from plasma following a single-exponential elimination process consistent with a one-compartment model, with a half-life of 18 minutes. Urine samples collected at 24 and 48 hours showed that only 16% of the administered dose was excreted in the urine as unmetabolized form, all within 24 hours of administration. In contrast, after gavage administration of the same dose of FB1, only 0.4% of FB1 was recovered in the urine. Fumonisin B1 (FB1) is a toxic and carcinogenic secondary metabolite produced by Fusarium moniliforme Sheldon. In this study, it was administered to African green monkeys (Cercopithecus aethiops) via intravenous injection or gavage. Following intravenous injection in two female African green monkeys, FB1 was rapidly cleared from the plasma, with a mean elimination half-life of 40 minutes. Analysis of urine and feces within 5 days post-administration showed a mean recovery rate of 47% for FB1 and its hydrolyzed analogues. Two additional female African green monkeys received a single gavage administration of 14C-labeled FB1. Over the following 3 days, the average excretion of radioactive material in feces was 61% of the administered dose, and in urine, it was 1.2%. Small amounts of residual radioactive material were recovered from skeletal muscle (1%), liver (0.4%), brain (0.2%), kidney, heart, plasma, erythrocytes, and bile (all 0.1%), while intestinal contents accounted for 12% of the radioactive dose. A total of 76% of the administered radioactive material was recovered. Analysis of feces, intestinal contents, and urine showed that over 90% of the radioactive material in these samples originated from fumonisin B1 and its hydrolysis products. A method for determining fumonisin B1 (FB1) in the feces of non-human primates (long-tailed macaques) has been developed. After injecting animals with FB1 labeled with 14C, the feces were repeatedly extracted with 0.1 M ethylenediaminetetraacetic acid (EDTA). The extract was purified using a reversed-phase (C18) solid-phase extraction column, and FB1 was determined by phthalaldehyde derivatization and reversed-phase high-performance liquid chromatography (RP-HPLC). The analytical method for FB1 in fecal extract showed good reproducibility (relative standard deviation (RSD) of 2.6%) and high accuracy (recovery of spiked blank extract was 93 ± 2.9% RSD). High performance liquid chromatography (HPLC) and thin-layer chromatography (TLC) were used to further confirm the presence of FB1 in feces. The results showed that the extracted radioactive substances were mainly FB1 and a novel metabolite, whose chromatographic properties were similar to those of the fungal toxin. Mass spectrometry (MS) and nuclear magnetic resonance (NMR) analysis identified a novel metabolite as an equilibrium mixture of two structural isomers of partially hydrolyzed fumonisin B1 (FB1), formed by the hydrolysis of one ester group of the fungal toxin. The fungal toxin fumonisin B1 (FB1) can cause various health problems in animals, and epidemiological evidence suggests its association with esophageal cancer in humans. We investigated the residue of FB1 in milk using an in vitro bovine udder perfusion model. 2 mg of FB1 was injected into the perfused blood from three udders, and the FB1 levels in milk and perfused serum were measured within 150 minutes. The results showed that FB1 could cross the mammary gland barrier and enter milk, but the concentration was extremely low, and the risk to consumers was negligible.

Toxicity Summary
Identification: Fumonisin B1 is the most common fumonisin, produced by Fusarium moniliforme and other Fusarium fungi. The pure substance is a white, hygroscopic powder, soluble in water, acetonitrile-water, and methanol. It is stable under food processing temperatures and light. Fumonisin B1 is the most common fungal metabolite associated with corn. It accumulates significantly in corn when climatic conditions are favorable for kernel decay. Human Exposure: No acute toxicity associated with this compound has been recorded. Existing correlational studies suggest an association between dietary exposure and esophageal cancer. Other studies have not reached a definitive conclusion regarding the potential carcinogenicity of fumonisin B1. Animal/Plant Studies: Fumonisin B1 is hepatotoxic in all tested animal species, including mice, rats, equines, pigs, rabbits, and non-human primates. Except for Syrian hamsters, embryotoxicity or teratogenicity occurs only during or after maternal toxicity. Fumonisin is nephrotoxic in pigs, rats, sheep, mice, and rabbits. In rats and rabbits, the nephrotoxic dose is lower than the hepatotoxic dose. Fumonisin is known to cause leukomalacia in equines and pulmonary edema syndrome in pigs. It is hepatocarcinogenic in one strain of male rats and renal carcinogenic in another strain. Fumonisin B1 is a specific inhibitor of de novo sphingolipid synthesis. This compound inhibits cell growth, leading to the accumulation of free sphingosine bases and altering lipid metabolism in animals, plants, and certain yeasts (such as Saccharomyces cerevisiae). This compound does not induce bacterial gene mutations or unplanned DNA synthesis in primary rat hepatocytes, but at low concentrations it increases chromosomal aberrations in a dose-dependent manner. This compound is phytotoxic, damaging cell membranes and reducing chlorophyll synthesis. Based on studies in pigs, laying hens, and long-tailed macaques, this compound has low oral absorption and is rapidly cleared from the plasma or circulatory system and excreted in feces; bile excretion is important; enterohepatic circulation is also important in some animals. Small amounts of the compounds are excreted in urine, while some remain in the liver and kidneys. Fumonisin's structure is similar to the long-chain base backbone of sphingolipids, thus it can inhibit the biosynthesis of sphingosine and more complex sphingolipids by inhibiting ceramide synthase. This leads to the accumulation of sphingosine, sphingosine, and possibly sphingosine-1-phosphate in cells and tissues, resulting in apoptosis. Mycotoxins typically enter the liver and kidneys via human organic anion transporters (hOATs) and human organic cation transporters (hOCTs). They can also inhibit the uptake of anions and cations by these transporters, thereby interfering with the secretion of endogenous metabolites, drugs, and exogenous substances, including the mycotoxins themselves. This leads to an increased accumulation of toxic compounds within cells, causing nephrotoxicity and hepatotoxicity. (A704, L1937, A2947, A3014)

[1]. Impact of Deuterium Substitution on the Pharmacokinetics of Pharmaceuticals. Ann Pharmacother. 2019 Feb;53(2):211-220.

[2]. The toxicity of fumonisin B1, B2, and B3, individually and in combination, in chicken embryos. Poult Sci. 2001 Apr;80(4):401-7.

[3]. Effect of fumonisin B₁ on the cell cycle of normal human liver cells. Mol Med Rep. 2013 Jun;7(6):1970-6.

According to the International Agency for Research on Cancer (IARC) of the World Health Organization and the National Toxicology Program (NTP) of the United States, fumonisin B1 is carcinogenic. 2-[2-({19-amino-6-[(3,4-dicarboxybutyryl)oxy]-11,16,18-trihydroxy-5,9-dimethyleicosano-7-yl}oxy)-2-oxoethyl]succinic acid is a fumonisin. Data have shown that fumonisin B1 has been detected in both Fusarium fujikuroi and Streptomyces rapamycinicus. Fumonisin B1 is a fungal toxin produced by Fusarium moniliforme. It is a contaminant in grains, especially corn. Epidemiological studies have shown that fumonisin B1 is associated with a high incidence of esophageal cancer in humans in South Africa and China, as well as liver cancer in animal models. Fumonisin B1 is derived from Fusarium moniliforme. Fumonisin B1 is an inhibitor of ceramide synthase. Fumonisin B1 belongs to the monoterpenoid class of compounds. These compounds consist of two isoprene units. See also: Fumonisin B1 (note moved to). Mechanism of Action: Fumonisin is an inhibitor of sphingosine and the more complex sphingolipid biosynthesis. In eukaryotic cells, the inhibition of sphingolipid biosynthesis by fumonisin is due to its inhibition of ceramide synthase activity. Within hours of exposure to fumonisin and/or Alternaria toxin (AAL toxin), free sphingosine concentrations increase significantly in plant and animal cells. Some sphingosine is metabolized to other bioactive intermediates, while some is released from the cells. In animals, free sphingosine accumulates in tissues and rapidly appears in blood and urine. Free sphingosine bases are toxic to most cells, while complex sphingolipids are essential for normal cell growth. Fumonisin B1 stimulates sphingosine-dependent DNA synthesis in Swiss 3T3 cells, but has mitochondrial inhibitory effects in other cell types. In cultured cells, the accumulation of bioactive long-chain sphingosine bases and the depletion of complex sphingolipids are clearly factors contributing to fumonisin's inhibitory effect on cell growth, increased cell death, and (in Swiss 3T3 cells) mitogenic effects. While sphingolipid metabolism disorders directly affect cells, they may also indirectly affect certain tissues. For example, fumonisin B1 impairs the barrier function of endothelial cells in vitro. Adverse effects on endothelial cells may indirectly lead to fumonisin-induced neurotoxicity and pulmonary edema. It is speculated that fumonisin-induced changes in target tissue sphingolipid composition may directly or indirectly contribute to all diseases associated with Fusarium moniliforme. Fumonisin is an inhibitor of sphingosine N-acyltransferase (ceramide synthase) in vitro, and exhibits competitive inhibition of both substrates of this enzyme (sphingosine and fatty acyl-CoA). Removing the tricarboxylic acid group from fumonisin B1 reduces its potency by at least 10-fold; fumonisin A1 (aminoacetylated) is essentially inactive. Studies on various cell types (hepatocytes, neurons, kidney cells, fibroblasts, macrophages, and plant cells) have shown that fumonisin B1 not only blocks the biosynthesis of complex sphingolipids but also leads to the accumulation of sphingosine. Some sphingosine is metabolized to 1-phosphate esters and further degraded to hexadecaldehyde and phosphate ethanolamine, the latter of which can be incorporated into phosphatidylethanolamine. Sphingosine is also released from cells and, due to its presence in blood and urine, can serve as a biomarker of exposure. The accumulation of these bioactive compounds and the depletion of complex sphingolipids may be the cause of fumonisin toxicity and even carcinogenicity. Fumonisin B1, produced by Fusarium moniliforme, belongs to a new class of sphingosine analogue fungal toxins and is widely distributed in the food chain. Epidemiological studies have shown that fumonisin B1 is associated with esophageal cancer in humans in China and South Africa. Fumonisin B1 also causes acute pulmonary edema in pigs and leukomalacia in equines. These diseases are thought to be caused by fumonisin B1 inhibiting intracellular ceramide synthesis. To further investigate its pathogenesis, this study examined the effects of FB1 on cell viability (3–54 μM), protein synthesis (2.5–20 μM), DNA synthesis (2.5–50 μM), and cell cycle (3–18 μM) of rat C6 glioma cells after 24 hours of incubation. Cell viability assays showed that FB1 concentrations of 3 μM and 54 μM resulted in C6 cell mortality rates of 10.2% and 47.4%, respectively. Pre-incubation with vitamin E (25 μM) for 24 hours effectively inhibited FB1-induced cytotoxicity. Furthermore, FB1 also exhibited epigenetic properties, as it induced DNA hypermethylation (9–18 μM). FB1 significantly inhibited protein synthesis, with an IC50 value of 6 μM, indicating that C6 glioma cells were highly sensitive to FB1. However, DNA synthesis was only slightly inhibited at FB1 concentrations as high as 20 μM. Flow cytometry analysis showed that, compared with the control group, the proportion of cells in S phase was significantly reduced in the 9 μM FB1 treatment group (p = 0.01), decreasing from 18.7 ± 2.5% to 8.1 ± 1.1%. Compared with the control group, the proportion of cells in G2/μM phase was significantly increased in the 9 μM FB1 treatment group (p < 0.05), increasing from 45.7 ± 0.4% to 54.8 ± 1.1%, while the proportion of cells in G0/G1 phase remained unchanged. These results indicate that cytotoxic concentrations of FB1 can induce G2/μM phase cell cycle arrest in rat C6 glioma cells, which may be related to genotoxic events. The molecular mechanisms of action of fumonisins are not yet fully understood; however, these compounds share significant structural similarities with sphingosine, the long-chain (sphingosine-like) backbone of sphingolipids, cerebrosides, thiolipins, gangliosides, and other sphingolipids. Sphingolipids are thought to be involved in the regulation of cell growth, differentiation, and tumor transformation, and their mechanisms may include involvement in intercellular communication and cell-matrix interactions, and possibly through interactions with cell receptors and signaling systems. Incubation of rat hepatocytes with fumonisins B1 and B2 inhibited the incorporation of (14)C-serine into the sphingosine moiety of cellular sphingolipids, with an IC50 value of 0.1 μM. Conversely, fumonisin B1 increased the content of the biosynthetic intermediate sphingosine, suggesting that fumonisins inhibit the conversion of (14)C-sphingosine to N-acyl-(14)C-sphingosine, a step thought to precede the introduction of the 4,5-trans double bond of sphingosine. Consistent with this mechanism, fumonisin B1 inhibited the activity of sphingosine N-acyltransferase (ceramide synthase) in rat liver microsomes, achieving an inhibition rate of 50% at a concentration of approximately 0.1 μM, and reduced the conversion of (3)H-sphingosine to (3)H-ceramide in intact hepatocytes. Fumonisin B1 (1 μM) almost completely inhibited the production of (14)C-sphingosine in hepatocytes.

13C34H59NO15

755.58

721.388

1217458-62-2

Fumonisin B1;116355-83-0

3431

Powder

2 °C

-0.5

8

16

31

50

1070

0

O([13C]([13CH2][13C@H]([13C](=O)O)[13CH2][13C](=O)O)=O)[13C@@H]([13CH2][13C@@H]([13CH3])[13CH2][13C@H]([13CH2][13CH2][13CH2][13CH2][13C@@H]([13CH2][13C@H]([13C@H]([13CH3])N)O)O)O)[13C@@H]([13C@@H]([13CH3])[13CH2][13CH2][13CH2][13CH3])O[13C]([13CH2][13C@H]([13C](=O)O)[13CH2][13C](=O)O)=O

UVBUBMSSQKOIBE-UHFFFAOYSA-N

InChI=1S/C34H59NO15/c1-5-6-9-20(3)32(50-31(44)17-23(34(47)48)15-29(41)42)27(49-30(43)16-22(33(45)46)14-28(39)40)13-19(2)12-24(36)10-7-8-11-25(37)18-26(38)21(4)35/h19-27,32,36-38H,5-18,35H2,1-4H3,(H,39,40)(H,41,42)(H,45,46)(H,47,48)

2-[2-[19-amino-6-(3,4-dicarboxybutanoyloxy)-11,16,18-trihydroxy-5,9-dimethylicosan-7-yl]oxy-2-oxoethyl]butanedioic acid

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)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

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.

---

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).

View More

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)

---

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).

View More

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

---

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.

---

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