Sphingosine N-acyltransferase/ceramide synthase

Fumonisin B1 (FB1) and fumonisin B2 (FB2) are the most abundant fumonisins (FBs) occurring worldwide in maize, infected mainly by Fusarium verticillioides and F. proliferatum. A total of 307 corn kernel samples were collected from 45 districts of Gansu, Shandong, Ningxia and the Inner Mongolia provinces of the north and northwest China. The samples were analysed for FB1 and FB2 by high-performance liquid chromatography. The FBs (FB1+ FB2) incidence rate in samples from Gansu, Shandong, Ningxia and Inner Mongolia were 31.5%, 81.1%, 46.2% and 53.6%, respectively. Average FBs concentration was 703 μg/kg and the concentrations ranged from ≤11 to 13,110 μg kg(-1). Results were compared with the European Commission (EC) regulation for FB1+ FB2 in unprocessed maize for human consumption of 4 mg kg(-1). Contamination in 17 samples was higher than these levels. More than 80% of the samples from Liaocheng county, which is located in the Shandong province, were contaminated with FBs, with a mean total FB concentration of 2496 μg/kg. The result was significantly different from that of the Inner Mongolia (1399 μg/kg), Ningxia (373 μg/kg) and Gansu (175 μg/kg). Average exposure to FBs (0.12 μg/kg body weight/day) is within the provisional maximum tolerable daily intake of 2.0 mg/kg of body weight set by the Joint Food and Agriculture Organization and World Health Organization Expert Committee on Food Additives [1].

Three recently described and toxicologically important mycotoxins, fumonisin B1 (FB1), fumonisin B2 (FB2), and fumonisin B3 (FB3), produced by Fusarium moniliforme in various grains, have been associated with a number of diseases in both humans and animals. The toxicity of purified FB1, FB2, and FB3, individually and in combination (3:1:1 ratio), were evaluated with regard to their embryo toxicity by injection of the toxins into the air cell of chicken eggs at 72 h of incubation. Under these conditions, FB1 at doses of 0, 2, 4, 8, 16, 32, and 64 microg per egg resulted in embryonic mortality of 5, 12.5, 17.5, 20.0, 52.5, 77.5, and 100%, respectively. The 50% lethal dose for FB1, when injected into the air cell of embryonating chicken eggs, was determined to be 18.73 microg per egg. A comparison of the toxicity of FB1, FB2, and FB3, individually and in combination (3:1:1 ratio), at doses of 16 microg of total fumonisin per egg, indicated that the toxicity of the fumonisins differed, FB1 being the most toxic. Microscopic examination of chicken embryos exposed to fumonisin did not reveal any gross developmental abnormalities; however, severe hemorrhages of the head, neck, and thoracic area of the dead embryos were evident.[1]

---

The fumonisin mycotoxins are produced by Fusarium moniliforme Sheldon, a contaminant of corn worldwide. The two most abundant analogues (fumonisins B1 and B2) are known to be potent inhibitors of sphingosine N-acyltransferase (ceramide synthase) and hence to disrupt de novo sphingolipid biosynthesis. The sphingoid bases, sphingosine and sphinganine (and hence their ratio), were measured at varying intervals over a period of 60 weeks in the serum of non-human primates (vervet monkeys; Cercopithecus aethiops) which were consuming diets containing 'low' and 'high' amounts of F. moniliforme culture material, such that their total daily fumonisin intake was approximately 0.3 and 0.8 mg/kg body weight/day, respectively. Although no significant differences were found in the serum levels of sphingosine compared to controls, serum sphinganine levels in the experimental groups (mean of 219 nM and 325 nM, respectively) were significantly (P = 0.02) elevated above the levels in controls (mean 46 nM). As a consequence, the ratio sphinganine:sphingosine was significantly (P = 0.003) elevated from a mean of 0.43 in the control group to 1.72 and 2.57 in the experimental groups, respectively. Similar changes in sphingolipid profiles were also measured in urine with an increase of the ratio from 0.87 in controls to 1.58 and 2.17 in the experimental groups, although the differences were not statistically significant. Hence, the disruption of sphingolipid biosynthesis in vervet monkeys by fumonisins in culture material added to their diet can effectively be monitored in the serum as an elevation of the sphinganine:sphingosine ratio[2].

The Committee reviewed studies available since the last assessment in 2011 and concluded that these studies do not alter the Committee’s previous overall toxicological assessment. Therefore, the Committee maintained the previously established PMTDI for FB1, FB2, and FB3 (alone or in combination) at 2 µg/kg body weight. The Committee noted that the international exposure estimates for FB1 and total fumonisins were lower than those estimated at the Committee’s seventy-fourth session in 2011. In this assessment, a higher proportion of incidence data from WHO European Region countries compared to 2011 led to a decrease in the overall level of fumonisins in maize. Information on fumonisin levels in maize from countries in the African, Eastern Mediterranean, or Southeast Asian regions, where high concentrations of fumonisins are typically detected, was not available in this assessment. Given these limitations of the incidence data used in the exposure assessment, and the high exposure levels reported in some countries in the literature, fumonisin exposure levels in areas where maize is a major food crop and where high concentrations of fumonisin contamination may exist are likely higher than the Committee’s estimates at this session, as demonstrated in previous assessments based on larger, more representative datasets. At its eighty-third session, the Committee also assessed the co-exposure to aflatoxin and fumonisin. Both fumonisin and aflatoxin are common contaminants in cereals and cereal products. Aflatoxin is a common contaminant in peanuts and nuts. In areas where these foods are frequently consumed, co-exposure to these two mycotoxins is likely. Although previous and current assessments have provided evidence in laboratory animals suggesting an additive or synergistic effect of co-exposure to fumonisin and aflatoxin on the development of precancerous lesions or hepatocellular carcinoma, there are currently no data on such effects in humans. The Committee concluded that the existing data are insufficient to support that co-exposure is a contributing factor to human disease. However, the interaction between aflatoxin B1 (AFB1), a compound known to be genotoxic, and fumonisin, which has the potential to induce regenerative cell proliferation (especially at exposure levels above PMTDI), remains a concern. This is because in some parts of the world, exposure to both mycotoxins is high, and the presence of co-exposure has been confirmed by biomarkers, in areas with high rates of chronic liver disease and developmental delays.

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

[2]. Disruption of sphingolipid metabolism in non-human primates consuming diets of fumonisin-containing Fusarium moniliforme culture material. Toxicon. 1996 May;34(5):527-34.

[3]. Natural occurrence of fumonisins B1 and B2 in corn in four provinces of China. Food Addit Contam Part B Surveill. 2013;6(4):270-4.

Fumonisin B2 is a fumonisin with the chemical name (2S,3S,12S,14S,15R,16R)-2-amino-12,16-dimethyleicosano-3,14,15-triol, in which the hydroxyl groups at positions 14 and 15 condense with the 1-carboxyl group of 3-carboxyglutaric acid to form an ester group (generating an R-configuration 3-carboxyglutaric acid ester group). It is a metabolite of Aspergillus and a carcinogen. It is a fumonisin, a primary amino compound, a diol, and a diester. Fumonisin B2 has been reported to be detected in Fusarium fujikuroi, Streptomyces, and Aspergillus niger, and relevant data are available for reference.

C34H59NO14

705.83056

705.393

C, 57.86; H, 8.43; N, 1.98; O, 31.73

116355-84-1

Fumonisin B2-13C34;1217481-36-1

2733489

White to yellow solid powder

1.2±0.1 g/cm3

864.4±65.0 °C at 760 mmHg

<3200(dec)

476.6±34.3 °C

0.0±0.6 mmHg at 25°C

1.520

4.39

7

15

31

49

1040

9

CCCC[C@@H](C)[C@H]([C@H](C[C@@H](C)CCCCCC[C@H](C[C@@H]([C@H](C)N)O)O)OC(=O)C[C@@H](CC(=O)O)C(=O)O)OC(=O)C[C@@H](CC(=O)O)C(=O)O

UXDPXZQHTDAXOZ-STOIETHLSA-N

InChI=1S/C34H59NO14/c1-5-6-12-21(3)32(49-31(43)18-24(34(46)47)16-29(40)41)27(48-30(42)17-23(33(44)45)15-28(38)39)14-20(2)11-9-7-8-10-13-25(36)19-26(37)22(4)35/h20-27,32,36-37H,5-19,35H2,1-4H3,(H,38,39)(H,40,41)(H,44,45)(H,46,47)/t20-,21+,22-,23+,24+,25+,26-,27-,32+/m0/s1

(2R)-2-[2-[(5R,6R,7S,9S,16R,18S,19S)-19-amino-6-[(3R)-3,4-dicarboxybutanoyl]oxy-16,18-dihydroxy-5,9-dimethylicosan-7-yl]oxy-2-oxoethyl]butanedioic acid

fumonisin b2; 116355-84-1; fumonisin-B2; Fumonisin B2, Fusarium moniliforme; CCRIS 4434; CHEBI:38225; UX4WHT4MKB; (2R)-2-[2-[(5R,6R,7S,9S,16R,18S,19S)-19-amino-6-[(3R)-3,4-dicarboxybutanoyl]oxy-16,18-dihydroxy-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.)