Mycotoxin found in Fusarium

This review focuses on the toxicity and metabolism of T-2 toxin and analytical methods used for the determination of T-2 toxin. Among the naturally occurring trichothecenes in food and feed, T-2 toxin is a cytotoxic fungal secondary metabolite produced by various species of Fusarium. Following ingestion, T-2 toxin causes acute and chronic toxicity and induces apoptosis in the immune system and fetal tissues. T-2 toxin is usually metabolized and eliminated after ingestion, yielding more than 20 metabolites. Consequently, there is a possibility of human consumption of animal products contaminated with T-2 toxin and its metabolites. Several methods for the determination of T-2 toxin based on traditional chromatographic, immunoassay, or mass spectroscopy techniques are described. This review will contribute to a better understanding of T-2 toxin exposure in animals and humans and T-2 toxin metabolism, toxicity, and analytical methods, which may be useful in risk assessment and control of T-2 toxin exposure [1].

T-2 toxin, one of the most toxic trichothecene mycotoxins, causes economic losses in animal production. Little information is available on the toxicokinetic parameters of T-2 toxin and its major metabolites (i.e., HT-2 toxin and T-2 triol) in broiler chickens. In this study, toxicokinetics of T-2 toxin and its major metabolites were evaluated in broiler chickens after a single intravenous (0.5 mg/kg b.w.) and multiple oral administrations (2.0 mg/kg b.w., every 12 h for 2 days). Plasma concentration profiles of T-2 toxin and its metabolites were analyzed by a noncompartmental model method. Following intravenous administration, the terminal elimination half-lives (t(1/2λz)) of T-2 toxin, HT-2 toxin, and T-2 triol were 17.33 ± 1.07 min, 33.62 ± 3.08 min, and 9.60 ± 0.50 min, respectively. Following multiple oral administrations, no plasma levels above the limit of quantification were observed for HT-2 toxin. The t(1/2λz) of T-2 toxin and T-2 triol was 23.40 ± 2.94 min and 87.60 ± 29.40 min, respectively. Peak plasma concentrations (Cmax ) of 53.10 ± 10.42 ng/mL (T-2 toxin) and 47.64 ± 9.19 ng/mL (T-2 triol) were observed at Tmax of 13.20 ± 4.80 min and 38.40 ± 15.00 min, respectively. T-2 toxin had a low absolute oral bioavailability (17.07%). Results showed that the T-2 toxin was rapidly absorbed and most of the T-2 toxin was extensively transformed to metabolites in broiler chickens [2].

Metabolism of T-2 [1]
T-2 is usually metabolized and eliminated after ingestion. In general, T-2 is soluble in water, and the major metabolic reactions are usually hydrolysis, hydroxylation, de-epoxidation, and conjugation. The most typical metabolites of T-2 are HT-2 toxin (hydrolysis), T-2 triol, T-2 tetraol, neosolaniol (NEO), 3′-hydroxy HT-2, 3′-hydroxy T-2, 3′-hydroxy T-2 triol, and dihydroxy HT-2 (Figure 2) and de-epoxy-3′-hydroxy T-2 and de-epoxy-3′-hydroxy HT-2 (Figure 3). Because human consumption of animal products contaminated with T-2 and its metabolites is a possibility, distribution and metabolism studies of T-2 toxin in animals could provide important information for both evaluating and controlling human exposure to residual T-2 metabolites in foods of animal origin.

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Liver Metabolic Systems [1]
Studies on the metabolism of T-2 have been carried out on liver S-9 fractions and microsomes. During initial studies, HT-2 was considered as the sole metabolite in bovine and human liver homogenates and in liver microsomes of various animals. However, new metabolites of T-2 were subsequently detected. Upon incubation of T-2 in a rat liver S-9 fraction, T-2 was rapidly converted into HT-2, T-2 tetraol, and two unknown metabolites, which were designated TMR-1 and TMR-2. TMR-1 was characterized as 4-deacetylneosolaniol (Figure 2) by spectroscopic analysis. TMR-1, TMR-2, and T-2 tetraol were also found in the incubation mixture of HT-2, which suggested that the three compounds were converted from T-2 via HT-2 by hydrolysis at the C-4 position. Along with these metabolites, four other metabolites of T-2 were detected in homogenates of mouse and monkey livers. These new metabolites included neosolaniol, 15-deacetylneosolaniol, 3′-hydroxy T-2, and 3′-hydroxy HT-2 (Figure 2). The hydroxylation reactions were enhanced by treating mice with phenobarbital (PB). Liver microsomes from rat, chicken, and mouse can biotransform T-2 into a variety of metabolites including HT-2, neosolaniol, 4-deacetylneosolaniol, T-2 triol, 3′-hydroxy T-2, and 3′-hydroxy HT-2 (Figure 2), and two unidentified compounds, RLM-2 and RLM-3. These two additional compounds were tentatively identified as isomers of 3′-hydroxy T-2 by gas chromatography−mass spectrometry (GC-MS). The major metabolite in microsomal preparations from both control and PB-induced microsomes was HT-2. Following incubation of PB-induced chickens with T-2, 3′-hydroxy T-2 was the major metabolite. However, 30 and 79% of the added T-2 remained unchanged 60 min after incubation in PB-induced and control chickens, respectively. The significant increase in hydroxylated metabolites formed by liver microsomes from PB-induced animals may be caused by cytochrome P-450 catalysis. This effect has been described in liver homogenates prepared from mice and monkeys and has been used to enhance the in vitro production of 3′-hydroxy metabolites by liver S-9 fractions isolated from pigs and rats. Treatment of a rat hepatic S-9 preparation with T-2 yielded primarily 3′-hydroxy T-2 (Figure 2) as the major metabolic product (>85%), and a new minor metabolite, RLM-3, was identified by GC-MS and 1H and 13C NMR experiments as 4′-hydroxy T-2. In work by Pace, [3H]T-2 was administered to perfused rat livers and used to study the metabolism and clearance of T-2. T-2 was metabolized and eliminated as 3′-hydroxy HT-2, 3′-hydroxy T-2 triol, 4-deacetylneosolaniol, and T-2 tetraol (Figure 2) and as glucuronide conjugates of HT-2, 3′-hydroxy HT-2, and T-2 tetraol. (90) The biochemical pathways of T-2 metabolism in perfused rat liver were the same as those observed in vivo. Again, bile was observed to be the major excretion route of T-2 and its metabolites, and the perfusion model was considered to be useful as a tool for the isolation of minor metabolites for structural analysis.

Animals [2]
Twenty 5-week-old clinically healthy chickens weighing 1.3–1.4 kg were used in this study. The broilers were kept under conditions of controlled temperature (25 °C) and humidity (45%). Chickens were allowed a 7-day acclimation period prior to the study initiation. T-2 toxin-free feeds and drinks were supplied ad libitum. The composition of the feeds was 56.8% corn, 25.0% soybean meal, 8% bran wheat, and other ingredients. They could meet the daily nutrition of the chickens.

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Experimental design [2]
Twenty chickens were randomly divided into two groups. Twelve chickens in group A were administered with T-2 toxin by a single intravenous bolus injection (0.5 mg/kg b.w.); eight chickens in group B received T-2 toxin orally at a dosage of 2.0 mg/kg b.w., every 12 h for 2 days. The solutions for intravenous (i.v.) and oral administrations were freshly prepared daily at a concentration of 2 mg/mL by dissolving T-2 toxin standard in ethyl alcohol—sterilized deionized water (1:1) mixture. T-2 toxin was administered intravenously into the right wing vein of the chickens in group A and was administered orally directly to the craw of the chickens in group B using a thin plastic tube attached to a syringe.
Blood samples (1.0 mL) were collected from the left wing vein of each chicken in groups A and B. Samples were collected into a heparinized tube through a needle at the following time points: 0, 2.5, 5, 7.5, 10, 15, 20, 30, 45 min, 1, 1.5, and 2 h postadministration for the i.v. administration and 0, 5, 10, 15, 20, 30, 45 min, 1, 1.5, 2, 2.5, 3, 4.5, and 6 h postadministration after the last dose for the oral administration. Blood samples were centrifuged at 1500 g for 10 min. The supernatants were stored frozen at −20 °C until analysis.

Absorption, Distribution and Excretion
T2-Trichothecene is readily absorbed through skin & the gut in pigs & rats.
T-2 toxin is transmitted in the milk in lactating cattle & pigs.
Estimated that the eggs from chickens treated orally with 1 mg T-2 toxin/kg body weight daily for 8 consecutive days, which is equivalent to 1.6 mg/kg dietary T-2, contain 0.9 ug of this material.
The radioactivity of orally admin (3)H-T2-trichothecene (1 mg/kg body wt) to mice & rats was recovered in feces (55%) & urine (15%) within 72 hr. It was distributed in the liver, kidneys & other organs, without specific accumulation.
(3)H-T-2 Toxin given orally to mice and rats was distributed rapidly to tissues and eliminated in feces and urine. Maximal levels of radiolabel were found after 30 min in plasma of mice after oral administration ... and of guinea pigs after intramuscular injection ... . In chicks administered (3)H-T-2 toxin in the diet, maximal levels were reached by 4 hr in blood, plasma, abdominal fat, heart, kidneys, gizzard, liver and the remainder of the carcass and by 12 hr in muscle, skin, bile and gall bladder ... . The distribution of T-2 toxin in tissues of swine was similar to that in chickens ... .

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Metabolism / Metabolites
Two major metabolites were obtained from the urine of a lactating cow given 180 mg of T-2 toxin orally. They were 3'-hydroxy-HT 2 toxin & 3'-hydroxy T 2 toxin.
Human liver enzymes deacetylate T2-trichothecene to HT2-trichothecene in vitro.
The radioactivity of orally admin (3)H-T2-trichothecene (1 mg/kg body wt) to mice & rats was recovered in feces (55%) & urine (15%) within 72 hr. ... Analysis of the radioactivity recovered in feces of rats revealed that 2.7% of the dose was excreted as unchanged T2-trichothecene & 7.5% as 4-O-deacetylated T2-trichothecene (HT2-trichothecene)...the remaining fecal excretion products were not identified. In urine, HT2-trichothecene, representing 1.4% of the total dose & 8-hydroxydiacetoxyscirpenol (1.8%) were identified; 3 unidentified metabolites...were also isolated. The epoxide moeity...seems to be essential for its toxicological activity; the liver detoxifies T2-trichothecene, probably through epoxide hydrolase. In vitro, rat liver homogenate metabolizes T2-trichothecene to HT2-trichothecene, T2-trichothecene tetraol, 4-deacetylneosolaniol...& neosolaniol... The same metabolites were obtained from HT2-trichothecene, indicating that T2-trichothecene was preferentially hydrolyzed at the C-4 position to give NT2-trichothecene.
Trichothecenes are sesquiterpenoid toxins produced by Fusarium species. Since these mycotoxins are very stable, there is interest in microbial transformations that can remove toxins from contaminated grain or cereal products. Twenty-three yeast species assigned to the Trichomonascus clade (Saccharomycotina, Ascomycota), including four Trichomonascus species and 19 anamorphic species presently classified in Blastobotrys, were tested for their ability to convert the trichothecene T-2 toxin to less-toxic products. These species gave three types of biotransformations: acetylation to 3-acetyl T-2 toxin, glycosylation to T-2 toxin 3-glucoside, and removal of the isovaleryl group to form neosolaniol. Some species gave more than one type of biotransformation. Three Blastobotrys species converted T-2 toxin into T-2 toxin 3-glucoside, a compound that has been identified as a masked mycotoxin in Fusarium-infected grain. This is the first report of a microbial whole-cell method for producing trichothecene glycosides, and the potential large-scale availability of T-2 toxin 3-glucoside will facilitate toxicity testing and development of methods for detection of this compound in agricultural and other products.
For more Metabolism/Metabolites (Complete) data for T-2 TOXIN (6 total), please visit the HSDB record page.

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Biological Half-Life
The plasma half-life for T-2 toxin is less than 20 minutes.
T-2 toxin was converted to 3'-hydroxy-HT 2 when incubated with 9000 g supernatants of human or bovine liver homogenates for 75 min at 37 °C. The metabolism of T-2 toxin was more rapid in human (20 min half-life) than in bovine (40 min half-life). The metabolite was as toxic & produced emesis almost as rapidly as T-2 toxin.

Toxicity Data
LC50 (rat) = 20 mg/m3/10min

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Interactions
Experiments were conducted to determine the effect of dietary fibers on T-2 toxicosis in rats. Weanling rats were fed varying levels of cellulose, hemicellulose, lignin and pectin with and without T-2 toxin (3 ug/g feed) for 2 weeks. Only lignin showed promise of overcoming feed refusal and growth depression in animals fed T-2 toxin. Further experiments feeding alfalfa meal (0, 5, 10, 15, 20 or 25%) with and without T-2 toxin indicated that this lignin-rich feedstuff could largely overcome feed refusal and growth depression caused by the toxin. There was no effect of diet, however, on the activity of hepatic esterase, the enzyme believed to catabolize T-2 toxin. Rats were fed diets containing 0, 5, 12.5 or 20% alfalfa for 2 weeks and then dosed orally with [(3)H]T-2 toxin. Dietary alfalfa increased fecal excretion of 3H, whereas urinary excretion was unaffected. Residual (3)H in kidney and muscle was reduced with alfalfa feeding when [(3)H]T-2 toxin was administered orally. Residual (3)H in the digesta in the intestinal lumen increased. Alfalfa feeding was found to reduce intestinal transit time. It was concluded that the feeding of alfalfa reduced T-2 toxicosis in rats by binding the toxin in the intestinal lumen thereby promoting fecal excretion.
Active oxygen species are reported to cause organ damage. This study was therefore designed to determine whether oxidative stress contributed to the initiation or progression of hepatic DNA damage produced by T-2 toxin. The aim of the study was also to investigate the behavior of the antioxidants coenzyme Q10 (CoQ10), and alpha-tocopherol (vitamin E) against DNA damage in the livers of mice fed T-2 toxin. Treatment of fasted mice with a single dose of T-2 toxin (1.8 or 2.8 mg/kg body weight) by oral gavage led to 76% hepatic DNA fragmentation. T-2 toxin also decreased hepatic glutathione (GSH) levels markedly. Pretreatment with CoQ10 (6 mg/kg) together with alpha tocopherol (6 mg/kg) decreased DNA damage. The CoQ10 and vitamin E showed some protection against toxic cell death and glutathione depletion caused by T-2 toxin. Oxidative damage caused by T-2 toxin may be one of the underlying mechanisms for T-2 toxin-induced cell injury and DNA damage, which eventually lead to tumourigenesis.
The objective of this study was to determine whether two antioxidant vitamins, vitamins E and C, were able to counteract the production of lipid peroxides and the corresponding toxic signs of two important but diverse mycotoxins, T-2 toxin and ochratoxin A (OA). Experiment 1 was designed in a 3 x 3 factorial arrangement using three doses of vitamin E (dl-alpha-tocopheryl acetate) in the diet of Leghorn cockerels (required level according to NRC, 10x, and 100x requirements) and three toxin treatment [no toxin (Diets 1, 2, and 3), 4 mg T-2/kg of diet (Diets 4, 5, and 6), and 2.5 mg OA/kg of diet (Diets 7, 8, and 9)]. The experimental design for Experiment 2 was the same as for Experiment 1 except that Vitamin C (0, 200, and 1,000 mg/kg of diet) was used in place of vitamin E and the concentration of T-2 in Diets 4, 5, and 6 was increased to 5 mg/kg of diet. Six replicates were used per treatment with four birds per replicate. In both experiments, OA and T-2 decreased the performance of the chicks significantly. The concentration of uric acid in the plasma increased (P < 0.001) when OA was added to the diet, whereas the supplementation of the diet with vitamin E (100x the requirement) partially counteracted this effect (P = 0.07). The presence of T-2, and especially OA, in the diet decreased the concentration of alpha-tocopherol in the liver (P < 0.001). Consistent with these findings were increased values of malondialdehyde (MDA) in the liver due to OA. In Experiment 1, vitamin E supplementation partially ameliorated the prooxidative effects of OA by decreasing the concentrations of MDA (P < 0.05). These data suggest that lipid peroxides are formed in vivo by T-2 and especially by OA and that these effects can be partially counteracted by an antioxidant such as vitamin E but not by vitamin C.
The objective of this study is to observe pathogenic lesions of joint cartilages in rats fed with T-2 toxin under a selenium deficiency nutrition status in order to determine possible etiological factors causing Kashin-Beck disease (KBD). Sprague-Dawley rats were fed selenium-deficient or control diets for 4 weeks prior to their being exposed to T-2 toxin. Six dietary groups were formed and studied 4 weeks later, i.e., controls, selenium-deficient, low T-2 toxin, high T-2 toxin, selenium-deficient diet plus low T-2 toxin, and selenium-deficient diet plus high T-2 toxin. Selenium deficiencies were confirmed by the determination of glutathione peroxidase activity and selenium levels in serum. The morphology and pathology (chondronecrosis) of knee joint cartilage of experimental rats were observed using light microscopy and the expression of proteoglycans was determined by histochemical staining. Chondronecrosis in deep zone of articular cartilage of knee joints was seen in both the low and high T-2 toxin plus selenium-deficient diet groups, these chondronecrotic lesions being very similar to chondronecrosis observed in human KBD. However, the chondronecrosis observed in the rat epiphyseal growth plates of animals treated with T-2 toxin alone or T-2 toxin plus selenium-deficient diets were not similar to that found in human KBD. /These/ results indicate that the rat can be used as a suitable animal model for studying etiological factors contributing to the pathogenesis (chondronecrosis) observed in human KBD. However, those changes seen in epiphyseal growth plate differ from those seen in human KBD probably because of the absence of growth plate closure in the rat.
For more Interactions (Complete) data for T-2 TOXIN (22 total), please visit the HSDB record page.

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Non-Human Toxicity Values
LC50 Pig inhalation 1.5-3.0 mg/kg (18 hr)
LD50 Pig i.v. 1.21 mg/kg
LD50 Mice inhalation 0.16 mg/kg (24 hr)
LD50 Mice i.v. or i.p. 3.0-5.3 mg/kg
For more Non-Human Toxicity Values (Complete) data for T-2 TOXIN (11 total), please visit the HSDB record page.

[1]. T-2 toxin, a trichothecene mycotoxin: review of toxicity, metabolism, and analytical methods. J Agric Food Chem. 2011 Apr 27;59(8):3441-53.

[2]. Toxicokinetics of T-2 toxin and its major metabolites in broiler chickens after intravenous and oral administration. J Vet Pharmacol Ther. 2015 Feb;38(1):80-5.

T-2 toxin is a trichothecene mycotoxin produced by fungi of the genus Fusarium. It is a common contaminant in food and feedstuffs of cereal origin and is known to cause a range of toxic effects in humans and animals. It has a role as a mycotoxin, a cardiotoxic agent, a neurotoxin, an environmental contaminant, an apoptosis inducer, a DNA synthesis inhibitor and a fungal metabolite. It is a trichothecene, an acetate ester and an organic heterotetracyclic compound. It is functionally related to a HT-2 toxin.
T2 Toxin has been reported in Fusarium heterosporum, Fusarium chlamydosporum, and other organisms with data available.
T-2 Toxin is a type A trichothecene mycotoxin produced by Fusarium langsethiae, Fusarium poae, and Fusarium sporotrichioides that interferes with the metabolism of membrane phospholipids by inhibiting protein synthesis and disrupting DNA and RNA synthesis. It is frequently responsible for the contamination of various grain crops and elicits a severe inflammatory reaction in animals.
A potent mycotoxin produced in feedstuffs by several species of the genus FUSARIUM. It elicits a severe inflammatory reaction in animals and has teratogenic effects.

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Mechanism of Action
Studies with whole cells, cell-free protein synthetic system, & acid-insol cell fractions of Tetrahymena pyriformis indicated that T-2 toxin inhibited protein synthesis by impairing the 60 S ribosome subunit & inhibited RNA & dna synthesis by disturbing the cell membrane function.
T2-trichothecene binds in vitro to active SH groups of creatine phosphokinase, lactate dehydrogenase & alcohol dehydrogenase, inhibiting their catalytic activity.
The high affinity of T2-trichothecene & higher trichothecenes to SH compounds provides a molecular basis for an interaction with the spindle fiber mechanism. ...
T-2 toxin could inhibit synthesis of DNA and RNA both in vivo (0.75 mg/kg bw single or multiple doses) and in vitro (> 0.1-1 ng/mL).
For more Mechanism of Action (Complete) data for T-2 TOXIN (14 total), please visit the HSDB record page.

C24H34O9

466.52136

466.22

C, 61.79; H, 7.35; O, 30.86

21259-20-1

T-2 Toxin-13C24

5284461

White to off-white solid powder

1.3±0.1 g/cm3

544.9±50.0 °C at 760 mmHg

151.5℃

177.0±23.6 °C

0.0±3.3 mmHg at 25°C

1.547

2.25

1

9

9

33

881

8

CC1=C[C@@H]2[C@](C[C@@H]1OC(=O)CC(C)C)([C@]3([C@@H]([C@H]([C@H]([C@@]34CO4)O2)O)OC(=O)C)C)COC(=O)C

BXFOFFBJRFZBQZ-QYWOHJEZSA-N

InChI=1S/C24H34O9/c1-12(2)7-18(27)32-16-9-23(10-29-14(4)25)17(8-13(16)3)33-21-19(28)20(31-15(5)26)22(23,6)24(21)11-30-24/h8,12,16-17,19-21,28H,7,9-11H2,1-6H3/t16-,17+,19+,20+,21+,22+,23+,24-/m0/s1

[(1S,2R,4S,7R,9R,10R,11S,12S)-11-acetyloxy-2-(acetyloxymethyl)-10-hydroxy-1,5-dimethylspiro[8-oxatricyclo[7.2.1.02,7]dodec-5-ene-12,2'-oxirane]-4-yl] 3-methylbutanoate

T-2 TOXIN; T2 Toxin; 21259-20-1; T2-Trichothecene; Mycotoxin T-2; Isaritoxin; Fusariotoxine T2; Fusariotoxin T-2;

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)

DMSO : ≥ 100 mg/mL (~214.35 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (5.36 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.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (5.36 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.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (5.36 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.

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