Ochratoxin B

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

SMALL SPILLS AND LEAKAGE: If you spill this chemical, FIRST REMOVE ALL SOURCES OF IGNITION. You should then dampen the solid spill material with 60-70% ethanol, then transfer the dampened material to a suitable container. Use absorbent paper dampened with ethanol to pick up any remaining material. Your contaminated clothing and absorbent paper should be sealed in a vapor-tight plastic bag for eventual disposal. Solvent-wash contaminated surfaces with 60-70% ethanol followed by washing with a soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.

SRP: Criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

RECOMMENDED RESPIRATOR: Where the neat test chemical is weighed and diluted, wear a NIOSH-approved half face respirator equipped with a combination filter cartridge, i.e. organic vapor/acid gas/HEPA (specific for organic vapors, HCl, acid gas, SO2 and a high efficiency particulate filter). (NTP, 1992)

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 300(SRC), determined from an estimated log Kow of 3.77(2) and a regression-derived equation(2), indicates that the neutral species of ochratoxin B is expected to have moderate mobility in soil(SRC). The estimated pKa values of ochratoxin B are 3.3 and 7.0(3), indicating that this compound will exist almost entirely in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(4). Volatilization from moist soil is not expected because the compound exists as an anion and anions do not volatilize. Ochratoxin B is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 6.4X10-15 mm Hg at 25 °C(SRC), determined from a fragment constant method(2). Biodegradation data in soil were not available(SRC, 2013).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 300(SRC), determined from an estimated log Kow of 3.77(2) and a regression-derived equation(2), indicates that the neutral species of ochratoxin B is expected to adsorb to suspended solids and sediment(SRC). Estimated pKa values of 3.3 and 7.0(3) indicate ochratoxin B will exist almost entirely in the anion form at pH values of 5 to 9 and, therefore, volatilization from water surfaces is not expected to be an important fate process(SRC). According to a classification scheme(4), an estimated BCF of 3(SRC), from its estimated log Kow(2) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Ochratoxin B may undergo hydrolysis as it contains a cyclic ester functionality which can hydrolyze under environmental conditions (pH 5 to 9)(5). Biodegradation data in water were not available(SRC, 2013).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), ochratoxin B, which has an estimated vapor pressure of 6.4X10-15 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely in the particulate phase in the ambient atmosphere. Particulate-phase ochratoxin B may be removed from the air by wet and dry deposition(SRC). Ochratoxin B absorbs UV light at wavelengths >290 nm(3) and, therefore, may be susceptible to direct photolysis by sunlight(SRC).

The presence of 34 mycotoxins in dietary supplements containing green coffee bean (GCB) extracts was determined. Ochratoxin B was found in 32% of tested products. The concentration of ochratoxin B ranged from <1.0-20.2 ug/kg(1).

Five independent episodes of ochratoxicosis in about 970,000 turkeys, two episodes in about 70,000 laying hens, and two episodes in about 12,000,000 broiler chickens were investigated. Ochratoxin A concentrations in suspect feed and ingredients ranged from <0.2 to 16 ppm. Feed samples tested for T-2 toxin, F-2 toxin, heavy metals, and polychlorinated biphenyls were negative. Minor amounts of aflatoxin (<60 ppb) were found in suspect feed from two episodes. ... Eight of the 9 episodes were traced to the corn supply and the ninth episode was traced to corn gluten meal that became contaminated during storage after manufacture. Evidence was obtained that the ochratoxin was unstable and declined in concentration during storage. ... The ochratoxin extracted from high potency samples consisted of ochratoxins A, B, and C in ratios of about 90:8:2(1).

The effects of temperature and length of incubation on ochratoxin A production in various substrates were studied. The optimal temperature for toxin production by Aspergillus ochraceus NRRL-3174 was found to be around 28 C. Very low levels of ochratoxin A are produced in corn, rice, and wheat bran at 4 C. The optimal time for ochratoxin A production depends on the substrate, ranging from 7 to 14 days at 28 C. Ochratoxin B and dihydroisocoumaric acid, i.e., one of the hydrolysis products of ochratoxin A, were produced in rice but at levels considerably lower than ochratoxin A. No ochratoxin C was produced in rice at 28 C. When added to rice cereal or oatmeal, the toxin was found to be very stable over prolonged storage and even to autoclaving for 3 hr.

Using a structure estimation method based on molecular connectivity indices(1), the Koc of ochratoxin B can be estimated to be 300(SRC). According to a classification scheme(2), this estimated Koc value suggests that ochratoxin B is expected to have moderate mobility in soil. The estimated pKa values of ochratoxin B are 3.3 and 7.0(3), indicating that this compound will exist almost entirely in the anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(4).

Ochratoxins are toxic metabolites from Aspergillus ochraceus, A. sulphureus, A. melleus and Penicillium viridicatum. As these molds occur widely, some toxins have been found as natural contaminants on corn, peanuts, storage grains, cottonseed, and other decaying vegetation. /Ochratoxins/

/GENOTOXICITY/ To elucidate the effects of three structurally related mycotoxins, namely, ochratoxin A (OTA), ochratoxin B (OTB), and citrinin (CIT), on human health, ...their acute toxic, mitogenic, and genotoxic effects in the human-derived liver cell line (HepG2) /were investigated/. These compounds are found in moldy foods in endemic areas of nephropathy, which is associated with urinary tract cancers. In agreement with previous experiments, /investigators/ found that OTA causes a dose-dependent induction of micronuclei (MN) and DNA migration in the single-cell gel electrophoresis (SCGE) assay, which was statistically significant at concentrations of > or =5 ug/mL. In contrast, OTB was devoid of genotoxic activity under identical conditions, but the compound caused pronounced inhibition of cell division even at doses lower than OTA (10 ug/mL). CIT caused an effect similar to that of OTA in MN assays (significant at dose levels of > or =2.5 ug/mL) but was negative in the SCGE test. All compounds failed to induce mutations in Salmonella/microsome assays in strains TA98 and TA100 after addition of HepG2-derived enzyme homogenate (S9-mix). By use of DNA-centromeric probes /investigators/ found that induction of MN by OTA involves chromosome breaking effects (55-60% of the MN were centromere negative), whereas CIT-induced MN were predominantly centromere positive (78-82%). /These/ findings indicate that OTB is devoid of genotoxic activity in human-derived cells and therefore probably not a genotoxic carcinogen in humans. In contrast, CIT was an equally potent inducer of MN in HepG2 cells as OTA, but this effect is caused by a different mechanism, namely, aneuploidy.

A toxic metabolite of Aspergillus ochraceus, Aspergillus sulphureus, Aspergillus melleus, and Penicillium viridicatum molds. Ochratoxins are natural contaminants of corn, peanuts, storage grains, cottonseed, and other decaying vegetables; Used as an experimental teratogen and carcinogen; [Merck Index]

Experimentally as teratogen and carcinogen /Ochratoxins/

Human exposure occurs mainly through consumption of improperly stored food products, particularly contaminated grain and pork products, as well as coffee, wine grapes and dried grapes. (L1939)

Dichlorvos at 1 mg/100 mL of yeast extract-sucrose medium decreased production of ochratoxin b in cultures of Aspergillus ochraceus by 50%, but growth of culture was not affected. Concentrations of 10-30 mg/100 mL, dichlorvos decreased production of ochratoxin b 50-90%; growth was decreased 9-21%.

Isolations: van Walbeek et al, Can J Microbiol 14, 131 (1968); Shotwell et al, Appl Microbiol 17, 765 (1969); Nesheim, J Assoc Offic Anal Chem 52, 975 (1969); Natori et al, Chem Pharm Bull 18, 2259 (1970). /Ochratoxins/

As these molds occur widely, some toxins have been found as natural contaminants on corn, peanuts, storage grains, cottonseed, and other decaying vegetation. /Ochratoxins/

Ochratoxion B ... /is/ the less toxic ... /non-chlorinated/ derivative of ochratoxin A.

Two strains of Aspergillus ochraceus isolated from country cured hams produced ochratoxin B on rice, defatted peanut meal, and country cured ham.