OCHRATOXIN A
Flammability | 1 | |
Toxicity | 4 | |
Body Contact | 2 | |
Reactivity | 0 | |
Chronic | 3 | |
SCALE: Min/Nil=0 Low=1 Moderate=2 High=3 Extreme=4 |
The ochratoxins constitute a group of closely linked derivatives of isocoumarine linked to
L- phenylalanine and are classified according to biosynthetic origin as " pentaketides"
within the group of polyketides. Naturally occurring mycotoxins (phytotoxins) produced by
Aspergillus ochraceus, A. sulphureus, A. meleus, Penicillium viridicatum. In colder
climates, ochratoxins are produced by Penicillium strains, whilst in tropical and
subtropical regions, they are produced by Aspergillus. As these molds occur widely, the
toxin has been found as a natural contaminant on corn, peanuts, storage grains, cottonseed
and other decaying vegetation. Residues of ochratoxin have been detected in samples of
animals slaughter immediately after consuming contaminated feed. It has been detected at
levels of 10- 920 ug/kg in sausage, ham and bacon samples. Residues of ochratoxin are not
generally found in ruminants because ochratoxin is cleaved in the fore- stomachs by
protozoan and bacterial enzymes to the non- toxic ochratoxin alpha. In some calves
however, ochratoxin A has been found at low levels in the kidneys indicating that the
calves are not yet functioning as ruminants.
C20-H18-Cl-N-O6, C20-H18-Cl-N-O6, N-(((3R)-5-chloro-8-hydroxy-3-methyl-1-oxo-7-
isochromanyl)carbonyl)-3-phenyl-L-alanine, N-(((3R)-5-chloro-8-hydroxy-3-methyl-1-oxo-7-
isochromanyl)carbonyl)-3-phenyl-L-alanine, (-)-N-((5-chloro-8-hydroxy-3-methyl-1-oxo-7-
isochromanyl)carbonyl)-3-phenylalanine, (-)-N-((5-chloro-8-hydroxy-3-methyl-1-oxo-7-
isochromanyl)carbonyl)-3-phenylalanine, "(R)-N-((5-chloro-3, 4-dihydro-8-hydroxy-3-methyl-
1-oxo-1H-2-benzopran-7-yl)carbonyl)phenylalanine", "(R)-N-((5-chloro-3, 4-dihydro-8-
hydroxy-3-methyl-1-oxo-1H-2-benzopran-7-yl)carbonyl)phenylalanine", NCI-C56586,
"pentaketide/ polyketide/ mycotoxin/ phytotoxin"
Very toxic if swallowed.
May cause CANCER.
Severely toxic effects may result from the accidental ingestion of the material; animal experiments indicate that ingestion of less than 5 gram may be fatal or may produce serious damage to the health of the individual.
Although the material is not thought to be an irritant, direct contact with the eye may produce transient discomfort characterized by tearing or conjunctival redness (as with windburn).
The material is not thought to produce adverse health effects or skin irritation following contact (as classified using animal models). Nevertheless, good hygiene practice requires that exposure be kept to a minimum and that suitable gloves be used in an occupational setting. Open cuts, abraded or irritated skin should not be exposed to this material. Toxic effects may result from skin absorption.
The material is not thought to produce adverse health effects or irritation of the respiratory tract (as classified using animal models). Nevertheless, good hygiene practice requires that exposure be kept to a minimum and that suitable control measures be used in an occupational setting.
There is ample evidence that this material can be regarded as being able to cause cancer in humans based on experiments and other information.
Principal routes of exposure are usually by skin contact and inhalation of generated dust. The incidence of and mortality from urothelial urinary tract tumours have been correlated with geographical distribution of Balkan endemic nephropathy in Bulgaria and Yugoslavia. A relatively high frequency of contamination of cereals and bread with ochratoxin A has been reported in an area of Yugoslavia where Balkan endemic nephropathy is present. Balkan endemic nephropathy is a chronic disease that predominantly affects women and progresses slowly up to death. Autopsy shows that kidneys are notably reduced in size. The histological lesions are interstitial fibrosis, tubular degeneration and hyalization of glomeruli in the more superficial part of the cortex. One study revealed the presence of ochratoxin in the serum of significant number of the inhabitants of 2 villages (6.6% of 639 samples taken) from the area in which the disease occurred. A similar study conducted in Poland revealed similar results whilst a study conducted in the former Federal Republic of Germany showed 56.6% of serum samples contained ochratoxin A. When administered by gavage, ochratoxin substantially increased the incidence of uncommon cell carcinomas of the kidney in male and female rats and also increased the incidence and multiplicity of the mammary glands in female rats. When introduced into the diet, renal adenomas and carcinomas were observed in male mice and some hepatocellular carcinomas were observed in female mice In another study dietary ochratoxin A induced hepatomas and renal cell tumors in male mice. Intraperitoneal injection of pregnant mice with ochratoxin A resulted in increased prenatal mortality, decreased foetal weight and various foetal malformations, including exencephaly and anomalies of the eyes, face, digits and tail. Subcutaneous administration to rats on gestation days 5-7 resulted in a high number of malformations including hydroencephaly, omphalocele and anophthalmia as well as a shift in the position of the oesophagus. In a further study low levels of dietary protein were shown to enhance the teratogenic potential of ochratoxin A in the rat.