3658 Ochratoxin A Ochratoxin A is found in barley. Mycotoxin. Ochratoxin A is produced by Aspergillus melleus, Aspergillus sulphureus and Penicillium viridicatum.Potential contaminant of foodstuffs, especially cereals. Ochratoxin A is found in stored grain products in UK (1997).Ochratoxin A, a toxin produced by Aspergillus ochraceus and Penicillium verrucosum, is one of the most abundant food-contaminating mycotoxins in the world. 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. The toxin has been found in the tissues and organs of animals, including human blood and breast milk. Ochratoxin A toxicity has large species- and sex-specific differences. Ochratoxin a belongs to the family of Ochratoxins and related substances. These are compounds containing the ochratoxin skeleton, which is structurally characterized by the presence of a 3-phenylpropanoic acid N-linked to a 8-hydroxy-3-methyl-1-oxo-3,4-dihydro-1H-2-benzopyran-7-carboxamide moiety[1]. (Reference: [1] http://www.inchem.org/documents/ehc/ehc/ehc105.htm). 303-47-9 442530 C20H18ClNO6 Crystals from xylene. Exhibits green fluorescence. (A715) 169°C Oral, dermal, inhalation, and parenteral (contaminated drugs). (A3101) Ochratoxin A has been shown to be weakly mutagenic, possibly by induction of oxidative DNA damage. The nephrotoxin ochratoxin A (OTA) causes a reduction of glomerular filtration rate (GFR) and of para-aminohippuric acid (PAH) clearance. It is a nephrotoxin which blocks plasma membrane anion conductance in Madin-Darby canine kidney (MDCK) cells. Some cytochrome P-450 enzymes, such as CYP2C9, are known to metabolize ochratoxin A into more cytotoxic compounds capable of forming DNA adducts. (A2869, A3099) Ochratoxin A is cleaved into phenylalanine and a less toxic iso-coumarin derivative (ochratoxin alpha) by the microbial flora of the colon, and by carboxypeptidase A and alpha-chymotrypsim. This is is the major metabolic pathway. 4-Hydroxyochratoxin A is the main hepatic metabolite and its formation appears to be via a polymorphic-like debrisoquine 4-hydroxylation. Some cytochrome P-450 enzymes, such as CYP2C9, and known to metabolize ochratoxin A into more cytotoxic compounds. (T35, A2870, A3099) LD50: 20 mg/kg (Oral, Rat) (A716) LD50: 12,600 ug/kg (Intraperitoneal, Rat) (A716) LD50: 12,750 ug/kg (Intravenous, Rat ) (A716) LD50: 46 mg/kg (Oral, Mouse) (A716) 2B, possibly carcinogenic to humans. (L135) 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) Ochratoxin exposure has been associated with acute tubular necrosis and Balkan endemic nephropathy. Ochratoxin A has been shown to be nephrotoxic and might delay sexual maturation. It can cause immunosuppression and immunotoxicity in animals. It's immunosuppressant activity in animals may include depressed antibody responses, reduced size of immune organs (such as the thymus, spleen, and lymph nodes), changes in immune cell number and function, and altered cytokine production. Immunotoxicity probably results from cell death following apoptosis and necrosis, in combination with slow replacement of affected immune cells due to inhibition of protein synthesis. (A704, L1939) Might cause respiratory irritation. (A704) Care is symptomatic and supportive. (A704) 2009-11-13T22:25:18Z 2026-03-26T20:59:06Z http://en.wikipedia.org/wiki/Ochratoxin_A C09955 7719 true CYP1A2 CYP2D6 CYP2C9 (A2876, A3099) CC1CC2=C(Cl)C=C(C(O)=NC(CC3=CC=CC=C3)C(O)=O)C(O)=C2C(=O)O1 C20H18ClNO6 InChI=1S/C20H18ClNO6/c1-10-7-12-14(21)9-13(17(23)16(12)20(27)28-10)18(24)22-15(19(25)26)8-11-5-3-2-4-6-11/h2-6,9-10,15,23H,7-8H2,1H3,(H,22,24)(H,25,26) RWQKHEORZBHNRI-UHFFFAOYSA-N 403.813 403.08226502 Exogenous Solid 4.74 HMDB29399 390954 CHEM002581 DTXSID7021073 NS00003381 2-{[(5-chloro-8-hydroxy-3-methyl-1-oxo-3,4-dihydro-1H-2-benzopyran-7-yl)(hydroxy)methylidene]amino}-3-phenylpropanoic acid