Citrinin

Citrinin (4.41) is a mycotoxin that is formed in quite large amounts by Penicillium citrinum, where it co-occurs with related metabolites such as the isocoumarins 4.42 and 4.43, the phenols 4.44 and 4.45, and decarboxycitrinin. Some dimers have also been isolated. Citrinin was first isolated by Raistrick in 1931 and its structure was proposed by Robertson in 1948. Although it exists as a quinone-methide in the crystalline state, it forms a hydrate rather rapidly. Much of the chemistry of citrinin can be understood in terms of the ready formation of this hydrate. The lactol of citrinin hydrate is readily oxidized to a 

---

Ochratoxin A, citrinin, penicillic acid, sterigmatocystine, zearalenone... 

After the dipped or sprayed chromatogram has been dried in a stream of cold air long-wave UV light (2 = 365 nm) reveals fluorescent yellow zones (flavonoids). Sterigmatocystine, which can be detected without derivatization on account of its red intrinsic fluorescence (detection limit 0.5 pg), also fluoresces pale yellow after being heated to 80°C [9] or 100°C [13] for 10 min on the other hand, citrinine, zearalenone and vomitoxin fluoresce blue. 

Although not a heteroaromatic compound, the case of citrinin studied by Destro and Luz ([97JPC(A)5097] and references therein) is so significant that it deserves mention here. Citrinin exists in the crystal as a mixture of the p-quinone 5a and o-quinone 5b tautomers (Scheme 3). The equilibrium ii temperature dependent and by using CPMAS NMR (Section VI,F) and, more remarkably. X-ray crystallography, the authors were able to determine the AH and AS values (the rate is extremely fast on the NMR time scale, >10 s ). 

Citrinine la 69,147,148 Citronellal la 158,159 CitroneUol la 68-70,327 Citronellyl acetate la 68 Claisen-Tischenko reaction 15 54 Clathrate complex 15 303 Clavin alkaloids 15 243 Clavine alkaloids 15 246,252 Cleanup la 119 Clemastin 15 354 Clenbuterol 15 106,107,354 Clobutinol 15 354 Cloforex 15 194,296 Clomethiazole lb 354 Clomipramine 15 352,354,355 Clonacillin lb 301 Clonidine 15 354 Clopamide 15 354 Clorexolon 15321 Clotrimazol 15 98,99,401,402 Cloxacillin 1584,188 Clozapin 15 354 Cnicin 15 290... 

The main concern regarding the utilization of Monascus pigments relates to the production of the citrinin mycotoxin in Monascus cultures. Several methods for controlling the mycotoxin production were proposed, including selection of non-toxinogenic strains, control of citrinin biosynthesis, and modifications of culture conditions. Despite their wide and traditional food applications in Asian countries, Monascus pigments have not been approved for use in the United States or European Union. 

Pseudomonas. It was shown that this molecule was citrinin and its production by various Monascus species was smdied using different culture media and conditions. 

In order to identify chemically the so-caUed monascidin A discussed by some Chinese scientists in their papers as a component suitable for the preservation of food, it was isolated and chemical investigations using mass spectrometry and NMR were undertaken. Monascidin A was characterized as citrinin which is known to be a mycotoxin responsible for nephropathies. Thus, in order to avoid the production of this toxin, various strains were screened in order to see whether all were toxino-genic and it was shown that among the species of Monascus available in pubhc collections, non-toxinogenic strains were obtainable. 

Hajjaj, H. et al.. The biosynthetic pathway of citrinin in the filamentous fungi Monascus ruber as revealed by C-NMR, Appl. Env. Microbiol, 65, 311, 1999. Hajjaj, H. et al.. Medium-chain fatty acids affect citrinin production in the filamentous fungus Monascus ruber, Appl. Env. Microbiol, 66, 1120, 2000. 

Hajjaj, H. et al.. Kinetic analysis of red pigment and citrinin production by Monascus ruber as a function of organic acid accumulation, Enz. Microb. Technol, 27, 619, 2000. 

Franco, C. M., Fente, C. A., Vazquez, B., Cepeda, A., Lallaoui, L., Prognon, P., and Mahuzier, G., Simple and sensitive high-performance liquid chromatography-fluorescence method for the determination of citrinin. Application to the analysis of fungal cultures and cheese extracts, /. Chromatogr. A, 723, 69, 1996. 

Crystal data and details of data collection, data reduction and final refinement are reported in Table 1. The procedure for data collection and processing, which included a correction for scan-truncation effects, were similar to those recently described for syn-l,6 8,13-biscarbonyl[14]annulene [10] and citrinin [11], Figure 1 shows the numbering scheme adopted in the present analysis. 

Hokby E, Hult K, Gatenbeck S and Rutqvist L (1979), Ochratoxin A and citrinin in 1976 crop of barley stored on farms in Sweden , Acta Agricu. Scand., 29, 174-178. 

Chromium compounds interact synergistically or antagonistically with many chemicals. For example, potassium dichromate administered by subcutaneous injection potentiated the effects of mercuric chloride, citrinin, and hexachloro-1,3-butadiene on rat kidneys (USPHS 1993). Chromium effects were lessened by ascorbic acid and Vitamin E, and N-acetyl cysteine was effective in increasing urinary excretion of chromium in rats (USPHS 1993)... 

Aleo, M.D., Wyatt, R.D. and Schnellmann, R.G. (1991). The role of altered mitochondrial function in citrinin-induced toxicity to rat renal proximal tubule suspensions. Toxicol. Appl. Pharmacol. 109 455 463. 

Baggett, J.M. and Bemdt, W.O. (1984). Interaction of potassium dichromate with the nephrotoxins, mercuric chloride and citrinin. Toxicology 33(2) 157-169. 

Penicillium expansum is the major producer of the mycotoxins patulin and citrinin. Patulin is a mycotoxin mainly found in apple and apple products. P. expansum grows from 3 to 35°C, with an optimum of 25°C. Patulin is synthesized from 0 to 25°C with its optimum at 25°C. Citrinin is also produced along with patulin by P. expansum. 

Contamination of crops and products with ochratoxin A and related metabolites is not as directly associated with a particular fungus as is the case with the aflatoxins. Ochratoxin A is also likely to occur with other mycotoxins, such as citrinin and penicillic acid or patulin. In addition, it is not certain whether ochratoxin A contamination is only a storage problem or perhaps a dual field and storage problem. In cases such as coffee crops, the use of insecticides might help to control insect activity and consequently fungal infection. Coffee-berry borers are a major insect pest which can act as vectors to carry fungal spores, resulting in crop infection and ochratoxin accumulation. 

Liu, B.H. et al., Evaluation of genotoxic risk and oxidative DNA damage in mammalian cells exposed to mycotoxins, patulin and citrinin, Toxicol. Appl. Pharmacol., 191, 255, 2003. 

Antibiotic C6, Cellocidin, Chloramphenicol, Citrinin, Erythromycin, Gramicidin, Kana-mycin. Novobiocin, Penicillin, Phtobacteri-omycin, Polymycin, Pol3rmyxin, Rhizopin, Streptomycin, Agrimycin, Phytostrep, Tetracycline, and Vancomycin. 

Actidione5Actinomycin D, Blasticidin, Chloramphenicol, Citrinin, Daunomycin, Dextro-mycin, Ferrimycidin, Formycin, Imanin, Kanamycin, Laurisin, Miharamycin, Mitomycin C, Naramycin, Ohyamycin, Pentaene G8, Polyoxin A, Puromycin, Streptomycin. 

CaM, their eflfect on the activity of two CaM-dependent en2ymes, namely PDEl and NADK, was investigated. All the tested compounds except citrinin (53) showed significant inhibitory effect on PDE activity in a concentration-dependent manner [IC50 values for compounds 44—52 were 8.1 xM, 7.2 xM, 6.1 xM, 5 8 xM, 7.6 xM, 6.6 xM, 4.8 xM, 4.7 xM and 5.2 xM, respectively]. The inhibitory activity was higher or comparable to that of chlorpromazine (IC50 = 10.6 xM). It is important to point out that none of the tested compounds affected the basal activity of PDE at the concentrations tested. 

Endophytic Penicilliumjanthinellum from the fruits oiMelia d2Mdarach in Brazil yielded known anthraquinones, emodin, citreorosein, and a related compound, citrinin, as well as a novel anthraquinone, janthinone... 

Baggett JM, Berndt WO. 1984. Renal and hepatic glutathione concentrations in rats after treatment with hexachloro-1,3-butadiene and citrinin. Arch Toxicol 56 46-49. 

Terrein, patulin, citrinin, citreoviridin, territrem see A. terreus... 

---