3,4-Dihydro-8-hydroxy-3-methylisocoumarin

Dihydro-8-hydroxy-3-methylisocoumarin (Ar4) (mellein) is the trail pheromone of the ants Formica rufa225 and Lasius (Dendrolasius) fuliginosus226 It is also the male pheromone of the moth Aphomia sociella227 and a... 

Hutchinson, R.D., and P.S. Steyn The Isolation and Structure of 4-Hydroxyochra-toxin A and 7-Carboxy-3,4-dihydro-8-hydroxy-3-methylisocoumarin from Penicil-lium viridicatum. Tetrahedron Letters 1971, 4033. 

From a toxicological point of view, the most important representative of this group of mycotoxins is ochratoxin A, 3R)-N-[(5-chloro-3,4-dihydro-8-hydroxy-3-methyl-1-0X0-lH-2-benzo-pyran-7-yl)carbonyl]-L-phenylalanine (12-92), the molecule of which phenylalanine JV-substituted with a derivative of 3R)-3,4-dihydro-3-methylisocoumarine that contains at C-5 a chlorine atom to which are attributed the toxic effects of ochratoxin A. The incorporation of the chlorine atom into the skeleton of ochratoxin A is done by the action of chloroperoxidase the chlorine donor is inorganic chloride. Ochratoxin B (12-92) differs from ochratoxin A only in the absence of the chlorine atom, while ochratoxin C (12-92) is an ethyl ester of ochratoxin A. Ochratoxins a, p and y resulting from from parent compounds by the loss of phenylalanine caused by peptide bond hydrolysis, are virtually non-toxic, in addition to ochratoxin B, and are not routinely monitored. 

Formica sanguinea W-HG Trail following antennal responses 3,4 - Dihydro - 8 -hydroxy- 3,7- dim e thyliso-coumarin 120 3-ethyl-3,4-dihydro-8-hydroxy-7-methylisocoumarin 130 [172,173]... 

Mellein (19) has been taken as the parent compound for simple isocoumarins. Thus the commonly occurring 3,4-dihydro-8-hydroxy-6-methoxy-3-methylisocoumarin (53) is known as 6-methoxymellein. This greatly aids discussion of these compounds. 

Nozawa, K., S. Nakajima, M. Yamada, and K.-I. Kawai. Synthesis of Two Microbial Metabolites, 5-Chloro-3,4-dihydro-8-hydroxy-6-methoxy-3-methyl-isocoumarin and 8-Hydroxy-6-methoxy-3-methylisocoumarin. Chem. Pharm. Bull. (Japan) 28, 1622 (1980). 

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