Lactarius picinus

De Bernardi, M., G. Vidari, P. Vita-Finzi, and G. Fronza The Chemistry of Lactarius fuliginosus and Lactarius picinus. Tetrahedron, 48, 7331 (1992). 

CoNCA, E., M. De Bernardi, G. Fronza, M.A. Girometta, G. Mellerio, G. Vidari, and P. Vita-Finzi Fungal Metabolites 10. New Chromenes from Lactarius fuliginosus Fries and Lactarius picinus Fries. Tetrahedron Letters, 22, 4327 (1981). 

Conca E, De Bernard M, Fronza G, Girometta M A, Mellerio G, Vidari G, Vita-Finzi P 1981 Fungal metabolites 10. New chromenes from Lactarius fuliginosus Fries and Lactarius picinus Fries. Tetrahedron Lett 43 4327-4330... 

Furthermore, a qualitative evaluation of the contents of different extracts of the same or different Lactarius species of the Section Plinthogali has been carried out by GC and GC-MS analysis, using a Dexsil 300 column (125). By this method, the simple 2,2-dimethylchromene (23.4) has been identified in an extract of L. picinus (102). 

Fatty acid esters of metabolites different from sesquiterpenes have been isolated from intact fruiting bodies of particular Lactarius species the colourless phenol stearate 22.2 is a typical metabolite of L. fuliginosus and L. picinus (102), while L. lignyotus contains a mixture (22.7) of fatty acid esters of geranylgeranylhydroquinone (23). 

C3oH,o03, Mr 458.73, mp. 100-101 C. A component of the latex m the toadstools Lactarius fuliginosus and L picinus (Basidiomycetes). When the fruit bodies are injured the mild-tasting ester is enzymatically saponified to 4-methoxy-2-(3-methyl-2-butenyl) phenol which is responsible for the bitter taste of the fungi. The phenol is unstable and after some time is oxidized to 6-methoxy-2,2-dimethyl-2//-chromene, 2-(l-hydroxy- 1 -methylethyl)-5-methoxybenzofuran, dimeric compounds, and red pigments. M. is thus probably responsible for the pink discoloration of the milk juices on bruising these toadstools. 

Separation of the EtOAc extracts of L. fuliginosus and L. picinus by silica gel column chromatography allowed isolation of the first examples of benzofuran and chromene derivatives among the constituents of Lactarius species. These compounds are revealed on TLC plates by the sulpho-vanillin reagent as characteristic green spots 140), 141) (Parts 22, 23). 

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