6-Allyl-5,6-dihydro-5-hydroxypyran-2-one, a lactone produced by a new Drechslera species: specified 1H and 13C NMR assignments, mutagenic and immunomodulating testings.

A lactone (6-allyl-5,6-dihydro-5-hydroxypyran-2-one) was isolated from a new Drechslera sp. 1H and 13C NMR assignments, not previously specified, are published. No mutagenic activity on Ames/Salmonella test (strains TA98 and TA100 has been observed. Results on the respiratory metabolism of J774.1 murine macrophage indicate that the lactone might exhibit immunomodulating activity as a function of time of cellular contact and of concentration.