Norstictic Acid as a Hymenial Constituent of Letharia

SUMMARY

The depsidone norstictic acid was identified from the hymenium of about half the individuals studied of the commonly apotheciate lichen Letharia californica (Lèv.) Hue. This is the first report of the restriction to the hymenium of an orcinol or a β-orcinol derivative, compound types constituting most of the secondary natural products peculiar to lichens. Norstictic acid was also demonstrated in apothecia of the rarely fertile L. vulpina (L.) Hue, but the apothecial site of its occurrence could not be determined. Both species also produce vulpinic acid and atranorin in the cortex.