Phenolics, depsides and triterpenes from the chilean lichen pseudocyphellaria nudata (zahlbr.) D.J. Galloway

Indexación: ScieloThe lichen Pseudocyphellaria nudata is a species endemic to southern South América. From the lichen tallus, methyl orsellinate, 2-methoxy-3,6-dimethyl-4-hydroxybenzaldehyde, methyl-evernate, tenuiorin, hopan-6ß,22-diol and hopan-6α,76,22-triol were isolated and identified as the main lichen constituents. This is the first report of the occurrence of 2-methoxy-3,6-dimethyl-4-hydroxybenzaldehyde in lichens.http://www.scielo.cl/scielo.php?script=sci_arttext&pid=s0717-97072008000300017&nrm=is

Exogenous and endogenous conditions determining the accurnulation level of usnic acid in lichens

En poblaciones de Protousnea malacea (Stirt) Krog, liquen fruticuloso que crece en diferentes habitats, se estudiaron los niveles de acumulación de ácido úsnico -metabolito con propiedades antimicrobianas- en relación a factores ambientales y a la edad de los teiidos. El ácido úsnico se cuantificó mediante HPTLC. Las concentraciones variaron sinificativamente en individuos provenientes " de distintos sitios forestales; al interior de los talos se observó un gradiente de concentración creciente desde los sectores de mayor edad a las ramificaciones más jóvenes.Using single populations of Protousnea malacea (Stirt) Krog, a fruticose lichen growing in different habitats, the study of the accumulation levels of usnic acid -a metabolite with antimicrobial properties- was undertaken. Environmental conditions and tissues age were considered in this research. The quantitative determination of usnic acid was done by HPTLC. The concentration values varied from different forestry sites; the content of usnic acid was much higher in young branchlets than in the old parts of the thallus.Colegio de Farmacéuticos de la Provincia de Buenos Aire