PARTE UTILIZADA= Used part: Planta entera. 

ACCIÓN FARMACOLÓGICA= Pharmacological action: Insecticida, emenagogo (planta entera).

COMPOSICIÓN QUÍMICA= Chemical composition: Three new coumarins, 5-hydroxy-6,7-methylenedioxycoumarin, 5-(2-hydroxy-3-methoxy-3-methylbutoxy)-6,7-methylenedioxycoumarin and 5-(2-hydroxy-3-methyl-3-butenyloxy)coumarin, were isolated from the petrol ether extract of the aerial parts of Pterocaulon virgatum. Their structures were elucidated based on spectroscopic evidence. 

ZONA GEOGRÁFICA= Geografical zone: Paraguay, N. y Centro de Argentina. 

DIVERSIDAD GENÉTICA Y MEJORAMIENTO DE PLANTAS MEDICINALES= Medicinal plants and improvement of medicinal herbs

The synthesis of a number of naturally occurring coumarins from Pterocaulon virgatum (L.) and Conyza obscura DC is described for the first time. It concerns the synthesis of 7-(2-hydroxy-3-methoxy-3-methylbutoxy)-6- methoxycoumarin (virgatol, 1), 7-(2-hydroxy-3-methyl-3-butenyloxy)-6- methoxycoumarin (virgatenol, 2) and 7-(2,3-epoxy-3-methylbutoxy)-6- methoxycoumarin (3). In addition, a straightforward synthesis of scopoletin (4) (7-hydroxy-6-methoxycoumarin) is reported and the synthesis of a new coumarin derivative, 6-methoxy-7-(2-oxo-3-methylbutoxy)coumarin (7), is described.

ÚLTIMOS AVANCES EN LA QUÍMICA Y ACTIVIDADES BACTERIOLÓGICAS EN LAS PLANTAS MEDICINALES= Medicinal plants, last advances on chemistry and bacteria activities on the medicinal herbs

1) A new 5,6,7-trioxygenated coumarin, named isopurpurasol (I), was isolated from the chloroform exts. of the aerial parts of Pterocaulon virgatum.  The structural elucidation of this regioisomer of purpurasol was performed by detailed spectroscopic anal.

2) From the petrol and chloroform exts. of the aerial parts of Pterocaulon virgatum, two new coumarins, virgatenol (I) and virgatol (II), were isolated, as well as the four known coumarins, 7-(3-methyl-2-butenyloxy)-6-methoxycoumarin, 7-(2,3-dihydroxy-3-methylbutoxy)-6-methoxycoumarin, ayapin, and scopoletin.  Their structures were elucidated on the basis of spectroscopic methods.

1) TOURSARKISSIAN, Martín. Plantas medicinales de Argentina : sus nombres botánicos, vulgares, usos y distribución geográfica. Buenos Aires : Hemisferio Sur, 1980.

2) DEBENEDETTI, S.L., et al. 5-(3-methyl-2-butenyloxy)-6,7-methylenedioxycoumarin, a 5,6,7-trioxygenated coumarin from Pterocaulon virgatum. Journal of Natural Products . 1994, vol.57, nº11, p.1539-1542.
 
3) DEMYTTENAERE, J., et al. Synthesis of virgatol and virgatenol, two naturally occurring coumarins from Pterocaulon virgatum (L.) DC, and 7-(2,3-epoxy-3-methylbutoxy)-6- methoxycoumarin, isolated from Conyza obscura DC. Synthesis . 2004, vol.11, p.1844-1848.
 
4) DEBENEDETTI, Silvia L., et al. Isopurpurasol, a coumarin from Pterocaulon virgatum. Phytochemistry . 1999, vol.51, nº5, p.701-703.
 
5) DEBENEDETTI, Silvia L., et al. Two 6,7-dioxygenated coumarins from Pterocaulon virgatum.  Phytochemistry. 1998, Vol.48, nº4, p.707-710