PARTE UTILIZADA= Used part: Hoja.

ACCIÓN FARMACOLÓGICA= Pharmacological action: Refrescante, diurético.

COMPOSICIÓN QUÍMICA= Chemical composition: A new clerodane diterpenoid (I) with a caged hemiacetal ring has been isolated as a minor constituent from Portulaca grandiflora and its structure elucidated by extensive spectral studies. The compd. might be of significance in the biosynthesis and in the chemosystematics of constituents of the genus Portulaca. The structural features of I provide important clues for the proposal of a chem. reasonable scheme for the biosynthesis of portulal.

ZONA GEOGRÁFICA= Geografical zone: Argentina. 

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

Mature pollen grains of 295 angiosperm species were screened by epifluorescence microscopy for a marker that denotes the mode of cytoplasmic inheritance. We used the DNA fluorochrome DAPI (4′ ,6-diamidino-2-phenylindole) for pollen cell staining. The presence or absence of fluorescence of cytoplasmic DNA in the generative cell or sperm cells was examined in each species. The species examined represented 254 genera and 98 families, and 40 of these families had not been previously studied in this regard. The cytoplasmic DNA of the generative cell or sperm cells did not fluoresce in 81% of the species examined, from 83% of the genera and 87% of the families examined, indicating the potential for maternal cytoplasmic inheritance in these species. In contrast, the male reproductive cells of 19% of the species, from 17% of the genera and 26% of the families examined, displayed fluorescence of the cytoplasmic DNA, indicating the potential for biparental cytoplasmic inheritance in these species. The results revealed the potential for biparental cytoplasmic inheritance in several species in which the inheritance mode was previously unknown, including plants in the Bignoniaceae, Cornaceae, Cruciferae (Brassicaceae), Cyperaceae, Dipsacaceae, Hydrocharitaceae, Papaveraceae, Portulacaceae, Tiliaceae, Valerianaceae, and Zingiberaceae. Electron microscopy revealed that the sperm cells of Portulaca grandiflora contain both plastid and mitochondrial DNA. However, in the generative cells of Musella lasiocarpa, the mitochondria contain DNA, but the plastids do not. These data provide a foundation for further studies of cytoplasmic inheritance in angiosperms.

1) OHSAKI, Ayumi, et al. Portulene Acetal, a Novel Minor Constituent of Portulaca grandiflora with Significance for the Biosynthesis of Portulal. Journal of Natural Products. 1997, vol.60, nº9, p.912-914.
 
2) ZHANG, Q.; LIU, Y.; Sodmergen. Examination of the Cytoplasmic DNA in Male Reproductive Cells to Determine the Potential for Cytoplasmic Inheritance in 295 Angiosperm Species. Plant and Cell Physiology. 2003, vol.44, nº9, p.941-951.