Bioassay-guided fractionation of hexane extracts of Gymnosperma glutinosum (Asteraceae) leaves, collected in North Mexico, afforded the known compounds hentriacontane (1) and (+)-13S,14R,15-trihydroxy-ent-labd-7-ene (2), as well as the new ent-labdane diterpene (-)-13S,14R,15-trihydroxy-7-oxo-ent-labd-8(9)-ene (3). In addition, D-glycero-D-galactoheptitol… (More)
Full and unambiguous assignment of all 1 Hand 13 C-NMR resonances of the isomers due to restricted C-N amide bond rotation of N-formyl-o-toluidine and N,N'-bis-formyl-o-tolidine in DMSO-d 6 is reported. The cis-isomer predominates in the equilibrium mixture of both compounds as 1D-NOE difference experiments show.
Amoebiasis caused by Entamoeba histolytica is associated with high morbidity and mortality is becoming a major public health problem worldwide, especially in developing countries. Because of the side-effects and the resistance that pathogenic protozoa build against the standard antiparasitic drugs, e.g., metronidazole, much recent attention has been paid to… (More)