Pd-Mediated γ-C(sp3)-H Bond Activation in Ammonia-Ugi 4-CR Adducts by Using Picolinamide as Directing Group.

The development of a novel protocol for the fast introduction of the picolinamide directing group in aliphatic ketones by using the ammonia-Ugi 4-CR reaction and the subsequent evaluation of the Pd-mediated γ-C(sp3)-H bond activation is described. The methodology allows the efficient construction of a series of γ-arylated α-aminoamides bearing a congested carbon in two steps.

Trixis angustifolia hexanic extract displays synergistic antibacterial activity against M. tuberculosis.

A phytochemical and antibacterial study of Trixis angustifolia, a species endemic to Mexico, was performed allowing the isolation of six flavones. The minimal inhibitory concentration (MIC) of the hexanic extract, against Mycobacterium tuberculosis H37Rv was 25 µg/mL. The hexanic extract caused a significant inhibition of intracellular mycobacterial growth at 12.5 µg/mL. The biodirected assay of hexane extract enabled the detection of an active fraction (AF) against M. tuberculosis (MIC = 12.5 µg/mL), and a major flavone 1 (pebrellin) with no antimycobacterial activity (MIC > 200 µg/mL). A subsequent combination antimicrobial assay showed a synergistic antimycobacterial effect of AF in combination with pebrellin; the results of the synergistic activity suggest that the antimycobacterial activity found in T. angustifolia is due to the combined action of diverse metabolites present in the plant.