2 research outputs found
Formal Total Syntheses of (−)- and (+)-Actinophyllic Acid
The
formal total syntheses of (−)-actinophyllic acid and
its enantiomer starting from the same chiral intermediate are reported.
The synthesis features a photoredox organocatalytic asymmetric alkylation
to generate the original C15 chirality, a photocatalytic C–H
functionalization of 3-methylindole in flow for constructing the C16
all-carbon quaternary center, a regioselective 1,3-dipolar cycloaddition,
and an intramolecular Henry reaction to assemble the pentacyclic core
of the target molecule
Antibacterial Effects of a Cell-Penetrating Peptide Isolated from Kefir
Kefir
is a traditional fermented milk beverage used throughout
the world for centuries. A cell-penetrating peptide, F3, was isolated
from kefir by Sephadex G-50 gel filtration, DEAE-52 ion exchange,
and reverse-phase high-performance liquid chromatography. F3 was determined
to be a low molecular weight peptide containing one leucine and one
tyrosine with two phosphate radicals. This peptide displayed antimicrobial
activity across a broad spectrum of organisms including several Gram-positive
and Gram-negative bacteria as well as fungi, with minimal inhibitory
concentration (MIC) values ranging from 125 to 500 μg/mL. Cellular
penetration and accumulation of F3 were determined by confocal laser
scanning microscopy. The peptide was able to penetrate the cellular
membrane of Escherichia coli and Staphylococcus aureus. Changes in cell morphology
were observed by scanning electron microscopy (SEM). The results indicate
that peptide F3 may be a good candidate for use as an effective biological
preservative in agriculture and the food industry