A new acetylated triterpene saponin from Agrostemma githago L. modulates gene delivery efficiently and shows a high cellular tolerance.

Transfection is the process to deliver nucleic acid into eukaryotic cells. Different transfection techniques already exist. However, they can be expensive and toxic toward subjected cells. Previous research shed light on natural occurring molecules called triterpene saponins that have great potential for the non-viral gene delivery. Using a combination of different chromatographic techniques and in vitro transfection bioassays, a new triterpenoid saponin (agrostemmoside E) from the plant Agrostemma githago L. was isolated. Agrostemmoside E was characterized by mass spectrometry, intense NMR spectroscopy and was identified as 3-{O-ß-D-Galactopyranosyl-(1→2)]-[ß-D-xylopyranosyl-(1→3)]-ß-D-glucuronopyranosyl} quillaic acid 28-O-{[ß-D-4,6-di-(O-acetyl)-glucopyranosyl-(1→3)]-[ß-D-xylopyranosyl-(1→4)]-α-L-rhamnopyranosyl-(1→2)}-[3,4-di-(O-acetyl)-ß-D-quinovopyranosyl-(1→4)]-ß-D-fucopyranoside ester. Agrostemmoside E has a great potential for delivery of gene loaded nanoplexes and increased the transfection efficiency by 70% compared to 2% without agrostemmoside E. By comparative toxicity studies, we show that agrostemmoside E can be applied at high concentrations without toxicity, justifying its use as a new tool for gene transfections.