Abstract
The antiviral activities of the saponins, arganine C, and tieghemelin were described earlier [Gosse, B.K.; Gnabre, J.N.; Ito, Y.; Huang, R.C.; J. Liq. Chrom. Rel. Technol. 2002, 25 (20), 3199–3211]. In this paper, conversion of tieghemelin to arganine C, a stronger antiviral entry saponin for a new microbicide is described. The crude saponin fraction (arganine C/tieghemilin = 1:2) obtained by high‐speed countercurrent chromatography (HSCCC) [Ito, Y.: CRC Crit. Rev. Anal. Chem. 1986, 17 (1), 65–143], was treated with 2‐ethoxy‐1‐ethoxycarbonyl‐1,2‐dihydroquinoline (EEDQ) in dimethylformamide (DMF) and refluxed for 5 hr. The reaction mixture shows a single peak which represents arganine C by HSCCC. From 700 mg of the crude sample, 500 mg of pure arganine was obtained.