Step-gradient CCC separation of phenylpropanoid and iridoid glycosides from roots of Stachytarpheta cayennensis (Rich.) vahl

Glycosylated phenylpropanoids and iridoids were isolated from the ethyl acetate extract from the roots of Stachytarpheta cayennensis by step gradient countercurrent chromatography (CCC). The chosen gradient utilized a stepwise increase of the butanol ratio in a normal phase separation, utilizing a biphasic EtOAc:BuOH: H2O solvent system, 1:X:1 v/v/v, in four steps: A - X = 0.05, B - X = 0.2, C - X = 0.5 and D - X = 1.0. The sequential increase of BuOH in the organic phase of the CCC solvent system, and wash-off of stationary phase allowed the isolation of 4 compounds identified as martinoside, isoverbascoside, verbascoside, ipolamiide, and two more iridoid glycosides. These compounds covered a wide span of polarities.