Peas (Pisum sativum L.) contain two kinds of monodesmosidic, triterpene saponins, structurally comparable to
those from soybeans — saponin B (soyasaponin I) and DDMP saponin (soyasaponin βg).
A high-performance thin-layer chromatography (HPTLC) method for the fast and reliable estimation of saponins
in selected pea cultivars has been developed. Identification of the substances was achieved by coupling HPTLC
directly to electrospray ionization mass spectrometry (HPTLC-ESI-MS). Quantitative assessment of saponin B
and DDMP saponin was carried out densitometrically after post-chromatographic derivatization with
p-anisaldehyde sulphuric acid. The thermal stability of DDMP saponin was investigated at 50 °C and
60 °C with a time period of 24 h. Additionally, particular attention was on the hemolytic activity of the
saponins analyzed directly on blood-gelatin covered TLC plates.
The presence of DDMP saponin and saponin B in the pea samples was proven by HPTLC-ESI-MS and
matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). Their concentration
varied depending on the cultivar, with saponin B being always the more abundant compound, predominantly
located in the hulls. The temperature dependent decrease of DDMP saponin concentration was more pronounced at
60 °C than at 50 °C. When treating peas for 24 h, nearly all of the DDMP conjugate was converted to saponin B
whereas the total amount of saponins was more or less constant. Neither pea saponins nor those from soybeans
possess hemolytic activity. In sum, the results are consistent with previous reports and gave evidence that HPTLC
is an adequate methodology facilitating a fast and simultaneous analysis of numerous legume and further samples