Increased cytotoxic potential of infrequent triterpenoid saponins of Cephalaria taurica obtained through alkaline hydrolysis. (August 2018)

• Record Type: Journal Article
• Authors: Ozer, Ozgur; Sarikahya, Nazli Boke; Nalbantsoy, Ayse; Kirmizigul, Suheyla
• Is Part Of: Phytochemistry. Volume 152(2018)
• Page Start: 29
• Page End: 35
• Publication Date: 2018-08
• Subjects: Cephalaria taurica -- Caprifoliaceae -- Tauricosides A and B -- Saponins -- Cytotoxic activity; Botanical chemistry -- Periodicals; Biochemistry -- Periodicals; Botany -- Periodicals; Chimie végétale -- Périodiques; 572.2
• DOI: 10.1016/j.phytochem.2018.04.015
• Languages: English
• ISSNs: 0031-9422

Abstract

Abstract: Phytochemical investigations of the aerial parts of the plant Cephalaria taurica Szabó. (Caprifoliaceae) have resulted in the isolation of nine oleanane-type triterpenoid saponins, of which two still remain undescribed. The structures of tauricosides A and B were characterized based on NMR analysis, HRESIMS spectrometry, and chemical evaluations. The saponins tauricosides A and B have been rarely reported in the literature due to the presence of eight sugar moieties, and this is also the first report of saponins containing eight sugar moieties in the Caprifoliaceae family. The cytotoxic activities of tauricosides A and B, their undescribed prosapogenins, aglycone hederagenin, and n -butanol extract of C. taurica against the cancerous cells A-549, HeLa, PANC-1, and SH-SY5Y and the noncancerous HEK-293 cells were evaluated by the MTT method. Although tauricosides A and B and the crude n -butanol extract did not exhibit any activity at the tested concentrations on all the tested cells, after alkaline hydrolysis, the cytotoxic activity potential of the compounds was obviously improved. The most active compound, obtained after the alkaline hydrolysis of tauricoside B, showed a significant inhibitory effect, which was higher than that of the standard, commercially available drug doxorubicin, on the cancerous A-549, HeLa, PANC-1, and SH-SY5Y cells with IC50 values of 9.04, 8.75, 6.87, and 4.32 μM, respectively. In addition, prosapogenin, obtained after the alkaline hydrolysis of tauricoside A, exhibited considerable cytotoxic activity on the cancerous A-549, HeLa, PANC-1, and SH-SY5Y cells, with IC50 values of 13.19, 10.32, 11.91, and 7.49 μM, respectively. In conclusion, the alkaline hydrolysis of the saponins (tauricosides A and B) obviously improved their cytotoxic activity potential. Graphical abstract: Phytochemical investigations of Cephalaria taurica have resulted in the isolation of two undescribed saponins (tauricosides A-B), which were evaluated for their cytotoxic activities, along with seven known analogues. The alkaline hydrolysis of the saponins obviously improved their cytotoxic activity potential. Image 1 Highlights: Two undescribed saponins along with nine known ones were isolated from C. taurica. Alkaline hydrolysis of tauricosides A-B yielded two undescribed prosapogenins. Their structures were elucidated by use of extensive spectroscopic methods. Prosapogenin of tauricoside B showed significant inhibitory effect on cancer cells. The alkaline hydrolysis of the saponins improved their cytotoxic activity potential.