Assessment of the cytotoxicity, antioxidant activity and chemical composition of extracts from the cyanobacterium Fischerella major Gomont.

Cyanoprokaryotes (Cyanobacteria/Cyanophyta) are ancient photosynthetic prokaryotic organisms with cosmopolitan distribution. They are producers of a number of biologically active substances with antitumor and antifungal activity, vitamins, antibiotics, algaecides, insecticides, repellents, hormones, immunosuppressants and toxins. So far, the cyanobacterium Fischerella major Gomont has not been studied regarding its impact on the environment and human health. In this study, the cytotoxic, antioxidant and antitumor activities of four extracts prepared from Fischerella major were evaluated in vitro. In addition, the total phenolic content and the potential for production of cyanotoxins were also analyzed. The conducted GC/MS analysis identified 45 compounds with different chemical nature and biological activity. Presence of microcystins and saxitoxins was detected in all Fischerella major extracts. In vitro testing on cell cultures showed a significant concentration- and time-dependent cytotoxic effect on all cell lines (HeLa, SK-Hep-1 and FL) treated at three exposure times (24, 48 and 72 h) with four extracts. A selective antitumor effect was not observed. This is the first study demonstrating biological activity of extracts from Fischerella major, which makes it an interesting subject for further research, including environmental risk assessments (as producer of cyanotoxins) or as a potential source of pharmaceuticals.

Selective Profiling of Saponins from Gypsophila trichotoma Wend. by HILIC Separation and HRMS Detection.

INTRODUCTION: Roots of Gypsophila trichotoma Wend. (Caryophyllaceae) are rich sources of glucuronide oleanane-type triterpenoid carboxylic acid 3,28-O-bidesmosides (GOTCABs). These saponins have been reported to possess synergistic cytotoxicity in combination with type I ribosome-inactivating protein saporin. OBJECTIVE: To develop ultra high-performance liquid chromatography - electrospray ionisation/high resolution mass spectrometry (UHPLC-ESI/HRMS) acquisition strategy for the recognition of Gypsophila GOTCAB saponins. METHODOLOGY: A highly-selective hydrophilic interaction UHPLC method (Si-HILIC UHPLC) was developed for the separation of GOTCAB saponins from the methanol-aqueous root extract of G. trichotoma (GTR). UHPLC was coupled to an Orbitrap mass spectrometer equipped with heated electrospray ionisation (HESI) probe. ESI-HRMS and tandem mass spectrometry (MS/MS) data of the separated compounds was used for saponins structure assignment. RESULTS: Based on the conformity of the fragmentation of 11 previously identified GTR saponins, 21 GOTCAB forming between two and four isobaric and positional isomers are identified with proposals for their structures. Tables with assignment of characteristic fragment ions and more than 10 newly identified saponins in GTR were described. Fragmentation rules for tentative identification of three major types of saponins from GTR were summarised and possible fragmentation pathways were proposed. Type I and II consisted of acylated and sulphated GOTCABs, respectively, while type III included acylated and sulphated saponins. The type II sulphated GOTCAB saponins were all previously not described. CONCLUSIONS: The study demonstrates the potential of the coupling of highly-selective (Si)-HILIC UHPLC with HRMS and MS/MS detection for analysis and identification of triterpenoid saponins. Copyright © 2017 John Wiley & Sons, Ltd.