Phytochemical investigations of two South African plants 26 June 2007 Presentation by Eric Khorombi Researcher CSIR Biosciences Bioprospecting platform
© CSIR Introduction On Cancer Currently the CSIR screens extracts in vitro for anti-cancer activity against a panel of 3 human cancer cell lines namely, - melanoma UACC-62, - renal carcinoma TK-10, and - breast adenocarcinoma MCF-7. The screening technology was adopted from the NCI who host a 60 cell line panel
© CSIR Introduction continues Three plants were investigated and will now be discussed - Phylica paniculata Willd. - Pergularia daemia (Forsk.) Chiov. The plants chemistry will now be discussed with much emphasis on the - Extracts preparations - Testing of extracts in vitro for anti-cancer activity - Bioguided fractionation to isolate the active compounds
© CSIR Plant 1: Phylica paniculata Willd. Family: Rhamnaceae
© CSIR Phylica paniculata (plant 1) Literature review There are no records of previous biological or phytochemical studies on P. paniculata. A phytochemical report on the related species P. rogersii describes the isolation of the four alkaloids - reticuline, - methylcoclaurine, - isocorydine and - lauroscholtzine
© CSIR P paniculata Extraction & Testing for bioactivity
© CSIR P. paniculata bioassay guided fractionation
© CSIR Anti-cancer results of active compound from P. paniculata. TGI = 12.5 µg/ml NCI TGI = 3.45 E-5 M µg/ml
© CSIR Other compound from P. paniculata TGI > 25 µg/ml
© CSIR Discussions & Conclusions (plant 1) Triterpenoids have proved to have anti-cancer activity The active compound ursolic acid was patented for use as an anti-cancer agent by Japanese scientists Studies show that synthetic derivatives of this class of compounds have improved activity Since there is no record of prior isolation of compounds in this plant species, the results of this study will be published.
© CSIR Plant 2: Pergularia daemia (Forsk.) Chiov. Family: Asclepiadaceae
© CSIR Literature review Decoctions of this plant are taken for venereal diseases, arthritis, muscular pain, asthma and rheumatism This plant is reported to contain - Alkaloids - Glycosides From related species P. extensa was isolated - Cardenolides which were tested and showed anticancer activity Pergularia daemia (plant 2)
© CSIR Pergularia daemia Extraction & Testing for bioactivity TGI ~ 25 µg/ml
© CSIR P. daemia bioassay guided fractionation
© CSIR P. daemia Fractionation result Repeated flash chromatography of the organic extract afforded - β -sitosteryl glucoside, - β-sitosterol, - α-amyrin, - 3-O-acetyl-α-amyrin and, - a disaccharide, sucrose.
© CSIR Anti-cancer results of active compound from P. daemia. TGI ~ 6.25 µg/ml
© CSIR Anti-cancer results of compound from P. daemia.
© CSIR Disscussions & Conclusions (plant 2) The plant contains triterpenoids and steroidal compounds but of no significant anti-cancer activity The active compound coroglaucigenin was isolated previously from a different plant species Hence, an article for publication was drafted and awaiting approval. - The
© CSIR General remarks Cancer is a dreadful killer disease Research in this area needs to be strengthened Plants have proved to be a good source for biologically active compounds It is necessary to continue finding the clues
© CSIR Acknowledgements My thanks go to NRF for financial support. To my supervisors: - Prof Fanie van Heerden and - Prof Gerda Fouché
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