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Item Free radical scavengers from Cymbopogon citratus (DC.) stapf plants cultivated in bioreactors by the temporary immersion (TIS) principleAutores: Tapia, A.; Cheel, J.; Theoduloz, C.; Rodriguez, J.; Schmeda-Hirschmann, G.; Gerth, A.; Wilken, D.; Jordan, M.; Jimenez-Gonzalez, E.; Gomez-Kosky, R.; Mendoza, E.Q.The biomass production of Cymbopogon citratus shoots cultivated in bioreactors according to the temporary immersion (TIS) principle was assessed under different growth conditions. The effect of gassing with CO2-enriched air, reduced immersion frequency, vessel size and culture time on total phenolic and flavonoid content and free radical scavenging effect of the methanolic extracts was measured. From the TIS-culture of C. citratus, seven compounds were isolated and identified as caffeic acid (1), chlorogenic acid (2), neochlorogenic acid (3), p-hydroxybenzoic acid (4), p-hydroxybenzoic acid 3-O--d-glucoside (5), glutamic acid (6) and luteolin 6-C-fucopyranoside (7). The occurrence of compounds 1Ð7 and their variability in C. citratus grown under different TIS conditions was determined by HPLC. The free radical scavenging effect of the methanolic extract and compounds was measured by the discoloration of the free radical 1,1- diphenyl-2-picrylhydrazyl (DPPH). The main metabolites in 6- and 8-week-old cultures, both in 5 and 10 l vessels, were chlorogenic acid (2) (100Ð113 mg%) and neochlorogenic acid (3) (80Ð 119 mg%), while in the cultures with CO2-enriched air and reduced immersion frequency the main compound detected in the extracts was glutamic acid (6) (400 and 670 mg% for the green and white biomass and 619 and 630 mg% for the green and white biomass, respectively). The most active compounds, as free radical scavengers, in the DPPH discoloration assay were caffeic acid (1), chlorogenic acid (2), neochlorogenic acid (3) and the flavonoid luteolin 6-C-fucopyranoside (7).Item Free radical scavenging activity and secondary metabolites from in vitro cultures of Sanicula graveolensAutores: Cheel, J.; Schmeda-Hirschmann, G.; Jordan, M.; Theoduloz, C.; Rodriguez, J.; Gerth, A.; Wilken, D.An in vitro propagation system was developed to obtain shoot and root cultures from the Andean spice Sanicula graveolens (Apiaceae). Propagation of shoots, roots and plantlets was achieved by the temporary immersion system. The free radical scavenging effect of the methanol/ water (7 :3 v/v) extracts was determined by the discoloration of the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH). Total phenolic, flavonoid, chlorogenic acid (CA) and quercetin 3-O-glucoside content in the samples was assessed by spectrophotometry and DAD-HPLC analysis, respectively. On a dry weight basis, the crude extracts showed total phenolic values ranging from 3.57 to 6.93%, with highest content for the root culture sample. Total flavonoid content ranged from 1.23 to 2.23% and was lower for the root culture. Chlorogenic acid and neochlorogenic acid were identified by TLC in all samples. Highest free radical scavenging effect was observed for the root culture which also presented the highest CA content. Two of the shoot culture samples, with similar IC50 values in the DPPH discoloration assay, also presented close quercetin-3-O-glucoside content.Item Secondary metabolite content in rhizomes, callus cultures and in vitro regenerated plantlets of Solidago chilensisAutores: Schmeda-Hirschmann, G.; Jordan, M.; Gerth, A.; Wilken, D.An in vitro culture system leading to the formation of callus and plant regeneration, starting from nodal sections and shoot tips, was developed for Solidago chilensis (Asteraceae). The content of the gastroprotective diterpene solidagenone as well as the phenolics chlorogenic acid (CA) and rutin was determined either in rhizomes from wild growing plants and in callus and in in vitro regenerated plantlets by analytical HPLC. Additionally, total phenolic and flavonoid content was assessed in plant samples, callus and cell suspensions. In terms of dry starting material, the percentual solidagenone content in nine S. chilensis samples ranged from 0.5-3.5% for rhizomes from wild growing plants, 0.1-0.3% for callus and 0.3% for an in vitro regenerated plantlet, respectively. The highest solidagenone contents were found in the wild plant during the late summer in the months of March and April (3.52.2%) while highest values for chlorogenic acid (0.5%) and rutin (0.4%) were detected in May, before senescence. The callus tissue and cell suspensions contained some 1.8-2.0 and 1.2% of total phenolics, respectively. CA was the main phenolic in the cell suspension while only traces were found in the callus. Rutin was not detected in the callus nor cell culture.
