Annick Gargadennec

Polyphenol investigation of Argania spinosa (Sapotaceae) endemic tree from Morocco.

Abstract The leaves of Argania spinosa from Morocco were investigated for flavonoids and condensed tannins. Four flavonol glycosides were identified by 1H NMR as myricitrin, quercitrin, hyperoside and myricetin 3-O-galactoside. UV spectrophotometric and histochemical methods were carried out to quantify and locate flavonoids and condensed tannins from leaves, stems and thorns of A. spinosa. Both high content and cell localisation of total polyphenols could explain the Argan tree adaptation to aridity.

Culture of Plantago species as bioactive components resources: a 20-year review and recent applications

Abstract Most of species from the worldwide distributed Plantago genus are greatly used as herbal medicines. Phytochemical investigations of various Plantago organs (leaves, stems) reveal their high potential to produce a wide array of bioactive secondary metabolites. So, in vitro cultures of Plantago species are managed in order to deliberately restrict the ecological factors and then to control the culture conditions. Experimental culture parameters of Plantago species, i.e. seed germination, temperature, relative humidity, light, substrates and additional nutritive solutions as well as the in vitro culture media and growth regulators are reviewed. The expensive optimizations of in vitro culture and biotransformation processes are reported. Changes in the concentration and the pattern of bioactive polyphenol compounds synthesized from in vitro cultures are discussed in the examined species of the genus Plantago in order to conclude about their potential interest as future drug candidates.

EFFECTS OF CINNAMIC ACID ON POLYPHENOL PRODUCTION IN PLANTAGO LANCEOLATA

Abstract Ribwort ( Plantago lanceolata ) contains two main caffeic acid glycoside esters, plantamoside and verbascoside. These two polyphenols were investigated in the aerial and underground parts of in vitro cultured ribworts. For the first time, it is reported that, whatever the age of this plant, plantamoside and verbascoside are concentrated in the roots with plantamoside levels double those of verbascoside. When P. lanceolata was transferred into a medium containing 10 −3 M ( E )-cinnamic acid, this chemical stress induced a slow degeneration of the initial roots. These were superseded by neoroots whose morphology was atypical during the first eight days following their appearance. In the initial roots, ( E )-cinnamic acid induced a temporary appearance of two cinnamic acid derivatives (NCD), but did not change the plantamoside and verbascoside levels. In the neoroots, high NCD levels were detected for only eight days. After the large decrease of these NCD, plantamoside and verbascoside appeared and increased. These NCDs have been identified as glucoside esters of ferulic and p -coumaric acids. These two compounds, which are absent from the traditional chemical profile of ribwort, probably arose from a ( E )-cinnamic acid detoxification pathway.

Volatile components of Plantago lanceolata (Plantaginaceae)

Summary Fruits, leaves arid scapes of wild Plantago lanceolata (ribwort) were investigated for volatile compounds by GC/MS. Leaves of young ribworts (35-day-old) cultured in vitro were also analysed. The volatile compound proportion corresponds to 0.05%, 0.03% and 0.001% of fresh weight for fruits, leaves and scapes, respectively. Thirty-five and twenty-six components were identified from fruits and leaves, respectively, while scapes contained only seven volatile components. The major constituents of fruits were oct-1-en-3-ol (24.9%), hexahydrofarnesylacetone (15.7%), vanillic acid (9.8%) and neophytadienes (>10%); leaves contained mainly oct-1-en-3-ol (41.1%), (E),4(3-oxo-2,6,6-trimethylcyclo-hex-2-en-1-yl)-3-buten-2-ol (15.6%), 6-(3-hydroxy-1-butenyl)-1,5,5-trimethyl-7- oxabicyclo[4,1,0]heptan-3-ol (6.9%) and benzoic acid (6.3%). Neophytadienes were mainly found in both scapes of wild ribworts and leaves of seedling cultures.

Combined dyeing and antioxidative properties of some plant by-products

Abstract Aqueous extracts of plant by—products (carrot, onion, black carrot, sage, spinach and thyme) were investigated for dyeing capacity on fibres and for both colorant and antioxidant potential using colorimetric and chromatographic tools, and FTC assay, respectively. Regarding fibres, classical correlations between measured colours and phytochemical patterns of dyeing extracts were verified. Light fastness of onion, sage and thyme samples, evaluated following a normalised test, was very promising considering industrial restrictions; moreover, antioxidative activities of those aqueous plant extracts were very attractive when compared to the three others and to α-tocopherol used as standard. Our results were of great interest underlining new complementary valorisations for plant by-products, becoming in this way new and inexpensive natural resources for various industries.

Effect of a tertiary amine on alkaloid accumulation in Catharanthus roseus

Abstract The Madagascar periwinkle, Catharanthus roseus , produces numerous indole alkaloids, several of which have important therapeutic activities. These secondary metabolites are among the most expensive drugs because of their low abundance in intact plants. We investigated the biotransformation of a synthetic product ( N -(methoxycarbonylethyl)- N -[2-(1 H -indol-3yl)-ethyl]- β -methyl alaninate) in the roots and aerial parts of C. roseus cultivated in vitro , in order to stimulate de novo the biosynthesis of biologically active indole alkaloids. The results showed a large increase (90%) of ajmalicine in the roots whilst serpentine and yohimbine levels were unchanged. In the aerial parts, the synthetic product was recovered and the time courses of various alkaloids were unchanged. No new molecule was observed. The four alkaloids tested increased with plant age whilst yohimbine gradually decreased.

Evaluation of antioxidant and antiproliferative activities of dyeing plants

Abstract Natural dyes are nowadays re—investigated but few data are available about their biological properties. In this study, ten dyeing plants from several genera (belonging to Anacardiaceae, Asteraceae, Betulaceae, Resedaceae, Rosaceae, Rubiaceae) were investigated for both antioxidant and antiproliferative activities. Aqueous crude extracts containing flavonoids associated with either phenolic acids or tannins were particularly antioxidant whereas no extract seemed to present antiproliferative properties suggesting a potential absence of toxicity. Primary pharmacological data from this study are discussed in relation with dyeing properties of plant species in order to highlight the uses of multi—functionalised natural products.

Alkaloid repartition and DMSO effects on alkaloid cccumulation in Catharanthus seedlings

Summary Many studies have addressed the improvement of indole alkaloid production in Catharanthus roseus cell suspension culture, but only few of them were concerned with entire plants cultured in vitro . The aim of this work was to investigate alkaloid distribution and the influence of DMSO (dimethyl sulfoxide) on alkaloid accumulation in C. roseus seedlings grown in vitro . Thirty-day-old seedlings were cultured on hormone-free medium supplemented with DMSO and analysed by HPLC and TLC. An «abnormal» alkaloid distribution in seedling roots was characterised by the lack of catharanthine and the presence of yohimbine for the first time. Both ajmalicine and serpentine were also observed. Vindoline and catharanthine were detected in the aerial parts. The results with DMSO showed a decrease in alkaloid accumulation in both the roots and aerial parts.

In vitro rapid absorption of a synthetic amine by Catharanthus seedlings

Abstract We investigated the uptake of a synthetic amine ( N - (methoxycarbonylethyl)- N -[2-(1 H -indol-3-yl)-ethyl]- β -methyl alaninate) by seedlings of C. roseus cultivated in vitro, and its effects on indole alkaloid accumulation. Root and aerial part indole alkaloids were analysed by HPLC and TLC. The results showed rapid absorption in the roots, which started less than 5 min after treatment, followed by transport to aerial parts between 5 and 15 min. The time courses of various alkaloids such as ajmalicine, serpentine, yohimbine, vindoline and catharanthine were synthetic amine treatment independent.