This survey of the phenolic composition in Coffea leaves shows that mangiferin and HCE accumulation corresponds to lineage recognition and species delimitation, respectively. Knowledge of the spectrum of phenolic accumulation within species and populations could be of considerable significance for adaptation to specific environments. The potential health benefits of coffee-leaf tea, and beverages and masticatory products made from the fleshy parts of Coffea fruits, are supported by our phenolic quantification.

The paper reports an investigation of the colouring properties of 43 dyeing plants chosen for their widespread use in previous centuries. Colorimetric analysis showed that the principal colours on different fabric supports were yellow and mostly unsaturated. The nature of the support fibres investigated, protein‐ or cellulose‐based, was shown to play an important role in the perceived colours. Phytochemical analysis confirmed that yellow‐orange shades could be attributed to flavonoids and that red colours were due to anthraquinones. Colours from plants that contain anthocyanins varied from blue‐violet through reddish depending on the structure of the anthocyanins in the individual plants. Colour fastness was determined by applying standard test methods. Fastness to light appeared to be inadequate for industrial applications for most samples, but it seems that this could be improved by certain molecular associations. On the other hand, colour fastness to water was satisfactory.

Abstract.-Bean biochemical composition has been extensively analyzed inCoffea species because of its impact on coffee beverage quality. C. pseudozanguebariae appeared as an interesting wild species because of its low caffeine and chlorogenic acid content, compounds involved in coffee bitterness. Extending the study to its leaves revealed the presence of two unknown phenolic compounds. Isolation, then identification by MS and NMR analysis proved that these compounds are two C-glucosyl-xanthones: mangiferin and isomangiferin. HPLC analyses indicated very high mangiferin content in young leaves. This class of compounds is described for the first time not only in coffee plants but also in the Rubiaceae family. The interest of mangiferin identification in the Coffea genus is discussed.Key words : C-glucosyl-xanthones -Coffea pseudozanguebariae -leavesmangiferin -Rubiaceae.Résumé.-La composition biochimique des grains de café a été très étudiée en raison de son impact sur la qualité de la boisson. Coffea pseudozanguebariae apparaît comme une espèce sauvage intéressante en raison de sa faible teneur en caféine et en acide chlorogénique, composés participant à l'amertume du café. L'analyse étendue aux feuilles de cette espèce a révélé la présence de deux composés inconnus. Leur isolement puis leur détermination par SM et RMN prouvent qu'il s'agit de deux C-glucosyl-xanthones : la mangiférine et l'isomangiférine. Les dosages par CLHP ont montré une teneur particulièrement éle-vée en mangiférine dans les jeunes feuilles. C'est la première fois que cette classe de composés est décrite, non seulement chez un caféier mais aussi dans la famille des Rubiaceae. L'intérêt de l'identification de la mangiférine dans le genre Coffea est discuté.

Flavonoids extracted from marigold flowers were investigated for their dyeing potential. Patulitrin (1) and patuletin (2) were isolated and their structures established using NMR and HPLC-MS. These compounds were identified as the main flavonoids present in the dyeing bath. Following the dyeing process, it was demonstrated that aglycone 2 bound more strongly to wool fibres than its glucoside 1. Moreover, analysis focused on 1 and 2 dynamics during plant growth revealed that these components were only found in flowers during and after flowering. The influence of growing location was also investigated and it appeared that cultivation under Mediterranean conditions enhanced biosynthesis of 1 and 2 . Finally, several solvents were tested for their potential to extract the flavonoids: the use of a water-ethanol mixture gave a high extraction efficiency and allowed selective extraction of 1 and 2. The implications of these results are discussed in relation to the development of marigold as a potential dyeing plant.