Kaempferol-3,4'-di-O-beta-glucopyranoside-7-O-alpha-rhamnopyranoside as a new flavonoid from Iberis amara L.

A new flavonol glycoside, kaempferol-3,4'-di-O-beta-glucopyranoside-7-O-alpha-rhamno-pyranoside, was isolated from the ethanolic extract of the whole fresh plant of Iberis amara L., an European plant used in gastrointestinal medicine. The structure was established by a combination of 1D and 2D NMR techniques (COSY, HSQC, HMBC, NOESY) as well as UV, IR and mass spectral data.

Ex vivo/in vitro absorption of STW 5 (Iberogast) and its extract components.

To correlate the pharmacological effects of the fixed herbal combination STW 5 (Iberogast) containing nine extract components with its confirmed clinical efficacy, ex vivo/in vitro absorption tests were performed. For the investigation, the everted gut sac technique and, in a pilot study, the Caco-2-cell model were used. The absorption rate of the extracts was determined by measuring characteristic marker substances of each of the individual extracts using HPLC or GC techniques. The results allow us to conclude that the investigated substances from STW 5 possess a good bioavailability, which is in accordance with the rapid onset of the therapeutic efficacy and explains its known pharmacological effects and clinical efficacy in terms of multiple drug action and multi-target therapy, respectively.

Pharmaceutical prerequisites for a multi-target therapy.

The quality of a phytomedicine is defined by the quality of the herbal drug, the manufacturing of the drug preparations and the properties of the finished product, taking into account the special requirements of the individual herbal species in accordance with Good Manufacturing Practice (GMP) standards [2003. Medicinal Products for Human and Veterinary Use. Eudralex, vol. 4 (2003/94/EC)]. The quality control of the complete process is based on pharmacognostic methods, characteristic fingerprint chromatograms, defined amounts of marker substances, physicochemical characteristics and microbiological monitoring. For a herbal multi-component preparation used in multi-target therapy, these pharmaceutical prerequisites have to be ensured for all components and for their combination, as is exemplified by Iberogast((R)) (STW 5) a fixed combination of hydroethanolic extracts of bitter candytuft (Iberis amara), angelica root (Angelicae radix), milk thistle fruit (Silybi mariani fructus), celandine herb (Chelidonii herba), caraway fruit (Carvi fructus), liquorice root (Liquiritiae radix), peppermint herb (Menthae piperitae folium), balm leaf (Melissae folium) and chamomile flower (Matricariae flos) using in the therapy of gastrointestinal complaints (Rösch et al., 2006). The prerequisites for the quality of each of its components according to actual standards are at first the cultivation of the plant material according to the Guidelines for Good Agricultural Practice (GAP) conditions of Medicinal and Aromatic Plants [1998. Z. Arzn. Gew. Pfl. 3, 166-178] to yield a defined raw material of high quality. Characteristic compounds of the extracts had to be identified and different analytical methods such as HPLC, with low coefficients of variation had to be developed to analyze each of the standardized ethanolic extracts and the finished product. At the example of the extract of I. amara these necessary investigations are described. The variability of the plant material in its natural habitats, the identification of characteristic compounds and exemplary chromatograms for fingerprint evaluation and quantification are shown. These data are required for characterization of the profile of the active substances in the finished product.