Wolfgang Kubelka

Comparison of hormonal activity (estrogen, androgen and progestin) of standardized plant extracts for large scale use in hormone replacement therapy

Extracts from red clover (Trifolium pratense), soybean (Glycine max.) and black cohosh (Cimicifuga racemosa) are frequently used as alternative compounds for hormone replacement therapy (HRT) to treat menopausal disorders. Fifteen commercially available products made either from red clover, soybean or black cohosh were tested in in vitro assays in this study. The main polycyclic phenolic compounds of soy and red clover products were biochanin A, genistein, daidzein, formononetin, and glycitein. In red clover products glycitein was not abundant. All the compounds showed clear estrogenic activity through estrogen receptor alpha (ERalpha) and estrogen receptor beta (ERbeta) and affinity to progesterone receptor (PR) and androgen receptor (AR), whereas the compounds from black cohosh did not. This was corroborated by synthetic isoflavones such as biochanin A, daidzein, genistein and formononetin. They exerted affinity to PR and AR in the range of 0.39-110 mM. Statistical analysis applying principal component analysis (PCA) revealed that all red clover and soy products are grouped in different clusters. Red clover products showed a higher affinity to AR and PR than soy products, which is explained by the higher amount of isoflavones present. In vitro assays and chemical analysis showed that theoretical estrogenic activity expressed as equivalent E2 concentration is in the same range as recommended for synthetic estrogens. Broader spectrum of action and hypothesized lower side effects by action through ERbeta make them suitable for alternative hormone replacement therapy.

Plants used in Guatemala for the treatment of protozoal infections. II: Activity of extracts and fractions of five Guatemalan plants against Trypanosoma cruzi

The activities of crude plant extracts of five plants popularly used in Guatemala against bacterial and protozoal infections and some of their fractions have been evaluated against the trypomastigote and epimastigote forms of Trypanosoma cruzi in vitro. The most active fraction of Neurolaena lobata has also been screened in vivo. Main in vitro activities against trypomastigotes have been observed for the hexane and ethanol extracts of N. lobata (Asteraceae). Both extracts were also active against epimastigotes, whereas all other extracts tested had no effect on epimastigotes. For the hexane extracts of Petiveria alliacea (Phytolaccaceae) and Tridax procumbens (Asteraceae) a marked inhibition of trypomastigotes has been found. Also the ethanol extracts of Byrsonima crassifolia (Malpighiaceae) leafs and Gliricidia sepium (Papilionaceae) bark showed some trypanocidal activity. Fraction 2 of the ethanol extract of N. lobata was highly active against T. cruzi as well in vitro as in vivo. The chloroforme fraction of P. alliacea showed a high inhibition of trypomastigotes in vitro. Also three fractions of the active extract of B. crassifolia inhibited T. cruzi trypomastigotes. No fraction of G. sepium bark extract showed a marked trypanocidal activity.

Chemotaxonomic relevance of sesquiterpenes within the Achillea millefolium group

Abstract The chemotaxonomic relevance of sesquiterpenoids within the Achillea millefolium group has been evaluated by means of morphological, anatomical, cytological and phytochemical data. The sesquiterpene patterns of Achillea setacea Waldst. & Kit, Achillea asplenifolia Vent., Achillea roseoalba Ehrend., Achillea collina Becker, Achillea ceretanica Sennen, Achillea pratensis Saukel & Langer, Achillea distans subsp. styriaca Saukel in edit., Achillea millefolium L. and Achillea pannonica Scheele are described and shown to be characteristic for each species.

Gaschromatographische erfassung von 6-desoxyhexosen, pentosen und hexosen aus herzwirksamen glykosiden

Abstract A new, relatively simple and accurate method allows the identification and quantification of the monosaccharide compnents of cardiac glycosides. After hydrolysis under standard conditions the trimethylsilyl ethers of digitoxose, cymarose, fucose, rhamnose, 6-deoxyallose, 6-deoxygulose, 6-deoxyglucose, 6-dexyidose, 6-deoxytalose, 3-O-methylglucose, allose, altrose, gulose, idose, glucose, mannose, galactose, talose, arabinose, lyxose, ribose and xylose can be identified by gas chromatography on OV-101 or OV-17 as stationary phases. The retention times of the main peaks of each of the analysed monosaccharides, and the ratios of the peak areas of the different anomers were found to be characteristic and of good reproducibility. With phenyl-β- d -glucopyranoside as internal standard the quantification of the absolute amount of sugar present in cardiac glycosides of known constitution is possible, the recovery after hydrolysis being 71–92%. The method allows determination of the composition of the sugar chain in new cardiac glycosides and gives better information in a shorter time of analysis than other methods.

Intracellular distribution of cardiac glycosides in leaves of Convallaria majalis

Abstract In order to investigate the intracellular distribution of the cardiac glycosides in leaves of Convallaria majalis , cell organelles were prepared by several methods. After mechanical disruption of the cells and differential centrifugation, the cardenolide content obtained was determined using the Baljet reaction. Most of the cardiac glycoside fraction was found in the soluble supernatant. However, a low but significant amount was also found in the 10 000g particles. Protoplasts and vacuoles were prepared by enzymic digestion of leaves. The cardenolide to protein ratio of vacuoles was far higher than that of protoplasts or the cytoplasmic fraction. The cardenolide content of isolated vacuoles relative to their number agreed well with the corresponding value obtained for protoplasts. This demonstrates clearly that cardiac glycosides are stored predominantly in the vacuoles of Convallaria majalis .

Four major saponins from Solidago canadensis

Four new bisdesmosidic saponins each containing eight carbohydrate units were isolated from Solidago canadensis. GC, GC-MS, FABMS analysis and mainly the use of 2D NMR techniques allowed their identification as bayogeninglycosides (canadensissaponins 1-4) 3-O- [beta-D-glucopyranosyl-(1----3)-beta-D-glucopyranosyl]-28-O-[alpha-L- rhamnopyranosyl-(1----3)-beta-D-xylopyranosyl-(1----4)-[beta-D- xylopyranosyl-(1----3)]-alpha-L-rhamnopyranosyl-(1----2)-[beta-D- apio-D-furanosyl-(1----3)]-beta-D-6-deoxyglucopyranosyl- (1----]-bayogenin; -(1----2)-[beta-D-apio-D-furanosyl-(1----3)]-ara- binopyranosyl-(1----]-bayogenin; -[alpha-L-rhamnopyranosyl-(1----3)]-beta- D-6-deoxyglucopyranosyl-(1----]-bayogenin and - [alpha-L-rhamnopyranosyl- (1----3)]-arabinopyranosyl-(1----]-bayogenin.

Eudesmanolides from Achillea pratensis

Abstract From flower heads of Achillea pratensis five eudesmanolides were isolated by repeated column chromatography and HPLC. The compounds were identified as tauremisin, arglanin, 4-epi-arglanin, 4α-hydroperoxy-4α-dehydroxy-arglanin and santamarin.

Highly hydroxylated guaianolides of Achillea asiatica and Middle European Achillea species.

From flower heads of Achillea asiatica (L.) Serg., three new guaianolides were isolated by repeated column chromatography and HPLC. The constitution and the stereochemistry of these new, labile compounds were determined by MS, one ((1)H, (13)C, selective (1)H-TOCSY and (1)H-NOESY) and two-dimensional NMR experiments ((1)H, (1)H-COSY, (1)H, (13)C-HSQC, (1)H, (13)C-HMBC). The substances were identified as 8 alpha-angeloxy-2 alpha, 4 alpha,10 beta-trihydroxy-6 beta H,7 alpha H, 11 beta H-1(5)-guaien-12,6 alpha-olide (1), 8 alpha-angeloxy-1 beta,2 beta:4 beta,5 beta-diepoxy-10 beta-hydroxy-6 beta H, 7 alpha H, 11 beta H-12,6 alpha-guaianolide (2) and 8 alpha-angeloxy-4 alpha,10 beta-dihydroxy-2-oxo-6 beta H,7 alpha H, 11 beta H-1(5)-guaien-12,6 alpha-olide (3). They were also detected in Middle European species (Achillea collina, Achillea ceretanica (2x and 4x), Achillea roseoalba, Achillea asplenifolia) by HPLC, TLC and off line MS and have not been described before. The possibility that these compounds might be products of an oxidation process is discussed.

Saponins in Cyclamen species: configuration of cyclamiretin C and structure of isocyclamin

Abstract Five sapogenins and three saponins were identified in bulbs of 14 cytologically defined Cyclamen species and their structures were determined by means of mass, 1H and 13C NMR spectroscopy. In addition to the known products of hydrolysis, primulagenin A was found, and cyclamiretin C was shown to be identical with cyclamigenin C. The new saponin isocyclamin was identified as 3β-{O-β- d -glucopyranosyl-(1–6)-[O-β- d -xylopyranosyl-(1–2)]-O-β- d -glucopyranosyl-(1–4)-[O-β- d -glucopyranosyl-(1–2)] -α- l -arabinopyranosyl}-16α-hydroxy-13β, 28-epoxy-olean-30-al.

Zur biogenese von strophanthidin-glykosiden: Convallatoxol als vorstufe von convallatoxin in Convallaria majalis

Labelled convallatoxin was isolated from leaves of Convallaria majalis after administration of convallatoxol-19-3H and convallatoxol-U-14C, resp. Oxidation of-CH2OH → -CHO at the glycoside level therefore is a possible step in the biogenesis of strophanthidin glycosides.