Isolation of two cytotoxic diterpenes from the fern Pteris multifida.

From aerial parts of the fern Pteris multifida Poir. (Polypodiaceae) two diterpenes, entkaurane-2 beta, 16 alpha-diol and ent-kaur-16-ene-2 beta, 15 alpha-diol, were isolated by repeated column chromatography using silica gel and silica gel impregnated with silver nitrate. The structures were confirmed by spectroscopic methods. Both compounds showed a moderate cytotoxicity to Ehrlich ascites tumour cells.

Flavones and flavonol glycosides from Eupatorium cannabinum L.

The 6-methoxyflavones hispidulin and eupafolin have been identified for the first time from the aerial parts of Eupatorium cannabinum L. The presence of the previously known flavonol glycosides astragalin, kaempferol-3-rutinoside, hyperoside, isoquercitrin and rutin could be confirmed. Hispidulin, eupafolin and rutin were screened for cytotoxicity in vitro.

Gamma irradiation of Sennae Folium. Microbiological and phytochemical studies.

The effect of different doses of gamma irradiation on senna leaves was studied. No changes in sennoside content and composition were observed after irradiation with 25 kGy. It was demonstrated that a minimum dose of 10 kGy was necessary to obtain a product of good microbiological quality. Cold maceration of senna leaves has to be discouraged, because of unavoidable microbial growth. Hot extraction is the method of choice for tea preparation. The rationale of gamma irradiation is discussed.

Pyrrolizidine alkaloids, flavonoids and volatile compounds in the genus Eupatorium. Eupatorium cannabinum L., an ancient drug with new perspectives.

Within the scope of a study of antitumour compounds in higher plants a survey is given concerning the presence of pyrrolizidine alkaloids, flavonoids and volatile compounds in Eupatorium species. Preliminary results of a phytochemical study of these compounds in E. cannabinum are also presented. From the results of a GC-MS analysis of an alkaloid extract from aerial parts of E. cannabinum the conclusion can be drawn, that the composition of pyrrolizidine alkaloids is more complicated than reported in literature. This is caused by the fact that different stereoisomers exist. The presence of at least two alkaloids with a molecular weight of 283 (supinine or isomers) and four alkaloids with a molecular weight of 299 (echinatine or isomers) could be shown. In subterranean plant material also other pyrrolizidine alkaloids are present. A great number of flavonoids, also as glycosides, have been shown in Eupatorium species, often in low quantities. Rutin, present in many Eupatorium species, could not be detected in subterranean parts of E. cannabinum. Relatively little attention has been paid to the analysis of volatile compounds (essential oils) of Eupatorium species. Thymol derivatives are often reported to be present in Eupatorium species. Thirty-five compounds could be detected by means of a GC-MS analysis in the essential oil of E. cannabinum about which no literature data were available.

Alkaloids in ergot found on different Gramineae in The Netherlands.

The alkaloid content and the composition of the alkaloid complex of thirteen samples of ergot sclerotia from different gramineous host species collected in The Netherlands were investigated. Two samples collected in France were also examined. Ergot of Glyceria fluitans (L.) R.Br. did not contain alkaloids. The total alkaloid content of ergot found on the other wild grasses was more than 0.2%. The ratio between the contents of water soluble and water insoluble alkaloids of the investigated ergot sclerotia varies between 1:10 and 1:20. The composition of the alkaloid complex in the sclerotia was studied by quantitative thin-layer chromatography. The sclerotia could be grouped into three main categories: --sclerotia of Lolium perenne L., Festuca arundinacea Schreb. and Arrhenatherum elatius (L.) P.B. ex J. et C. Presl, containing predominantly ergocornine, alpha- and beta-ergokryptine and ergosine; --sclerotia of Dactylis glomerata L., Phalaris arundinacea L., Alopecurus geniculatus L. and Holcus mollis L., containing predominantly ergosine, ergocristine and ergotamine; --sclerotia of Molinia caerulea (L.) Moench, containing predominantly ergocristine, ergosine and ergometrine. A great similarity was found between the composition of the alkaloid complex in ergot of Lolium perenne L. from different locations and also in ergot of Molinia caerulea (L.) Moench from different locations. This similarity was less in ergot of Dactylis glomerata L. collected from different locations.