According to Scheu (5), a "pure chemical race" is defined using one oil component, which can be unequivocally considered as the main component. However, another way of defining a chemotype is to observe the whole peak distribution of the chromatogram (6). For example, following crossings between camphor and thujone chemotypes, the thujone types are divided into two different thujone types, thujone A and B (3,4). In this study, 80 per cent of the progeny of the artificial crosses of tansy ( TANACETUM VULGARE L.) appeared to belong to so-called "well-defined chemotypes", in which the concentration of the main component varied between 41-99 per cent. The "well-defined chemotypes" were distributed among eight main groups: sabinene, thujone, umbellulone, camphor, bornyl acetate, alpha-pinene, 1,8-cineole, and germacrene-D. The sesquiterpene germacrene-D was identified for the first time in the present study in the essential oil of tansy. Most of these "well-defined chemotypes" were again divided into subgroups A and B. In addition to the "well-defined chemotypes", a number of "mixed chemotypes" were also detected in the crossings. Those chemotypes accounted for 20 per cent of the whole crossing material.
Holopainen, M., Hiltunen, R., Lokki. J., Forsén, K. and Schantz, M. Von. 1987. Model for the genetic control of thujone, sabinene and umbellulone in tansy (Tanacetun vulgare L.). —Hereditas 106: 205–208. Lund, Sweden. ISSN 0018–0661. Received August 1, 1986
Seven parental tansy (Tanacerum vulgare L.) plants were crossed by artificial pollination in the experiments in order to develop a schematic model for the genetic control of the thujone skeleton monoterpenes: thujone, sabinene and umbellulone. The progeny, comprising 232 plant individuals, were analyzed by gas chromatography. The essential oil was isolated from the leaves by means of a micro‐extraction technique. The sabinene (SI) x sabinene (SII) crosses mainly produced progeny of the sabinene type (63%). The sabinene (SI) x umbellulone (UI) crosses were mainly of the sabinene type (50%), although the urnbellulone type (27.5%) also occurred. The back crosses and control crosses indicated that the thujone type TI, i.e., the parental plant of the sabinene type SI, differs genetically from the other thujone type (T3). The thujone type T1, which is also able to synthesize sabinene, seemed to transfer unwanted characteristics to the sabinene type S1 (F1 generation). This was also characteristic of the F2 generation. This partially explains the small number of sabinene types appearing in nature. A schematic model for the genetic control of thujoneline biosynthesis earlier developed for tansy by LOKKI et al(1973) was improved by incorporating the results of the study on thujone and sabinene. In addition, the pathway of umhellulone biosynthesis was added to the genetic model.
Eupatoriopicrin (EUP), the principal sesquiterpene lactone from Eupatorium cannabinum L., exhibits cytostatic activity in vitro as well as in vivo (1-3). After administration of EUP to tumour-bearing mice, reduction of glutathione (GSH) levels has been found in liver and tumour tissue (4). Moreover, it was demonstrated that the intensity of cytostatic action, in vitro and in vivo, depends on the GSH status of the cells: reduction of intracellular GSH by means of BSO, a specific inhibitor of GSH synthesis, enhanced the cytostatic effect of EUP (5).GSH protects the cells against xenobiotics by electrophilic thioether conjugation or by scavenging induced reactive oxy-
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