Detrimental effects of 2,5-Dihydroxymethyl-3,4-dihydroxypyrrolidine in some tropical legume seeds on larvae of the bruchid Callosobruchus maculatus

The secondary plant compound 2,5-Dihydroxymethyl-3,4-dihydroxypyrrolidine (DMDP), an analogue of -D-fructofuranose, is lethal to the larvae of the bruchid beetle Callosobruchus maculatus F. when incorporated into artificial diets at levels greater than 0.03%. In the range 0.003% to 0.03% the compound reduces larval survival in a dose-dependent manner. The -D-glucosidase digestive enzyme demonstrated in homogenates of the alimentary tract of the larvae is strongly inhibited by the compound in a competitive manner.

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Résumé La substance secondaire 2,5-dihydroxyméthyl-3,4-dihydroxypyrrolidine (DMDP), analogue du -fructofuranose, est létale pour les larves de C. maculatus lorsqu'elle est incorporée dans des régimes alimentaires à des taux supérieurs à 0.03%. Entre 0.003% et 0.03%, la substance réduit la survie larvaire proportionnellement à la dose. L'enzyme digestive -D-glucosidase observée dans les homogénats du tube digestif de la larve est fortement inhibée par la substance d'une façon compétitive.

     

展毛短柄乌头中的一个新二萜生物碱

从展毛短柄乌头(Aconitum brachypodum var.laxiflorum Fletcher et Lauener)根中分离鉴定了五个二萜生物碱,其中四个为已知成分,分别为乌头碱(aconitine)、3-去氧乌头碱(3-deoxyaconitine)、3-乙酰乌头碱(3-acetylaconitine)、雪乌碱(penduline),另一个为新成分,命名为丽鲁碱(laxiconitine),其结构通过光谱分析及化学反应测定如(1)。     

The lipid composition and conversion of tryptamine toN b-acetyltryptamine in aCatharanthus roseus cell line without indole alkaloids

Summary A cell line, NA13-2, was selected as a rapidly growing colony of protoplasts from a UV(254 nm)-fluorescent cell line, NA13-1, which originated from a tryptamine-resistant strain ofCatharanthus roseus NA13. Cell line NA13-2 lost the capability to produce indole alkaloids. Tryptophan fed to these cells was converted toN _b-acetyltryptamine as the major product. The free acetyl coenzyme A content of NA13-2 cells was 50% higher than in the mother cells. The total lipid content of the NA13-2 cells was 2.5-fold that in the NA13 cells. In spite of the similarity in the fatty acid content to that of the mother cell line NA13, the total lipid extract of NA13-2 cells appeared as a wax instead of an oil, resulting from the presence of sterol esters.This paper was presented in part at the Annual Meeting of the Society for Industrial Microbiology, Boston, MA, 1985, and the International Congress of the Plant Tissue Culture Association, Minneapolis, MN, 1986.     

Metabolic links between the biosynthesis of pyrrolizidine alkaloids and polyamines in root cultures of Senecio vulgaris

Isotope feeding and inhibitor experiments were performed in order to elucidate the pathway common to polyamine and alkaloid biosynthesis in root cultures of Senecio vulgaris L. -Difluoromethylarginine, a specific inhibitor of arginine decarboxylase, prevented completely the incorporation of radioactivity from [¹⁴C]arginine and [¹⁴C]ornithine into spermidine and the pyrrolizidine alkaloid senecionine N-oxide. In contrast, -difluoromethylornithine, a specific ornithine-decarboxylase inhibitor, had no effect on the flow of radioactivity from labelled ornithine and arginine into polyamines and alkaloids. Thus, putrescine, the common precursor of polyamines and pyrrolizidine alkaloids, is exclusively derived via the arginine-agmatine route. Ornithine is rapidly transformed into arginine. Recycling of the guanido moiety of agmatine back to ornithine can be excluded. Putrescine and spermidine were found to be reversibly interconvertable and to excist in a highly dynamic state. In contrast, senecionine N-oxide did not show any turnover but accumulated as a stable metabolic product. In-vivo evidence is presented that the carbon flow from arginine into the polyamine/alkaloid pathway may be controlled by spermidine. The possible importance of the metabolic coupling of pyrrolizidine-alkaloid biosynthesis to polyamine metabolism is discussed.Abbreviations DFMA D,l--difluoromethylarginine - DFMO D,l--difluoromethylornithine - FW fresh weight     

敦化乌头的二萜生物碱成份

从敦化乌头(Aconitum dunhuaense S.H.Li)的根中分得6个单体二萜生物碱成份,经光谱分析及同标准品对照,鉴定它们分别为乌头碱(aconitine,1)、下乌头碱(hypaconitine,2)、尼奥灵(nepline,3)、去氧乌头碱(3-deoxyaconitine,4)、中乌头碱(mesaconitine,5)和阿康诺辛(aconosine,6)。     

Stability of alkaloid production in cell suspension cultures of Tabernaemontana divaricata during long-term subculture

Two cell lines of Tabernaemontana divaricata cell suspension culture with different growth and alkaloid production profiles were transferred to the same medium. During 30 subcultures the changes in growth and alkaloid production were followed and compared to those of the original cell lines. The presence of NAA and BAP in the medium resulted in an increase of biomass and alkaloid yield. The effect on the growth proved to be stable during these 30 subcultures. Alkaloid production showed a maximum in the 4th subculture after the change of the medium, and stabilized on a higher level than found in the original cell lines. During some growth cycles also the activities of tryptophan decarboxylase (TDC), strictosidine synthase (SSS), and phenylalanineammonia-lyase (PAL) were measured. In both the original cell lines and the derived cell lines, growth and alkaloid production proved to be stable all through the experiment, although the derived cell lines had a period of adaptation to the new medium with increased productivity.Abbreviations 2,4-D 2,4-dichlorophenoxyacetic acid - NAA naphthaleneacetic acid - BAP benzylaminopurine - DW dry weight - TDC tryptophan decarboxylase - SSS strictosidine synthase - PAL phenylalanineammonia-lyase - PAT phenylalanineammonia-transaminase     

Cultivation of Thalictrum rugosum cell suspension in an improved airlift bioreactor: stimulatory effect of carbon dioxide and ethylene on alkaloid production

Airlift bioreactor operations have been studied for the growth-associated production of secondary metabolites from plant cell suspension cultures. The model system used in this work was Thalictrum rugosum producing berberine, an isoquinoline alkaloid. The airlift system was well suited for growth of Thalictrum cell suspension cultures unless the cell density was high. At high cell density, the airlift system with a draught tube was not adequate due to large aggregates clogging the recirculation paths. This was overcome by use of a cell scraper in the reactor. For berberine production, gas-stripping also played a significant role and it was discovered that CO(2) and ethylene were important for product formation. By supplying a mixture of CO(2) and ethylene into the airlift system, the specific berberine content was increased twofold. It is evident that continuous gas sparging was harmful for the production of berberine without supplementation with other gases.     

伊犁贝母药用资源研究现状与开发前景

伊犁贝母的主要药用部位是鳞茎,具有清热化痰、润肺止咳的功效,野生伊犁贝母资源曾被滥采滥挖,导致其药用资源短缺,新疆多地开展了人工伊犁贝母培育工作,但仍有许多不尽人意之处。本文就伊犁贝母鳞茎中以西贝素为主要代表的生物碱的化学成分、药理活性、临床作用、栽培工艺、开发应用现状及前景等方面进行全面的综述,为伊犁贝母药用资源的进一步深入研究和开发提供有益的参考和对策。     

Endophytes of fescue grasses enhance susceptibility ofPopillia japonica larvae to an entomopathogenic nematode

We evaluated tritrophic level interactions among fungal endophytes (Acremonium spp.) of fescue grasses (Festuca spp.), the root-feeding Japanese beetlePopillia japonica Newman larvae, and the entomopathogenic nematodeHeterorhabditis bacteriophora Poinar. Third-instarP. japonica larvae were introduced into pots containing endophyteinfected or endophyte-free plants of tall fescueFestuca arundinacea Schreber (cultivars Kentucky 31 and Georgia Jesup Improved) and the Chewings fescueFestuca rubra commutata Guad. (cultivars F-93 and Jamestown II). After two weeks, the surviving larvae were recovered, and their susceptibility to nematodes was evaluated in sand columns. Endophytes enhanced the rate of nematode-induced mortality in all cultivars except Georgia Jesup Improved, and increased the proportion of dead larvae with nematodes in all cultivars except Jamestown II. Endophytes in the cultivar Kentucky 31 were associated with improved nematode establishment in the larvae. No effect on nematode reproduction was found. Since endophytes produce biologically active alkaloids, we tested the effects of an ergot alkaloid, ergotamine tartrate, on the feeding behavior and weight ofP. japonica larvae in agar medium. The alkaloid caused feeding deterrence, and reduced the consumption of medium by the larvae, resulting in weight loss. These larvae were more susceptible toH. bacteriophora than the untreated larvae. Unfed ‘starved’ larvae were more susceptible to nematodes than those fed on untreated agar. Our results support the hypothesis that endophyte-induced starvation ofP. japonica would reduce larval vigor, and render them more susceptible to entomopathogenic nematodes.