Biological properties of alkaloids. Influence of quinolizidine alkaloids and gramine on the germination and development of powdery mildew,Erysiphe graminis f.sp.hordei

Summary The quinolizidine alkaloids sparteine, lupanine and 13-tigloyl-oxylupanine and the indole alkaloid gramine inhibited the germination of conidia ofErysiphe graminis f.sp.hordei Marchal and also the further development to appressoria. Half-maximal inhibitory concentrations of these alkaloids were 1–5 mmol/l. This result provides further evidence for a role of alkaloids as chemical defense compounds in plants.     

Pyrrolizidine alkaloids fromSymphytum officinale L. and their percutaneous absorption in rats

Summary An analysis of a commercial sample of Symphyti radix originating from Poland with a total alkaloid content of 0.07% revealed the presence of 7 pyrrolizidine alkaloid-N-oxides: 7-acetyl intermedine, 7-acetyl lycopsamine as the main constituents and lycopsamine, intermedine, symphytine and traces of 2 further not yet identified alkaloids. The percutaneous absorption of these alkaloids was investigated in rats, using a crude alcoholic extract of the plant corresponding to a dose of 194 mg alkaloid-N-oxides/kg b.wt. The excretion of N-oxides in the urine during 2 days was in the range of 0.1–0.4% of the dose. The dermally absorbed N-oxides are not or only to a small extent converted to the free alkaloids in the organism. The oral application led to a 20–50 times higher excretion of N-oxides and free alkaloids in the urine.We thank Dr C. C.J. Culvenor, Parkville, Australia, for providing authentic samples of 7-acetylintermedine, 7-acetyllycopsamine and echimidine, and B. Karlhuber, Finnigan, Basle, for the GC-MS analysis.     

Na-demethyl-purpeline and Na-demethyl-dihydropurpeline,new alkaloids fromRauwolfia cumminsii stapf

Summary N_a-demethyl-purpeline and N_a-demethyl-dihydropurpeline, new indole alkaloids, were isolated from the stem bark of Rauwolfia cumminsii Stapf. Dihydroindole alkaloids have not previously been reported as occurring in this species.     

Host-plant pyrrolizidine alkaloids inNyctemera annulata Boisduval: Their persistence through the life-cycle and transfer to a parasite

Summary Larvae ofNyctemera annulata Boisduval ingest pyrrolizidine alkaloids fromSenecio spathulatus A. Rich. which subsequently appear in the adult months and their eggs; the acquisition of the alkaloids by a parasite of theN. annulata larvae provides a further illustration of their ability to persist in insects.Acknowledgments. We thank Dr R. Yamdagni of the Chemistry Department, University of Calgary, Canada, and Dr O. Madsen of the Organic Chemistry Department, The Technical University of Denmark, Lyngby, Denmark, for much help with the MS data collection. We are also very grateful to Dr C.C.J. Culvenor, CSIRO Animal Health Lab., Parkville, Victoria, Australia, who most generously provided us with authentic reference specimens of pyrrolizidine alkaloids.     

Structure and toxicity of the alkaloids of Russian comfrey (Symphytum x uplandicum Nyman), a medicinal herb and item of human diet

Summary Eight pyrrolizidine alkaloids of hepatotoxic type have been indentified in leaves ofSymphytum × uplandicum The combined alkaloids exhibit chronic hepatotoxicity in rats.The authors thank N. Anderton and P. Stewart for skilled assistance and V. Lord for statistical analyses.     

Betel nut residues in archaeological samples of human teeth from the Mariana Islands

Two tetrahydropyridine alkaloids, arecaidine and guvacine that are characteristic of betel nut (Areca catechu L.) have been detected in the deliberately stained labial surface of female teeth excavation on Rota, Mariana Islands. This was accomplished using selected ion monitoring techniques in conjunction with gas chromatography/electron impact-mass spectrometry. These alkaloids were not present on the buccal surface of the teeth and indicate the use of betel nut to effect the staining.     

拟南芥基因组中注释为小檗碱桥环酶基因的分子克隆及异源表达

小檗碱桥环酶(BBE)催化(S)-牛心果碱((S)-reticuline)中N-CH3与分子内苄基部分中羟基的邻位芳香碳之间C-C键的形成,该酶属于双共价黄素蛋白家族,是苄基异喹啉类生物碱向小檗碱类生物碱转化的关键酶.迄今,在拟南芥(Arabidopsis thaliana)中尚未发现复杂生物碱,但其基因组测序结果表明拟南芥含有众多可能与复杂生物碱生物合成相关的基因,其中与BBE类似的基因有12个.基于与已知功能的BBE及拟南芥中BBE序列的分析,选定拟南芥中4个注释为BBE的编码基因为目的基因,设计特异引物,从拟南芥cDNA中扩增并克隆到pGM-T载体中,筛选重组子,测序并分析,获得了4个BBE目的基因,分别为AT2G34810、AT5G44400、AT5G44410和AT5G44440.将上述基因克隆至表达载体pET-28a或pET-30a中,分别转入大肠杆菌Rosetta(DE3)中,IPTG诱导实现了上述基因的异源表达.     

Pyrrolizidine alkaloids in overwintering monarch butterflies (Danaus plexippus) from mexico

Summary North American populations of the monarch butterfly,Danaus plexippus, have been found to contain pyrrolizidine alkaloids and their N-oxides. Analytical methods (TLC, GC, and GC/MS) have been developed to isolate, quantitate, and structurally elucidate the alkaloids. Examples of at least two classes of pyrrolizidine alkaloids have been identified, the macrocyclic diesters, senecionine, integerrimine, and seneciphylline, and the monoesters, echinatine, intermedine, and lycopsamine.21 November 1986This work was supported by NSF (Grants BSR-81-19391 and BSR-81-19382), and a Stauffer Chemical Company fellowship. We thank David Hodapp, Mark Stelljes, and Cordula Bruenner for technical help, Dr T.P. Krick, University of Minnesota, St. Paul, Minn., USA, for assistance in GC/MS analysis of PAs, and Dr J.A. Edgar, CSIRO, Parkville, Victoria, Australia, for samples of authentic reference compounds.     

Pyrrolizidine alkaloids inDanaus plexippus L. andDanaus chrysippus L.

Summary Danaus plexippus L. andDanaus chrysippus L. have been found to store pyrrolizidine alkaloids obtained from adult food plants and it is suggested that the alkaloids contribute to the unpalatability of the butterflies to potential predators.Acknowledgment. We thank Dr.C. C. J. Culvenor for rearing some of the butterflies andJ. M. Smith for plant collection. The plants were identified by the national Herbarium, Melbourne.     

Vincanorin und Vincarein,zwei neue Alkaloide ausVinca minor L.

Summary The isolation of two new alkaloids fromVinca minor L. (Apocynaceae) is described. Vincarein, C₂₁H₂₄N₂O₄, and Vincanorin, C₁₉H₂₂N₂O, both probably belong to the group of indol alkaloids.     

Completion of the natural groups of ergot alkaloids: Syntheses and pharmacological profiles ofβ-ergosine andβ-ergoptine

Summary The syntheses and pharmacological potencies of -ergosine and -ergoptine, the missing links in the natural groups of ergot peptide alkaloids are described.86th communication on ergot alkaloids.     

Ableitung der absoluten Konfiguration von Alkaloiden der Aspidospermingruppe durch optischen Vergleich mit Alkaloiden der Strychningruppe

Summary The absolute configuration of certain alkaloids of the Aspidospermin group is suggested.     

Completion of the natural groups of ergot alkaloids: syntheses and pharmacological profiles of beta-ergosine and beta-ergoptine

The syntheses and pharmacological potencies of beta-ergosine and beta-ergoptine, the missing links in the natural groups of ergot peptide alkaloids are described.     

Isolation of alkaloids fromAthrotaxis selaginoides

Summary A novel series of alkaloids has been obtained from the Tasmanian plantAthrotaxis selaginoides, the first to be isolated from the plant family Taxodiaceae.     

Alkaloide ausSchizozygia caffaeoides (Boj.) Baill.

Summary FromSchizozygia caffaeoides (Boj.) Baill. (Apocynaceae), one major and ten minor new alkaloids have been isolated and characterised. Most of them are N-acylindoline derivatives, partly with the hitherto unknown 5,6-methylendioxyindoline system. Some possible correlations between these alkaloids are discussed.

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Den Herren Dres.H. Fritz, R. W. Schmid undH. Wagner und ihren Mitarbeitern danken wir für Spektren und Mikroanalysen.     

Ergot alkaloids modified in the cyclitol moiety

Summary Birch reduction of 9, 10-dihydroergot alkaloids (I) yields a compound to which structureII is assigned.     

Voacamidin und Voacristin,zwei neue Alkaloide ausVoacanga africana Stapf

Summary From the bark and the root-bark ofVoacanga africana Stapf, two new alkaloids have been isolated and characterized.     

Evolutionary implications of pyrrolizidine alkaloid assimilation by danaine and ithomiine larvae (Lepidoptera: Nymphalidae)

Summary Larvae of danaine and ithomiine butterflies assimilate pyrrolizidine alkaloids painted on their larval host plants. This finding supports the theory of the common ancestral use of these compounds by Ithomiinae and Danainae.     

Directed biosynthesis of analogues of ergot peptide alkaloids with Claviceps purpurea

Analogues of peptide ergot alkaloids can be obtained by feeding a producing culture of Claviceps purpurea with an analogue of one of the amino acids of the peptide chain of the alkaloid.     

Effects of phthalimide on growth and alkaloid formation ofDatura metel L.

Summary When administered toDatura metel L. by foliar or root application, the new plant growth regulator phthalimide exercises a favorable effect on the vegetative growth and also stimulates the formation of tropane alkaloids.