Chemotaxonomical investigations of theSymphytum officinale polyploid complex andS. asperum (Boraginaceae): The pyrrolizidine alkaloids

By means of thin layer chromatography in conjunction with mass spectrometry the pyrrolizidine alkaloid patterns derived fromSymphytum asperum, several cytotypes ofS. officinale agg. and the artificial hybrids of the former taxa, were compared. The obtained patterns were not essentially affected by variation in cytotype, harvesting times and -location of plants. Lycopsamine, acetyl-lycopsamine and symphytine or their isomers were generally found in theS. officinale cytotypes, echimidine and symphytine inS. asperum. The interspecific hybrids contained all alkaloids mentioned. The definite lack of echimidine in the 2 n=40 cytotype proves that it is conspecific withS. officinale and does not belong to a hybrid-swarmS. asperum × S. officinale with 2 n=48. Part I of this series of contributions.     

Chemo- and karyotaxonomic studies on some rhizomatous species of the genusSymphytum (Boraginaceae)

InS. tuberosum subspp.tuberosum andnodosum, S. grandiflorum andS. ibericum the presence of the pyrrolizidine alkaloids lycopsamine, echimidine and symphytine could be demonstrated. The taxonS. tuberosum contains an unknown compound that seems to be specific for this taxon. This compound is not the pyrrolizidine alkaloid anadoline which has previously been reported for this species. It is possibly represented by a peak on GC/MS with a molecular ion peak at m/z 623 (as TMS derivative) and can be used as a chemotaxonomic marker for the speciesS. tuberosum. The pyrrolizidine alkaloid pattern of the two subspecies ofS. tuberosum reinforces the close relationship. Fresh material ofS. tuberosum contained the triterpene isobauerenol, but in herbarium material isobauerenol was lacking. InS. grandiflorum, neither fresh nor dried material contains isobauerenol. In herbarium material ofS. ibericum also no isobauerenol could be found. More extensive chemotaxonomical research is necessary to support the view thatS. abchasicum is more closely related toS. ibericum than toS. grandiflorum.     

Uptake and metabolism of pyrrolizidine alkaloids in<Emphasis Type="Italic"> Longitarsus</Emphasis> flea beetles (Coleoptera: Chrysomelidae) adapted and non-adapted to alkaloid-containing host plants

Several Longitarsus flea beetle species sequester pyrrolizidine alkaloids acquired from their Asteraceae and Boraginaceae host plants. We carried out feeding and injection experiments using radioactively labeled pyrrolizidine alkaloids to investigate the physiological mechanisms of uptake, metabolism and storage of alkaloids in adult beetles. We examined six Longitarsus species belonging to different phylogenetic clades in a comparative approach. All species that accepted pyrrolizidine alkaloids in a preceding food choice study showed the ability both to store pyrrolizidine alkaloid N-oxides and to metabolize tertiary pyrrolizidine alkaloids into their N-oxides. Regardless of whether the beetles' natural host plants contain pyrrolizidine alkaloids or not, these species were found to possess an oxidizing enzyme. This oxygenase appears to be specific to pyrrolizidine alkaloids: [³H]Atropine and [¹⁴C]nicotine, two alkaloids not related to pyrrolizidine alkaloids, were neither stored nor N-oxidized by any of the tested species. One species, L. australis, that strictly avoids pyrrolizidine alkaloids behaviorally, exhibited a lack of adaptations to pyrrolizidine alkaloids on a physiological level as well. After injection of tertiary [¹⁴C]senecionine, beetles of this species neither N-oxidized nor stored the compounds, in contrast to L. jacobaeae, an adapted species that underwent the same treatment. L. jacobaeae demonstrated the same efficiency in N-oxidation and storage when fed or injected with tertiary [¹⁴C]senecionine.Communicated by G. Heldmaier     

Tritrophic interactions between aphids (Aphis jacobaeae Schrank), ant species,Tyria jacobaeae L., and Senecio jacobaea L. lead to maintenance of genetic variation in pyrrolizidine alkaloid concentration

Summary We hypothesize that the tritrophic interaction between ants, the aphid Aphis jacobaeae, the moth Tyria jacobaeae, and the plant Senecio jacobaea can explain the genetic variation observed in pyrrolizidine alkaloid concentration in natural populations of S. jacobaea. The ant Lasius niger effectively defends S. jacobaea plants infested with A. jacobaeae against larvae of T. jacobaeae. S. jacobaea plants with A. jacobaeae which are defended by ants escape regular defoliation by T. jacobaeae. Plants with aphids and ants have a lower pyrrolizidine alkaloid concentration than plants without aphids and ants. When these data are fitted to an existing theoretical model for temporal variation in fitness it is shown that varying herbivore pressure by T. jacobaeae in interaction with ants defending aphid-infested plants with a low pyrrolizidine alkaloid concentration can lead to a stable polymorphism in pyrrolizidine alkaloid concentration. Costs of the production and maintenance of pyrrolizidine alkaloids are not accounted for in the model.Publication of the Meijendel-comité, new series no. 114     

A reconsideration of the genusRabdosiella (Lamiaceae,Nepetoideae, Ocimeae)

The two generaPlectranthus andIsodon are compared and found to be very dissimilar.Isodon ist considered to be misplaced inOcimeae subtribePlectranthinae and apparently is more closely related to subtribeHyptidinae. The disjunct genusRabdosiella is compared to these two genera and regarded to be polyphyletic. The AfricanR. calycina (Benth.)Codd is returned toPlectranthus and calledP. calycinus Benth., while the AsianR. ternifolia (D. Don)Codd is placed inIsodon sect.Pyramidium and calledI. ternifolius (D. Don)Kudo.     

Alkaloid diversity in eleven species of Ormosia and in Clathrotropis macrocarpa (Leguminosae-Papilionoideae)

Quinolizidine alkaloids were surveyed using gas chromatography (GC) and combined mass spectroscopy (MS) in bark or leaves of eleven species ofOrmosia Jackson as well as inClathrotropis macrocarpa Ducke from tropical forests in Latin America. A list of detected alkaloids, with their MS fragmentation patterns and GC retention indices, is given, as are the distribution of alkaloids among the samples and their detected concentrations. Alkaloid diversity inOrmosia was high, and the taxonomic distribution of specific alkaloids was not congruent with morphological taxonomic criteria: Of 143 alkaloids apparent in 14 samples, 65 were observed in only one sample, and no single alkaloid was common to all samples. Within a species, alkaloid concentrations were inconsistent and therefore cannot be used as a taxonomic character. This was shown for leaf alkaloid concentrations of two neighboring conspecific trees in the same habitat. Hemos analizado mediante cromatografia de gases (CG) y espectrometría de masas (EM) la composición en alcaloides quinolizidínicos de muestras de corteza y hojas de once especies deOrmosia Jackson y deClathrotropis macrocarpa Ducke, procedentes de las selvas de Latinoamérica. Presentamos una lista completa de los alcaloides detectados incluyendo sus fragmentos en EM y su índice de retención en CG. También presentamos la distribución de los alcaloides en las muestras y su concentración. La variedad de alcaloides era alta y su distribución por especies no se ajustó con criterios taxonómicos morfológicos: De los 143 alcaloides detectados en 14 muestras, 65 alcaloides estaban presentes en una sola muestra y ningún en todas las muestras. La concentración de los alcaloides en una especie no fue consistente y por lo tanto no puede utilizarse como carácter taxonómico. Esta conclusión proviene del análisis de la concentración de alcaloides en hojas de dos árboles de la misma especie en el mismo hábitat.     

Pyrrolizidine alkaloids of probable host-plant origin in the pronotal and elytral secretion of the leaf beetle Oreina cacaliae

Oreina cacaliae (Coleoptera, Chrysomelidae) produces in its elytral and pronotal defensive secretion seneciphylline N-oxide together with small amounts of another pyrrolizidine alkaloid tentatively identified as senecionine N-oxide. This is a strong departure from the chemical composition of the defensive secretions in related species, characterized by complex mixtures of cardenolides, synthesized by the beetles from cholesterol. It is suggested that O. cacaliae sequesters the alkaloids from its host-plant, Adenostyles leucophylla. Other specimens of O. cacaliae from far distant populations feeding on Senecio nemorensis, Petasites paradoxus or P. album also produced pyrrolizidine alkaloids, but not O. speciosissima feeding on the same food plants and producing cardenolides. In addition to pyrrolizidine alkaloids, O. cacaliae secretes ethanolamine, which is also found in all the cardenolide-producing species.     

Giemsa karyotypes and their evolutionary significance inScilla bifolia,S. drunensis,andS. vindobonensis (Liliaceae)

Quantitatively evaluated C-banded and conventional karyograms are presented for the related speciesScilla bifolia subsp.danubialis Speta,S. drunensis (Speta)Speta, andS. vindobonensis Speta. On the basis of banding patterns and karyotype structureS. bifolia subsp.danubialis (2n = 18, 2×) andS. drunensis (2n = 36, 4×) are quite similar, whileS. vindobonensis (2n = 18, 2×) is entirely different. There is a moderate degree of karyotypic variation withinS. bifolia subsp.danubialis andS. drunensis. However, inS. vindobonensis karyotypes and banding patterns are almost completely stable over a geographical range of about 500 km. The present results confirm the recent taxonomic separation ofS. vindobonensis fromS. bifolia, and suggest a considerable phylogenetic distance between these two diploid species. The results are discussed with reference to the morphological characters of the species and their geographical distribution.Evolution ofScilla and Related Genera, II.Dedicated to Univ.-Prof. Dr.Elisabeth Tschermak-Woess on the occasion of her 60th birthday.     

A chemotaxonomical study of someBoraginaceae: pyrrolizidine alkaloids and phenolic compounds

By means of thin layer chromatography pyrrolizidine alkaloids and phenolic compounds in some members of the familyBoraginaceae, subfamiliesHeliotropioideae andBoraginoideae, were studied. FromOmphalodes verna a main alkaloid was isolated with an isoretronecanol (or stereoisomeric) nucleus. The chemotaxonomical model ofTétényi forBoraginaceae based on fatty acids is generally supported, but relationships betweenHeliotropioideae andCynoglosseae appear to be closer, suggesting parallel developments from common ancesters.     

Chemotaxonomical investigations of theSymphytum officinale polyploid complex andS. asperum (Boraginaceae): Phytosterols and triterpenoids

From a comparison of phytosterol and triterpenoid patterns of severalSymphytum officinale cytotypes,S. asperum and their interspecific hybrids,S. ×uplandicum, which were obtained from thin layer chromatography and gaschromatography (also in combination with mass spectrometry), the hybrid character of the latter taxon is clearly shown. The specific value of the triterpenoid isobauerenol as a chemotaxonomical marker within this group is discussed in some detail.     

Cynoglossopsis somaliensis,sp. nov., und die GattungCynoglossopsis (Boraginaceae)

Cynoglossopsis somaliensis H. Riedl, sp. nov., is described as a new species of the hitherto monotypic genusCynoglossopsis Brand which is closest related toCynoglossum L. but has to be included inBoraginoideae-Eritrichieae from the way the nutlets are attached to the gynobasis.

     

Alkaloids of theSedum acre-group (Crassulaceae)

The 16 species of theSedum acre-group were investigated for the presence of alkaloids. They areS. acre ofS. ser.Acria, S. alpestre, S. annuum, S. apoleipon, S. borissovae, S. euxinum, S. grisebachii, S. laconicum, S. multiceps, S. sexangulare, S. tuberiferum, S. tuberosum, S. ursi, andS. urvillei ofS. ser.Alpestria, S. samium ofS. ser.Samia, andS. litoreum ofS. ser.Litorea. S. acre differs significantly from the other species. It contains sedamine, hydroxy sedamine, and a number of 2,6-disubstituted piperidine alkaloids. The leafy parts of the species ofS. ser.Alpestria, S. ser.Samia, andS. ser.Litorea contain 4 piperidine alkaloids which also occur inS. acre, and in addition 4 pyrrolidine alkaloids not present inS. acre. The composition of the alkaloid fraction agrees with the infrageneric classification (series) based on the hybridization patterns of the species (comparia).     

Cephalodiate Arten der GattungLecidea sensu lato (Ascomycetes lichenisati)

(1) The ability to produce cephalodia is usually a genus-specific character in lichens. (2)Lecidea shushanii Thoms., is a member of the genusTephromela, closely related toT. aglaea. It is not clear, whether or not the cephalodia of this taxon are true cephalodia or colonies of epiphytic cyanobacteria and whether or notLecidea shushanii is an independent species. (3)Lecidea dovrensis Nyl., is, in contrast to the traditional concept, not conspecific withLecidea alpestris Sommerf., but an earlier name forLecidea pallida Th. Fr. (4)Lecidea dovrensis is described in some detail. Chemically the species is characterized by the presence of isousnic acid (previously unknown in lecideoid lichens). It is restricted to areas north of the 60th parallel with an oceanic climate. (5) In connection with the attempt to clarify the taxonomic relationships ofLecidea dovrensis, figures of ascus apical structures of the following species are given (marked by an asterisk are genera where we found discrepancies with published data):Austrolecia antarctica, Catillaria chalybeia, Lecidea alpestris, L. caesioatra, L. limosa, Lecidoma demissum, Koerberiella wimmeriana, Micarea assimilata, M. crassipes, M. melaenida, M. prasina, Pilophorus robustus, Placodiella olivacea, Placolecis opaca, Porpidia trullisata, Protoblastenia rupestris, Psilolechia lucida, Psorula rufonigra, Squamarina gypsacea, Xanthopsorella texana. (6) Among crustaceous lichens we find no groups related toLecidea dovrensis. We supportTimal's concept of including this species in the genusPilophorus. Pilophorus, as well asLecidea dovrensis is characterized by the same ascus type, by a similar structure of thallus, cephalodia, paraphyses, and ascocarp (although there is no pseudopodetium developed inLecidea dovrensis), and the presence of isousnic acid. In addition, both taxa are restricted to cool oceanic climates and non-calciferous substrates. The following combination is proposed:Pilophorus dovrensis (Nyl.)Timdal, Hertel & Rambold, comb. nova. (7) The species of theLecidea alpestris-group form an independent genus, probably near toAustrolecia Hertel.

Frau Prof. Dr.Elisabeth Tschermak-Woess zu ihrem 70. Geburtstag gewidmet.     

Induced responses in three alkaloid-containing plant species

In this paper we test three plant species for the inducibility of their alkaloid production. The plants were heavily damaged by cutting off 50% of their leaf surface using a pair of scissors. The cut-off leaf tips were used as controls for possible diurnal fluctuations. After 3, 6, 12, 24 and 48 h, respectively, the leaf bases of the damaged plants were harvested and the alkaloid concentration was measured. In Senecio jacobaea the pyrrolizidine alkaloid (Pa) concentration in damaged plants decreased within 6–12 h after damage. Within 24 h after damage the Pa concentration of Cynoglossum officinale doubled compared to control values. Indole alkaloid production in Catharanthus roseus was found not to be induced in this experiment. The responses are discussed in a functional context. We hypothesize that the nature of the response is not a feature of the type of secondary metabolite, but is related to whether the plants are damaged mainly by generalist or by specialist herbivores.     

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     

Selective uptake of pyrrolizidine N-oxides by cell suspension cultures from pyrrolizidine alkaloid producing plants

The N-oxides of pyrrolizidine alkaloids such as senecionine or monocrotaline are rapidly taken up and accumulated by cell suspension cultures obtained from plants known to produce pyrrolizidines, i.e. Senecio vernalis, vulgaris, viscosus (Asteraceae) and Symphytum officinale (Boraginaceae). The transport of the N-oxides into the cells is a specific and selective process. Other alkaloid N-oxides such as sparteine N-oxide are not taken up. Cell cultures from plant species which do not synthesize pyrrolizidine alkaloids are unable to accumulate pyrrolizidine N-oxides. The suitability of the pyrrolizidine N-oxides in alkaloid storage and accumulation is emphasized.     

On the taxonomic position ofSilene thebana (Caryophyllaceae)

Silene thebana Orph. exBoiss. is transferred as a subspecies toS. fabaria (L.)Sm., resulting in the new combinationS. fabaria (L.)Sm. subsp.thebana (Orph. exBoiss.)Melzh. The chromosome count of 2n = 24 is recorded for the first time for this taxon.Dedicated to Prof. DrK. H. Rechinger on the occasion of his 80th birthday, 16th October 1986.     

Stachys beckeana (Labiatae) in Albanien und Jugoslawien

Morphological and cytological investigations were carried out inStachys beckeana Dörfler & Hayek andS. recta L. subsp.sarajevensis sensuHayek. These two taxa have the same morphological characteristics (shape and indumentum of leaves; morphology of sepals, petals and fruits) and both have 2n = 2x = 34 chromosomes. They cannot be considered as different taxa;S. beckeana Dörfler & Hayek is the valid name (synonyms:S. recta L. subsp.sarajevensis sensuHayek,S. hayekii Malý,S. recta L. subsp.hayekii Malý).

Erster Beitrag zur Neubearbeitung der Artengruppe derStachys recta L.     

Zwei neue Arten der GattungSaponaria (Caryophyllaceae) aus Afghanistan und Pakistan

Saponaria stenopetala sp.n. in Eastern Afghanistan is close toS. pachyphylla Rech. f. andS. subrosularis Rech. f.—The nearest allies ofS. makranica sp.n. from Western Pakistan and Southeastern Iran areS. kermanensis Bornm. andS. floribunda (Kar. & Kir.)Boiss.

Flora Iranicae praecursores 36–37. — Praecursores praecurrentes in Pl. Syst. Evol.139, 313–317 (1982).     

Allozyme divergence among four species ofPodaechmea s. l. and the status ofUrsulaea (Bromeliaceae, Bromelioideae)

The genetic relationships ofAechmea mexicana, A. lueddemanniana, A. macvaughii andA. tuitensis were investigated using starch gel electrophoresis. Eight enzyme systems encoded by ten putative gene loci were resolved in seventeen populations.Nei's (1978) genetic distances were obtained from allelic frequencies and used with UPGMA algorithm. Results indicate that some populations belonging to different species display genetic similarities closer to each other than to some conspecific populations. Our results do not support the proposed genusUrsulaea (Read & Baensch 1994), sinceA. tuitensis was closer toA. lueddemanniana andA. mexicana than toA. macvaughii.