Alkaloidal variation in the genus Pearsonia

Several quinolizidine alkaloids, including various angelate esters, are known from the genus Pearsonia. In a detailed variation study which included 98 samples from nine of the 11 species, large qualitative and quantitative differences were recorded. The observed variation is ascribed to the following: 1, species (the alkaloids of some species and subspecies are diagnostically different); 2, provenance (various populations of the same species may have unique combinations of alkaloids); 3, developmental stage (in P. cajanifolia there is a marked decreased in esterification towards the end of the growing season); 4, plant parts extracted (seeds, for example, have high concentrations of hydroxylated lupanine-type alkaloids and only small amounts of esters). These results highlight some of the problems associated with the use of alkaloids as taxonomic characters.     

Alkaloids as taxonomic characters in the tribe Crotalarieae (Fabaceae)

Recent studies of alkaloids have led to a better understanding of the intricate taxonomic relationships in the tribe Crotalarieae. Data from alkaloidal metabolites are largely congruent with morphological data, but allow refinement of the understanding of the phylogeny. A well-supported and almost fully resolved cladogram is presented, which shows that the genera can be grouped into four main clades: (1) an unspecialized group without -pyridone alkaloids and without esters of alkaloids (Aspalathus, Lebeckia, Rafnia, Wiborgia and perhaps Spartidiurn); (2) a group specializing in lupanine-type esters (Pearsonia and Rothia); (3) a group with macrocyclic pyrrolizidine alkaloids (Crotalaria andLotononis); and (4) a specialized group with -pyridone alkaloids (Argyrolobium, Dichilus, Melolobium and Polhillia).     

Quinolizidine alkaloid status of Styphnolobium and Cladrastis (Leguminosae)

Reports of quinolizidine alkaloids in Styphnolobium Schott and Cladrastis Raf. (Leguminosae) conflict with their position in recent molecular phylogenies because they are not members of a major clade of quinolizidine alkaloid-accumulating taxa. The alkaloid status of these two genera was therefore re-investigated using gas chromatography–mass spectrometry. Quinolizidine alkaloids could not be detected in extracts of leaves, flowers or seeds of S. japonicum (L.) Schott, nor in leaves of S. affine (Torrey & A. Gray) Walp., C. delavayi (Franch.) Prain, C. kentukea (Dum.-Cours.) Rudd or C. platycarpa Mak. In contrast, Calia secundiflora (Ortega) Yakovlev, also currently placed outside the major clade of quinolizidine alkaloid-producing genera in molecular phylogenies, was confirmed to accumulate a range of quinolizidine alkaloids.     

Alkaloid distribution in some new world Lupinus species

Alkaloidal profiles of 21 Lupinus species indigenous to North and South America have been determined. Nineteen quinolizidine alkaloids were identified, including aphyllidine and N-methylcytisine, which have not previously been found in the genus. Two dipiperidine alkaloids were also detected. The pattern of alkaloidal distribution is related to a taxonomic classification of the genus.     

Alkaloid distribution in some species of the Papilionaceous tribes Thermopsideae and Genisteae

Alkaloid profiles of extracts of fourteen papilionaceous species in the tribes Thermopsideae and Genisteae (sensu Polhill) have been determined. Altogether, eighteen quinolizidine alkaloids, representative of four structural groups, and one dipiperidine alkaloid were identified among the legumes studied. The chemotaxonomic implications of these data are discussed.     

Influence of dietary alkaloids on survival and growth of Spodoptera littoralis

A total of 25 alkaloids including benzylisoquinoline, monoterpenoid indole, quinolizidine, tobacco and tropane alkaloids were studied for deleterious effects towards neonate larvae of the generalist herbivore Spodoptera littoralis. Alkaloids were incorporated into artificial diet at several concentrations including the respective natural concentration as present in planta as well as two arbitrarily chosen concentrations (0.1 and 0.2% g⁻¹ fresh wt.) for comparison of the bioactivities. After 5 days of exposure almost all of the alkaloids studied reduced larval growth compared to controls. Larval survival, however, was reduced by more than 50% compared to controls only in the presence of berberine, colchicine and nicotine. Several compounds including for example the Cinchona alkaloids quinidine, quinine or cinchonidine which showed little effect on larval survival after 5 days of exposure turned out to be considerably more active when insects were exposed to the respective alkaloids for their whole larval period. In the chronic exposure studies all of the latter alkaloids caused high larval mortality. The pupal weights were significantly lower than those of the controls. Dietary utilization studies indicated that feeding deterrency is important for the adverse effects caused for example by berberine, quinine or quinidine whereas the high larval mortality observed in the presence of cholchicine or nicotine seems to be primarily due to the acute toxicity of these latter alkaloids.     

Alkaloid profiles of Dermatophyllum arizonicum,Dermatophyllum gypsophilum,Dermatophyllum secundiflorum,Styphnolobium affine,and Styphnolobium japonicum previously classified as Sophora species

Sophora arizonica, Sophora gypsophila, Sophora secundiflora, Sophora affinis, and Sophora japonica were recently reclassified as Dermatophyllum arizonicum, Dermatophyllum gypsophilum, Dermatophyllum secundiflorum, Styphnolobium affine, and Styphnolobium japonicum, respectively. Some legumes of the sub family Papilionoideae including Sophora species are reported to contain a variety of quinolizidine alkaloids. The quinolizidine alkaloid profiles of D. arizonicum, D. gypsophilum, D. secundiflorum, S. affine, and S. japonicum were investigated qualitatively and quantitatively using field collections and herbarium specimens throughout their range of geographical distribution for the native species. This is the first report of the alkaloid profiles of D. arizonicum and D. gypsophilum. Alkaloid profiles of the other species were compared to previous reports. The Dermatophyllum species contain quinolizidine alkaloids, and the teratogen anagyrine (11), while the Styphnolobium species do not contain quinolizidine alkaloids. The chemotaxonomic data are consistent with the reclassification of each species.     

Five New Alkaloids from the Roots of Sophora flavescens

Five new quinolizidine alkaloids, including three sparteine‐type alkaloids ( 1  –  3 ) and two cytisine‐type alkaloids ( 4 and 5 ), along with four known ones, were isolated from the roots of Sophora flavescens. Their structures were determined by extensive spectroscopic techniques including IR, UV, NMR, and HR‐ESI‐MS. All the compounds were evaluated for their antibacterial activities against Staphylococcus aureus and Escherichia coli.     

Leontidine-type quinolizidine alkaloids in Orphanodendron (Leguminosae)

Herbarium leaf fragments of the two known species of Orphanodendron (Leguminosae), O. bernalii and O. grandiflorum, were found to contain the quinolizidine alkaloids camoensine (1), camoensidine (2) and guianodendrine (3), supporting the recent phylogenetic placement of the genus in the genistoid clade of subfamily Papilionoideae rather than its traditional placement in subfamily Caesalpinioideae.     

Quinolizidine/indolizidine alkaloids from the seed of Camoensia brevicalyx

The seeds of Camoensia brevicalyx have yielded five quinolizidine/indolizidine alkaloids. The known alkaloids camoensine and camoensidine and the n     

Occurrence of pyrrolizidine alkaloids in three Ethiopian Solanecio species

Three Ethiopian Solanecio species, namely Solanecio angulatus (Vahl) C. Jeffrey, Solanecio mannii (Hook. f.) C. Jeffrey, and Solanecio tuberosus (Sch. Bip. ex A. Rich.) C. Jeffrey var. tuberosus were analysed by capillary gas chromatography–mass spectrometry (GLS–MS) for their pyrrolizidine alkaloid content. All the extracts investigated contain pyrrolizidine alkaloids. Whilst only traces of alkaloids could be detected in the leaf extract of S. angulatus, the content of alkaloids in the other samples ranged between 0.13% dry weight (for the flowers of S. angulatus) and 0.58% (for the tubers of S. tuberosus). Altogether 17 alkaloids were detected out of which 14 were unambiguously identified by comparing their retention indices, molecular masses and mass fragmentation patterns with defined reference data from PAs database or in some cases with reference compounds. The hepatotoxic macrocyclic diesters senecionine and retrosine figured as major alkaloids in the flowers of S. angulatus, whereas the platynecine type alkaloid, 7-O-senecioylplatynecine occurred in higher amount than the other alkaloids detected in the leaves of S. mannii. The tuberous annual herb, S. tuberosus contains eruciflorine as a major alkaloid in the leaves, flowers and tubers. Senecionine figures as one of the major components of the tubers of S. tuberosus. To the best of our knowledge this is the first published report on the occurrence of pyrrolizidine alkaloids in the genus Solanecio. In addition to the chemotaxonomic significance of the detected alkaloids, a brief remark is made on the findings in the light of the use of these plants as medicinal herbs and/or as nectar or pollen source for the production of honey.     

Support for the removal of Cyclolobium from tribe Millettieae (Leguminosae) from its quinolizidine alkaloid status

Fruits of Cyclolobium brasiliense Benth. (Leguminosae; Papilionoideae) were found to contain quinolizidine alkaloids. Several tetracyclic sparteine-type alkaloids, the bipiperidyl alkaloid ammodendrine and the α-pyridone alkaloid N-methylcytisine were identified. The presence of quinolizidine alkaloids in this monotypic genus supports a relationship with tribe Brongniartieae and genistoid tribes rather than its current placement in tribe Millettieae.     

Complete elimination of hostplant quinolizidine alkaloids by larvae of a polyphagous lycaenid butterfly,Callophrys rubi

Caterpillars of the lycaenid butterfly Callophrys rubi accept a variety of hostplants. When fed inflorescences or leaves of Genista tinctoria (a natural hostplant) or Lupinus polyphyllus (a non-host), the larvae completely eliminate quinolizidine alkaloids ingested from their food in their frass. No alkaloids are stored. Infestation by the parasitoid wasp Distatrix sancus (Braconidae) did not affect alkaloid elimination. The presence of an effective anti-toxin system is discussed with reference to the evolution of hostplant relationships in the genus Callophrys. There is no evidence that in the secondarily myrmecoxenous larvae of C. rubi hostplantderived chemical defense takes the place of former myrmecophily.     

Inhibition of seed germination by quinolizidine alkaloids

Germination of Lactuca sativa L. was inhibited by mixtures of quinolizidine alkaloids. The alkaloid esters resulted in the strongest inhibition: 6 mM 13-tigloyloxylupanine inhibited germination by 100%, whereas the other lupin alkaloids, such as lupanine and sparteine, gave a 45 and 20% inhibition, respectively. Seedlings of Lupinus albus L., which are not affected by quinolizidine alkaloids, excrete lupanine and 13-tigloyloxylupanine into the surrounding medium by their roots. It is assumed that lupin alkaloids are potential compounds of plant-plant interaction (i.e. allelopathy) besides their role in plant-herbivore interrelations.     

Quinolizidine alkaloids as systematic markers of the papilionoideae

The structural characteristics of quinolizidine alkaloids have been quantified on the basis of their biogenetic origins. Such data have been used to determine evolutionary advancement parameters for genera of the Papilionoideae. These analyses indicate a correlation of the structural characters of alkaloids with ecogeography and morphology of the genera, suggesting an adaptive radiation of the taxa from tropical Africa in three major directions along a southern temperate “pre-cytisine” route, a northern temperatre “pre-cytisine-cytisine” route and a tropical “ormosanine” route with a temperate cytisine branch. The data also suggest the division of the Sophoreae into three chemical groups giving rise to Liparieae, Genisteae, Thermopsideae and Bossiaeeae. These concepts are embodied in a tentative phyletic classification of all genera of the Papilionoideae which contain quinolizidine alkaloids.     

Turnover and transport of quinolizidine alkaloids. Diurnal fluctuations of lupanine in the phloem sap,leaves and fruits of Lupinus albus L.

Quinolizidine alkaloids formed in the leaves of Lupinus albus L. are translocated via the phloem to the other plant organs, especially the maturing fruits. Compared with amino-acid transport in the phloem, the alkaloids contribute about 8% to the overall nitrogen being exported from the leaf. Since it is likely that the alkaloids are subsequently degraded in the target tissues a minor role of quinolizidine alkaloids might be nitrogen transport. A marked diurnal fluctuation of alkaloids was observed in the leaves, the phloem sap, the roots and the fruits with an increase during the day and an amplitude of several hundred percent thus providing evidence for a rapid turnover of endogenous alkaloids.Abbreviations QA quinolizidine alkaloids - GLC gas-liquid chromatography     

Use of the metabolic grid to explain the metabolism of quinolizidine alkaloids in Leguminosae

Evidence from feeding experiments with lysine-[2-¹⁴C] and from metabolism experiments published previously suggest the operation of a gridlike conversion of quinolizidine alkaloids in Leguminosae. Using these results and the taxonomical distribution of alkaloids a metabolic grid was devised to explain the conversion of lysine into lupin alkaloids and their interconversions.     

Alkaloids of some south american erythroxylum species

Fourteen South American species of Erythroxylum representing four sections of the genus were examined for tropane and related alkaloids. The alkaloid content of the dried material ranged from 0.002 to 0.20 %. Commonly, the alkaloids involved were esters of various tropanols with benzoic and phenylacetic acids. A new alkaloid, nortropacocaine, was isolated from E. mamacoca. Mass spectrometry indicated the existence of other new bases, cuscohygrine and, in some species dihydrocuscohygrine. Chemotaxonomic implications are discussed.     

Alkaloids from stem barks of Oricia renieri and Oricia gabonensis

The stem barks of Oricia renieri and O. gabonensis have yielded nine alkaloids, including furoquinolines, acridones, 3,4-pyrano-2-quinolones and a 2-amino-benzophenone. One of the pyranoquinolones isolated from O. renieri, 7-methoxy-N-methylflindersine, is reported for the first time. All alkaloids were identified on the basis of spectral data. The chemotaxonomic significance of the alkaloids of these two species is discussed.     

Stirtonia, a new genus of the tribe Podalyrieae (Leguminosae) from South Africa

The genus Stirtonia is described to accommodate three anomalous species, hitherto placed in Podalyria . The new genus differs from Podalyria mainly in the decussate (geminate) inflorescence structure (racemose in Podalyria ), the yellow flower colour (purple, pink or white in Podalyria ), the non-fleshy rim-aril of the seeds (seed aril invariably fleshy and collar-like in Podalyria ) and in the diagnostically different combination of quinolizidine alkaloids. The major alkaloidal metabolites are carboxylic acid esters of lupanine and virgiline, but these compounds are totally absent in Podalyria . The morphology of inflorescences, leaves, flowers and seeds are described and illustrated. Chromosome numbers (2n = 18) are reported for the first time. A formal taxonomic treatment of the three species, S. tayloriana, S. chrysantha and S. insignis , is presented.