Supinine

Survey of pyrrolizidine alkaloids in seven varieties of Lappula squarrosa: An alternative source of heart-healthy vegetable oil.[Pubmed:26895990]

Phytochem Anal. 2016 Mar-Apr;27(2):133-9.

INTRODUCTION: Growing demand for heart-healthy omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), is putting stress on wild fish stocks. There is now a compelling need for new and novel sources of non-traditional seed oils containing high stearidonic acid (SDA), a precursor of EPA and DHA, to reduce this demand. The seed oil of Lappula squarrosa is one of the richest sources of SDA, however, the plant has been found to contain toxic pyrrolizidine alkaloids (PAs). OBJECTIVE: In this study, the PA concentrations of seven varieties (A-G) of Lappula squarrosa were analysed to determine the most suitable varieties for commercial seed oil production. METHODS: Whilst the clean-up procedure for the PAs in the roots, flowers and leaves was on diatomaceous earth columns and finally analysed with GC-EI-MS, that of the seeds was through SCX-SPE and a more sensitive HPLC-ESI-MS/MS sum parameter method was used in the analysis. RESULTS: Altogether six PAs (Supinine, amabiline, intermedine, lycopsamine and 3'-acetylintermedine) including one unknown retronecine-type PA were identified with variety C recording the lowest total PA concentration (4.64 mg seneciphylline equivalents (SE)/g dry weight (d.w.)). Besides, the total PA concentrations in the seeds of Lappula squarrosa varieties ranged between 2.88 mug PA/g and 10.36 mug PA/g d.w. CONCLUSION: Based solely on overall PA concentrations and PA distribution, variety D (5.95 mg SE/g d.w.) was found to be a potential candidate for commercial seed oil cultivation.

Pro-toxic dehydropyrrolizidine alkaloids in the traditional Andean herbal medicine "asmachilca".[Pubmed:26087231]

J Ethnopharmacol. 2015 Aug 22;172:179-94.

ETHNOPHARMACOLOGICAL RELEVANCE: Asmachilca is a Peruvian medicinal herb preparation ostensibly derived from Aristeguietia gayana (Wedd.) R.M. King & H. Rob. (Asteraceae: Eupatorieae). Decoctions of the plant have a reported bronchodilation effect that is purported to be useful in the treatment of respiratory allergies, common cold and bronchial asthma. However, its attractiveness to pyrrolizidine alkaloid-pharmacophagous insects indicated a potential for toxicity for human consumers. AIM OF THE STUDY: To determine if commercial asmachilca samples, including fully processed herbal teas, contain potentially toxic 1,2-dehydropyrrolizidine alkaloids. MATERIALS AND METHODS: Two brands of "Asmachilca" herbal tea bags and four other commercial samples of botanical materials for preparing asmachilca medicine were extracted and analyzed using HPLC-esi(+)MS and MS/MS for the characteristic retention times and mass spectra of known dehydropyrrolizidine alkaloids. Other suspected dehydropyrrolizidine alkaloids were tentatively identified based on MS/MS profiles and high resolution molecular weight determinations. Further structure elucidation of isolated alkaloids was based on 1D and 2D NMR spectroscopy. RESULTS: Asmachilca attracted many species of moths which are known to pharmacophagously gather dehydropyrrolizidine alkaloids. Analysis of 5 of the asmachilca samples revealed the major presence of the dehydropyrrolizidine alkaloid monoesters rinderine and Supinine, and their N-oxides. The 6th sample was very similar but did not contain Supinine or its N-oxide. Small quantities of other dehydropyrrolizidine alkaloid monoesters, including echinatine and intermedine, were also detected. In addition, two major metabolites, previously undescribed, were isolated and identified as dehydropyrrolizidine alkaloid monoesters with two "head-to-tail" linked viridifloric and/or trachelanthic acids. Estimates of total pyrrolizidine alkaloid and N-oxide content in the botanical components of asmachilca varied from 0.4% to 0.9% (w/dw, dry weight) based on equivalents of lycopsamine. The mean pyrrolizidine alkaloid content of a hot water infusion of a commercial asmachilca herbal tea bag was 2.2+/-0.5mg lycopsamine equivalents. Morphological and chemical evidence showed that asmachilca is prepared from different plant species. CONCLUSIONS: All asmachilca samples and the herbal tea infusions contained toxicologically-relevant concentrations of pro-toxic 1,2-dehydropyrrolizidine alkaloid esters and, therefore, present a risk to the health of humans. This raises questions concerning the ongoing unrestricted availability of such products on the Peruvian and international market. In addition to medical surveys of consumers of asmachilca, in the context of chronic disease potentially associated with ingestion of the dehydropyrrolizidine alkaloids, the botanical origins of asmachilca preparations require detailed elucidation.

Tissue distribution, core biosynthesis and diversification of pyrrolizidine alkaloids of the lycopsamine type in three Boraginaceae species.[Pubmed:17320124]

Phytochemistry. 2007 Apr;68(7):1026-37.

Three species of the Boraginaceae were studied: greenhouse-grown plants of Heliotropium indicum and Agrobacterium rhizogenes transformed roots cultures (hairy roots) of Cynoglossum officinale and Symphytum officinale. The species-specific pyrrolizidine alkaloid (PA) profiles of the three systems were established by GC-MS. All PAs are genuinely present as N-oxides. In H. indicum the tissue-specific PA distribution revealed the presence of PAs in all tissues with the highest levels in the inflorescences which in a flowering plant may account for more than 70% of total plant alkaloid. The sites of PA biosynthesis vary among species. In H. indicum PAs are synthesized in the shoot but not roots whereas they are only made in shoots for C. officinale and in roots of S. officinale. Classical tracer studies with radioactively labelled precursor amines (e.g., putrescine, spermidine and homospermidine) and various necine bases (trachelanthamidine, supinidine, retronecine, heliotridine) and potential ester alkaloid intermediates (e.g., trachelanthamine, Supinine) were performed to evaluate the biosynthetic sequences. It was relevant to perform these comparative studies since the key enzyme of the core pathway, homospermidine synthase, evolved independently in the Boraginaceae and, for instance, in the Asteraceae [Reimann, A., Nurhayati, N., Backenkohler, A., Ober, D., 2004. Repeated evolution of the pyrrolizidine alkaloid-mediated defense system in separate angiosperm lineages. Plant Cell 16, 2772-2784.]. These studies showed that the core pathway for the formation of trachelanthamidine from putrescine and spermidine via homospermidine is common to the pathway in Senecio ssp. (Asteraceae). In both pathways homospermidine is further processed by a beta-hydroxyethylhydrazine sensitive diamine oxidase. Further steps of PA biosynthesis starting with trachelanthamidine as common precursor occur in two successive stages. Firstly, the necine bases are structurally modified and either before or after this modification are converted into their O(9)-esters by esterification with one of the stereoisomers of 2,3-dihydroxy-2-isopropylbutyric acid, the unique necic acid of PAs of the lycopsamine type. Secondly, the necine O(9)-esters may be further diversified by O(7)- and/or O(3')-acylation.

Stereochemical inversion of pyrrolizidine alkaloids byMechanitis polymnia (Lepidoptera: Nymphalidae: Ithomiinae): Specificity and evolutionary significance.[Pubmed:24241922]

J Chem Ecol. 1994 Nov;20(11):2883-99.

Pyrrolizidine alkaloids (PAs), acquired by adults or larvae of Danainae and Ithomiinae butterflies and Arctiidae moths from plants, protect these lepidopterans against predators and are biosynthetic precursors of male sex pheromones. The investigation of PAs in many species of wild-caught adults of Ithomiinae showed lycopsamine (1) [(7R)-OH, (2'S)-OH, (3'S)-OH] as the main alkaloid. In incorporation experiments, PA-free (freshly emerged) adults of the ithomiineMechanitis polymnia were fed seven PAs: lycopsamine and four of its known natural stereoisomers-indicine (2) [(7R)-OH, (2'R)-OH, (3'S)-OH], intermedine (3) [(7R)-OH, (2'S)-OH, (3'R)-OH], rinderine (4) [(7S)-OH, (2'S)-OH, (3'R)-OH], and echinatine (5) [(7S)-OH, (2'S)-OH, (3'S)-OH], and two PAs without the 7-OH: Supinine (6) [(2'S)-OH, (3'R)-OH] and amabiline (7) [(2'S)-OH, (3'S)-OH]. Males epimerized PAs 3, 4, and 5 mainly to lycopsamine (1). Females fed these same three PAs changed a smaller proportion to lycopsamine; their lesser capacity to modify PAs corresponds to their normal acquisition of already transformed PAs from males during mating rather than through visits of adults to plant sources of PAs. The alkaloids1 and2, both 7R and 3'S, were incorporated without or with minimum change by males and females. Feeding experiments with6 and7 (males only) showed an inversion at the 3' center of6 and no change in7. The inversion from 7S to 7R (probably via oxyreduction) may be closely related to the evolution of acquisition of PAs by butterflies and moths. Two hypotheses are discussed: (1) The ancestral butterflies are probably adapted to tolerate, assimilate, and use (7R)-PAs (most common in plants; all widespread 1,2-unsaturated macrocyclic PA diesters show this configuration). The development of (7R)-PA receptors in the butterflies could lead to a specialization on this configuration in two ways: to help find PA plants and to utilize these components in sexual chemical communication. A later appearance of (7S)-PAs in plants could have selected an enzymatic system for the inversion of this chiral center in order to continue producing (7R)-PA-derived pheromones. (2) The inversion would be due to the evolution of a enzyme system specialized in the transport of (7R)-PAs to the integument; the failure of this system to carry (7S)-PAs led to an enzymatic system to invert them to transportable (7R)-PAs. In this case, the 7R configuration is an effect and not a cause of (7R)-PA-derived pheromones. In both hypotheses, the partial inversion of the 3'-asymmetric center, when the butterfly was fed intermedine (3), rinderine (4), and Supinine (6), could be fortuitous due to the conformation of the molecule and/or the enzymatic system.

Pyrrolizidine alkaloids in the arctiid mothHyalurga syma.[Pubmed:24249009]

J Chem Ecol. 1993 Apr;19(4):669-79.

The arctiid mothHyalurga syma (subfamily Pericopinae) sequesters pyrrolizidine alkaloids (PAs) from its larval food plantHeliotropium transalpinum (Boraginaceae). Colorimetric quantification of total PAs in the larvae, pupae, and adults ofHyalurga revealed mean values of about 286-445mug per individual (1.4-2.6% of dry weight). The PA mixtures found in the moth and its larval food plant were evaluated by GC-MS. Food-piant leaves were found to contain the diastereoisomeric retronecine esters indicine (IIIa), intermedine (IIIb), and lycopsamine (IIIc), and the heliotridine ester rinderine (IIId) only as minor constituents, whereas 3'-acetylrinderine (IVc) (68% of total PAs) and the respective 3'-acetyl esters of indicine (IVa) and intermedine (IVb) (both 17%) were the major alkaloids. Supinine (IIa) is detectable in traces only. The PA mixtures in eggs, larvae, pupae, and imagines ofHyalurga were identical: indicine, intermedine, and lycopsamine accompanied by considerable amounts of Supinine and amabiline or coromandalinine (IIb/IIc) were the major components. Only larvae were found to store small quantities of a 3'-acetyl derivative. Rinderine and its 3'-acetyl ester were never found in the insects. Low concentrations of the arctiidspecific PA callimorphine (I) were present in larvae, pupae, and imagines. The differences in the PA patterns of the insects and their larval food plant suggest thatHyalurga is capable of modifying plant-derived PAs by inversion of the 7-OH configuration (conversion of the necine base heliotridine into retronecine), and perhaps the inversion of the 3'-OH [conversion of (+)-trachelanthic acid into (-)-viridifloric acid], although the possibility of a selective sequestration of the respective retronecine esters cannot be excluded. Some trials with the orb-weaving spiderNephila clavipes, a common neotropical predator, showed that both freshly emerged and field-caught adults ofHyalurga syma are liberated unharmed by the spider. The liberation could be related to the presence of PAs in the moths.

Structure/activity relationships of the genotoxic potencies of sixteen pyrrolizidine alkaloids assayed for the induction of somatic mutation and recombination in wing cells of Drosophila melanogaster.[Pubmed:1643665]

Chem Biol Interact. 1992 Jun 15;83(1):1-22.

Sixteen pyrrolizidine alkaloids (PAs) were examined for their genotoxic potency in the wing spot test of Drosophila melanogaster following oral application. This in vivo assay tests for the induction of somatic mutation and mitotic recombination in cells of the developing wing primordia. All PAs tested except the C9-monoester Supinine were clearly genotoxic. Depending on their chemical structure, however, genotoxicity of the PAs varied widely in a range encompassing about three orders of magnitude. In general, macrocyclic diester-type PAs were the most and 7-hydroxy C9-monoester types the least genotoxic representatives studied, while open diesters were intermediate in this respect. Stereoisomeric PAs mostly showed similar, but sometimes also clearly unequal genotoxicity. An increasing number of hydroxy groups in the PA molecule seemed to reduce its genotoxic potency. With respect to the structure/activity relationships, there appears to be a good correlation between hepatotoxicity of PAs in experimental rodents and genotoxicity in the wing spot test of Drosophila. This suggests that PAs are bioactivated along similar pathways in the mammalian liver and in the somatic cells of Drosophila. The genotoxic potential of PAs in the Drosophila wing spot test and their carcinogenic potential in mammals also seem correlated, although the information in the literature on carcinogenicity of the non-macrocyclic PAs with moderate to low genotoxic potency is concededly limited. Comparisons with other genotoxicity tests suggest that the wing spot test is particularly suitable for genotoxins like PAs, on the one hand because of the versatile metabolic bioactivation system of Drosophila and on the other hand also because of its excellent sensitivity to the crosslinking agents among the genotoxins.

Pyrrolizidine alkaloid composition of three Chinese medicinal herbs, Eupatorium cannabinum, E. japonicum and Crotalaria assamica.[Pubmed:1471612]

Am J Chin Med. 1992;20(3-4):281-8.

The pyrrolizidine alkaloid composition of three Chinese herbs, "pei lan", "cheng gan cao" and "zi xiao rong," identified respectively as Eupatorium cannabinum, Eupatorium japonicum (Compositae) and Crotalaria assamica (Leguminosae), were studied by fast atom bombardment mass spectrometry and gas chromatography-electron impact mass spectrometry. Viridiflorine, cynaustraline, amabiline, Supinine, echinatine, rinderine and isomers of these alkaloids were found in the Eupatorium species. Monocrotaline was the only pyrrolizidine alkaloid detected in the Crotalaria species.

Investigation into the Presence of Pyrrolizidine Alkaloids in Eupatorium cannabinum by Means of Positive and Negative Ion Chemical Ionization GC-MS.[Pubmed:17269067]

Planta Med. 1987 Oct;53(5):456-61.

It is demonstrated that the combination of positive ion chemical ionization and negative ion chemical ionization GC-MS analyses of herb and root extracts of EUPATORIUM CANNABINUM L. offers a rapid, tentative structure elucidation of pyrrolizidine alkaloids (PAs). Compounds identified in aerial parts of E. CANNAHIMUM in this way are four echinatine isomers, like lycopsamine and intermedine, and a number of their beta-acetyl, beta-angelyl/tiglyl and beta-(iso)valeryl esters. PAs without a substituent at C-7 were tentatively identified as Supinine and amabiline. In addition to a number of these alkaloids, some beta-(iso)butyryl, beta-angelyl/tiglyl, and beta-(iso)valeryl esters of Supinine or amabiline were detected in subterranean parts of the plant. PAS with a saturated necine base like the three trachelanthamine isomers and some beta-anglyl/tiglyl esters could be detected in the root material only. A C-9-viridifloryl/trachelanthyl ester of a saturated amino-alcohol like turneforcidine and one of its beta-angelyl/tiglyl esters have also been found. The latter 2 compounds, the beta-(iso)butyryl, the beta-(iso)valeryl, and the beta-angelyl/tiglyl esters of Supinine or amabiline and the beta-(iso)valeryl ester of an echinatine isomer have not been described in nature before.

Pyrrolizidine alkaloids, flavonoids and volatile compounds in the genus Eupatorium. Eupatorium cannabinum L., an ancient drug with new perspectives.[Pubmed:6364036]

Pharm Weekbl Sci. 1983 Dec 16;5(6):281-6.

Within the scope of a study of antitumour compounds in higher plants a survey is given concerning the presence of pyrrolizidine alkaloids, flavonoids and volatile compounds in Eupatorium species. Preliminary results of a phytochemical study of these compounds in E. cannabinum are also presented. From the results of a GC-MS analysis of an alkaloid extract from aerial parts of E. cannabinum the conclusion can be drawn, that the composition of pyrrolizidine alkaloids is more complicated than reported in literature. This is caused by the fact that different stereoisomers exist. The presence of at least two alkaloids with a molecular weight of 283 (Supinine or isomers) and four alkaloids with a molecular weight of 299 (echinatine or isomers) could be shown. In subterranean plant material also other pyrrolizidine alkaloids are present. A great number of flavonoids, also as glycosides, have been shown in Eupatorium species, often in low quantities. Rutin, present in many Eupatorium species, could not be detected in subterranean parts of E. cannabinum. Relatively little attention has been paid to the analysis of volatile compounds (essential oils) of Eupatorium species. Thymol derivatives are often reported to be present in Eupatorium species. Thirty-five compounds could be detected by means of a GC-MS analysis in the essential oil of E. cannabinum about which no literature data were available.

Pyrrolizidine alkaloids: actions on muscarinic receptors in the guinea-pig ileum.[Pubmed:5579465]

Br J Pharmacol. 1971 Apr;41(4):683-90.

1. Eleven pyrrolizidine alkaloids have been tested on the isolated guinea-pig ileum preparation.2. Platyphylline, Supinine, heleurine and cynaustraline were more potent in antagonizing responses to acetylcholine and carbachol than responses to histamine. Their anticholinergic activity appeared to involve a competitive mechanism.3. Lasiocarpine, monocrotaline, spectabiline, sarracine, 7-angelylheliotridine, heliotrine and senecionine had similar antagonistic potencies against responses to both acetylcholine and histamine.4. The alkaloids had no appreciable activity as antagonists of acetylcholine in the isolated toad rectus abdominis preparation.5. These results are discussed with respect to interactions of the alkaloids at receptor sites involved in anticholinergic activity at the muscarinic receptor.