Principal opium alkaloids as possible biochemical markers for the source identification of Indian opium.

PubMed

Mohana, Mudiam; Reddy, Krishna; Jayshanker, Gurumurthy; Suresh, Velayudhan; Sarin, Rajendra Kumar; Sashidhar, R B

2005-08-01

A total of 124 opium samples originating from different licit opium growing divisions of India were analyzed for their principal alkaloid (thebaine, codeine, morphine, papaverine, and narcotine) content by capillary zone electrophoresis (CZE) without derivatization or purification. Absence of papaverine in Bareilly, Tilhar, and most of the samples originating from Kota is a significant observation in relation to the source of Indian opium. Multiple discriminant analysis was applied to the quantitative principal alkaloid data to determine an optimal classifier in order to evaluate the source of Indian opium. The predictive value based on the discriminant analysis was found to be 85% in relation to the source of opium and the study also revealed that all the principal alkaloids have to be analyzed for source identification of Indian opium. Chemometrics performed with principal alkaloids analytical data was used successfully in discriminating the licit opium growing divisions of India into three major groups, viz., group I, II, and III. The methodology developed may find wide forensic application in identifying the source of licit or illicit opium originating from India, and to differentiate it from opium originating from other opium producing countries.

Phosphorylated Derivatives of Alkaloids and Nitrogen-containing Heterocycles — Cholinesterase Inhibitors

NASA Astrophysics Data System (ADS)

Sadykov, Abid S.; Dalimov, D. N.; Godovikov, Nikolai N.

1983-10-01

The review deals with the synthesis and anticholinesterase activities of phosphorylated derivatives of certain alkaloids and nitrogen-containing heterocycles. It is shown that the conformational properties of the alkaloid and nitrogen-containing heterocycle residues in the composition of the organophosphorus inhibitor (OPI) molecule play an important role in the inhibition of the catalytic activity of cholinesterases. The type of inhibition of cholinesterases also varies as a function of chemical structure. The bibliography includes 45 references.

An ergot alkaloid biosynthesis gene and clustered hypothetical genes from Aspergillus fumigatus.

PubMed

Coyle, Christine M; Panaccione, Daniel G

2005-06-01

The ergot alkaloids are a family of indole-derived mycotoxins with a variety of significant biological activities. Aspergillus fumigatus, a common airborne fungus and opportunistic human pathogen, and several fungi in the relatively distant taxon Clavicipitaceae (clavicipitaceous fungi) produce different sets of ergot alkaloids. The ergot alkaloids of these divergent fungi share a four-member ergoline ring but differ in the number, type, and position of the side chains. Several genes required for ergot alkaloid production are known in the clavicipitaceous fungi, and these genes are clustered in the genome of the ergot fungus Claviceps purpurea. We investigated whether the ergot alkaloids of A. fumigatus have a common biosynthetic and genetic origin with those of the clavicipitaceous fungi. A homolog of dmaW, the gene controlling the determinant step in the ergot alkaloid pathway of clavicipitaceous fungi, was identified in the A. fumigatus genome. Knockout of dmaW eliminated all known ergot alkaloids from A. fumigatus, and complementation of the mutation restored ergot alkaloid production. Clustered with dmaW in the A. fumigatus genome are sequences corresponding to five genes previously proposed to encode steps in the ergot alkaloid pathway of C. purpurea, as well as additional sequences whose deduced protein products are consistent with their involvement in the ergot alkaloid pathway. The corresponding genes have similarities in their nucleotide sequences, but the orientations and positions within the cluster of several of these genes differ. The data indicate that the ergot alkaloid biosynthetic capabilities in A. fumigatus and the clavicipitaceous fungi had a common origin.

An Ergot Alkaloid Biosynthesis Gene and Clustered Hypothetical Genes from Aspergillus fumigatus†

PubMed Central

Coyle, Christine M.; Panaccione, Daniel G.

2005-01-01

The ergot alkaloids are a family of indole-derived mycotoxins with a variety of significant biological activities. Aspergillus fumigatus, a common airborne fungus and opportunistic human pathogen, and several fungi in the relatively distant taxon Clavicipitaceae (clavicipitaceous fungi) produce different sets of ergot alkaloids. The ergot alkaloids of these divergent fungi share a four-member ergoline ring but differ in the number, type, and position of the side chains. Several genes required for ergot alkaloid production are known in the clavicipitaceous fungi, and these genes are clustered in the genome of the ergot fungus Claviceps purpurea. We investigated whether the ergot alkaloids of A. fumigatus have a common biosynthetic and genetic origin with those of the clavicipitaceous fungi. A homolog of dmaW, the gene controlling the determinant step in the ergot alkaloid pathway of clavicipitaceous fungi, was identified in the A. fumigatus genome. Knockout of dmaW eliminated all known ergot alkaloids from A. fumigatus, and complementation of the mutation restored ergot alkaloid production. Clustered with dmaW in the A. fumigatus genome are sequences corresponding to five genes previously proposed to encode steps in the ergot alkaloid pathway of C. purpurea, as well as additional sequences whose deduced protein products are consistent with their involvement in the ergot alkaloid pathway. The corresponding genes have similarities in their nucleotide sequences, but the orientations and positions within the cluster of several of these genes differ. The data indicate that the ergot alkaloid biosynthetic capabilities in A. fumigatus and the clavicipitaceous fungi had a common origin. PMID:15933009

Network-analysis-guided synthesis of weisaconitine D and liljestrandinine

NASA Astrophysics Data System (ADS)

Marth, C. J.; Gallego, G. M.; Lee, J. C.; Lebold, T. P.; Kulyk, S.; Kou, K. G. M.; Qin, J.; Lilien, R.; Sarpong, R.

2015-12-01

General strategies for the chemical synthesis of organic compounds, especially of architecturally complex natural products, are not easily identified. Here we present a method to establish a strategy for such syntheses, which uses network analysis. This approach has led to the identification of a versatile synthetic intermediate that facilitated syntheses of the diterpenoid alkaloids weisaconitine D and liljestrandinine, and the core of gomandonine. We also developed a web-based graphing program that allows network analysis to be easily performed on molecules with complex frameworks. The diterpenoid alkaloids comprise some of the most architecturally complex and functional-group-dense secondary metabolites isolated. Consequently, they present a substantial challenge for chemical synthesis. The synthesis approach described here is a notable departure from other single-target-focused strategies adopted for the syntheses of related structures. Specifically, it affords not only the targeted natural products, but also intermediates and derivatives in the three subfamilies of diterpenoid alkaloids (C-18, C-19 and C-20), and so provides a unified synthetic strategy for these natural products. This work validates the utility of network analysis as a starting point for identifying strategies for the syntheses of architecturally complex secondary metabolites.

Viability of a [2 + 2 + 1] Hetero-Pauson-Khand Cycloaddition Strategy toward Securinega Alkaloids: Synthesis of the BCD-Ring Core of Securinine and Related Alkaloids.

PubMed

Chirkin, Egor; Michel, Sylvie; Porée, François-Hugues

2015-07-02

Preliminary results related to the development of [2 + 2 + 1]-oxa-hetero-Pauson-Khand cycloaddition strategy toward the Securinega alkaloids are reported. The critical tricyclic BCD-ring core was assembled in only nine linear steps from cheap 4-hydroxy-l-proline. The study provides valuable insight into the scope of a rare hetero-Pauson-Khand reaction, a powerful tool for the rapid construction of butenolide-containing natural products.

Leptopyrine, new alkaloid from Leptopyrum fumarioides L. (Ranunculaceae).

PubMed

Doncheva, Tsvetelina; Solongo, Amgalan; Kostova, Nadezhda; Gerelt-Od, Yadamsuren; Selenge, Dangaa; Philipov, Stefan

2015-01-01

A new type of isoquinoline alkaloid leptopyrine was isolated from the aerial parts of Leptopyrum fumarioides L. (Ranunculaceae) of Mongolian origin. The known alkaloids protopine and thalifoline were isolated for the first time from this the species. All structures were established by physical and spectral analyses.

Total synthesis of the Daphniphyllum alkaloid daphenylline

NASA Astrophysics Data System (ADS)

Lu, Zhaoyong; Li, Yong; Deng, Jun; Li, Ang

2013-08-01

The Daphniphyllum alkaloids are a large class of natural products isolated from a genus of evergreen plants widely used in Chinese herbal medicine. They display a remarkable range of biological activities, including anticancer, antioxidant, and vasorelaxation properties as well as elevation of nerve growth factor. Daphenylline is a structurally unique member among the predominately aliphatic Daphniphyllum alkaloids, and contains a tetrasubstituted arene moiety mounted on a sterically compact hexacyclic scaffold. Herein, we describe the first total synthesis of daphenylline. A gold-catalysed 6-exo-dig cyclization reaction and a subsequent intramolecular Michael addition reaction, inspired by Dixon's seminal work, were exploited to construct the bridged 6,6,5-tricyclic motif of the natural product at an early stage, and the aromatic moiety was forged through a photoinduced olefin isomerization/6π-electrocyclization cascade followed by an oxidative aromatization process.

beta-Phenylethylamines and the isoquinoline alkaloids.

PubMed

Bentley, Kenneth W

2005-04-01

This review covers beta-phenylethylamines and isoquinoline alkaloids derived from them, including further products of oxidation, condensation with formaldehyde and rearrangement, some of which do not contain as isoquinoline system, together with napthylisoquinoline alkaloids, which have a different biogenetic origin. The occurrence of the alkaloids with the structures of new bases, together with their reactions and syntheses, are reported. The literature from July 2003 to June 2004 is reviewed, with 145 references cited.

Study of magnetization switching for MRAM based memory technologies

NASA Astrophysics Data System (ADS)

Pham, Huy

Amphibian alkaloids are attractive targets for synthesis due to their biological activity. An important class of amphibian alkaloids is the 2,5-disubstituted pyrrolidine-based family of compounds. There are many synthetic approaches for the preparation of the trans-2,5-disubstituted pyrrolidines, but methods for the construction of the cis-2,5-pyrrolidines are limited. Therefore, it was desired to develop an enantioselective approach for the preparation of cis-2,5-disubsituted pyrrolidines. (+)-Tropin-2-one derived from cocaine was used as starting material to exploit the inherent stereochemistry for construction of the cis-pyrrolidine ring. This permitted the unequivocal assignment of the absolute configuration of the target pyrrolidine. The structurally simple pyrrolidine alkaloid, 225H, was selected as a target to develop a general synthetic approach. The enantioselective synthesis of 225H was achieved in nine steps and good overall yield. The search for potent cannabinoid receptor partial agonist ligands as potential marijuana addiction therapeutic agents has led to an investigation of the synthesis of diaryl ether hybrid analogues of BAY 59-3074. A series of 2-(3-alkyl-5-hydroxyphenoxy)-6-(trifluoromethyl)benzonitriles, 3-(2-cyano-3-(trifluoromethyl)phenoxy)phenylalkanoates, and (3-(benzyloxy)phenoxy)-6-(trifluoromethyl)benzonitriles were synthesized and evaluated in vitro for CB1 affinity. The olivetol diaryl ether analogue was the most potent ligand of the alkyl series, but the diaryl ester analogues exhibited modest affinity for CB1 receptors. The most potent compound of the series was the 2-(3-(benzyloxy)phenoxy)-6-(trifluoromethyl)benzonitrile. Keywords. amphibian alkaloids, enantioselective synthesis, pyrrolidine, cannabinoid receptor, marijuana.

Beta-phenylethylamines and the isoquinoline alkaloids.

PubMed

Bentley, Kenneth W

2003-06-01

This review covers beta-phenylethylamines and isoquinoline alkaloids and compounds derived from them, including further products of oxidation, condensation with formaldehyde and rearrangement, some of which do not contain an isoquinoline system, together with naphthylisoquinoline alkaloids, which have a different biogenetic origin. The occurrence of the alkaloids, with the structures of new bases, together with their reactions, syntheses and biological activities are reported. The literature from July 2001 to June 2002 is reviewed, with 581 references cited.

Alkaloids from Mongolian species Hypecoum lactiflorum Kar. et Kir. Pazij.

PubMed

Philipov, Stefan; Istatkova, Ralitsa; Denkova, Pavletta; Dangaa, Selenge; Samdan, Javzan; Krosnova, Marieta; Munkh-Amgalan, Chogsom

2009-01-01

A new secoberbine alkaloid (-)-N-methylcorydalisol was isolated from the aerial parts of Hypecoum lactiflorum Kar. et Kir. Pazij. (Papaveraceae) of Mongolian origin and was characterised. The known alkaloids of protopine and protoberberine type protopine, allocryptopine, (-)-N-methylcanadine and (-)-N-methylstylopine were also isolated. (-)-N-methylstylopine is a new alkaloid for the genus, while (-)-N-methylcanadine is new for the species. All structures were established by physical and spectral analysis.

Two-step iron(0)-mediated N-demethylation of N-methyl alkaloids.

PubMed

Kok, Gaik B; Pye, Cory C; Singer, Robert D; Scammells, Peter J

2010-07-16

A mild and simple two-step Fe(0)-mediated N-demethylation of a number of tertiary N-methyl alkaloids is described. The tertiary N-methylamine is first oxidized to the corresponding N-oxide, which is isolated as the hydrochloride salt. Subsequent treatment of the N-oxide hydrochloride with iron powder readily provides the N-demethylated amine. Representative substrates include a number of opiate and tropane alkaloids. Key intermediates in the synthesis of semisynthetic 14-hydroxy pharmaceutical opiates such as oxycodone and oxymorphone are also readily N-demethylated using this method.

Binary stress induces an increase in indole alkaloid biosynthesis in Catharanthus roseus

PubMed Central

Zhu, Wei; Yang, Bingxian; Komatsu, Setsuko; Lu, Xiaoping; Li, Ximin; Tian, Jingkui

2015-01-01

Catharanthus roseus is an important medicinal plant, which produces a variety of indole alkaloids of significant pharmaceutical relevance. In the present study, we aimed to investigate the potential stress-induced increase of indole alkaloid biosynthesis in C. roseus using proteomic technique. The contents of the detectable alkaloids ajmalicine, vindoline, catharanthine, and strictosidine in C. roseus were significantly increased under binary stress. Proteomic analysis revealed that the abundance of proteins related to tricarboxylic acid cycle and cell wall was largely increased; while, that of proteins related to tetrapyrrole synthesis and photosynthesis was decreased. Of note, 10-hydroxygeraniol oxidoreductase, which is involved in the biosynthesis of indole alkaloid was two-fold more abundant in treated group compared to the control. In addition, mRNA expression levels of genes involved in the indole alkaloid biosynthetic pathway indicated an up-regulation in their transcription in C. roseus under UV-B irradiation. These results suggest that binary stress might negatively affect the process of photosynthesis in C. roseus. In addition, the induction of alkaloid biosynthesis appears to be responsive to binary stress. PMID:26284098

A Root-Expressed l-Phenylalanine:4-Hydroxyphenylpyruvate Aminotransferase Is Required for Tropane Alkaloid Biosynthesis in Atropa belladonna[C][W

PubMed Central

Bedewitz, Matthew A.; Góngora-Castillo, Elsa; Uebler, Joseph B.; Gonzales-Vigil, Eliana; Wiegert-Rininger, Krystle E.; Childs, Kevin L.; Hamilton, John P.; Vaillancourt, Brieanne; Yeo, Yun-Soo; Chappell, Joseph; DellaPenna, Dean; Jones, A. Daniel; Buell, C. Robin; Barry, Cornelius S.

2014-01-01

The tropane alkaloids, hyoscyamine and scopolamine, are medicinal compounds that are the active components of several therapeutics. Hyoscyamine and scopolamine are synthesized in the roots of specific genera of the Solanaceae in a multistep pathway that is only partially elucidated. To facilitate greater understanding of tropane alkaloid biosynthesis, a de novo transcriptome assembly was developed for Deadly Nightshade (Atropa belladonna). Littorine is a key intermediate in hyoscyamine and scopolamine biosynthesis that is produced by the condensation of tropine and phenyllactic acid. Phenyllactic acid is derived from phenylalanine via its transamination to phenylpyruvate, and mining of the transcriptome identified a phylogenetically distinct aromatic amino acid aminotransferase (ArAT), designated Ab-ArAT4, that is coexpressed with known tropane alkaloid biosynthesis genes in the roots of A. belladonna. Silencing of Ab-ArAT4 disrupted synthesis of hyoscyamine and scopolamine through reduction of phenyllactic acid levels. Recombinant Ab-ArAT4 preferentially catalyzes the first step in phenyllactic acid synthesis, the transamination of phenylalanine to phenylpyruvate. However, rather than utilizing the typical keto-acid cosubstrates, 2-oxoglutarate, pyruvate, and oxaloacetate, Ab-ArAT4 possesses strong substrate preference and highest activity with the aromatic keto-acid, 4-hydroxyphenylpyruvate. Thus, Ab-ArAT4 operates at the interface between primary and specialized metabolism, contributing to both tropane alkaloid biosynthesis and the direct conversion of phenylalanine to tyrosine. PMID:25228340

Horizontal acquisition of toxic alkaloid synthesis in a clade of plant associated fungi.

PubMed

Marcet-Houben, Marina; Gabaldón, Toni

2016-01-01

Clavicipitaceae is a fungal group that comprises species that closely interact with plants as pathogens, parasites or symbionts. A key factor in these interactions is the ability of these fungi to synthesize toxic alkaloid compounds that contribute to the protection of the plant host against herbivores. Some of these compounds such as ergot alkaloids are toxic to humans and have caused important epidemics throughout history. The gene clusters encoding the proteins responsible for the synthesis of ergot alkaloids and lolines in Clavicipitaceae have been elucidated. Notably, homologs to these gene clusters can be found in distantly related species such as Aspergillus fumigatus and Penicillium expansum, which diverged from Clavicipitaceae more than 400 million years ago. We here use a phylogenetic approach to analyze the evolution of these gene clusters. We found that the gene clusters conferring the ability to synthesize ergot alkaloids and loline emerged first in Eurotiomycetes and were then likely transferred horizontally to Clavicipitaceae. Horizontal gene transfer is known to play a role in shaping the distribution of secondary metabolism clusters across distantly related fungal species. We propose that HGT events have played an important role in the capability of Clavicipitaceae to produce two key secondary metabolites that have enhanced the ability of these species to protect their plant hosts, therefore favoring their interactions. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Biocatalytic organic synthesis of optically pure (S)-scoulerine and berbine and benzylisoquinoline alkaloids.

PubMed

Schrittwieser, Joerg H; Resch, Verena; Wallner, Silvia; Lienhart, Wolf-Dieter; Sattler, Johann H; Resch, Jasmin; Macheroux, Peter; Kroutil, Wolfgang

2011-08-19

A chemoenzymatic approach for the asymmetric total synthesis of the title compounds is described that employs an enantioselective oxidative C-C bond formation catalyzed by berberine bridge enzyme (BBE) in the asymmetric key step. This unique reaction yielded enantiomerically pure (R)-benzylisoquinoline derivatives and (S)-berbines such as the natural product (S)-scoulerine, a sedative and muscle relaxing agent. The racemic substrates rac-1 required for the biotransformation were prepared in 4-8 linear steps using either a Bischler-Napieralski cyclization or a C1-Cα alkylation approach. The chemoenzymatic synthesis was applied to the preparation of fourteen enantiomerically pure alkaloids, including the natural products (S)-scoulerine and (R)-reticuline, and gave overall yields of up to 20% over 5-9 linear steps.

Accumulation of Monoterpenoid Indole Alkaloids in Periwinkle Seedlings ("Catharanthus roseus") as a Model for the Study of Plant-Environment Interactions

ERIC Educational Resources Information Center

Miranda-Ham, Maria de Lourdes; Islas-Flores, Ignacio; Vazquez-Flota, Felipe

2007-01-01

Alkaloids are part of the chemical arsenal designed to protect plants against an adverse environment. Therefore, their synthesis and accumulation are frequently induced in response to certain environmental conditions and are mediated by chemical signals, which are formed as the first responses to the external stimulus. A set of experiments using…

Rhodium-Catalyzed Denitrogenative [3+2] Cycloaddition: Access to Functionalized Hydroindolones and the Framework of Montanine-Type Amaryllidaceae Alkaloids.

PubMed

Yang, Hongjian; Hou, Shengtai; Tao, Cheng; Liu, Zhao; Wang, Chao; Cheng, Bin; Li, Yun; Zhai, Hongbin

2017-09-18

Rhodium-catalyzed denitrogenative [3+2] cycloaddition of 1-sulfonyl-1,2,3-triazoles with cyclic silyl dienol ethers has been developed for the synthesis of functionalized hydroindolones or their corresponding silyl ethers. The present method has been employed to construct synthetically valuable bicyclo[3.3.1]alkenone derivatives and pyrrolidine-ring-containing bicyclic indole compounds. As a further synthetic application, a stereoselective synthesis of 5,11-methanomorphanthridin-3-one, which shares a key skeleton with montanine-type Amaryllidaceae alkaloids has been achieved by using this chemistry. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Structure, synthesis and biological properties of the pentacyclic guanidinium alkaloids.

PubMed

Shi, Yunlong; Moazami, Yasamin; Pierce, Joshua G

2017-06-01

The pentacyclic guanidinium alkaloids (PGAs) are a family of marine natural products that possess a polycyclic guanidine-containing core and a long alkyl chain tethered spermidine-derived tail that is rarely observed in other natural products. These natural products exhibit potent activities on a wide range of organisms and therefore have attracted the attention of many synthetic chemists; however, the structure-activity relationships and mechanisms of action of PGAs remain largely elusive. Herein we summarize the structure, synthesis, toxicity and mechanisms of action of PGAs and highlight their potential as chemical probes and/or therapeutic leads. Copyright © 2017 Elsevier Ltd. All rights reserved.

Rh-Catalyzed [3 + 2] Cycloaddition of 1-Sulfonyl-1,2,3-triazoles: Access to the Framework of Aspidosperma and Kopsia Indole Alkaloids.

PubMed

Li, Yun; Zhang, Qingyu; Du, Qiucheng; Zhai, Hongbin

2016-08-19

A Rh(II)-catalyzed dearomative intramolecular [3 + 2] dipolar cycloaddition involving the indolic C2-C3 carbon-carbon double bond has been developed. The reaction was launched from the triazole moiety within the substrate and proceeded efficiently under mild conditions. A wide range of functional groups could be tolerated. These features render the current reaction a highly useful tool for the synthesis of polycyclic indole alkaloids, as showcased by a rapid assembly of the core structure of Aspidosperma and the related alkaloids.

Enzymic synthesis of γ-coniceine in Conium maculatum chloroplasts and mitochondria.

PubMed

Roberts, M F

1981-08-01

Further studies of the transaminase responsible for the first committed step in alkaloid formation in Conium maculatum have shown the L-alanine: 5-ketooctanal transaminase to occur in both the mitochondria and chloroplast. Experiments suggest that these enzymes are the isoenzymes Transaminase A and B respectively previously isolated by the author. It is suggested that the chloroplast enzyme is normally responsible for alkaloid production.

Chemistry and Biology of the Pyrrole-Imidazole Alkaloids.

PubMed

Lindel, Thomas

More than a decade after our last review on the chemistry of the pyrrole-imidazole alkaloids, it was time to analyze once more the developments in that field. The comprehensive article focusses on the total syntheses of pyrrole-imidazole alkaloids that have appeared since 2005. The classic monomeric pyrrole-imidazole alkaloids have all been synthesized, sometimes primarily to demonstrate the usefulness of a new method, as in the case of the related molecules agelastatin A and cyclooroidin with more than 15 syntheses altogether. The phakellin skeleton has been made more than 10 times, too, with a focus on the target structure itself. Thus, some of the pyrrole-imidazole alkaloids are now available in gram amounts, and the supply problem has been solved. The total synthesis of the dimeric pyrrole-imidazole alkaloids is still mostly in its pioneering phase with two routes to palau'amine and massadine discovered and three routes to the axinellamines and ageliferin. In addition, the review summarizes recent discoveries regarding the biological activity of the pyrrole-imidazole alkaloids. Regarding the biosynthesis of sceptrin, a pathway is proposed that starts from nagelamide I and proceeds via two electrocyclizations and reduction. Copyright © 2017 Elsevier Inc. All rights reserved.

Bioinspired total synthesis and structural revision of yuremamine, an alkaloid from the entheogenic plant Mimosa tenuiflora.

PubMed

Calvert, Matthew B; Sperry, Jonathan

2015-04-11

Guided by a biosynthetic hypothesis, a serendipitous total synthesis of yuremamine has resulted in its structural revision from the putative pyrroloindole (1) to the flavonoidal indole (2), which was initially proposed as a biosynthetic intermediate.

A root-expressed L-phenylalanine:4-hydroxyphenylpyruvate aminotransferase is required for tropane alkaloid biosynthesis in Atropa belladonna.

PubMed

Bedewitz, Matthew A; Góngora-Castillo, Elsa; Uebler, Joseph B; Gonzales-Vigil, Eliana; Wiegert-Rininger, Krystle E; Childs, Kevin L; Hamilton, John P; Vaillancourt, Brieanne; Yeo, Yun-Soo; Chappell, Joseph; DellaPenna, Dean; Jones, A Daniel; Buell, C Robin; Barry, Cornelius S

2014-09-01

The tropane alkaloids, hyoscyamine and scopolamine, are medicinal compounds that are the active components of several therapeutics. Hyoscyamine and scopolamine are synthesized in the roots of specific genera of the Solanaceae in a multistep pathway that is only partially elucidated. To facilitate greater understanding of tropane alkaloid biosynthesis, a de novo transcriptome assembly was developed for Deadly Nightshade (Atropa belladonna). Littorine is a key intermediate in hyoscyamine and scopolamine biosynthesis that is produced by the condensation of tropine and phenyllactic acid. Phenyllactic acid is derived from phenylalanine via its transamination to phenylpyruvate, and mining of the transcriptome identified a phylogenetically distinct aromatic amino acid aminotransferase (ArAT), designated Ab-ArAT4, that is coexpressed with known tropane alkaloid biosynthesis genes in the roots of A. belladonna. Silencing of Ab-ArAT4 disrupted synthesis of hyoscyamine and scopolamine through reduction of phenyllactic acid levels. Recombinant Ab-ArAT4 preferentially catalyzes the first step in phenyllactic acid synthesis, the transamination of phenylalanine to phenylpyruvate. However, rather than utilizing the typical keto-acid cosubstrates, 2-oxoglutarate, pyruvate, and oxaloacetate, Ab-ArAT4 possesses strong substrate preference and highest activity with the aromatic keto-acid, 4-hydroxyphenylpyruvate. Thus, Ab-ArAT4 operates at the interface between primary and specialized metabolism, contributing to both tropane alkaloid biosynthesis and the direct conversion of phenylalanine to tyrosine. © 2014 American Society of Plant Biologists. All rights reserved.

A stereoselective synthesis of (+)-physoperuvine using a tandem aza-Claisen rearrangement and ring closing metathesis reaction.

PubMed

Zaed, Ahmed M; Swift, Michael D; Sutherland, Andrew

2009-07-07

A stereoselective synthesis of (+)-physoperuvine, a tropane alkaloid from Physalis peruviana Linne has been developed using a one-pot tandem aza-Claisen rearrangement and ring closing metathesis reaction to form the key amino-substituted cycloheptene ring.

Modulation of Ergot Alkaloids in a Grass-Endophyte Symbiosis by Alteration of mRNA Concentrations of an Ergot Alkaloid Synthesis Gene.

PubMed

Mulinti, Prashanthi; Florea, Simona; Schardl, Christopher L; Panaccione, Daniel G

2016-06-22

The profile of ergot alkaloids in perennial ryegrass (Lolium perenne) containing the endophytic fungus Epichloë typhina × festucae includes high concentrations of the early pathway metabolites ergotryptamine and chanoclavine-I in addition to the pathway end-product ergovaline. Because these alkaloids differ in activity, we investigated strategies to alter their relative concentrations. An RNAi-based approach reduced the concentration of mRNA from the gene easA, which encodes an enzyme required for a ring closure that separates ergotryptamine and chanoclavine-I from ergovaline. Lower easA mRNA concentrations correlated with lower concentrations of ergovaline and higher concentrations of ergotryptamine and chanoclavine-I. Overexpression of easA led to higher concentrations of ergovaline in leaf blades but not in pseudostems; concentrations of the early pathway metabolites were not altered in overexpression strains. The data indicate that altering the concentration of mRNA from a single gene can change alkaloid flux, but the magnitude of the change was limited and variable.

Racemic alkaloids from the fungus Ganoderma cochlear.

PubMed

Wang, Xin-Long; Dou, Man; Luo, Qi; Cheng, Li-Zhi; Yan, Yong-Ming; Li, Rong-Tao; Cheng, Yong-Xian

2017-01-01

Seven pairs of new alkaloid enantiomers, ganocochlearines C-I (1, 3-8), and three pairs of known alkaloids were isolated from the fruiting bodies of Ganoderma cochlear. The chemical structures of new compounds were elucidated on the basis of 1D and 2D NMR data. The absolute configurations of compounds 1, 3-10 were assigned by ECD calculations. Biological activities of these isolates against renal fibrosis were accessed in rat normal or diseased renal interstitial fibroblast cells. Importantly, the plausible biosynthetic pathway for this class of alkaloids was originally proposed. Copyright © 2016 Elsevier B.V. All rights reserved.

Part 1. Synthetic approaches to indole/imidazole marine alkaloids. Part 2. 1-cyanobenzotriazole as a cyanating agent. Part 3. Synthesis of potential molecular rectifiers

NASA Astrophysics Data System (ADS)

Hughes, Terry Vincent

1999-12-01

This dissertation consists of four chapters. The first chapter details the progress toward a total synthesis of securine A (1). Securine A is an indole/imidazole containing marine alkaloid which contains a 2,3-disubstituted indole ring and a 4,5- disubstituted imidazole ring with a 12-membered lactam connecting the two. The approach into the securine A ring system utilized the opening of a pyrano[3,4-b]indol-3-one ring system with a modified histamine derivative. Efforts in the synthesis of securine A were not successful, but the synthesis of a similar analogue, compound 53, which contained a 13-membered ring was achieved. Chapter two deals with the total synthesis of the indole/maleimide/imidazole containing marine alkaloids: the didemnimides A-D (84- 87). The total syntheses of didemnimide A-D were successful and utilized a base catalyzed condensation reaction of methyl indolyl-3-glyoxylate (102) and 1-trityl-4-imidazoleacetamide (104). Chapter three details a new and convenient synthesis of 1-cyanobenzotriazole (123) and efforts to use it as a source of +CN in carbon-carbon forming reactions. The synthesis is safer than previously reported methods and allows for 123 to be made in multi-gram scale rather inexpensively. It was demonstrated that 1-cyanobenzotriazole (123) is a good source of +CN in carbon-carbon forming reactions by reacting with a variety of sp3, Sp 2, and sp carbanions. Chapter four details a new synthesis of hexadecylquinolinium tricyanoquinodimethanide (171) which has been shown to be a molecular rectifier. In search of additional molecular rectifiers, this new methodology was applied to the synthesis of Z- β-(N-n -hexadecyl-2-benzothiazolium)-α-cyano-4-styryldicyanomethanide (181) as well as its selenium and tellurium analogues 190 and 200; respectively. Additionally, the synthesis of other T- D+-π-A- types of molecules was explored in search for other molecular rectifiers. However, of all the compounds synthesized herein, only 171 has been shown to rectify.

Formicine ants: An arthropod source for the pumiliotoxin alkaloids of dendrobatid poison frogs

PubMed Central

Saporito, Ralph A.; Garraffo, H. Martin; Donnelly, Maureen A.; Edwards, Adam L.; Longino, John T.; Daly, John W.

2004-01-01

A remarkable diversity of bioactive lipophilic alkaloids is present in the skin of poison frogs and toads worldwide. Originally discovered in neotropical dendrobatid frogs, these alkaloids are now known from mantellid frogs of Madagascar, certain myobatrachid frogs of Australia, and certain bufonid toads of South America. Presumably serving as a passive chemical defense, these alkaloids appear to be sequestered from a variety of alkaloid-containing arthropods. The pumiliotoxins represent a major, widespread, group of alkaloids that are found in virtually all anurans that are chemically defended by the presence of lipophilic alkaloids. Identifying an arthropod source for these alkaloids has been a considerable challenge for chemical ecologists. However, an extensive collection of neotropical forest arthropods has now revealed a putative arthropod source of the pumiliotoxins. Here we report on the presence of pumiliotoxins in formicine ants of the genera Brachymyrmex and Paratrechina, as well as the presence of these ants in the stomach contents of the microsympatric pumiliotoxin-containing dendrobatid frog, Dendrobates pumilio. These pumiliotoxins are major alkaloids in D. pumilio, and Brachymyrmex and Paratrechina ants now represent the only known dietary sources of these toxic alkaloids. These findings further support the significance of ant-specialization and alkaloid sequestration in the evolution of bright warning coloration in poison frogs and toads. PMID:15128938

Optimization of yeast-based production of medicinal protoberberine alkaloids.

PubMed

Galanie, Stephanie; Smolke, Christina D

2015-09-16

Protoberberine alkaloids are bioactive molecules abundant in plant preparations for traditional medicines. Yeast engineered to express biosynthetic pathways for fermentative production of these compounds will further enable investigation of the medicinal properties of these molecules and development of alkaloid-based drugs with improved efficacy and safety. Here, we describe the optimization of a biosynthetic pathway in Saccharomyces cerevisiae for conversion of rac-norlaudanosoline to the protoberberine alkaloid (S)-canadine. This yeast strain is engineered to express seven heterologous enzymes, resulting in protoberberine alkaloid production from a simple benzylisoquinoline alkaloid precursor. The seven enzymes include three membrane-bound enzymes: the flavin-dependent oxidase berberine bridge enzyme, the cytochrome P450 canadine synthase, and a cytochrome P450 reductase. A number of strategies were implemented to improve flux through the pathway, including enzyme variant screening, genetic copy number variation, and culture optimization, that led to an over 70-fold increase in canadine titer up to 1.8 mg/L. Increased canadine titers enable extension of the pathway to produce berberine, a major constituent of several traditional medicines, for the first time in a microbial host. We also demonstrate that this strain is viable at pilot scale. By applying metabolic engineering and synthetic biology strategies for increased conversion of simple benzylisoquinoline alkaloids to complex protoberberine alkaloids, this work will facilitate chemoenzymatic synthesis or de novo biosynthesis of these and other high-value compounds using a microbial cell factory.

Marine Indole Alkaloids

PubMed Central

Netz, Natalie; Opatz, Till

2015-01-01

Marine indole alkaloids comprise a large and steadily growing group of secondary metabolites. Their diverse biological activities make many compounds of this class attractive starting points for pharmaceutical development. Several marine-derived indoles were found to possess cytotoxic, antineoplastic, antibacterial and antimicrobial activities, in addition to the action on human enzymes and receptors. The newly isolated indole alkaloids of marine origin since the last comprehensive review in 2003 are reported, and biological aspects will be discussed. PMID:26287214

Enantioselective Synthesis of All-Carbon Quaternary Centers Structurally Related to Amaryllidaceae Alkaloids.

PubMed

Mikušek, Jiří; Jansa, Petr; Jagtap, Pratap R; Vašíček, Tomáš; Císařová, Ivana; Matoušová, Eliška

2018-05-18

Enantioselective synthesis of all-carbon quaternary centers remains a considerable challenge for synthetic organic chemists. Here, we report a two-step protocol to synthesize such centers including tandem cyclization/Suzuki cross-coupling followed by halocarbocyclization. During this process, two rings, three new C-C bonds and a stereochemically defined all-carbon quaternary center are formed. The absolute configuration of this center is controlled by the stereochemistry of the adjacent stereocenter, which derives from an appropriate enantioenriched starting material. Using this method, we synthesized polycyclic compounds structurally similar to Amaryllidaceae alkaloids in high enantiomeric excesses. Because these products resemble naturally occurring compounds, our protocol can be used to synthesize various potentially bioactive compounds. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

How polyamine synthesis inhibitors and cinnamic acid affect tropane alkaloid production.

PubMed

Marconi, Patricia L; Alvarez, María A; Pitta-Alvarez, Sandra I

2007-01-01

Hairy roots of Brugmansia candida produce the tropane alkaloids scopolamine and hyoscyamine. In an attempt to divert the carbon flux from competing pathways and thus enhance productivity, the polyamine biosynthesis inhibitors cyclohexylamine (CHA) and methylglyoxal-bis-guanylhydrazone (MGBG) and the phenylalanine-ammonia-lyase inhibitor cinnamic acid were used. CHA decreased the specific productivity of both alkaloids but increased significantly the release of scopolamine (approx 500%) when it was added in the mid-exponential phase. However, when CHA was added for only 48 h during the exponential phase, the specific productivity of both alkaloids increased (approx 200%), favoring scopolamine. Treatment with MGBG was detrimental to growth but promoted release into the medium of both alkaloids. However, when it was added for 48 h during the exponential phase, MGBG increased the specific productivity (approx 200%) and release (250- 1800%) of both alkaloids. Cinnamic acid alone also favored release but not specific productivity. When a combination of CHA or MGBG with cinnamic acid was used, the results obtained were approximately the same as with each polyamine biosynthesis inhibitor alone, although to a lesser extent. Regarding root morphology, CHA inhibited growth of primary roots and ramification. However, it had a positive effect on elongation of lateral roots.

[Polymethyleneamine alkaloids of animal origin: II. Polyamine neurotoxins].

PubMed

Rogoza, L N; Salakhutdinov, N F; Tolstikov, G A

2006-01-01

Information on the structure and biological activity of animal alkaloids, polymethyleneamine components of spider and wasp venoms, is considered and systematized. These natural compounds are used for the development and modification of medicines for treating the functional disturbances in the central nervous system of humans.

Enantioselective Synthesis of (-)-Vallesine: Late-Stage C17-Oxidation via Complex Indole Boronation.

PubMed

Antropow, Alyssa H; Garcia, Nicholas R; White, Kolby L; Movassaghi, Mohammad

2018-06-04

The first enantioselective total synthesis of (-)-vallesine via a strategy that features a late-stage regioselective C17-oxidation followed by a highly stereoselective transannular cyclization is reported. The versatility of this approach is highlighted by the divergent synthesis of the archetypal alkaloid of this family, (+)-aspidospermidine, and an A-ring-oxygenated derivative, (+)-deacetylaspidospermine, the precursor to (-)-vallesine, from a common intermediate.

Synthesis of indolizidinone analogues of cytotoxic alkaloids: monocyclic precursors are also active.

PubMed

Boto, Alicia; Miguélez, Javier; Marín, Raquel; Díaz, Mario

2012-05-15

Readily available proline derivatives can be transformed in just two steps into analogues of cytotoxic phenanthroindolizidine alkaloids. The key step uses a sequential radical scission-oxidation-alkylation process, which yields 2-substituted pyrrolidine amides. A second process effects the cyclization to give the desired alkaloid analogues, which possess an indolizidine core. The major and minor isomers (dr 3:2 to 3:1) can be easily separated, allowing their use to study structure-activity relationships (SAR). The process is versatile and allows the introduction of aryl and heteroaryl groups (including biphenyl, halogenated phenyl, and pyrrole rings). Some of these alkaloid analogues displayed a selective cytotoxic activity against tumorogenic human neuronal and mammary cancer cells, and one derivative caused around 80% cell death in both tumor lines at micromolar doses. The cytotoxicity of some monocyclic precursors was also studied, being comparable or superior to the bicyclic derivatives. Copyright © 2012 Elsevier Ltd. All rights reserved.

Marine Natural Product Bis-indole Alkaloid Caulerpin: Chemistry and Biology.

PubMed

Lunagariya, Jignesh; Bhadja, Poonam; Zhong, Shenghui; Vekariya, Rohit; Xu, Shihai

2017-09-27

Marine bis-indole alkaloids comprise a large and increasingly growing class of secondary metabolites, and continue to deliver a great variety of structural templates. The alkaloids derived from marine resources play a crucial role in medicinal chemistry and as chemical agents. In particular, bis-indole alkaloid caulerpin isolated from marine green algae Caulerpa and a red algae Chondria armata at various places around the world, and tested against several therapeutic areas such as anti-diabetic, antinociceptive, anti-inflammatory, anti-tumor, anti-larvicidal, anti-herpes, anti-tubercular, anti-microbial and immunostimulating activity as well as means of other chemical agents. Herein, we summarized discovery of caulerpin, and its potential medicinal and chemical applications in chronological order with various aspects. Additionally, synthesis of caulerpin, its functional analogues, and structural isomer have also been reviewed. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Indole alkaloid marine natural products: An established source of cancer drug leads with considerable promise for the control of parasitic, neurological and other diseases

PubMed Central

Gul, Waseem; Hamann, Mark T.

2016-01-01

The marine environment produces natural products from a variety of structural classes exhibiting activity against numerous disease targets. Historically marine natural products have largely been explored as anticancer agents. The indole alkaloids are a class of marine natural products that show unique promise in the development of new drug leads. This report reviews the literature on indole alkaloids of marine origin and also highlights our own research. Specific biological activities of indole alkaloids presented here include: cytotoxicity, antiviral, antiparasitic, anti-inflammatory, serotonin antagonism, Ca-releasing, calmodulin antagonism, and other pharmacological activities. PMID:16236327

Synthesis and evaluation of new antimalarial analogues of quinoline alkaloids derived from Cinchona ledgeriana Moens ex Trimen.

PubMed

Park, Byeoung-Soo; Kim, Dae-Young; Rosenthal, Philip J; Huh, Sun-Chul; Lee, Belinda J; Park, Eun -u; Kim, Sung-Min; Kim, Jang-Eok; Kim, Mi-Hee; Huh, Tae-Lin; Choi, Young-Jae; Suh, Ki-Hyung; Choi, Won-Sik; Lee, Sung-Eun

2002-05-20

In the course of attempts to develop antimalarial drugs, we have designed and synthesized a series of quinoline alkaloide derivatives. Three of them, N-(4-methoxy-3,5-di-tert-butylbenzyl)cinchonidinium bromide (OSL-5), O-benzyl-N-(3,5-di-tert-butyl-4-methoxybenzyl)cinchonidinium bromide (OSL-7), and N-(3,5-di-tert-butyl-4-methoxybenzyl)quininium bromide (OSL-14) show potent activity against Plasmodium falciparum.

Expedient preparation of nazlinine and a small library of indole alkaloids using flow electrochemistry as an enabling technology.

PubMed

Kabeshov, Mikhail A; Musio, Biagia; Murray, Philip R D; Browne, Duncan L; Ley, Steven V

2014-09-05

An expedient synthesis of the indole alkaloid nazlinine is reported. Judicious choice of flow electrochemistry as an enabling technology has permitted the rapid generation of a small library of unnatural relatives of this biologically active molecule. Furthermore, by conducting the key electrochemical Shono oxidation in a flow cell, the loading of electrolyte can be significantly reduced to 20 mol % while maintaining a stable, broadly applicable process.

Staphylococcal enterotoxin A gene-carrying Staphylococcus aureus isolated from foods and its control by crude alkaloid from papaya leaves.

PubMed

Handayani, Lita; Faridah, Didah Nur; Kusumaningrum, Harsi D

2014-11-01

Staphylococcus aureus is a known pathogen causing intoxication by producing enterotoxins in food. Staphylococcal enterotoxin A is one of the enterotoxins commonly implicated in staphylococcal food poisoning. The ability of crude alkaloid extract from papaya leaves to inhibit the growth of S. aureus and staphylococcal enterotoxin A synthesis was investigated. Staphylococcal enterotoxin A gene-carrying S. aureus was isolated from raw milk and ready-to-eat foods. Crude alkaloid was extracted from ground, dried papaya leaves using ultrasonic-assisted extraction, and a MIC of the alkaloid was determined by the broth macrodilution method. Furthermore, S. aureus isolate was exposed to the crude alkaloid extract at one- and twofold MIC, and the expression of sea was subsequently analyzed using a quantitative reverse transcription real-time PCR. Ten isolates of S. aureus were obtained, and nine of those isolates were sea carriers. The yield of crude alkaloid extract was 0.48 to 1.82% per dry weight of papaya leaves. A MIC of crude alkaloid to S. aureus was 0.25 mg/ml. After exposure to the alkaloid at 0.25 and 0.5 mg/ml for 2 h, a significant increase in cycle threshold values of sea was observed. The sea was expressed 29 and 41 times less when S. aureus was exposed to crude alkaloid at one- and twofold MIC, respectively. This study revealed that crude alkaloid of papaya leaves could control staphylococcal enterotoxin A gene-carrying S. aureus by suppressing the expression of sea, in addition to the ability to inhibit the growth of S. aureus. The expression of sea was successfully quantified.

[The biosynthesis of low-molecular-weight nitrogen-containing secondary metabolite-alkaloids by the resident strains of Penicillium chrysogenum and Penicillium expansum isolated on the board of the Mir space station ].

PubMed

Kozlovskiĭ, A G; Zhelifonova, V P; Adanin, V M; Antipova, T V; Shnyreva, A V; Viktorov, A N

2002-01-01

The analysis of the absorption spectra of the low-molecular-weight nitrogen-containing secondary metabolites--alkaloids--of 4 Penicillium chrysogenum strains and 6 Penicillium expansum strains isolated on board the Mir space station showed that all these strains synthesize metabolites of alkaloid origin (roquefortine, 3,12-dihydroroquefortine, meleagrin, viridicatin, viridicatol, isorugulosuvin, rugulosuvin B, N-acetyl-tryptamine, and a "yellow metabolite" containing the benzoquinone chromophore).

Development of the Vinylogous Pictet-Spengler Cyclization and Total Synthesis of (±)-Lundurine A.

PubMed

Nash, Aaron; Qi, Xiangbing; Maity, Pradip; Owens, Kyle; Tambar, Uttam K

2018-04-16

A novel vinylogous Pictet-Spengler cyclization has been developed for the generation of indole-annulated medium-sized rings. The method enables the synthesis of tetrahydroazocinoindoles with a fully substituted carbon center, a prevalent structural motif in many biologically active alkaloids. The strategy has been applied to the total synthesis of (±)-lundurine A. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Studies toward the synthesis of palhinine lycopodium alkaloids: a Morita-Baylis-Hillman/intramolecular Diels-Alder approach.

PubMed

Sizemore, Nicholas; Rychnovsky, Scott D

2014-02-07

A synthetic route to the isotwistane core of palhinine lycopodium alkaloids is described. A Morita-Baylis-Hillman/intramolecular Diels-Alder (IMDA) strategy sets the vicinal all-carbon quaternary centers present in this family of natural products. The regioselectivity of the IMDA reaction is dictated by the conditions employed for silyl enol ether formation, with one set of conditions providing the core of cardionine and alternate conditions generating the desired isotwistane core of isopalhinine.

Quantification of Aconitum alkaloids in aconite roots by a modified RP-HPLC method.

PubMed

Jiang, Zhi-Hong; Xie, Ying; Zhou, Hua; Wang, Jing-Rong; Liu, Zhong-Qiu; Wong, Yuen-Fan; Cai, Xiong; Xu, Hong-Xi; Liu, Liang

2005-01-01

The three Aconitum alkaloids, aconitine (1), mesaconitine (2) and hypaconitine (3), are pharmacologically active but also highly toxic. A standardised method is needed for assessing the levels of these alkaloids in aconite roots in order to ensure the safe use of these plant materials as medicinal herbs. By optimising extraction, separation and measurement conditions, a reliable, reproducible and accurate method for the quantitative determination of all three Aconitum alkaloids in unprocessed and processed aconite roots has been developed. This method should be appropriate for use in the quality control of Aconitum products. The three Aconitum alkaloids were separated by a modified HPLC method employing a C18 column gradient eluted with acetonitrile and ammonium bicarbonate buffer. Quantification of Aconitum alkaloids, detected at 240 nm, in different batches of samples showed that the content of 1, 2 and 3 varied significantly. In general, the alkaloid content of unprocessed roots was higher than that of processed roots. These variations were considered to be the result of differences in species, processing methods and places of origin of the samples.

Convergent Substitutions in a Sodium Channel Suggest Multiple Origins of Toxin Resistance in Poison Frogs.

PubMed

Tarvin, Rebecca D; Santos, Juan C; O'Connell, Lauren A; Zakon, Harold H; Cannatella, David C

2016-04-01

Complex phenotypes typically have a correspondingly multifaceted genetic component. However, the genotype-phenotype association between chemical defense and resistance is often simple: genetic changes in the binding site of a toxin alter how it affects its target. Some toxic organisms, such as poison frogs (Anura: Dendrobatidae), have defensive alkaloids that disrupt the function of ion channels, proteins that are crucial for nerve and muscle activity. Using protein-docking models, we predict that three major classes of poison frog alkaloids (histrionicotoxins, pumiliotoxins, and batrachotoxins) bind to similar sites in the highly conserved inner pore of the muscle voltage-gated sodium channel, Nav1.4. We predict that poison frogs are somewhat resistant to these compounds because they have six types of amino acid replacements in the Nav1.4 inner pore that are absent in all other frogs except for a distantly related alkaloid-defended frog from Madagascar, Mantella aurantiaca. Protein-docking models and comparative phylogenetics support the role of these replacements in alkaloid resistance. Taking into account the four independent origins of chemical defense in Dendrobatidae, phylogenetic patterns of the amino acid replacements suggest that 1) alkaloid resistance in Nav1.4 evolved independently at least seven times in these frogs, 2) variation in resistance-conferring replacements is likely a result of differences in alkaloid exposure across species, and 3) functional constraint shapes the evolution of the Nav1.4 inner pore. Our study is the first to demonstrate the genetic basis of autoresistance in frogs with alkaloid defenses. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Total synthesis of (+/-)-strychnine via a [4 + 2]-cycloaddition/rearrangement cascade.

PubMed

Zhang, Hongjun; Boonsombat, Jutatip; Padwa, Albert

2007-01-18

A new strategy for the synthesis of the Strychnos alkaloid (+/-)-strychnine has been developed and is based on an intramolecular [4 + 2]-cycloaddition/rearrangement cascade of an indolyl-substituted amidofuran. The critical D-ring was assembled by an intramolecular palladium-catalyzed enolate-driven cross-coupling of an N-tethered vinyl iodide. [reaction: see text].

Total Synthesis of (±)-Strychnine via a [4+2]-Cycloaddition/Rearrangement Cascade

PubMed Central

Zhang, Hongjun; Boonsombat, Jutatip

2008-01-01

A new strategy for the synthesis of the Strychnos alkaloid (±)-strychnine has been developed and is based on an intramolecular [4+2]-cycloaddition/rearrangement cascade of an indolyl substituted amidofuran. The critical D-ring was assembled by an intramolecular palladium catalyzed enolate-driven cross-coupling of an N-tethered vinyl iodide. PMID:17217284

An old yellow enzyme gene controls the branch point between Aspergillus fumigatus and Claviceps purpurea ergot alkaloid pathways.

PubMed

Coyle, Christine M; Cheng, Johnathan Z; O'Connor, Sarah E; Panaccione, Daniel G

2010-06-01

Ergot fungi in the genus Claviceps and several related fungal groups in the family Clavicipitaceae produce toxic ergot alkaloids. These fungi produce a variety of ergot alkaloids, including clavines as well as lysergic acid derivatives. Ergot alkaloids are also produced by the distantly related, opportunistic human pathogen Aspergillus fumigatus. However, this fungus produces festuclavine and fumigaclavines A, B, and C, which collectively differ from clavines of clavicipitaceous fungi in saturation of the last assembled of four rings in the ergoline ring structure. The two lineages are hypothesized to share early steps of the ergot alkaloid pathway before diverging at some point after the synthesis of the tricyclic intermediate chanoclavine-I. Disruption of easA, a gene predicted to encode a flavin-dependent oxidoreductase of the old yellow enzyme class, in A. fumigatus led to accumulation of chanoclavine-I and chanoclavine-I-aldehyde. Complementation of the A. fumigatus easA mutant with a wild-type allele from the same fungus restored the wild-type profile of ergot alkaloids. These data demonstrate that the product of A. fumigatus easA is required for incorporation of chanoclavine-I-aldehyde into more-complex ergot alkaloids, presumably by reducing the double bond conjugated to the aldehyde group, thus facilitating ring closure. Augmentation of the A. fumigatus easA mutant with a homologue of easA from Claviceps purpurea resulted in accumulation of ergot alkaloids typical of clavicipitaceous fungi (agroclavine, setoclavine, and its diastereoisomer isosetoclavine). These data indicate that functional differences in the easA-encoded old yellow enzymes of A. fumigatus and C. purpurea result in divergence of their respective ergot alkaloid pathways.

An Old Yellow Enzyme Gene Controls the Branch Point between Aspergillus fumigatus and Claviceps purpurea Ergot Alkaloid Pathways▿

PubMed Central

Coyle, Christine M.; Cheng, Johnathan Z.; O'Connor, Sarah E.; Panaccione, Daniel G.

2010-01-01

Ergot fungi in the genus Claviceps and several related fungal groups in the family Clavicipitaceae produce toxic ergot alkaloids. These fungi produce a variety of ergot alkaloids, including clavines as well as lysergic acid derivatives. Ergot alkaloids are also produced by the distantly related, opportunistic human pathogen Aspergillus fumigatus. However, this fungus produces festuclavine and fumigaclavines A, B, and C, which collectively differ from clavines of clavicipitaceous fungi in saturation of the last assembled of four rings in the ergoline ring structure. The two lineages are hypothesized to share early steps of the ergot alkaloid pathway before diverging at some point after the synthesis of the tricyclic intermediate chanoclavine-I. Disruption of easA, a gene predicted to encode a flavin-dependent oxidoreductase of the old yellow enzyme class, in A. fumigatus led to accumulation of chanoclavine-I and chanoclavine-I-aldehyde. Complementation of the A. fumigatus easA mutant with a wild-type allele from the same fungus restored the wild-type profile of ergot alkaloids. These data demonstrate that the product of A. fumigatus easA is required for incorporation of chanoclavine-I-aldehyde into more-complex ergot alkaloids, presumably by reducing the double bond conjugated to the aldehyde group, thus facilitating ring closure. Augmentation of the A. fumigatus easA mutant with a homologue of easA from Claviceps purpurea resulted in accumulation of ergot alkaloids typical of clavicipitaceous fungi (agroclavine, setoclavine, and its diastereoisomer isosetoclavine). These data indicate that functional differences in the easA-encoded old yellow enzymes of A. fumigatus and C. purpurea result in divergence of their respective ergot alkaloid pathways. PMID:20435769

Flexible synthesis of poison-frog alkaloids of the 5,8-disubstituted indolizidine-class. II: Synthesis of (-)-209B, (-)-231C, (-)-233D, (-)-235B", (-)-221I, and an epimer of 193E and pharmacological effects at neuronal nicotinic acetylcholine receptors.

PubMed

Kobayashi, Soushi; Toyooka, Naoki; Zhou, Dejun; Tsuneki, Hiroshi; Wada, Tsutomu; Sasaoka, Toshiyasu; Sakai, Hideki; Nemoto, Hideo; Garraffo, H Martin; Spande, Thomas F; Daly, John W

2007-01-01

The 5,8-disubstituted indolizidines constitute the largest class of poison-frog alkaloids. Some alkaloids have been shown to act as noncompetitive blockers at nicotinic acetylcholine receptors but the proposed structures and the biological activities of most of the 5,8-disubstituted indolizidines have not been determined because of limited supplies of the natural products. We have therefore conducted experiments to confirm proposed structures and determine biological activities using synthetic compounds. Recently, we reported that one of this class of alkaloids, (-)-235B', acts as a noncompetitive antagonist for α4β2 nicotinic receptors, and its sensitivity is comparable to that of the classical competitive antagonist for this receptor, dihydro-β-erythroidine. The enantioselective syntheses of (-)-209B, (-)-231C, (-)-233D, (-)-235B", (-)-221I, and what proved to be an epimer of natural 193E, starting from common chiral lactams have been achieved. When we performed electrophysiological recordings to examine the effects of the synthetic alkaloids on two major subtypes of nicotinic receptors (α4β2 and α7) expressed in Xenopus laevis oocytes, (-)-231C effectively blocked α4β2 receptor responses (IC(50 )value, 1.5 μM) with a 7.0-fold higher potency than for blockade of α7 receptor responses. In contrast, synthetic (-)-221I and (-)-epi-193E were more potent in blocking α7 receptor responses (IC(50 )value, 4.4 μM and 9.1 μM, respectively) than α4β2 receptor responses (5.3-fold and 2.0-fold, respectively). We achieved the total synthesis of (-)-209B, (-)-231C, (-)-233D, (-)-235B", (-)-221I, and an epimer of 193E starting from common chiral lactams, and the absolute stereochemistry of natural (-)-233D was determined. Furthermore, the relative stereochemistry of (-)-231C and (-)-221I was also determined. The present asymmetric synthesis of the proposed structure for 193E revealed that the C-8 configuration of natural 193E should be revised. The selectivity for α4β2 and α7 nicotinic receptors differed markedly for the 5,8-disubstituted indolizidines tested, and thus it appears that the nature of the side chains in these indolizidines is crucial with regard to subtype-selectivity.

Unravelling the architecture and dynamics of tropane alkaloid biosynthesis pathways using metabolite correlation networks.

PubMed

Nguyen, Thi-Kieu-Oanh; Jamali, Arash; Lanoue, Arnaud; Gontier, Eric; Dauwe, Rebecca

2015-08-01

The tropane alkaloid spectrum in Solanaceae is highly variable within and between species. Little is known about the topology and the coordination of the biosynthetic pathways leading to the variety of tropine and pseudotropine derived esters in the alkaloid spectrum, or about the metabolic dynamics induced by tropane alkaloid biosynthesis stimulating conditions. A good understanding of the metabolism, including all ramifications, is however necessary for the development of strategies to increase the abundance of pharmacologically interesting compounds such as hyoscyamine and scopolamine. The present study explores the tropane alkaloid metabolic pathways in an untargeted approach involving a correlation-based network analysis. Using GC-MS metabolite profiling, the variation and co-variation among tropane alkaloids and primary metabolites was monitored in 60 Datura innoxia Mill. individuals, of which half were exposed to tropane alkaloid biosynthesis stimulating conditions by co-culture with Agrobacterium rhizogenes. Considerable variation was evident in the relative proportions of the tropane alkaloids. Remodeling of the tropane alkaloid spectrum under co-culture with A. rhizogenes involved a specific and strong increase of hyoscyamine production and revealed that the accumulation of hyoscyamine, 3-tigloyloxy-6,7-epoxytropane, and 3-methylbutyryloxytropane was controlled independently of the majority of tropane alkaloids. Based on correlations between metabolites, we propose a biosynthetic origin of hygrine, the order of esterification of certain di-oxygenated tropanes, and that the rate of acetoxylation contributes to control of hyoscyamine production. Overall, this study shows that the biosynthesis of tropane alkaloids may be far more complex and finely controlled than previously expected. Copyright © 2015 Elsevier Ltd. All rights reserved.

Synthesis of Antiproliferative Cephalotaxus Esters and Their Evaluation against Several Human Hematopoietic and Solid Tumor Cell Lines: Uncovering Differential Susceptibilities to Multidrug Resistance

PubMed Central

Eckelbarger, Joseph D.; Wilmot, Jeremy T.; Epperson, Matthew T.; Thakur, Chandar S.; Shum, David; Antczak, Christophe; Tarassishin, Leonid; Djaballah, Hakim; Gin, David Y.

2008-01-01

Deoxyharringtonine (2), homoharringtonine (3), homodeoxyharringtonine (4), and anhydroharringtonine (5) are reported to be among the most potent members of the antileukemia alkaloids isolated from the Cephalotaxus genus. Convergent syntheses of these four natural products are described, each involving novel synthetic methods and strategies. These syntheses enabled evaluation of several advanced natural and non-natural compounds against an array of human hematopoietic and solid tumor cells. Potent cytotoxicity was observed in several cell lines previously not challenged with these alkaloids. Variations in the structure of the ester chain within this family of alkaloids confer differing activity profiles against vincristine-resistant HL-60/RV+, signalling new avenues for molecular design of these natural products to combat multi-drug resistance. PMID:18366032

How Cinchona Alkaloid-Derived Primary Amines Control Asymmetric Electrophilic Fluorination of Cyclic Ketones

PubMed Central

2015-01-01

The origin of selectivity in the α-fluorination of cyclic ketones catalyzed by cinchona alkaloid-derived primary amines is determined with density functional calculations. The chair preference of a seven-membered ring at the fluorine transfer transition state is key in determining the sense and level of enantiofacial selectivity. PMID:24967514

Alkaloid Cluster Gene ccsA of the Ergot Fungus Claviceps purpurea Encodes Chanoclavine I Synthase, a Flavin Adenine Dinucleotide-Containing Oxidoreductase Mediating the Transformation of N-Methyl-Dimethylallyltryptophan to Chanoclavine I ▿

PubMed Central

Lorenz, Nicole; Olšovská, Jana; Šulc, Miroslav; Tudzynski, Paul

2010-01-01

Ergot alkaloids are indole-derived secondary metabolites synthesized by the phytopathogenic ascomycete Claviceps purpurea. In wild-type strains, they are exclusively produced in the sclerotium, a hibernation structure; for biotechnological applications, submerse production strains have been generated by mutagenesis. It was shown previously that the enzymes specific for alkaloid biosynthesis are encoded by a gene cluster of 68.5 kb. This ergot alkaloid cluster consists of 14 genes coregulated and expressed under alkaloid-producing conditions. Although the role of some of the cluster genes in alkaloid biosynthesis could be confirmed by a targeted knockout approach, further functional analyses are needed, especially concerning the early pathway-specific steps up to the production of clavine alkaloids. Therefore, the gene ccsA, originally named easE and preliminarily annotated as coding for a flavin adenine dinucleotide-containing oxidoreductase, was deleted in the C. purpurea strain P1, which is able to synthesize ergot alkaloids in axenic culture. Five independent knockout mutants were analyzed with regard to alkaloid-producing capability. Thin-layer chromatography (TLC), ultrapressure liquid chromatography (UPLC), and mass spectrometry (MS) analyses revealed accumulation of N-methyl-dimethylallyltryptophan (Me-DMAT) and traces of dimethylallyltryptophan (DMAT), the first pathway-specific intermediate. Since other alkaloid intermediates could not be detected, we conclude that deletion of ccsA led to a block in alkaloid biosynthesis beyond Me-DMAT formation. Complementation with a ccsA/gfp fusion construct restored alkaloid biosynthesis. These data indicate that ccsA encodes the chanoclavine I synthase or a component thereof catalyzing the conversion of N-methyl-dimethylallyltryptophan to chanoclavine I. PMID:20118373

Alkaloid cluster gene ccsA of the ergot fungus Claviceps purpurea encodes chanoclavine I synthase, a flavin adenine dinucleotide-containing oxidoreductase mediating the transformation of N-methyl-dimethylallyltryptophan to chanoclavine I.

PubMed

Lorenz, Nicole; Olsovská, Jana; Sulc, Miroslav; Tudzynski, Paul

2010-03-01

Ergot alkaloids are indole-derived secondary metabolites synthesized by the phytopathogenic ascomycete Claviceps purpurea. In wild-type strains, they are exclusively produced in the sclerotium, a hibernation structure; for biotechnological applications, submerse production strains have been generated by mutagenesis. It was shown previously that the enzymes specific for alkaloid biosynthesis are encoded by a gene cluster of 68.5 kb. This ergot alkaloid cluster consists of 14 genes coregulated and expressed under alkaloid-producing conditions. Although the role of some of the cluster genes in alkaloid biosynthesis could be confirmed by a targeted knockout approach, further functional analyses are needed, especially concerning the early pathway-specific steps up to the production of clavine alkaloids. Therefore, the gene ccsA, originally named easE and preliminarily annotated as coding for a flavin adenine dinucleotide-containing oxidoreductase, was deleted in the C. purpurea strain P1, which is able to synthesize ergot alkaloids in axenic culture. Five independent knockout mutants were analyzed with regard to alkaloid-producing capability. Thin-layer chromatography (TLC), ultrapressure liquid chromatography (UPLC), and mass spectrometry (MS) analyses revealed accumulation of N-methyl-dimethylallyltryptophan (Me-DMAT) and traces of dimethylallyltryptophan (DMAT), the first pathway-specific intermediate. Since other alkaloid intermediates could not be detected, we conclude that deletion of ccsA led to a block in alkaloid biosynthesis beyond Me-DMAT formation. Complementation with a ccsA/gfp fusion construct restored alkaloid biosynthesis. These data indicate that ccsA encodes the chanoclavine I synthase or a component thereof catalyzing the conversion of N-methyl-dimethylallyltryptophan to chanoclavine I.

Concise synthesis of the hasubanan alkaloid (±)-cepharatine A using a Suzuki coupling reaction to effect o,p-phenolic coupling.

PubMed

Magnus, Philip; Seipp, Charles

2013-09-20

Suzuki coupling of 10 and 11 resulted in 9, which was O-alkylated to provide 12. Treatment of 12 with CsF in DMF resulted in the formation of the completed core structure 13 in a single step. Reductive amination of 13 completed the synthesis of (±)-cepharatine A, 4.

Organocatalytic sequential alpha-amination-Horner-Wadsworth-Emmons olefination of aldehydes: enantioselective synthesis of gamma-amino-alpha,beta-unsaturated esters.

PubMed

Kotkar, Shriram P; Chavan, Vilas B; Sudalai, Arumugam

2007-03-15

A novel and highly enantioselective method for the synthesis of gamma-amino-alpha,beta-unsaturated esters via tandem alpha-amination-Horner-Wadsworth-Emmons (HWE) olefination of aldehydes is described. The one-pot assembly has been demonstrated for the construction of functionalized chiral 2-pyrrolidones, subunits present in several alkaloids. [structure: see text

DMSO/Tf2O-mediated cross-coupling of tryptamine with substituted aniline to access C3a-N1'-linked pyrroloindoline alkaloids.

PubMed

Tayu, Masanori; Ishizaki, Takako; Higuchi, Kazuhiro; Kawasaki, Tomomi

2015-04-07

The cross-coupling of tryptamine with substituted aniline to access C3a-nitrogen-linked pyrroloindolines has been developed via the consecutive cyclization of tryptamine with DMSO/Tf2O and the substitution of 3a-pyrroloindolylthionium intermediate with aniline. The use of 2,3-dihydrotryptamine instead of aniline enabled easy access to 3a-(1-indolyl)pyrroloindoline and the concise synthesis of C3a-N1'-linked pyrroloindoline alkaloid (±)-psychotriasine was accomplished.

Concise Synthesis of (-)-Hodgkinsine, (-)-Calycosidine, (-)-Hodgkinsine B, (-)-Quadrigemine C, and (-)-Psycholeine via Convergent and Directed Modular Assembly of Cyclotryptamines.

PubMed

Lindovska, Petra; Movassaghi, Mohammad

2017-12-06

The enantioselective total synthesis of (-)-hodgkinsine, (-)-calycosidine, (-)-hodgkinsine B, (-)-quadrigemine C, and (-)-psycholeine through a diazene-directed assembly of cyclotryptamine fragments is described. Our synthetic strategy enables multiple and directed assembly of intact cyclotryptamine subunits for convergent synthesis of highly complex bis- and tris-diazene intermediates. Photoextrusion of dinitrogen from these intermediates enables completely stereoselective formation of all C3a-C3a' and C3a-C7' carbon-carbon bonds and all the associated quaternary stereogenic centers. In a representative example, photoextrusion of three dinitrogen molecules from an advanced intermediate in a single-step led to completely controlled introduction of four quaternary stereogenic centers and guided the assembly of four cyclotryptamine monomers en route to (-)-quadrigemine C. The synthesis of these complex diazenes was made possible through a new methodology for synthesis of aryl-alkyl diazenes using electronically attenuated hydrazine-nucleophiles for a silver-promoted addition to C3a-bromocyclotryptamines. The application of Rh- and Ir-catalyzed C-H amination reactions in complex settings were used to gain rapid access to C3a- and C7-functionalized cyclotryptamine monomers, respectively, used for diazene synthesis. This convergent and modular assembly of intact cyclotryptamines offers the first solution to access these alkaloids through completely stereoselective union of monomers at challenging linkages and the associated quaternary stereocenters as illustrated in our synthesis of five members of the oligocyclotryptamine family of alkaloids.

The coffee genome provides insight into the convergent evolution of caffeine biosynthesis.

PubMed

Denoeud, France; Carretero-Paulet, Lorenzo; Dereeper, Alexis; Droc, Gaëtan; Guyot, Romain; Pietrella, Marco; Zheng, Chunfang; Alberti, Adriana; Anthony, François; Aprea, Giuseppe; Aury, Jean-Marc; Bento, Pascal; Bernard, Maria; Bocs, Stéphanie; Campa, Claudine; Cenci, Alberto; Combes, Marie-Christine; Crouzillat, Dominique; Da Silva, Corinne; Daddiego, Loretta; De Bellis, Fabien; Dussert, Stéphane; Garsmeur, Olivier; Gayraud, Thomas; Guignon, Valentin; Jahn, Katharina; Jamilloux, Véronique; Joët, Thierry; Labadie, Karine; Lan, Tianying; Leclercq, Julie; Lepelley, Maud; Leroy, Thierry; Li, Lei-Ting; Librado, Pablo; Lopez, Loredana; Muñoz, Adriana; Noel, Benjamin; Pallavicini, Alberto; Perrotta, Gaetano; Poncet, Valérie; Pot, David; Priyono; Rigoreau, Michel; Rouard, Mathieu; Rozas, Julio; Tranchant-Dubreuil, Christine; VanBuren, Robert; Zhang, Qiong; Andrade, Alan C; Argout, Xavier; Bertrand, Benoît; de Kochko, Alexandre; Graziosi, Giorgio; Henry, Robert J; Jayarama; Ming, Ray; Nagai, Chifumi; Rounsley, Steve; Sankoff, David; Giuliano, Giovanni; Albert, Victor A; Wincker, Patrick; Lashermes, Philippe

2014-09-05

Coffee is a valuable beverage crop due to its characteristic flavor, aroma, and the stimulating effects of caffeine. We generated a high-quality draft genome of the species Coffea canephora, which displays a conserved chromosomal gene order among asterid angiosperms. Although it shows no sign of the whole-genome triplication identified in Solanaceae species such as tomato, the genome includes several species-specific gene family expansions, among them N-methyltransferases (NMTs) involved in caffeine production, defense-related genes, and alkaloid and flavonoid enzymes involved in secondary compound synthesis. Comparative analyses of caffeine NMTs demonstrate that these genes expanded through sequential tandem duplications independently of genes from cacao and tea, suggesting that caffeine in eudicots is of polyphyletic origin. Copyright © 2014, American Association for the Advancement of Science.

Biogenetically-Inspired Total Synthesis of Epidithiodiketopiperazines and Related Alkaloids

PubMed Central

2015-01-01

Conspectus Natural products chemistry has historically been the prime arena for the discovery of new chemical transformations and the fountain of insights into key biological processes. It remains a fervent incubator of progress in the fields of chemistry and biology and an exchange mediating the flow of ideas between these allied fields of science. It is with this ethos that our group has taken an interest in and pursued the synthesis of a complex family of natural products termed the dimeric epipolythiodiketopiperazine (ETP) alkaloids. We present here an Account of the highly complex target molecules to which we pegged our ambitions, our systematic and relentless efforts toward those goals, the chemistry we developed in their pursuit, and the insight we have gained for their translational potential as potent anticancer molecules. The dimeric ETP alkaloids are fungal metabolites that feature a highly complex molecular architecture comprising a densely functionalized core structure with many stereogenic centers, six of which are fully substituted, and a pair of vicinal quaternary carbon stereocenters, decorated on polycyclic architectures in addition to the unique ETP motif that has been recognized as acid-, base-, and redox-sensitive. A cyclo-dipeptide consisting of an essential tryptophan residue and a highly variable ancillary amino acid lies at the core of these structures; investigation of the transformations that take this simplistic core to the complex alkaloids lies at the heart of our research program. The dimeric epidithiodiketopiperazine alkaloids have largely resisted synthesis on account of their complexity since the 1970s when the founding members of this class, chaetocin A (HauserD. et al. Helv. Chim. Acta1970, 53, 10615448218) and verticillin A (KatagiriK. et al. J. Antibiot.1970, 23, 4205465723), were first isolated. This was despite their potent cytotoxic and bacteriostatic activities, which were well appreciated at the time of their discovery. In the past decade, an increasing number of studies have uncovered powerful new biological processes that these molecules can uniquely effect, such as the inhibition of histone methyltransferases by chaetocin A (GreinerD. et al. Nat. Chem. Biol.2005, 1, 14316408017). In fact, the complete collection of hexahydropyrroloindoline alkaloids features a diverse range of potent biological properties including cytotoxic, antitumor, antileukemic, antiviral, antibiotic, and antinematodal activities (JiangC.-S.; GuoY.-W.Mini-Rev. Med. Chem.2011, 11, 72821651467). This mélange of activities is reflective of their structural diversity. Under the precepts of retrobiosynthetic analysis, we have accomplished the syntheses of more than a dozen natural products, including members of the bionectin, calycanthaceous, chaetocin, gliocladin, naseseazine, and verticillin alkaloids. More importantly, these molecules have acted as venerable venues for the development of new strategies to address structural challenges including, but not limited to, C3–C3′ vicinal quaternary centers, heterodimeric linkages, C3–Csp2 linkages, diketopiperazine oxidation, stereoselective thiolation, homologue-specific polysulfidation, and C12-hydroxyl incorporation. Synthesis of these natural products has resulted in the structural confirmation, and sometimes revision such as the case of (+)-naseseazines A and B, as well as access to many plausible biogenetically relevant intermediates and new synthetic ETP derivatives. Furthermore, our studies have paved the way for the formulation of a comprehensive SAR profile and the identification of lead compounds with in vitro subnanomolar IC50’s against a broad range of cancer types. PMID:25843276

Is there no end to the total syntheses of strychnine? Lessons to be learned for strategy and tactics in total synthesis**

PubMed Central

Cannon, Jeffrey S.; Overman, Larry E.

2013-01-01

From the 19th century to the present, the complex indole alkaloid strychnine has engaged the chemical community. In this review, we examine why strychnine has been and remains today an important target for directed synthesis efforts. A selection of the diverse syntheses of strychnine is discussed with the aim of identifying their influence on the evolution of the strategy and tactics of organic synthesis. PMID:22431197

Microbial and Functional Biodiversity Patterns in Sponges that Accumulate Bromopyrrole Alkaloids Suggest Horizontal Gene Transfer of Halogenase Genes.

PubMed

Rua, Cintia P J; de Oliveira, Louisi S; Froes, Adriana; Tschoeke, Diogo A; Soares, Ana Carolina; Leomil, Luciana; Gregoracci, Gustavo B; Coutinho, Ricardo; Hajdu, Eduardo; Thompson, Cristiane C; Berlinck, Roberto G S; Thompson, Fabiano L

2018-03-15

Marine sponge holobionts harbor complex microbial communities whose members may be the true producers of secondary metabolites accumulated by sponges. Bromopyrrole alkaloids constitute a typical class of secondary metabolites isolated from sponges that very often display biological activities. Bromine incorporation into secondary metabolites can be catalyzed by either halogenases or haloperoxidases. The diversity of the metagenomes of sponge holobiont species containing bromopyrrole alkaloids (Agelas spp. and Tedania brasiliensis) as well as holobionts devoid of bromopyrrole alkaloids spanning in a vast biogeographic region (approx. Seven thousand km) was studied. The origin and specificity of the detected halogenases was also investigated. The holobionts Agelas spp. and T. brasiliensis did not share microbial halogenases, suggesting a species-specific pattern. Bacteria of diverse phylogenetic origins encoding halogenase genes were found to be more abundant in bromopyrrole-containing sponges. The sponge holobionts (e.g., Agelas spp.) with the greatest number of sequences related to clustered, interspaced, short, palindromic repeats (CRISPRs) exhibited the fewest phage halogenases, suggesting a possible mechanism of protection from phage infection by the sponge host. This study highlights the potential of phages to transport halogenases horizontally across host sponges, particularly in more permissive holobiont hosts, such as Tedania spp.

Marine toxins and nonmarine toxins: convergence or symbiotic organisms?

PubMed

Daly, John W

2004-08-01

Bioactive marine natural products occur only rarely in nonmarine sources. The converse also is true. Divergent evolutionary pathways for the biosynthesis of bioactive secondary metabolites seem to be the rule. Marine biosynthetic pathways lead to a wide variety of different structural classes, among which polyethers, macrolides, terpenes, unusual amino acids/peptides, and alkaloids are notable. Nonmarine biosynthetic pathways also lead to a similar wide variety of structural classes. However, the structures are usually quite different from the marine analogues. The alkaloids of plants are notable, but again there appears little convergence between the marine and nonmarine alkaloids. However, tetrodotoxin, a remarkable, highly polar, marine alkaloid, does occur in various amphibians. The occurrence and possible origin of tetrodotoxin and congeners, including chiriquitoxin, and of the saxitoxin analogue zetekitoxin in amphibians are reviewed.

Bioinspired chemical synthesis of monomeric and dimeric stephacidin A congeners

NASA Astrophysics Data System (ADS)

Mukai, Ken; de Sant'ana, Danilo Pereira; Hirooka, Yasuo; Mercado-Marin, Eduardo V.; Stephens, David E.; Kou, Kevin G. M.; Richter, Sven C.; Kelley, Naomi; Sarpong, Richmond

2018-01-01

Stephacidin A and its congeners are a collection of secondary metabolites that possess intriguing structural motifs. They stem from unusual biosynthetic sequences that lead to the incorporation of a prenyl or reverse-prenyl group into a bicyclo[2.2.2]diazaoctane framework, a chromene unit or the vestige thereof. To complement biosynthetic studies, which normally play a significant role in unveiling the biosynthetic pathways of natural products, here we demonstrate that chemical synthesis can provide important insights into biosynthesis. We identify a short total synthesis of congeners in the reverse-prenylated indole alkaloid family related to stephacidin A by taking advantage of a direct indole C6 halogenation of the related ketopremalbrancheamide. This novel strategic approach has now made possible the syntheses of several natural products, including malbrancheamides B and C, notoamides F, I and R, aspergamide B, and waikialoid A, which is a heterodimer of avrainvillamide and aspergamide B. Our approach to the preparation of these prenylated and reverse-prenylated indole alkaloids is bioinspired, and may also inform the as-yet undetermined biosynthesis of several congeners.

Functional analysis of the gene controlling hydroxylation of festuclavine in the ergot alkaloid pathway of Neosartorya fumigata

PubMed Central

Bilovol, Yulia; Panaccione, Daniel G.

2016-01-01

Bioactive ergot alkaloids produced by several species of fungi are important molecules in agriculture and medicine. Much of the ergot alkaloid pathway has been elucidated, but a few steps, including the gene controlling hydroxylation of festuclavine to fumigaclavine B, remain unsolved. Festuclavine is a key intermediate in the fumigaclavine branch of the ergot alkaloid pathway of the opportunistic pathogen Neosartorya fumigata and also in the dihydrolysergic acid-based ergot alkaloid pathway of certain Claviceps species. Based on several lines of evidence, the N. fumigata gene easM is a logical candidate to encode the festuclavine-hydroxylating enzyme. To test this hypothesis we disrupted easM function by replacing part of its coding sequences with a hygromycin resistance gene and transforming N. fumigata with this construct. High pressure liquid chromatography analysis demonstrated that easM deletion mutants were blocked in the ergot alkaloid pathway at festuclavine, and downstream products were eliminated. An additional alkaloid, proposed to be a prenylated form of festuclavine on the basis of mass spectral data, also accumulated to higher concentrations in the easM knockout. Complementation with the wild-type allele of easM gene restored the ability of the fungus to produce downstream compounds. These results indicate that easM encodes an enzyme required for fumigaclavine B synthesis likely by hydroxylating festuclavine. The festuclavine-accumulating strain of N. fumigata may facilitate future investigations of the biosynthesis of dihydrolysergic acid derivatives, which are derived from festuclavine and are the basis for several important drugs. PMID:26972831

Functional analysis of the gene controlling hydroxylation of festuclavine in the ergot alkaloid pathway of Neosartorya fumigata.

PubMed

Bilovol, Yulia; Panaccione, Daniel G

2016-11-01

Bioactive ergot alkaloids produced by several species of fungi are important molecules in agriculture and medicine. Much of the ergot alkaloid pathway has been elucidated, but a few steps, including the gene controlling hydroxylation of festuclavine to fumigaclavine B, remain unsolved. Festuclavine is a key intermediate in the fumigaclavine branch of the ergot alkaloid pathway of the opportunistic pathogen Neosartorya fumigata and also in the dihydrolysergic acid-based ergot alkaloid pathway of certain Claviceps species. Based on several lines of evidence, the N. fumigata gene easM is a logical candidate to encode the festuclavine-hydroxylating enzyme. To test this hypothesis we disrupted easM function by replacing part of its coding sequences with a hygromycin resistance gene and transforming N. fumigata with this construct. High-pressure liquid chromatography analysis demonstrated that easM deletion mutants were blocked in the ergot alkaloid pathway at festuclavine, and downstream products were eliminated. An additional alkaloid, proposed to be a prenylated form of festuclavine on the basis of mass spectral data, also accumulated to higher concentrations in the easM knockout. Complementation with the wild-type allele of easM gene restored the ability of the fungus to produce downstream compounds. These results indicate that easM encodes an enzyme required for fumigaclavine B synthesis likely by hydroxylating festuclavine. The festuclavine-accumulating strain of N. fumigata may facilitate future investigations of the biosynthesis of dihydrolysergic acid derivatives, which are derived from festuclavine and are the basis for several important drugs.

Synthesis and Anticancer Activity of Epipolythiodiketopiperazine Alkaloids

PubMed Central

Boyer, Nicolas; Morrison, Karen C.; Kim, Justin; Hergenrother, Paul J.; Movassaghi, Mohammad

2013-01-01

The epipolythiodiketopiperazine (ETP) alkaloids are a highly complex class of natural products with potent anticancer activity. Herein, we report the application of a flexible and scalable synthesis, allowing the construction of dozens of ETP derivatives. The evaluation of these compounds against cancer cell lines in culture allows for the first expansive structure–activity relationship (SAR) to be defined for monomeric and dimeric ETP-containing natural products and their synthetic cognates. Many ETP derivatives demonstrate potent anticancer activity across a broad range of cancer cell lines, and kill cancer cellsviainduction of apoptosis. Several traits thatbode well for the translational potential of the ETP class of natural products includeconcise and efficient synthetic access, potent induction of apoptotic cell death, activity against a wide range of cancer types, and a broad tolerance for modifications at multiple sitesthat should facilitate small-molecule drug development, mechanistic studies, and evaluation in vivo. PMID:23914293

Design, synthesis, antiviral activity and mode of action of phenanthrene-containing N-heterocyclic compounds inspired by the phenanthroindolizidine alkaloid antofine.

PubMed

Yu, Xiuling; Wei, Peng; Wang, Ziwen; Liu, Yuxiu; Wang, Lizhong; Wang, Qingmin

2016-02-01

The phenanthroindolizidine alkaloid antofine and its analogues have excellent antiviral activity against tobacco mosaic virus (TMV). To simplify the structure and the synthesis of the phenanthroindolizidine alkaloid, a series of phenanthrene-containing N-heterocyclic compounds (compounds 1 to 33) were designed and synthesised, based on the intermolecular interaction of antofine and TMV RNA, and systematically evaluated for their anti-TMV activity. Most of these compounds exhibited good to reasonable anti-TMV activity. The optimum compounds 5, 12 and 21 displayed higher activity than the lead compound antofine and commercial ribavirin. Compound 12 was chosen for field trials of antiviral efficacy against TMV, and was found to exhibit better activity than control plant virus inhibitors. Compounds 5 and 12 were chosen for mode of action studies. The changes in fluorescence intensity of compounds 5 and 12 on separated TMV RNA showed that these small molecules can also bind to TMV RNA, but the mode is very different from that of antofine. The compounds combining phenanthrene and an N-heterocyclic ring could maintain the anti-TMV activity of phenanthroindolizidines, but their modes of action are different from that of antofine. The present study lays a good foundation for us to find more efficient anti-plant virus reagents. © 2015 Society of Chemical Industry.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Borszeky, K.; Mallat, T.; Aeschiman, R.

The chemo- and enantioselective hydrogenation of pyruvic acid oxime have been studied on Pd/alumina, the latter in the presence of the 1,2-amino alcohol type alkaloids ephedrine, cinchonidine, and cinchonine. High yields of racemic alanine (90-98%) were obtained in the absence of alkaloids in polar solvents at 0-45{degrees}C and 10 bar. Enantioselection increased with higher temperature and alkalid: oxime molar ratio. A 1:1 ephedrine: oxime molar ratio afforded the best enantiomeric excess (26%). The presence of alkaloid resulted in a decrease of reaction rate by a factor of up to 140, compared to the racemic hydrogenation. Based on X-ray crystal structuremore » analysis of the alkaloid-pyruvic acid oxime adduct, a mechanism is proposed for the steric course of the reaction. Extended interactions by multiple H bonds between the adsorbed alkaloid-oxime salt units on the Pd surface is assumed to be at the origin of the moderate enantioselectivity and the very low enantioselective hydrogenation rate. 28 refs., 5 figs., 3 tabs.« less

Biologically active quinoline and quinazoline alkaloids part I.

PubMed

Shang, Xiao-Fei; Morris-Natschke, Susan L; Liu, Ying-Qian; Guo, Xiao; Xu, Xiao-Shan; Goto, Masuo; Li, Jun-Cai; Yang, Guan-Zhou; Lee, Kuo-Hsiung

2018-05-01

Quinoline and quinazoline alkaloids, two important classes of N-based heterocyclic compounds, have attracted tremendous attention from researchers worldwide since the 19th century. Over the past 200 years, many compounds from these two classes were isolated from natural sources, and most of them and their modified analogs possess significant bioactivities. Quinine and camptothecin are two of the most famous and important quinoline alkaloids, and their discoveries opened new areas in antimalarial and anticancer drug development, respectively. In this review, we survey the literature on bioactive alkaloids from these two classes and highlight research achievements prior to the year 2008 (Part I). Over 200 molecules with a broad range of bioactivities, including antitumor, antimalarial, antibacterial and antifungal, antiparasitic and insecticidal, antiviral, antiplatelet, anti-inflammatory, herbicidal, antioxidant and other activities, were reviewed. This survey should provide new clues or possibilities for the discovery of new and better drugs from the original naturally occurring quinoline and quinazoline alkaloids. © 2017 Wiley Periodicals, Inc.

Effects of down-regulating ornithine decarboxylase upon putrescine-associated metabolism and growth in Nicotiana tabacum L.

PubMed Central

Dalton, Heidi L.; Blomstedt, Cecilia K.; Neale, Alan D.; Gleadow, Ros; DeBoer, Kathleen D.; Hamill, John D.

2016-01-01

Transgenic plants of Nicotiana tabacum L. homozygous for an RNAi construct designed to silence ornithine decarboxylase (ODC) had significantly lower concentrations of nicotine and nornicotine, but significantly higher concentrations of anatabine, compared with vector-only controls. Silencing of ODC also led to significantly reduced concentrations of polyamines (putrescine, spermidine and spermine), tyramine and phenolamides (caffeoylputrescine and dicaffeoylspermidine) with concomitant increases in concentrations of amino acids ornithine, arginine, aspartate, glutamate and glutamine. Root transcript levels of S-adenosyl methionine decarboxylase, S-adenosyl methionine synthase and spermidine synthase (polyamine synthesis enzymes) were reduced compared with vector controls, whilst transcript levels of arginine decarboxylase (putrescine synthesis), putrescine methyltransferase (nicotine production) and multi-drug and toxic compound extrusion (alkaloid transport) proteins were elevated. In contrast, expression of two other key proteins required for alkaloid synthesis, quinolinic acid phosphoribosyltransferase (nicotinic acid production) and a PIP-family oxidoreductase (nicotinic acid condensation reactions), were diminished in roots of odc-RNAi plants relative to vector-only controls. Transcriptional and biochemical differences associated with polyamine and alkaloid metabolism were exacerbated in odc-RNAi plants in response to different forms of shoot damage. In general, apex removal had a greater effect than leaf wounding alone, with a combination of these injury treatments producing synergistic responses in some cases. Reduced expression of ODC appeared to have negative effects upon plant growth and vigour with some leaves of odc-RNAi lines being brittle and bleached compared with vector-only controls. Together, results of this study demonstrate that ornithine decarboxylase has important roles in facilitating both primary and secondary metabolism in Nicotiana. PMID:27126795

Alkaloids and leishmania donovani UDP-galactopyarnose mutase: Anovel approach in drug designing against Visceral leishmaniasis.

PubMed

Srivastava, Ankita; Chandra, Deepak

2017-06-05

The unsatisfactory treatment options for Visceral Leishmaniasis (VL), needs identification of new drug targets. Among natural products, Alkaloids have been proved to be highly effective against number of diseases. In Leishmania UDP-galactopyranose mutase (UGM) is a critical enzyme required for cell wall synthesis and thus a drug target for structure based drug designing against L. donovani. To build the homology model of UDP galactopyranse mutase and investigate the interaction of selected alkaloids with this modeled UDP galactopyranose mutase by molecular docking. Since there is no crystal structure record has been found with this protein, a homology modeling was performed and a three dimensional structure of L. donovani UGM was created using MODELLER v9.9, structure quality was validated using PROCHECK and QMEAN programs which confirms that the structure is reliable. Further Molecular docking was performed with previously reported 15 alkaloids. It was found that Protopine shows a binding energy of -12.39Kcal/mole, binds at Flavin adenine dinucleotide (FAD) biding site. Concluding that Protopine, an alkaloid could interrupt the functional aspect of L. donovani UGM and thus may be useful for drug designing studies. These finding would contribute to the understanding of effect of drug on the parasite. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Isostrychnine synthesis mediated by hypervalent iodine reagent.

PubMed

Jacquemot, Guillaume; Maertens, Gaëtan; Canesi, Sylvain

2015-05-18

Althought there are several reported synthetic routes to strychnine, one of the most widely recognized alkaloids, we report an unexplored route with an oxidative dearomatizing process mediated by hypervalent iodine as the key step. The new syntheses of isostrychnine and strychnine have been achieved from an readily available phenol in nine and ten steps. In addition to the key step, these syntheses involve an aza Michael-ether-enol tandem transformation, two heck type cyclizations, a reductive isomerization, and a double reductive amination in cascade leading to the alkaloid main core. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis and Antiproliferative Activity of 2,5-bis(3′-Indolyl)pyrroles, Analogues of the Marine Alkaloid Nortopsentin

PubMed Central

Carbone, Anna; Parrino, Barbara; Barraja, Paola; Spanò, Virginia; Cirrincione, Girolamo; Diana, Patrizia; Maier, Armin; Kelter, Gerhard; Fiebig, Heinz-Herbert

2013-01-01

2,5-bis(3′-Indolyl)pyrroles, analogues of the marine alkaloid nortopsentin, were conveniently prepared through a three step procedure in good overall yields. Derivatives 1a and 1b exhibited concentration-dependent antitumor activity towards a panel of 42 human tumor cell lines with mean IC50 values of 1.54 μM and 0.67 μM, respectively. Investigating human tumor xenografts in an ex-vivo clonogenic assay revealed selective antitumor activity, whereas sensitive tumor models were scattered among various tumor histotypes. PMID:23455514

Towards the Shell Biorefinery: Sustainable Synthesis of the Anticancer Alkaloid Proximicin A from Chitin.

PubMed

Sadiq, Alejandro D; Chen, Xi; Yan, Ning; Sperry, Jonathan

2018-02-09

A shell biorefinery would involve fractionation of crustacean shells and incorporation of the components into value-added products, particularly those that contain nitrogen. In a proof-of-concept study that validates this concept, the anticancer alkaloid proximicin A has been synthesized from the chitin-derived platform chemical 3-acetamido-5-acetylfuran (3A5AF). This study accentuates the leading role chitin is likely to play in the sustainable production of nitrogen-containing fine chemicals that are not directly attainable from lignocellulose. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A review on indole alkaloids isolated from Uncaria rhynchophylla and their pharmacological studies.

PubMed

Ndagijimana, Andre; Wang, Xiaoming; Pan, Guixiang; Zhang, Fan; Feng, Hong; Olaleye, Olajide

2013-04-01

Uncaria rhynchophylla (Miq.) Jacks, Rubiaceae, is one of the original plants of the important Chinese crude drug, Gou-teng, mainly used for the treatment of convulsion, hypertension, epilepsy, eclampsia, and cerebral diseases. The pharmacological activities of this plant are related to the presence of active compounds predominantly indole alkaloids. In this article, we have reviewed some reports about the pharmacological activities of the main indole alkaloids isolated from U. rhynchophylla. This review paper will contribute to the studies on the chemistry, safety and quality control of medicinal preparations containing Uncaria species. Copyright © 2013 Elsevier B.V. All rights reserved.

Synthesis of diazatricyclic core of Madangamines from cis-perhydroisoquinolines.

PubMed

Quirante, Josefina; Paloma, Laura; Diaba, Faïza; Vila, Xavier; Bonjoch, Josep

2008-01-18

Synthesis of the tricyclic core of madangamine alkaloids has been achieved in a 10-step sequence starting from a 4-(aminomethyl)anisole derivative. A Birch reduction and acylation with cyanoacetic acid followed by an intramolecular Michael process renders a polyfunctionalized cis-perhydroisoquinoline. A diastereoselective allylation and reduction of amide, nitrile, and ketone groups leads to a bicyclic alcohol, which undergoes aminocyclization through the nosyl derivative to the diazatricyclic ring.

Biogenetically inspired synthesis and skeletal diversification of indole alkaloids.

PubMed

Mizoguchi, Haruki; Oikawa, Hideaki; Oguri, Hiroki

2014-01-01

To access architecturally complex natural products, chemists usually devise a customized synthetic strategy for constructing a single target skeleton. In contrast, biosynthetic assembly lines often employ divergent intramolecular cyclizations of a polyunsaturated common intermediate to produce diverse arrays of scaffolds. With the aim of integrating such biogenetic strategies, we show the development of an artificial divergent assembly line generating unprecedented numbers of scaffold variations of terpenoid indole alkaloids. This approach not only allows practical access to multipotent intermediates, but also enables systematic diversification of skeletal, stereochemical and functional group properties without structural simplification of naturally occurring alkaloids. Three distinct modes of [4+2] cyclizations and two types of redox-mediated annulations provided divergent access to five skeletally distinct scaffolds involving iboga-, aspidosperma-, andranginine- and ngouniensine-type skeletons and a non-natural variant within six to nine steps from tryptamine. The efficiency of our approach was demonstrated by successful total syntheses of (±)-vincadifformine, (±)-andranginine and (-)-catharanthine.

Ergot cluster-encoded catalase is required for synthesis of chanoclavine-I in Aspergillus fumigatus.

PubMed

Goetz, Kerry E; Coyle, Christine M; Cheng, Johnathan Z; O'Connor, Sarah E; Panaccione, Daniel G

2011-06-01

Genes required for ergot alkaloid biosynthesis are clustered in the genomes of several fungi. Several conserved ergot cluster genes have been hypothesized, and in some cases demonstrated, to encode early steps of the pathway shared among fungi that ultimately make different ergot alkaloid end products. The deduced amino acid sequence of one of these conserved genes (easC) indicates a catalase as the product, but a role for a catalase in the ergot alkaloid pathway has not been established. We disrupted easC of Aspergillus fumigatus by homologous recombination with a truncated copy of that gene. The resulting mutant (ΔeasC) failed to produce the ergot alkaloids typically observed in A. fumigatus, including chanoclavine-I, festuclavine, and fumigaclavines B, A, and C. The ΔeasC mutant instead accumulated N-methyl-4-dimethylallyltryptophan (N-Me-DMAT), an intermediate recently shown to accumulate in Claviceps purpurea strains mutated at ccsA (called easE in A. fumigatus) (Lorenz et al. Appl Environ Microbiol 76:1822-1830, 2010). A ΔeasE disruption mutant of A. fumigatus also failed to accumulate chanoclavine-I and downstream ergot alkaloids and, instead, accumulated N-Me-DMAT. Feeding chanoclavine-I to the ΔeasC mutant restored ergot alkaloid production. Complementation of either ΔeasC or ΔeasE mutants with the respective wild-type allele also restored ergot alkaloid production. The easC gene was expressed in Escherichia coli, and the protein product displayed in vitro catalase activity with H(2)O(2) but did not act, in isolation, on N-Me-DMAT as substrate. The data indicate that the products of both easC (catalase) and easE (FAD-dependent oxidoreductase) are required for conversion of N-Me-DMAT to chanoclavine-I.

Inhibition of hematopoietic prostaglandin D2 Synthase (H-PGDS) by an alkaloid extract from Combretum molle

PubMed Central

2014-01-01

Background Hematopoietic prostaglandin D2 synthase (H-PGDS, GST Sigma) is a member of the glutathione S-transferase super family of enzymes that catalyses the conjugation of electrophilic substances with reduced glutathione. The enzyme catalyses the conversion of PGH2 to PGD2 which mediates inflammatory responses. The inhibition of H-PGDS is of importance in alleviating damage to tissues due to unwarranted synthesis of PGD2. Combretum molle has been used in African ethno medicinal practices and has been shown to reduce fever and pain. The effect of C. molle alkaloid extract on H-PGDS was thus, investigated. Methods H-PGDS was expressed in Escherichia coli XL1-Blue cells and purified using nickel immobilized metal affinity chromatography. The effect of C. molle alkaloid extract on H-PGDS activity was determined with 1-chloro-2, 4-dinitrobenzene (CDNB) as substrate. The effect of C. molle alkaloid extract with time on H-PGDS was determined. The mechanism of inhibition was then investigated using CDNB and glutathione (GSH) as substrates. Results A specific activity of 24 μmol/mg/min was obtained after H-PGDS had been purified. The alkaloid extract exhibited a 70% inhibition on H-PGDS with an IC50 of 13.7 μg/ml. C. molle alkaloid extract showed an uncompetitive inhibition of H-PGDS with Ki = 41 μg/ml towards GSH, and non-competitive inhibition towards CDNB with Ki = 7.7 μg/ml and Ki′ = 9.2 μg/ml. Conclusion The data shows that C. molle alkaloid extract is a potent inhibitor of H-PGDS. This study thus supports the traditional use of the plant for inflammation. PMID:24996417

Inhibition of hematopoietic prostaglandin D2 synthase (H-PGDS) by an alkaloid extract from Combretum molle.

PubMed

Moyo, Rejoice; Chimponda, Theresa; Mukanganyama, Stanley

2014-07-05

Hematopoietic prostaglandin D2 synthase (H-PGDS, GST Sigma) is a member of the glutathione S-transferase super family of enzymes that catalyses the conjugation of electrophilic substances with reduced glutathione. The enzyme catalyses the conversion of PGH2 to PGD2 which mediates inflammatory responses. The inhibition of H-PGDS is of importance in alleviating damage to tissues due to unwarranted synthesis of PGD2. Combretum molle has been used in African ethno medicinal practices and has been shown to reduce fever and pain. The effect of C. molle alkaloid extract on H-PGDS was thus, investigated. H-PGDS was expressed in Escherichia coli XL1-Blue cells and purified using nickel immobilized metal affinity chromatography. The effect of C. molle alkaloid extract on H-PGDS activity was determined with 1-chloro-2, 4-dinitrobenzene (CDNB) as substrate. The effect of C. molle alkaloid extract with time on H-PGDS was determined. The mechanism of inhibition was then investigated using CDNB and glutathione (GSH) as substrates. A specific activity of 24 μmol/mg/min was obtained after H-PGDS had been purified. The alkaloid extract exhibited a 70% inhibition on H-PGDS with an IC50 of 13.7 μg/ml. C. molle alkaloid extract showed an uncompetitive inhibition of H-PGDS with Ki = 41 μg/ml towards GSH, and non-competitive inhibition towards CDNB with Ki = 7.7 μg/ml and Ki' = 9.2 μg/ml. The data shows that C. molle alkaloid extract is a potent inhibitor of H-PGDS. This study thus supports the traditional use of the plant for inflammation.

Total Synthesis of Strychnine.

PubMed

Lee, Geun Seok; Namkoong, Gil; Park, Jisook; Chen, David Y-K

2017-11-16

The total synthesis of the flagship Strychnos indole alkaloid, strychnine, has been accomplished. The developed synthetic sequence features a novel vinylogous 1,4-addition, a challenging iodinium salt mediated silyl enol ether arylation, a palladium-catalyzed Heck reaction, and a streamlined late-stage conversion to strychnine. Furthermore, an application of asymmetric counterion-directed catalysis (ACDC) in the context of target-oriented organic synthesis has been rendered access to an optically active material. The synthetic sequence described herein represents the most concise entry to optically active strychnine to date. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Is there no end to the total syntheses of strychnine? Lessons learned in strategy and tactics in total synthesis.

PubMed

Cannon, Jeffrey S; Overman, Larry E

2012-04-27

From the 19th century to the present, the complex indole alkaloid strychnine has engaged the chemical community. In this Review, we examine why strychnine has been and remains today an important target for directed synthesis efforts. A selection of the diverse syntheses of strychnine is discussed with the aim of identifying their influence on the evolution of the strategy and tactics of organic synthesis. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pyrrolizidine Alkaloids from Echium vulgare in Honey Originate Primarily from Floral Nectar.

PubMed

Lucchetti, Matteo A; Glauser, Gaetan; Kilchenmann, Verena; Dübecke, Arne; Beckh, Gudrun; Praz, Christophe; Kast, Christina

2016-06-29

Pyrrolizidine alkaloids (PAs) in honey can be a potential human health risk. So far, it has remained unclear whether PAs in honey originate from pollen or floral nectar. We obtained honey, nectar, and plant pollen from two observation sites where Echium vulgare L. was naturally abundant. The PA concentration of honey was determined by targeted analysis using a high pressure liquid chromatography-mass spectrometry system (HPLC-MS/MS), allowing the quantification of six different PAs and PA-N-oxides present in E. vulgare. Echium-type PAs were detected up to 0.153 μg/g in honey. Nectar and plant pollen were analyzed by nontargeted analysis using ultrahigh pressure liquid chromatography-high resolution-mass spectrometry (UHPLC-HR-MS), allowing the detection of 10 alkaloids in small size samples. Echium-type PAs were detected between 0.3-95.1 μg/g in nectar and 500-35000 μg/g in plant pollen. The PA composition in nectar and plant pollen was compared to the composition in honey. Echimidine (+N-oxide) was the main alkaloid detected in honey and nectar samples, while echivulgarine (+N-oxide) was the main PA found in plant pollen. These results suggest that nectar contributes more significantly to PA contamination in honey than plant pollen.

Enantioselective Synthesis of SNAP-7941

PubMed Central

Goss, Jennifer M.; Schaus, Scott E.

2009-01-01

An enantioselective synthesis of SNAP-7941, a potent melanin concentrating hormone receptor antagonist, was achieved using two organocatalytic methods. The first method utilized to synthesize the enantioenriched dihydropyrimidone core was the Cinchona alkaloid-catalyzed Mannich reaction of β-keto esters to acyl imines and the second was chiral phosphoric acid-catalyzed Biginelli reaction. Completion of the synthesis was accomplished via selective urea formation at the N3 position of the dihydropyrimidone with the 3-(4-phenylpiperidin-1-yl)propyl amine side chain fragment. The synthesis of SNAP-7921 highlights the utility of asymmetric organocatalytic methods in the construction of an important class of chiral heterocycles. PMID:18767801

Zoaramine, a zoanthamine-like alkaloid with a new skeleton.

PubMed

Cen-Pacheco, Francisco; Norte, Manuel; Fernández, José J; Daranas, Antonio Hernández

2014-06-06

Chemical investigation of an Atlantic variety of Zoanthus sp. led to the isolation of two new metabolites, zoaramine and zoarenone. Their structures were deduced by the use of NMR spectroscopy and computational calculation of (1)H and (13)C chemical shifts. The core of these novel compounds resembles the structure of norzoanthamine alkaloids, and their isolation represents an important step toward a better understanding of the biogenetic origin of this group of antiosteoporotic molecules.

A General, Concise Strategy that Enables Collective Total Syntheses of over 50 Protoberberine and Five Aporhoeadane Alkaloids within Four to Eight Steps.

PubMed

Zhou, Shiqiang; Tong, Rongbiao

2016-05-17

A concise, catalytic, and general strategy that allowed efficient total syntheses of 22 natural 13-methylprotoberberines within four steps for each molecule is reported. This synthesis represents the most efficient and shortest route to date, featuring three catalytic processes: CuI-catalyzed redox-A(3) reaction, Pd-catalyzed reductive carbocyclization, and PtO2 -catalyzed hydrogenation. Importantly, this new strategy to the tetracyclic framework has also been applied to the collective concise syntheses of >30 natural protoberberines (without 13-methyl group) and five aporhoeadane alkaloids. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Emulating the logic of monoterpenoid alkaloid biogenesis to access a skeletally diverse chemical library.

PubMed

Liu, Song; Scotti, John S; Kozmin, Sergey A

2013-09-06

We have developed a synthetic strategy that mimics the diversity-generating power of monoterpenoid indole alkaloid biosynthesis. Our general approach goes beyond diversification of a single natural product-like substructure and enables production of a highly diverse collection of small molecules. The reaction sequence begins with rapid and highly modular assembly of the tetracyclic indoloquinolizidine core, which can be chemoselectively processed into several additional skeletally diverse structural frameworks. The general utility of this approach was demonstrated by parallel synthesis of two representative chemical libraries containing 847 compounds with favorable physicochemical properties to enable its subsequent broad pharmacological evaluation.

Gold(I)-catalyzed tandem cyclization approach to tetracyclic indolines.

PubMed

Liu, Yongxiang; Xu, Wenqing; Wang, Xiang

2010-04-02

Two highly stereoselective cationic gold(I)-catalyzed tandem cyclization reactions of alkynylindoles are described. These reactions demonstrated a novel and general strategy to rapidly construct highly functionalized polycyclic indolines. This approach was successfully employed for a formal synthesis of the akuammiline alkaloid minfiensine.

Chemo-enzymatic synthesis of physiologically modified avenanthramides

USDA-ARS?s Scientific Manuscript database

Avenanthramides are a group of phenolic alkaloids produced, among food crops, uniquely by oats. These metabolites function as phytoalexins in vegetative tissue and they are produced in the grain where their function is unknown. In vitro the avenanthramides inhibit the activation of nuclear factor ka...

An unexpected reaction pathway in the synthesis of the ABCE framework of strychnine-type alkaloids - A multidisciplinary study

NASA Astrophysics Data System (ADS)

Šoral, Michal; Markus, Jozef; Doháňošová, Jana; Šoralová, Stanislava; Dvoranová, Dana; Chyba, Andrej; Moncol, Ján; Berkeš, Dušan; Liptaj, Tibor

2017-01-01

Acid-catalyzed cyclization of spirocyclic 1‧-benzyl-2‧-(prop-2-en-1-yl)spiro[indole-3,3‧-pyrrolidine]-5‧-one (1) was performed. The pentacyclic product of Povarov-like imino-Diels-Alder reaction was isolated in high yield instead of expected tetracyclic aza-Prins intermediate. The unusual exotic alkaloid-type structure of the resulting molecule 2 was unambiguously confirmed by a detailed NMR analysis using a set of 2D NMR spectra including an INADEQUATE experiment. The relative configuration of 2 was predicted from the synthesis mechanism and DFT geometry calculations and independently confirmed using NOESY and residual dipolar coupling (RDC) assisted NMR analysis in stretched crosslinked polystyrene gels. The reversibility of the cycloaddition in aprotic solvents was observed. A new reaction pathway yielding a rare 6-5-5-5 tetracyclic spiroindoline 3 was suggested. The relative configuration within the tetracyclic framework was ultimately proved using Single-crystal X-ray diffraction analysis of compound 4.

Synthesis of 4-hydroxy-1-methylindole and benzo[b]thiophen-4-ol based unnatural flavonoids as new class of antimicrobial agents.

PubMed

Yadav, Prem P; Gupta, Prasoon; Chaturvedi, A K; Shukla, P K; Maurya, Rakesh

2005-03-01

Synthesis of nitrogen and sulfur heterocyclic mimics of furanoflavonoids have been achieved for the first time. Synthesized flavonoid alkaloids and thiophenyl flavonoids have been screened for antifungal and antibacterial activities. All the test compounds barring 25 exhibited antifungal activity. The compound 19 was the best and showed comparable MICs to the known compound karanjin. Compounds 5, 12, 14 and 22 also showed comparable MIC to karanjin.

The t-Butylsulfinamide Lynchpin in Transition Metal-Mediated Multiscaffold Library Synthesis

PubMed Central

Bauer, Renato A.; DiBlasi, Christine M.; Tan, Derek S.

2010-01-01

A unified synthetic approach to diverse polycyclic scaffolds has been developed using transition metal-mediated cycloaddition and cyclization reactions of enynes and diynes. The t-butylsulfinamide group has been identified as a particularly versatile lynchpin in these reactions, with a reactivity profile uniquely suited for efficient, stereoselective substrate synthesis and downstream transformations. This approach provides ten distinct, functionalized scaffold classes related to common core structures in alkaloid and terpenoid natural products. PMID:20356070

Structure-Activity Relationships of 33 Piperidines as Toxicants Against Female Adults of Aedes aegypti (Diptera: Culicidae)

DTIC Science & Technology

2007-03-01

alkaloid piperine and 12 syn- thetic derivatives have been evaluated against epimas- tigote and amastigote forms of the protozoan parasite Trypanosoma...O. Kris- tiansen, P. Maienfisch, A. Pascual, and A. Rindlisbacher. 2001. Synthesis and structure-activity relationships of benzophenone hydrazone...Am. J. Trop. Med. Hyg. 22: 124Ð 129. Creemer, L. C., H. A. Kirst, J.W. Paschal, and T. V.Worden. 2000. Synthesis and insecticidal activity of spinosyn

PhI(OAc)2-mediated one-pot oxidative decarboxylation and aromatization of tetrahydro-β-carbolines: synthesis of norharmane, harmane, eudistomin U and eudistomin I.

PubMed

Kamal, Ahmed; Tangella, Yellaiah; Manasa, Kesari Lakshmi; Sathish, Manda; Srinivasulu, Vunnam; Chetna, Jadala; Alarifi, Abdullah

2015-08-28

Iodobenzene diacetate was employed as a mild and efficient reagent for one-pot oxidative decarboxylation of tetrahydro-β-carboline acids and dehydrogenation of tetrahydro-β-carbolines to access the corresponding aromatic β-carbolines. To the best of our knowledge this is the first synthesis of β-carbolines via a one-pot oxidative decarboxylation at ambient temperature. The utility of this protocol has been demonstrated in the synthesis of β-carboline alkaloids norharmane (2o), harmane (2p), eudistomin U (9) and eudistomin I (12).

[Pyrrolizidine alkaloids and seneciosis in farm animals. Part 1: occurrence, chemistry and toxicology].

PubMed

Petzinger, E

2011-01-01

Pyrrolizidine alkaloids belong to a class of phytotoxins which are present in more than 6000 plant species. The disease seneciosis in farm animals represents the severe poisoning by pyrrolizidine alkaloids from plants of the genus Senecio. This form of poisoning has been known since the end of the 19th century in Germany, the USA, Canada and New Zealand, and is mainly caused by Senecio jacobaea and related Senecio spp. in farm animals, including poultry. Animal poisoning by pyrrolizidine alkaloids is of worldwide importance. In Germany poisoning of horses and cattle by Senecio jacobaea, which was earlier named Schweinsberg disease, is of renewed relevance for veterinary medicine. The disease occurs almost entirely as a consequence of chronic poisoning and in general ends fatally. The ultimate cause is the formation of toxic metabolites of pyrrolizidine alkaloids in the liver, and their covalent binding to nucleic acids and proteins leading to liver cirrhosis. Because many pyrrolizidine alkaloids possess mutagenic, and a few also carcinogenic properties, European and international authorities are concerned about possible residue levels in food of animal origin. The review addresses in its first part several aspects, being the occurrence, the chemistry, and the toxicology of pyrrolizidine alkaloids as well as animal intoxications by poisonous plants. In the second part (46) clinical characteristics of animal seneciosis, the therapeutic interventions, the significant species differences and a critical assessment of so-called nontoxic amounts of Senecio plants in animal fodder with reference to cumulative lethal toxin doses are presented.

A new general access to either type of Securinega alkaloids: synthesis of securinine and (-)-allonorsecurinine.

PubMed

Alibés, Ramon; Ballbé, Marta; Busqué, Félix; de March, Pedro; Elias, Laia; Figueredo, Marta; Font, Josep

2004-05-27

The syntheses of securinine and (-)-allonorsecurinine have been achieved starting from easily available alpha-amino acid derivatives and using as key steps a RCM and a Heck reaction for the formation of rings D and C, respectively. [reaction: see text

Enantioselective total synthesis of (-)-strychnine using the catalytic asymmetric Michael reaction and tandem cyclization.

PubMed

Ohshima, Takashi; Xu, Youjun; Takita, Ryo; Shimizu, Satoshi; Zhong, Dafang; Shibasaki, Masakatsu

2002-12-11

The enantioselective total synthesis of (-)-strychnine was accomplished through the use of the highly practical catalytic asymmetric Michael reaction (0.1 mol % of (R)-ALB, more than kilogram scale, without chromatography, 91% yield and >99% ee) as well as a tandem cyclization that simultaneously constructed B- and D-rings (>77% yield). Moreover, newly developed reaction conditions for thionium ion cyclization, NaBH3CN reduction of the imine moiety in the presence of Lewis acid to prevent ring opening reaction, and chemoselective reduction of the thioether (desulfurization) in the presence of exocyclic olefin were pivotal to complete the synthesis. The described chemistry paves the way for the synthesis of more advanced Strychnos alkaloids.

Second generation benzofuranone ring substituted noscapine analogs: Synthesis and biological evaluation

PubMed Central

Mishra, Ram Chandra; Karna, Prasanthi; Gundala, Sushma Reddy; Pannu, Vaishali; Stanton, Richard A.; Gupta, Kamlesh Kumar; Robinson, Mary; Lopus, Manu; Wilson, Leslie; Henary, Maged; Aneja, Ritu

2011-01-01

Microtubules, composed of α/β tubulin heterodimers, represent a validated target for cancer chemotherapy. Thus, tubulin- and microtubule-binding antimitotic drugs such as taxanes and vincas are widely employed for the chemotherapeutic management of various malignancies. Although quite successful in the clinic, these drugs are associated with severe toxicity and drug resistance problems. Noscapinoids represent an emerging class of microtubule-modulating anticancer agents based upon the parent molecule noscapine, a naturally-occurring non-toxic cough-suppressant opium alkaloid. Here we report in silico molecular modeling, chemical synthesis and biological evaluation of novel analogs derived by modification at position-7 of the benzofuranone ring system of noscapine. The synthesized analogs were evaluated for their tubulin polymerization activity and their biological activity was examined by their antiproliferative potential using representative cancer cell lines from varying tissue-origin [A549 (lung), CEM (lymphoma), MIA PaCa-2 (pancreatic), MCF-7 (breast) and PC-3 (prostate)]. Cell-cycle studies were performed to explore their ability to halt the cell-cycle and induce subsequent apoptosis. The varying biological activity of these analogs that differ in the nature and bulk of substituent at position-7 was rationalized utilizing predictive in silico molecular modeling. PMID:21501599

Influence of tryptophan and related compounds on ergot alkaloid formation in Claviceps purpurea (FR.) Tul.

PubMed

Erge, D; Schumann, B; Gröger, D

1984-01-01

L-Tryptophan did not exert any influence on peptide alkaloid formation in an ergotamine and in an ergosine-accumulating C. purpurea strain. A different picture was observed in a series of related C. purpurea strains. Tryptophan showed a slight stimulatory effect on the ergotoxine producer Pepty 695/S. A blocked mutant of it, designated as Pepty 695/ch which was able to accumulate secoclavines gave similar results. In a high-yielding elymoclavine strain Pepty 695/e, the progeny of the former one, tryptophan up to a concentration of 25 mM stimulated remarkably clavine biosynthesis. Furthermore, tryptophan could overcome the block of synthesis by inorganic phosphate. Increased specific activities of chanoclavine cyclase but not DMAT synthetase were observed in cultures of strain Pepty 695/e supplemented with tryptophan. 5-Methyltryptophan and bioisosteres of tryptophan were ineffective in alkaloid stimulation. These results are compared with those obtained with the grass ergot strain SD 58 and discussed with the relation to other induction phenomena.

Access to 6a-Alkyl Aporphines: Synthesis of (±)-N-Methylguattescidine.

PubMed

Ku, Angela F; Cuny, Gregory D

2016-10-21

(-)-N-Methylguattescidine (3) is an alkaloid recently isolated from Fissistigma latifolium and assigned as a rare example of a 6a-alkyl aporphine. Herein, we report the synthesis of (±)-3 and the des-hydroxyl derivative 4 using our previously reported ortho-phenol arylation methodology mediated by the XPhos precatalyst as a key synthetic step. In addition, substituents on the aryl halide portion of the ortho-phenol arylation substrates significantly influenced the formation of an oxidized side product.

Novel FeII and CoII Complexes of Natural Product Tryptanthrin: Synthesis and Binding with G-Quadruplex DNA

PubMed Central

Zhong, Yi-ning; Zhang, Yan; Gu, Yun-qiong; Wu, Shi-yun; Shen, Wen-ying

2016-01-01

Tryptanthrin is one of the most important members of indoloquinoline alkaloids. We obtained this alkaloid from Isatis. Two novel FeII and CoII complexes of tryptanthrin were first synthesized. Single-crystal X-ray diffraction analyses show that these complexes display distorted four-coordinated tetrahedron geometry via two heterocyclic nitrogen and oxygen atoms from tryptanthrin ligand. Binding with G-quadruplex DNA properties revealed that both complexes were found to exhibit significant interaction with G-quadruplex DNA. This study may potentially serve as the basis of future rational design of metal-based drugs from natural products that target the G-quadruplex DNA. PMID:27698647

Direct Synthesis of Protoberberine Alkaloids by Rh-Catalyzed C-H Bond Activation as the Key Step.

PubMed

Jayakumar, Jayachandran; Cheng, Chien-Hong

2016-01-26

A one-pot reaction of substituted benzaldehydes with alkyne-amines by a Rh-catalyzed C-H activation and annulation to afford various natural and unnatural protoberberine alkaloids is reported. This reaction provides a convenient route for the generation of a compound library of protoberberine salts, which recently have attracted great attention because of their diverse biological activities. In addition, pyridinium salt derivatives can also be formed in good yields from α,β-unsaturated aldehydes and amino-alkynes. This reaction proceeds with excellent regioselectivity and good functional group compatibility under mild reaction conditions by using O2 as the oxidant. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pro-toxic dehydropyrrolizidine alkaloids in the traditional Andean herbal medicine “asmachilca”

PubMed Central

Colegate, Steven M.; Boppré, Michael; Monzón, Julio; Betz, Joseph M.

2015-01-01

Ethnopharmacological relevance Asmachilca is a Peruvian medicinal herb preparation ostensibly derived from Eupatorium gayanum Wedd. = 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 – 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 ± 0.5 mg 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. PMID:26087231

Hidden aconite poisoning: identification of yunaconitine and related aconitum alkaloids in urine by liquid chromatography-tandem mass spectrometry.

PubMed

Lai, Chi-Kong; Poon, Wing-Tat; Chan, Yan-Wo

2006-09-01

Poisoning from aconite occurs worldwide as a result of misuse of the potent plant. Laboratory investigation into suspected intoxication cases is challenging because the content of toxic aconitum alkaloids varies depending on the plant source, market processing, dosing protocol, hydrolytic degradation, and metabolic transformation. Using a triple-quadrupole tandem mass spectrometer, a group screening method was developed based on the mass-fragmentographic scheme of common aconitum alkaloids. The precursor-ion scans of m/z 105 and 135 permitted selective profiling of 14-O-benzoyl-norditerpenoids and the 14-O-anisoyl-norditerpenoids, respectively. Gradient reversed-phase liquid chromatography minimized coelution of isobaric compounds. The screening protocol was applied to a clinical investigation of suspected herbal poisoning. In total, 15 urine samples were thus screened positive for aconitum alkaloid over 5 years. The diagnoses of aconite poisoning in 11 patients were firmly established based on the known prescription history and the positive urine finding. In four patients, without aconitum herbs being listed in the herbal prescriptions, contamination of the herbal remedies by aconite was suspected to be the hidden cause of their acute poisoning. Yunaconitne, a highly toxic aconitum alkaloid, was thus identified in human urine for the first time. The group screening method of aconitum alkaloids in urine is an important diagnostic aid for acute poisoning by aconites of an unclear origin.

Metabolic flux phenotype of tobacco hairy roots engineered for increased geraniol production.

PubMed

Masakapalli, Shyam K; Ritala, Anneli; Dong, Lemeng; van der Krol, Alexander R; Oksman-Caldentey, Kirsi-Marja; Ratcliffe, R George; Sweetlove, Lee J

2014-03-01

The goal of this study was to characterise the metabolic flux phenotype of transgenic tobacco (Nicotiana tabacum) hairy roots engineered for increased biosynthesis of geraniol, an intermediate of the terpenoid indole alkaloid pathway. Steady state, stable isotope labelling was used to determine flux maps of central carbon metabolism for transgenic lines over-expressing (i) plastid-targeted geraniol synthase (pGES) from Valeriana officinalis, and (ii) pGES in combination with plastid-targeted geranyl pyrophosphate synthase from Arabidopsis thaliana (pGES+pGPPS), as well as for wild type and control-vector-transformed roots. Fluxes were constrained by the redistribution of label from [1-¹³C]-, [2-¹³C]- or [¹³C6]glucose into amino acids, sugars and organic acids at isotopic steady state, and by biomass output fluxes determined from the fractionation of [U-¹⁴C]glucose into insoluble polymers. No significant differences in growth and biomass composition were observed between the lines. The pGES line accumulated significant amounts of geraniol/geraniol glycosides (151±24 ng/mg dry weight) and the de novo synthesis of geraniol in pGES was confirmed by ¹³C labelling analysis. The pGES+pGPPS also accumulated geraniol and geraniol glycosides, but to lower levels than the pGES line. Although there was a distinct impact of the transgenes at the level of geraniol synthesis, other network fluxes were unaffected, reflecting the capacity of central metabolism to meet the relatively modest demand for increased precursors in the transgenic lines. It is concluded that re-engineering of the terpenoid indole alkaloid pathway will only require simultaneous manipulation of the steps producing the pathway precursors that originate in central metabolism in tissues engineered to produce at least an order of magnitude more geraniol than has been achieved so far. Copyright © 2013 Elsevier Ltd. All rights reserved.

Synthesis of the Strychnos Alkaloid (-)-Strychnopivotine and Confirmation of its Absolute Configuration.

PubMed

Maertens, Gaëtan; Canesi, Sylvain

2016-05-17

The first enantioselective synthesis of (-)-strychnopivotine from a known and inexpensive phenol has been achieved in 15 steps. The strategy is based on a new diastereoselective aza-Michael-enol-ether cascade desymmetrization of a dienone, guided by a removable lactic acid-derived chiral auxiliary. Synthesis involves a phenol dearomatization, a conjugated silicon addition, a stereoselective double reductive amination, and two Heck-type carbopalladations as key steps. The absolute configuration of the natural compound, which, to date, has been uncertain, was confirmed by using circular dichroism (CD) spectroscopy and X-ray analyses. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Concise total syntheses of (+/-)-strychnine and (+/-)-akuammicine.

PubMed

Sirasani, Gopal; Paul, Tapas; Dougherty, William; Kassel, Scott; Andrade, Rodrigo B

2010-05-21

Concise total syntheses of Strychnos alkaloids strychnine (1) and akuammicine (2) have been realized in 13 and 6 operations, respectively. Key steps include (1) the vinylogous Mannich reaction; (2) a novel, sequential one-pot spirocyclization/intramolecular aza-Baylis-Hillman reaction; and (3) a Heck cyclization. The synthesis of 1 proceeds via the Wieland-Gumlich aldehyde (26).

Percy Julian, Robert Robinson, and the Identity of Eserethole

ERIC Educational Resources Information Center

Ault, Addison

2008-01-01

The Nova production "Percy Julian--Forgotten Genius" included the very public disagreement between Percy Julian, an unknown American chemist, and Robert Robinson, possibly the best known organic chemist of the day, as to the identity of "eserethole", the key intermediate for the synthesis of the alkaloid physostigmine. The Nova production,…

De Novo Assembly and Characterization of Fruit Transcriptome in Black Pepper (Piper nigrum)

PubMed Central

Hu, Lisong; Hao, Chaoyun; Fan, Rui; Wu, Baoduo; Tan, Lehe; Wu, Huasong

2015-01-01

Black pepper is one of the most popular and oldest spices in the world and valued for its pungent constituent alkaloids. Pinerine is the main bioactive compound in pepper alkaloids, which perform unique physiological functions. However, the mechanisms of piperine synthesis are poorly understood. This study is the first to describe the fruit transcriptome of black pepper by sequencing on Illumina HiSeq 2000 platform. A total of 56,281,710 raw reads were obtained and assembled. From these raw reads, 44,061 unigenes with an average length of 1,345 nt were generated. During functional annotation, 40,537 unigenes were annotated in Gene Ontology categories, Kyoto Encyclopedia of Genes and Genomes pathways, Swiss-Prot database, and Nucleotide Collection (NR/NT) database. In addition, 8,196 simple sequence repeats (SSRs) were detected. In a detailed analysis of the transcriptome, housekeeping genes for quantitative polymerase chain reaction internal control, polymorphic SSRs, and lysine/ornithine metabolism-related genes were identified. These results validated the availability of our database. Our study could provide useful data for further research on piperine synthesis in black pepper. PMID:26121657

De Novo Assembly and Characterization of Fruit Transcriptome in Black Pepper (Piper nigrum).

PubMed

Hu, Lisong; Hao, Chaoyun; Fan, Rui; Wu, Baoduo; Tan, Lehe; Wu, Huasong

2015-01-01

Black pepper is one of the most popular and oldest spices in the world and valued for its pungent constituent alkaloids. Pinerine is the main bioactive compound in pepper alkaloids, which perform unique physiological functions. However, the mechanisms of piperine synthesis are poorly understood. This study is the first to describe the fruit transcriptome of black pepper by sequencing on Illumina HiSeq 2000 platform. A total of 56,281,710 raw reads were obtained and assembled. From these raw reads, 44,061 unigenes with an average length of 1,345 nt were generated. During functional annotation, 40,537 unigenes were annotated in Gene Ontology categories, Kyoto Encyclopedia of Genes and Genomes pathways, Swiss-Prot database, and Nucleotide Collection (NR/NT) database. In addition, 8,196 simple sequence repeats (SSRs) were detected. In a detailed analysis of the transcriptome, housekeeping genes for quantitative polymerase chain reaction internal control, polymorphic SSRs, and lysine/ornithine metabolism-related genes were identified. These results validated the availability of our database. Our study could provide useful data for further research on piperine synthesis in black pepper.

Integration of Fermentation and Organic Synthesis: Studies of Roquefortine C and Biosynthetic Derivatives

NASA Astrophysics Data System (ADS)

Gober, Claire Marie

Roquefortine C is one of the most ubiquitous indoline alkaloids of fungal origin. It has been isolated from over 30 different species of Penicillium fungi and has garnered attention in recent years for its role as a biosynthetic precursor to the triazaspirocyclic natural products glandicoline B, meleagrin, and oxaline. The triazaspirocyclic motif, which encompasses three nitrogen atoms attached to one quaternary carbon forming a spirocyclic scaffold, is a unique chemical moiety that has been shown to impart a wide array of biological activity, from anti-bacterial activity and antiproliferative activity against cancer cell lines to anti-biofouling against marine organisms. Despite the promise of these compounds in the pharmaceutical and materials industries, few syntheses of triazaspirocycles exist in the literature. The biosynthesis of roquefortine C-derived triazaspirocycles, however, provides inspiration for the synthesis of these compounds, namely through a nitrone-promoted transannular rearrangement. This type of internal rearrangement has never been carried out synthetically and would provide an efficient stereoselective synthesis of triazaspirocycles. This work encompasses efforts towards elucidating the biosynthetic pathway of roquefortine C-derived triazaspirocycles as well as synthetic efforts towards the construction of triazaspirocycles. Chapter 1 will discuss a large-scale fermentation procedure for the production of roquefortine C from Penicillium crustosum. Chapters 2 and 3 explore (through enzymatic and synthetic means, respectively) the formation of the key indoline nitrone moiety required for the proposed transannular rearrangement. Finally, chapter 4 will discuss synthetic efforts towards the synthesis of triazaspirocycles. This work has considerably enhanced our understanding of the roquefortine C biosynthetic pathway and the unique chemistry of this natural product, and our efforts towards the synthesis of triazaspirocycles will facilitate the use of these compounds in numerous applications.

The biology and chemistry of the zoanthamine alkaloids.

PubMed

Behenna, Douglas C; Stockdill, Jennifer L; Stoltz, Brian M

2008-01-01

Marine natural products have long played an important role in natural products chemistry and drug discovery. Mirroring the rich variety and complicated interactions of the marine environment, the substances isolated from sea creatures tend to be incredibly diverse in both molecular structure and biological activity. The natural products isolated from the polyps of marine zoanthids are no exception. The zoanthamine alkaloids, the first of which were isolated over 20 years ago, are of particular interest to the synthetic community because they feature a novel structural framework and exhibit a broad range of biological activities. In this Review, we summarize the major contributions to understanding the zoanthamine natural products with regard to their isolation and structure determination, as well as studies on their biological activity and total synthesis.

The killer of Socrates: Coniine and Related Alkaloids in the Plant Kingdom.

PubMed

Hotti, Hannu; Rischer, Heiko

2017-11-14

Coniine, a polyketide-derived alkaloid, is poisonous to humans and animals. It is a nicotinic acetylcholine receptor antagonist, which leads to inhibition of the nervous system, eventually causing death by suffocation in mammals. Coniine's most famous victim is Socrates who was sentenced to death by poison chalice containing poison hemlock in 399 BC. In chemistry, coniine holds two historical records: It is the first alkaloid the chemical structure of which was established (in 1881), and that was chemically synthesized (in 1886). In plants, coniine and twelve closely related alkaloids are known from poison hemlock ( Conium maculatum L.), and several Sarracenia and Aloe species. Recent work confirmed its biosynthetic polyketide origin. Biosynthesis commences by carbon backbone formation from butyryl-CoA and two malonyl-CoA building blocks catalyzed by polyketide synthase. A transamination reaction incorporates nitrogen from l-alanine and non-enzymatic cyclization leads to γ-coniceine, the first hemlock alkaloid in the pathway. Ultimately, reduction of γ-coniceine to coniine is facilitated by NADPH-dependent γ-coniceine reductase. Although coniine is notorious for its toxicity, there is no consensus on its ecological roles, especially in the carnivorous pitcher plants where it occurs. Lately there has been renewed interest in coniine's medical uses particularly for pain relief without an addictive side effect.

Marine-Derived 2-Aminoimidazolone Alkaloids. Leucettamine B-Related Polyandrocarpamines Inhibit Mammalian and Protozoan DYRK & CLK Kinases

PubMed Central

Loaëc, Nadège; Attanasio, Eletta; Villiers, Benoît; Durieu, Emilie; Tahtouh, Tania; Cam, Morgane; Alencar, Aline; Roué, Mélanie; Bourguet-Kondracki, Marie-Lise; Proksch, Peter; Limanton, Emmanuelle; Guiheneuf, Solène; Carreaux, François; Bazureau, Jean-Pierre; Klautau, Michelle

2017-01-01

A large diversity of 2-aminoimidazolone alkaloids is produced by various marine invertebrates, especially by the marine Calcareous sponges Leucetta and Clathrina. The phylogeny of these sponges and the wide scope of 2-aminoimidazolone alkaloids they produce are reviewed in this article. The origin (invertebrate cells, associated microorganisms, or filtered plankton), physiological functions, and natural molecular targets of these alkaloids are largely unknown. Following the identification of leucettamine B as an inhibitor of selected protein kinases, we synthesized a family of analogues, collectively named leucettines, as potent inhibitors of DYRKs (dual-specificity, tyrosine phosphorylation regulated kinases) and CLKs (cdc2-like kinases) and potential pharmacological leads for the treatment of several diseases, including Alzheimer’s disease and Down syndrome. We assembled a small library of marine sponge- and ascidian-derived 2-aminoimidazolone alkaloids, along with several synthetic analogues, and tested them on a panel of mammalian and protozoan kinases. Polyandrocarpamines A and B were found to be potent and selective inhibitors of DYRKs and CLKs. They inhibited cyclin D1 phosphorylation on a DYRK1A phosphosite in cultured cells. 2-Aminoimidazolones thus represent a promising chemical scaffold for the design of potential therapeutic drug candidates acting as specific inhibitors of disease-relevant kinases, and possibly other disease-relevant targets. PMID:29039762

Marine-Derived 2-Aminoimidazolone Alkaloids. Leucettamine B-Related Polyandrocarpamines Inhibit Mammalian and Protozoan DYRK & CLK Kinases.

PubMed

Loaëc, Nadège; Attanasio, Eletta; Villiers, Benoît; Durieu, Emilie; Tahtouh, Tania; Cam, Morgane; Davis, Rohan A; Alencar, Aline; Roué, Mélanie; Bourguet-Kondracki, Marie-Lise; Proksch, Peter; Limanton, Emmanuelle; Guiheneuf, Solène; Carreaux, François; Bazureau, Jean-Pierre; Klautau, Michelle; Meijer, Laurent

2017-10-17

A large diversity of 2-aminoimidazolone alkaloids is produced by various marine invertebrates, especially by the marine Calcareous sponges Leucetta and Clathrina . The phylogeny of these sponges and the wide scope of 2-aminoimidazolone alkaloids they produce are reviewed in this article. The origin (invertebrate cells, associated microorganisms, or filtered plankton), physiological functions, and natural molecular targets of these alkaloids are largely unknown. Following the identification of leucettamine B as an inhibitor of selected protein kinases, we synthesized a family of analogues, collectively named leucettines, as potent inhibitors of DYRKs (dual-specificity, tyrosine phosphorylation regulated kinases) and CLKs (cdc2-like kinases) and potential pharmacological leads for the treatment of several diseases, including Alzheimer's disease and Down syndrome. We assembled a small library of marine sponge- and ascidian-derived 2-aminoimidazolone alkaloids, along with several synthetic analogues, and tested them on a panel of mammalian and protozoan kinases. Polyandrocarpamines A and B were found to be potent and selective inhibitors of DYRKs and CLKs. They inhibited cyclin D1 phosphorylation on a DYRK1A phosphosite in cultured cells. 2-Aminoimidazolones thus represent a promising chemical scaffold for the design of potential therapeutic drug candidates acting as specific inhibitors of disease-relevant kinases, and possibly other disease-relevant targets.

Divergent Synthesis of Solanidine and 22-epi-Solanidine.

PubMed

Hou, Ling-Li; Shi, Yong; Zhang, Zhi-Dan; Wu, Jing-Jing; Yang, Qing-Xiong; Tian, Wei-Sheng

2017-07-21

A divergent synthesis of solanidine and 22-epi-solanidine, two 25S natural steroidal alkaloids, from 25R-configured diosgenin acetate, is described. Initially, solanidine was synthesized through a series of transformations including a cascade ring-switching process of furostan-26-acid, an epimerization of C25 controlled by the conformation of six-membered lactone ring, an intramolecular Schmidt reaction, and an imine reduction/intramolecular aminolysis process. To address the epimerization issue during Schmidt reaction, an improved synthesis was developed, which also led to a synthesis of 22-epi-solanidine. In this synthesis, selective transformation of azido lactone to azido diol and amino diol was realized through a reduction relay tactic. The azido diol was transformed to solanidine via an intramolecular Schmidt reaction/N-alkylation/reduction process and to 22-epi-solanidine via an intramolecular double N-alkylation process.

Synthesis of densely functionalized enantiopure indolizidines by ring-closing metathesis (RCM) of hydroxylamines from carbohydrate-derived nitrones

PubMed Central

Bonanni, Marco; Marradi, Marco; Cardona, Francesca; Cicchi, Stefano; Goti, Andrea

2007-01-01

Background Indolizidine alkaloids widely occur in nature and display interesting biological activity. This is the reason for which their total synthesis as well as the synthesis of non-natural analogues still attracts the attention of many research groups. To establish new straightforward accesses to these molecules is therefore highly desirable. Results The ring closing metathesis (RCM) of enantiopure hydroxylamines bearing suitable unsaturated groups cleanly afforded piperidine derivatives in good yields. Further cyclization and deprotection of the hydroxy groups gave novel highly functionalized indolizidines. The synthesis of a pyrroloazepine analogue is also described. Conclusion We have developed a new straightforward methodology for the synthesis of densely functionalized indolizidines and pyrroloazepine analogues in 6 steps and 30–60% overall yields from enantiopure hydroxylamines obtained straightforwardly from carbohydrate-derived nitrones. PMID:18076753

Efficient synthesis of optically active 4-nitro-cyclohexanones via bifunctional thiourea-base catalyzed double-Michael addition of nitromethane to dienones.

PubMed

Wu, Bin; Liu, Guo-Gui; Li, Mei-Qiu; Zhang, Yong; Zhang, Shao-Yun; Qiu, Jun-Ru; Xu, Xiao-Ping; Ji, Shun-Jun; Wang, Xing-Wang

2011-04-07

Thiourea-modified cinchona alkaloids as bifunctional catalysts and a base could catalyze a stepwise [5+1] cyclization of divinyl ketones with nitromethane via double Michael additions, furnishing optically active 4-nitro-cyclohexanones with good yields, excellent diastereoselectivities (>20 : 1) and high enantiomeric ratios (up to 97 : 3).

Rapid and simultaneous analysis of five alkaloids in four parts of Coptidis Rhizoma by near-infrared spectroscopy

NASA Astrophysics Data System (ADS)

Jintao, Xue; Yufei, Liu; Liming, Ye; Chunyan, Li; Quanwei, Yang; Weiying, Wang; Yun, Jing; Minxiang, Zhang; Peng, Li

2018-01-01

Near-Infrared Spectroscopy (NIRS) was first used to develop a method for rapid and simultaneous determination of 5 active alkaloids (berberine, coptisine, palmatine, epiberberine and jatrorrhizine) in 4 parts (rhizome, fibrous root, stem and leaf) of Coptidis Rhizoma. A total of 100 samples from 4 main places of origin were collected and studied. With HPLC analysis values as calibration reference, the quantitative analysis of 5 marker components was performed by two different modeling methods, partial least-squares (PLS) regression as linear regression and artificial neural networks (ANN) as non-linear regression. The results indicated that the 2 types of models established were robust, accurate and repeatable for five active alkaloids, and the ANN models was more suitable for the determination of berberine, coptisine and palmatine while the PLS model was more suitable for the analysis of epiberberine and jatrorrhizine. The performance of the optimal models was achieved as follows: the correlation coefficient (R) for berberine, coptisine, palmatine, epiberberine and jatrorrhizine was 0.9958, 0.9956, 0.9959, 0.9963 and 0.9923, respectively; the root mean square error of validation (RMSEP) was 0.5093, 0.0578, 0.0443, 0.0563 and 0.0090, respectively. Furthermore, for the comprehensive exploitation and utilization of plant resource of Coptidis Rhizoma, the established NIR models were used to analysis the content of 5 active alkaloids in 4 parts of Coptidis Rhizoma and 4 main origin of places. This work demonstrated that NIRS may be a promising method as routine screening for off-line fast analysis or on-line quality assessment of traditional Chinese medicine (TCM).

Synthesis of (+)-dumetorine and congeners by using flow chemistry technologies.

PubMed

Riva, Elena; Rencurosi, Anna; Gagliardi, Stefania; Passarella, Daniele; Martinelli, Marisa

2011-05-23

An efficient total synthesis of the natural alkaloid (+)-dumetorine by using flow technology is described. The process entailed five separate steps starting from the enantiopure (S)-2-(piperidin-2-yl)ethanol 4 with 29% overall yield. Most of the reactions were carried out by exploiting solvent superheating and by using packed columns of immobilized reagents or scavengers to minimize handling. New protocols for performing classical reactions under continuous flow are disclosed: the ring-closing metathesis reaction with a novel polyethylene glycol-supported Hoveyda catalyst and the unprecedented flow deprotection/Eschweiler-Clarke methylation sequence. The new protocols developed for the synthesis of (+)-dumetorine were applied to the synthesis of its simplified natural congeners (-)-sedamine and (+)-sedridine. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Elucidating the mass spectrum of the retronecine alkaloid using DFT calculations.

PubMed

Modesto-Costa, Lucas; Martinez, Sabrina T; Pinto, Angelo C; Vessecchi, Ricardo; Borges, Itamar

2018-06-23

Pyrrolizidine alkaloids are natural molecules playing important roles in different biochemical processes in nature and in humans. In this work, the electron ionization mass spectrum (EI-MS) of retronecine, an alkaloid molecule found in plants, is investigated computationally. Its mass spectrum can be characterized by three main fragment ions having the following m/z ratios: 111, 94 and 80. In order to rationalize the mass spectrum, minima and transition state geometries were computed using density functional theory (DFT). It was showed that the dissociation process includes an aromatization of the originally five-membered ring of retronecine converted into a six-membered ring compound. A fragmentation pathway mechanism involving dissociation activation barriers that are easily overcome by the initial ionization energy was found. From the computed quantum chemical geometric, atomic charges and energetic parameters, the abundance of each ion in the mass spectrum of retronecine was discussed. This article is protected by copyright. All rights reserved.

Biopharmaceutical potentials of Prosopis spp. (Mimosaceae, Leguminosa).

PubMed

Henciya, Santhaseelan; Seturaman, Prabha; James, Arthur Rathinam; Tsai, Yi-Hong; Nikam, Rahul; Wu, Yang-Chang; Dahms, Hans-Uwe; Chang, Fang Rong

2017-01-01

Prosopis is a commercially important plant genus, which has been used since ancient times, particularly for medicinal purposes. Traditionally, Paste, gum, and smoke from leaves and pods are applied for anticancer, antidiabetic, anti-inflammatory, and antimicrobial purposes. Components of Prosopis such as flavonoids, tannins, alkaloids, quinones, or phenolic compounds demonstrate potentials in various biofunctions, such as analgesic, anthelmintic, antibiotic, antiemetic, microbial antioxidant, antimalarial, antiprotozoal, antipustule, and antiulcer activities; enhancement of H + , K + , ATPases; oral disinfection; and probiotic and nutritional effects; as well as in other biopharmaceutical applications, such as binding abilities for tablet production. The compound juliflorine provides a cure in Alzheimer disease by inhibiting acetylcholine esterase at cholinergic brain synapses. Some indirect medicinal applications of Prosopis spp. are indicated, including antimosquito larvicidal activity, chemical synthesis by associated fungal or bacterial symbionts, cyanobacterial degradation products, "mesquite" honey and pollens with high antioxidant activity, etc. This review will reveal the origins, distribution, folk uses, chemical components, biological functions, and applications of different representatives of Prosopis. Copyright © 2016. Published by Elsevier B.V.

Geographic variation in alkaloid production in Conium maculatum populations experiencing differential herbivory by Agonopterix alstroemeriana.

PubMed

Castells, Eva; Berhow, Mark A; Vaughn, Steven F; Berenbaum, May R

2005-08-01

Conium maculatum, a Eurasian weed naturalized in North America, contains high concentrations of piperidine alkaloids that act as chemical defenses against herbivores. C. maculatum was largely free from herbivory in the United States, until approximately 30 yr ago, when it was reassociated via accidental introduction with a monophagous European herbivore, the oecophorid caterpillar Agonopterix alstroemeriana. At present, A. alstroemeriana is found in a continuum of reassociation time and intensities with C. maculatum across the continent; in the Pacific Northwest, A. alstroemeriana can cause severe damage, resulting in some cases in complete defoliation. Studies in biological control and invasion biology have yet to determine whether plants reassociated with a significant herbivore from the area of indigeneity increase their chemical defense investment in areas of introduction. In this study, we compared three locations in the United States (New York, Washington, and Illinois) where C. maculatum experiences different levels of herbivory by A. alstroemeriana to determine the association between the intensity of the interaction, as measured by damage, and chemical defense production. Total alkaloid production in C. maculatum was positively correlated with A. alstroemeriana herbivory levels: plants from New York and Washington, with higher herbivory levels, invested two and four times more N to alkaloid synthesis than did plants from Illinois. Individual plants with lower concentrations of alkaloids from a single location in Illinois experienced more damage by A. alstroemeriana, indicative of a preference on the part of the insect for plants with less chemical defense. These results suggest that A. alstroemeriana may act either as a selective agent or inducing agent for C. maculatum and increase its toxicity in its introduced range.

Cyclopropanes and hypervalent iodine reagents: high energy compounds for applications in synthesis and catalysis.

PubMed

Fernández González, Davinia; De Simone, Filippo; Brand, Jonathan P; Nicolai, Stefano; Waser, Jérôme

2011-01-01

One of the major challenges faced by organic chemistry is the efficient synthesis of increasingly complex molecules. Since October 2007, the Laboratory of Catalysis and Organic Synthesis (LCSO) at EPFL has been working on the development of catalytic reactions based on the Umpolung of the innate reactivity of functional groups. Electrophilic acetylene synthons have been developed using the exceptional properties of ethynyl benziodoxolone (EBX) hypervalent iodine reagents for the alkynylation of heterocycles and olefins. The obtained acetylenes are important building blocks for organic chemistry, material sciences and chemical biology. The ring-strain energy of donor-acceptor cyclopropanes was then used in the first catalytic formal homo-Nazarov cyclization. In the case of aminocyclopropanes, the method could be applied in the synthesis of the alkaloids aspidospermidine and goniomitine. The developed methods are expected to have a broad potential for the synthesis and functionalization of complex organic molecules, including carbocycles and heterocycles.

Merging gold and organocatalysis: a facile asymmetric synthesis of annulated pyrroles.

PubMed

Hack, Daniel; Loh, Charles C J; Hartmann, Jan M; Raabe, Gerhard; Enders, Dieter

2014-04-01

The combination of cinchona-alkaloid-derived primary amine and Au(I) -phosphine catalysts allowed the selective C-H functionalization of two adjacent carbon atoms of pyrroles under mild reaction conditions. This sequential dual activation provides seven-membered-ring-annulated pyrrole derivatives in excellent yields and enantioselectivities. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Engineering microbial factories for synthesis of value-added products

PubMed Central

Du, Jing; Shao, Zengyi; Zhao, Huimin

2011-01-01

Microorganisms have become an increasingly important platform for the production of drugs, chemicals, and biofuels from renewable resources. Advances in protein engineering, metabolic engineering, and synthetic biology enable redesigning microbial cellular networks and fine-tuning physiological capabilities, thus generating industrially viable strains for the production of natural and unnatural value-added compounds. In this review, we describe the recent progress on engineering microbial factories for synthesis of valued-added products including alkaloids, terpenoids, flavonoids, polyketides, non-ribosomal peptides, biofuels, and chemicals. Related topics on lignocellulose degradation, sugar utilization, and microbial tolerance improvement will also be discussed. PMID:21526386

11-Step Total Synthesis of Araiosamines

PubMed Central

2016-01-01

A concise route to a small family of exotic marine alkaloids known as the araiosamines has been developed, and their absolute configuration has been assigned. The dense array of functionality, high polarity, and rich stereochemistry coupled with equilibrating topologies present an unusual challenge for chemical synthesis and an opportunity for innovation. Key steps involve the use of a new reagent for guanidine installation, a remarkably selective C–H functionalization, and a surprisingly simple final step that intersects a presumed biosynthetic intermediate. Synthetic araiosamines were shown to exhibit potency against Gram-positive and -negative bacteria despite a contrary report of no activity. PMID:27748593

Synthesis of (-)-pseudotabersonine, (-)-pseudovincadifformine, and (+)-coronaridine enabled by photoredox catalysis in flow.

PubMed

Beatty, Joel W; Stephenson, Corey R J

2014-07-23

Natural product modification with photoredox catalysis allows for mild, chemoselective access to a wide array of related structures in complex areas of chemical space, providing the possibility for novel structural motifs as well as useful quantities of less abundant congeners. While amine additives have been used extensively as stoichiometric electron donors for photocatalysis, the controlled modification of amine substrates through single-electron oxidation is ideal for the synthesis and modification of alkaloids. Here, we report the conversion of the amine (+)-catharanthine into the natural products (-)-pseudotabersonine, (-)-pseudovincadifformine, and (+)-coronaridine utilizing visible light photoredox catalysis.

Collective synthesis of natural products by means of organocascade catalysis

PubMed Central

Jones, Spencer B.; Simmons, Bryon; Mastracchio, Anthony; MacMillan, David W. C.

2012-01-01

Organic chemists are now able to synthesize small quantities of almost any known natural product, given sufficient time, resources and effort. However, translation of the academic successes in total synthesis to the large-scale construction of complex natural products and the development of large collections of biologically relevant molecules present significant challenges to synthetic chemists. Here we show that the application of two nature-inspired techniques, namely organocascade catalysis and collective natural product synthesis, can facilitate the preparation of useful quantities of a range of structurally diverse natural products from a common molecular scaffold. The power of this concept has been demonstrated through the expedient, asymmetric total syntheses of six well-known alkaloid natural products: strychnine, aspidospermidine, vincadifformine, akuammicine, kopsanone and kopsinine. PMID:21753848

Enantiodivergent Synthesis of (+)- and (-)-Pyrrolidine 197B: Synthesis of trans-2,5-Disubstituted Pyrrolidines by Intramolecular Hydroamination.

PubMed

Pérez, Sixto J; Purino, Martín A; Cruz, Daniel A; López-Soria, Juan M; Carballo, Rubén M; Ramírez, Miguel A; Fernández, Israel; Martín, Víctor S; Padrón, Juan I

2016-10-17

A highly efficient, diastereoselective, iron(III)-catalyzed intramolecular hydroamination/cyclization reaction involving α-substituted amino alkenes is described. Thus, enantiopure trans-2,5-disubstituted pyrrolidines and trans-5-substituted proline derivatives were synthesized by means of a combination of enantiopure starting materials, easily available from l-α-amino acids, with sustainable metal catalysts such as iron(III) salts. The scope of this methodology is highlighted in an enantiodivergent approach to the synthesis of both (+)- and (-)-pyrrolidine 197B alkaloids from l-glutamic acid. In addition, a computational study was carried out to gain insight into the complete diastereoselectivity of the transformation. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Total Synthesis and Biological Evaluation of 22-Hydroxyacuminatine

PubMed Central

Xiao, Xiangshu; Antony, Smitha; Pommier, Yves; Cushman, Mark

2008-01-01

A total synthesis of 22-hydroxyacuminatine, a cytotoxic alkaloid isolated from Camptotheca acuminata, is reported. The key step in the synthesis involves the reaction of 2,3-dihydro-1H-pyrrolo[3,4-b]quinoline with a brominated phthalide to generate a substituted pentacyclic 12H-5,11a-diazadibenzo[b,h]fluoren-11-one intermediate. Despite its structural resemblance to camptothecin and luotonin A, a biological evaluation of 22-hydroxyacuminatine in a topoisomerase I-deficient cell line P388/CPT45 has confirmed that the observed cytotoxicity is not due to topoisomerase I inhibition. This result is consistent with the hypothesis that π-π stacking is more important than hydrogen bonding interactions in determining topoisomerase I inhibitor binding in the ternary cleavage complex. PMID:16480276

De novo transcriptome sequencing and digital gene expression analysis predict biosynthetic pathway of rhynchophylline and isorhynchophylline from Uncaria rhynchophylla, a non-model plant with potent anti-alzheimer's properties.

PubMed

Guo, Qianqian; Ma, Xiaojun; Wei, Shugen; Qiu, Deyou; Wilson, Iain W; Wu, Peng; Tang, Qi; Liu, Lijun; Dong, Shoukun; Zu, Wei

2014-08-12

The major medicinal alkaloids isolated from Uncaria rhynchophylla (gouteng in chinese) capsules are rhynchophylline (RIN) and isorhynchophylline (IRN). Extracts containing these terpene indole alkaloids (TIAs) can inhibit the formation and destabilize preformed fibrils of amyloid β protein (a pathological marker of Alzheimer's disease), and have been shown to improve the cognitive function of mice with Alzheimer-like symptoms. The biosynthetic pathways of RIN and IRN are largely unknown. In this study, RNA-sequencing of pooled Uncaria capsules RNA samples taken at three developmental stages that accumulate different amount of RIN and IRN was performed. More than 50 million high-quality reads from a cDNA library were generated and de novo assembled. Sequences for all of the known enzymes involved in TIAs synthesis were identified. Additionally, 193 cytochrome P450 (CYP450), 280 methyltransferase and 144 isomerase genes were identified, that are potential candidates for enzymes involved in RIN and IRN synthesis. Digital gene expression profile (DGE) analysis was performed on the three capsule developmental stages, and based on genes possessing expression profiles consistent with RIN and IRN levels; four CYP450s, three methyltransferases and three isomerases were identified as the candidates most likely to be involved in the later steps of RIN and IRN biosynthesis. A combination of de novo transcriptome assembly and DGE analysis was shown to be a powerful method for identifying genes encoding enzymes potentially involved in the biosynthesis of important secondary metabolites in a non-model plant. The transcriptome data from this study provides an important resource for understanding the formation of major bioactive constituents in the capsule extract from Uncaria, and provides information that may aid in metabolic engineering to increase yields of these important alkaloids.

Characterization of Epichloë coenophiala within the U.S.: are all tall fescue endophytes created equal?

NASA Astrophysics Data System (ADS)

Young, Carolyn; Charlton, Nikki; Takach, Johanna; Swoboda, Ginger; Trammell, Michael; Huhman, David; Hopkins, Andrew

2014-11-01

Tall fescue (Lolium arundinaceum) is a valuable and broadly adapted forage grass that occupies approximately 14 million hectares across the United States. A native to Europe, tall fescue was likely introduced into the U.S. around the late 1800’s. Much of the success of tall fescue can be attributed to Epichloë coenophiala (formerly Neotyphodium coenophialum) a seed borne symbiont that aids in host persistence. Epichloë species are capable of producing a range of alkaloids (ergot alkaloids, indole-diterpenes, lolines and peramine) that provide protection to the plant host from herbivory. Unfortunately, most tall fescue within the U.S., commonly referred to as KY31, harbors the endophyte E. coenophiala that causes toxicity to grazing livestock due to the production of ergot alkaloids. Molecular analyses of tall fescue endophytes have identified four independent associations, representing tall fescue with E. coenophiala, Epichloë sp. FaTG-2, Epichloë sp. FaTG-3 or Epichloë sp. FaTG-4. Each of these Epichloë species can be further distinguished based on genetic variation that equates to differences in the alkaloid gene loci. Tall fescue samples were evaluated using markers to SSR and alkaloid biosynthesis genes to determine endophyte strain variation present within continental U.S. Samples represented seed and tillers from the Suiter farm (Menifee County, KY), which is considered the originating site of KY31, as well as plant samples collected from 14 states, breeder’s seed and plant introduction lines (National Plant Germplasm System, NPGS). This study revealed two prominent E. coenophiala genotypes based on presence of alkaloid biosynthesis genes and SSR markers and provides insight into endophyte variation within continental U.S. across historical and current tall fescue samples.

Rapid in situ detection of alkaloids in plant tissue under ambient conditions using desorption electrospray ionization.

PubMed

Talaty, Nari; Takáts, Zoltán; Cooks, R Graham

2005-12-01

Desorption electrospray ionization (DESI) mass spectrometry is applied to the in situ detection of alkaloids in the tissue of poison hemlock (Conium maculatum), jimsonweed (Datura stramonium) and deadly nightshade (Atropa belladonna). The experiment is carried out by electrospraying micro-droplets of solvent onto native or freshly-cut plant tissue surfaces. No sample preparation is required and the mass spectra are recorded under ambient conditions, in times of a few seconds. The impact of the sprayed droplets on the surface produces gaseous ions from organic compounds originally present in the plant tissue. The effects of operating parameters, including the electrospray high voltage, heated capillary temperature, the solvent infusion rate and the carrier gas pressure on analytical performance are evaluated and optimized. Different types of plant material are analyzed including seeds, stems, leaves, roots and flowers. All the previously reported alkaloids have been detected in C. maculatum, while fifteen out of nineteen known alkaloids for D. stramonium and the principal alkaloids of A. belladonna were also identified. All identifications were confirmed by tandem mass spectrometry. Results obtained show similar mass spectra, number of alkaloids, and signal intensities to those obtained when extraction and separation processes are performed prior to mass spectrometric analysis. Evidence is provided that DESI ionization occurs by both a gas-phase ionization process and by a droplet pick-up mechanism. Quantitative precision of DESI is compared with conventional electrospray ionization mass spectrometry (after sample workup) and the RSD values for the same set of 25 dicotyledonous C. maculatum seeds (one half of each seed analyzed by ESI and the other by DESI) are 9.8% and 5.2%, respectively.

Synthesis and preliminary biological evaluation of new derivatives of the marine alkaloid leucettamine B as kinase inhibitors.

PubMed

Debdab, Mansour; Renault, Stéven; Lozach, Olivier; Meijer, Laurent; Paquin, Ludovic; Carreaux, François; Bazureau, Jean-Pierre

2010-02-01

New derivatives of the marine alkaloid leucettamine B were prepared in five steps with overall yields ranging from 23 to 30%. The key step of our strategy has been the sulfur/nitrogen displacement under solvent-free microwave irradiation of (5Z) 5-benzo[1,3]-dioxo-5-ylmethylene-2-ethylsulfanyl-3,5-dihydroimidazol-4-one 3 with a mono-protected ethylenediamine 2. After deprotection of the N-Boc group, the amino derivative of leucettamine B 5 was subjected to reductive amination in two steps with retention of configuration of the double bond, to lead to eight new analogs of leucettamine B. The effect of these compounds on CK1alpha/beta, CDK5/p25, and GSK-3alpha/beta were investigated. Copyright 2009 Elsevier Masson SAS. All rights reserved.

A strategy for complex dimer formation when biomimicry fails: total synthesis of ten coccinellid alkaloids.

PubMed

Sherwood, Trevor C; Trotta, Adam H; Snyder, Scott A

2014-07-09

Although dimeric natural products can often be synthesized in the laboratory by directly merging advanced monomers, these approaches sometimes fail, leading instead to non-natural architectures via incorrect unions. Such a situation arose during our studies of the coccinellid alkaloids, when attempts to directly dimerize Nature's presumed monomeric precursors in a putative biomimetic sequence afforded only a non-natural analogue through improper regiocontrol. Herein, we outline a unique strategy for dimer formation that obviates these difficulties, one which rapidly constructs the coccinellid dimers psylloborine A and isopsylloborine A through a terminating sequence of two reaction cascades that generate five bonds, five rings, and four stereocenters. In addition, a common synthetic intermediate is identified which allows for the rapid, asymmetric formal or complete total syntheses of eight monomeric members of the class.

Spithioneines A and B, Two New Bohemamine Derivatives Possessing Ergothioneine Moiety from a Marine-Derived Streptomyces spinoverrucosus

PubMed Central

2015-01-01

Spithioneines A and B (1 and 2), two new bohemamine-type pyrrolizidine alkaloids possessing an unusual ergothioneine moiety, were isolated from a marine-derived Streptomyces spinoverrucosus. Their structures were elucidated by spectroscopic analysis, CD spectra, and chemical degradation and synthesis. Compounds 1 and 2 are rare natural products that incorporate the amino acid ergothioneine. PMID:26024315

Biosynthesis of the Pharmaceutically Important Fungal Ergot Alkaloid Dihydrolysergic Acid Requires a Specialized Allele of cloA

PubMed Central

Arnold, Stephanie L.

2017-01-01

ABSTRACT Ergot alkaloids are specialized fungal metabolites that are important as the bases of several pharmaceuticals. Many ergot alkaloids are derivatives of lysergic acid (LA) and have vasoconstrictive activity, whereas several dihydrolysergic acid (DHLA) derivatives are vasorelaxant. The pathway to LA is established, with the P450 monooxygenase CloA playing a key role in oxidizing its substrate agroclavine to LA. We analyzed the activities of products of cloA alleles from different fungi relative to DHLA biosynthesis by expressing them in a mutant of the fungus Neosartorya fumigata that accumulates festuclavine, the precursor to DHLA. Transformants expressing CloA from Epichloë typhina × Epichloë festucae, which oxidizes agroclavine to LA, failed to oxidize festuclavine to DHLA. In substrate feeding experiments, these same transformants oxidized exogenously supplied agroclavine to LA, indicating that a functional CloA was produced. A genomic clone of cloA from Claviceps africana, a sorghum ergot fungus that produces a DHLA derivative, was cloned and expressed in the festuclavine-accumulating mutant of N. fumigata, but several introns in this genomic clone were not processed properly. Expression of a synthetic intron-free version of C. africana cloA resulted in the accumulation of DHLA as assessed by fluorescence high-pressure liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS). In substrate feeding experiments, the C. africana CloA also accepted agroclavine as the substrate, oxidizing it to LA. The data indicate that a specialized allele of cloA is required for DHLA biosynthesis and that the pharmaceutically important compound DHLA can be produced in engineered N. fumigata. IMPORTANCE Ergot alkaloids are fungal metabolites that have impacted humankind historically as poisons and more recently as pharmaceuticals used to treat dementia, migraines, and other disorders. Much is known about the biosynthesis of ergot alkaloids that are derived from lysergic acid (LA), but important questions remain about a parallel pathway to ergot alkaloids derived from dihydrolysergic acid (DHLA). DHLA-derived alkaloids have minor structural differences compared to LA-derived alkaloids but can have very different activities. To understand how DHLA is made, we analyzed activities of a key enzyme in the DHLA pathway and found that it differed from its counterpart in the LA pathway. Our data indicate a critical difference between the two pathways and provide a strategy for producing DHLA by modifying a model fungus. The ability to produce DHLA in a model fungus may facilitate synthesis of DHLA-derived pharmaceuticals. PMID:28476772

Biosynthesis of the Pharmaceutically Important Fungal Ergot Alkaloid Dihydrolysergic Acid Requires a Specialized Allele of cloA.

PubMed

Arnold, Stephanie L; Panaccione, Daniel G

2017-07-15

Ergot alkaloids are specialized fungal metabolites that are important as the bases of several pharmaceuticals. Many ergot alkaloids are derivatives of lysergic acid (LA) and have vasoconstrictive activity, whereas several dihydrolysergic acid (DHLA) derivatives are vasorelaxant. The pathway to LA is established, with the P450 monooxygenase CloA playing a key role in oxidizing its substrate agroclavine to LA. We analyzed the activities of products of cloA alleles from different fungi relative to DHLA biosynthesis by expressing them in a mutant of the fungus Neosartorya fumigata that accumulates festuclavine, the precursor to DHLA. Transformants expressing CloA from Epichloë typhina × Epichloë festucae , which oxidizes agroclavine to LA, failed to oxidize festuclavine to DHLA. In substrate feeding experiments, these same transformants oxidized exogenously supplied agroclavine to LA, indicating that a functional CloA was produced. A genomic clone of cloA from Claviceps africana , a sorghum ergot fungus that produces a DHLA derivative, was cloned and expressed in the festuclavine-accumulating mutant of N. fumigata , but several introns in this genomic clone were not processed properly. Expression of a synthetic intron-free version of C. africana cloA resulted in the accumulation of DHLA as assessed by fluorescence high-pressure liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS). In substrate feeding experiments, the C. africana CloA also accepted agroclavine as the substrate, oxidizing it to LA. The data indicate that a specialized allele of cloA is required for DHLA biosynthesis and that the pharmaceutically important compound DHLA can be produced in engineered N. fumigata IMPORTANCE Ergot alkaloids are fungal metabolites that have impacted humankind historically as poisons and more recently as pharmaceuticals used to treat dementia, migraines, and other disorders. Much is known about the biosynthesis of ergot alkaloids that are derived from lysergic acid (LA), but important questions remain about a parallel pathway to ergot alkaloids derived from dihydrolysergic acid (DHLA). DHLA-derived alkaloids have minor structural differences compared to LA-derived alkaloids but can have very different activities. To understand how DHLA is made, we analyzed activities of a key enzyme in the DHLA pathway and found that it differed from its counterpart in the LA pathway. Our data indicate a critical difference between the two pathways and provide a strategy for producing DHLA by modifying a model fungus. The ability to produce DHLA in a model fungus may facilitate synthesis of DHLA-derived pharmaceuticals. Copyright © 2017 American Society for Microbiology.

Natural toxins of plant origin (phytotoxins)

USDA-ARS?s Scientific Manuscript database

Over 100,000 secondary compounds have been identified in plants including alkaloids, glycosides, proteins, polypeptides, amines and non-protein amino acids, organic acids, alcohols, polyacetylenes, resinous toxins and mineral toxins. For thousands of years man has used some of these compounds as fl...

Natural product-inspired cascade synthesis yields modulators of centrosome integrity.

PubMed

Dückert, Heiko; Pries, Verena; Khedkar, Vivek; Menninger, Sascha; Bruss, Hanna; Bird, Alexander W; Maliga, Zoltan; Brockmeyer, Andreas; Janning, Petra; Hyman, Anthony; Grimme, Stefan; Schürmann, Markus; Preut, Hans; Hübel, Katja; Ziegler, Slava; Kumar, Kamal; Waldmann, Herbert

2011-12-25

In biology-oriented synthesis, the scaffolds of biologically relevant compound classes inspire the synthesis of focused compound collections enriched in bioactivity. This criterion is, in particular, met by the scaffolds of natural products selected in evolution. The synthesis of natural product-inspired compound collections calls for efficient reaction sequences that preferably combine multiple individual transformations in one operation. Here we report the development of a one-pot, twelve-step cascade reaction sequence that includes nine different reactions and two opposing kinds of organocatalysis. The cascade sequence proceeds within 10-30 min and transforms readily available substrates into complex indoloquinolizines that resemble the core tetracyclic scaffold of numerous polycyclic indole alkaloids. Biological investigation of a corresponding focused compound collection revealed modulators of centrosome integrity, termed centrocountins, which caused fragmented and supernumerary centrosomes, chromosome congression defects, multipolar mitotic spindles, acentrosomal spindle poles and multipolar cell division by targeting the centrosome-associated proteins nucleophosmin and Crm1.

Total synthesis of rupestine G and its epimers

PubMed Central

Yusuf, Abdullah; Zhao, Jiangyu; Wang, Bianlin; Aibibula, Paruke; Aisa, Haji Akber

2018-01-01

Rupestine G is a guaipyridine sesquiterpene alkaloid isolated from Artemisia rupestris L. The total synthesis of rupestine G and its epimers was accomplished employing a Suzuki reaction to build a terminal diene moiety. The diene was further elaborated into the desired guaipyridine structure by a ring-closing metathesis reaction. Over all, rupestine G and its three epimers were obtained as a mixture in a sequence of nine linear steps with 18.9% yield. Rupestine G and its optically pure isomers were isolated by chiral preparative HPLC and fully characterized by 1H ,13C NMR, HRMS, optical rotation value, and experimental and calculated electronic circular dichroism spectroscopy. PMID:29657802

Asymmetric Synthesis of All the Known Phlegmarine Alkaloids

PubMed Central

Wolfe, Bradley H.; Libby, Adam H.; Al-awar, Rima S.; Foti, Christopher J.; Comins, Daniel L.

2010-01-01

The asymmetric synthesis of all four of the known natural phlegmarines and one synthetic derivative has been accomplished in 19 to 22 steps from 4-methoxy-3-(triisopropylsilyl)pyridine. Chiral N-acylpyridinium salt chemistry was used twice to set the stereocenters at the C-9 and C-2′ positions of the phlegmarine skeleton. Key reactions include the use of a mixed Grignard reagent for the second N-acylpyridinium salt addition, zinc/acetic acid reduction of a complex dihydropyridone, and a von Braun cyanogen bromide N-demethylation of a late intermediate. These syntheses confirmed the absolute stereochemistry of all the known phlegmarines. PMID:21077636

Synthesis of (−)-Pseudotabersonine, (−)-Pseudovincadifformine, and (+)-Coronaridine Enabled by Photoredox Catalysis in Flow

PubMed Central

2015-01-01

Natural product modification with photoredox catalysis allows for mild, chemoselective access to a wide array of related structures in complex areas of chemical space, providing the possibility for novel structural motifs as well as useful quantities of less abundant congeners. While amine additives have been used extensively as stoichiometric electron donors for photocatalysis, the controlled modification of amine substrates through single-electron oxidation is ideal for the synthesis and modification of alkaloids. Here, we report the conversion of the amine (+)-catharanthine into the natural products (−)-pseudotabersonine, (−)-pseudovincadifformine, and (+)-coronaridine utilizing visible light photoredox catalysis. PMID:25003992

Collective synthesis of natural products by means of organocascade catalysis.

PubMed

Jones, Spencer B; Simmons, Bryon; Mastracchio, Anthony; MacMillan, David W C

2011-07-13

Organic chemists are now able to synthesize small quantities of almost any known natural product, given sufficient time, resources and effort. However, translation of the academic successes in total synthesis to the large-scale construction of complex natural products and the development of large collections of biologically relevant molecules present significant challenges to synthetic chemists. Here we show that the application of two nature-inspired techniques, namely organocascade catalysis and collective natural product synthesis, can facilitate the preparation of useful quantities of a range of structurally diverse natural products from a common molecular scaffold. The power of this concept has been demonstrated through the expedient, asymmetric total syntheses of six well-known alkaloid natural products: strychnine, aspidospermidine, vincadifformine, akuammicine, kopsanone and kopsinine. ©2011 Macmillan Publishers Limited. All rights reserved

Synthesis of gold nanoparticles using renewable Punica granatum juice and study of its catalytic activity

NASA Astrophysics Data System (ADS)

Dash, Shib Shankar; Bag, Braja Gopal

2014-01-01

Punica granatum juice, a delicious multivitamin drink of great medicinal significance, is rich in different types of phytochemicals, such as terpenoids, alkaloids, sterols, polyphenols, sugars, fatty acids, aromatic compounds, amino acids, tocopherols, etc. We have demonstrated the use of the juice for the synthesis of gold nanoparticles (AuNPs) at room temperature under very mild conditions. The synthesis of the AuNPs was complete in few minutes and no extra stabilizing or capping agents were necessary. The size of the nanoparticles could be controlled by varying the concentration of the fruit extract. The AuNPs were characterized by surface plasmon resonance spectroscopy, high resolution transmission electron microscopy, fourier transform infrared spectroscopy and X-ray diffraction studies. Catalytic activity of the synthesized colloidal AuNPs has also been demonstrated.

Genomic and metabolic characterisation of alkaloid biosynthesis by asexual Epichloë fungal endophytes of tall fescue pasture grasses.

PubMed

Ekanayake, Piyumi N; Kaur, Jatinder; Tian, Pei; Rochfort, Simone J; Guthridge, Kathryn M; Sawbridge, Timothy I; Spangenberg, German C; Forster, John W

2017-06-01

Symbiotic associations between tall fescue grasses and asexual Epichloë fungal endophytes exhibit biosynthesis of alkaloid compounds causing both beneficial and detrimental effects. Candidate novel endophytes with favourable chemotypic profiles have been identified in germplasm collections by screening for genetic diversity, followed by metabolite profile analysis in endogenous genetic backgrounds. A subset of candidates was subjected to genome survey sequencing to detect the presence or absence and structural status of known genes for biosynthesis of the major alkaloid classes. The capacity to produce specific metabolites was directly predictable from metabolic data. In addition, study of duplicated gene structure in heteroploid genomic constitutions provided further evidence for the origin of such endophytes. Selected strains were inoculated into meristem-derived callus cultures from specific tall fescue genotypes to perform isogenic comparisons of alkaloid profile in different host backgrounds, revealing evidence for host-specific quantitative control of metabolite production, consistent with previous studies. Certain strains were capable of both inoculation and formation of longer-term associations with a nonhost species, perennial ryegrass (Lolium perenne L.). Discovery and primary characterisation of novel endophytes by DNA analysis, followed by confirmatory metabolic studies, offers improvements of speed and efficiency and hence accelerated deployment in pasture grass improvement programs.

Crystal structure of norcoclaurine-6-O-methyltransferase, a key rate-limiting step in the synthesis of benzylisoquinoline alkaloids.

PubMed

Robin, Adeline Y; Giustini, Cécile; Graindorge, Matthieu; Matringe, Michel; Dumas, Renaud

2016-09-01

Growing pharmaceutical interest in benzylisoquinoline alkaloids (BIA) coupled with their chemical complexity make metabolic engineering of microbes to create alternative platforms of production an increasingly attractive proposition. However, precise knowledge of rate-limiting enzymes and negative feedback inhibition by end-products of BIA metabolism is of paramount importance for this emerging field of synthetic biology. In this work we report the structural characterization of (S)-norcoclaurine-6-O-methyltransferase (6OMT), a key rate-limiting step enzyme involved in the synthesis of reticuline, the final intermediate to be shared between the different end-products of BIA metabolism, such as morphine, papaverine, berberine and sanguinarine. Four different crystal structures of the enzyme from Thalictrum flavum (Tf 6OMT) were solved: the apoenzyme, the complex with S-adenosyl-l-homocysteine (SAH), the complexe with SAH and the substrate and the complex with SAH and a feedback inhibitor, sanguinarine. The Tf 6OMT structural study provides a molecular understanding of its substrate specificity, active site structure and reaction mechanism. This study also clarifies the inhibition of Tf 6OMT by previously suggested feedback inhibitors. It reveals its high and time-dependent sensitivity toward sanguinarine. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

Synthesis and evaluation of novel marine bromopyrrole alkaloid-based derivatives as potential antidepressant agents.

PubMed

Rane, Rajesh A; Napahde, Shital; Bangalore, Pavan Kumar; Sahu, Niteshkumar U; Shah, Nishant; Kulkarni, Yogesh A; Barve, Kalyani; Lokare, Leena; Karpoormath, Rajshekhar

2014-11-01

Herein, we report synthesis and screening of a series of twenty derivatives of bromopyrrole alkaloids with aroyl hydrazone feature for antidepressant activity by forced swim test (FST), tail suspension test (TST), and actophotometer method. The molecules were further evaluated for in vitro human MAO's inhibitory activities. The tested compounds exhibited moderate to good antidepressant activity compared with standard fluoxetine. Among these, most promising antidepressant derivatives 5b (%DID = 60.48), 5e (%DID = 59), and 5j (%DID = 74.86) reduced immobility duration of 50-70% at 30 mg/kg dose levels in FST. Further, derivative 5b, 5e, and 5j displayed good antidepressant activity with %DID value of 47.50, 46.62, and 52.49, respectively, in TST compared with standard fluoxetine (66.56% DID). Compound 5b showed high in vitro MAO-A potency and selectivity (Ki MAO-A (μM) = 2.4 ± 0.99, SI = 0.06) with promising pharmacological activity recognizing its potential as antidepressant lead candidate for further drug development. Study revealed that the presence of halogen atoms such as chlorine and fluorine at ortho- and/or para-position of phenyl ring and N-alkylation of pyrrole core is favored features for antidepressant activity. © 2014 John Wiley & Sons A/S.

Characteristic Chromatogram: A Method of Discriminate and Quantitative Analysis for Quality Evaluation of Uncaria Stem with Hooks.

PubMed

Hou, Jinjun; Feng, Ruihong; Zhang, Yibei; Pan, Huiqin; Yao, Shuai; Han, Sumei; Feng, Zijin; Cai, Luying; Wu, Wanying; Guo, De-An

2018-04-01

It remains a challenge to establish new monographs for herbal drugs derived from multiple botanical sources. Specifically, the difficulty involves discriminating and quantifying these herbs with components whose levels vary markedly among different samples. Using Uncaria stem with hooks as an example, a characteristic chromatogram was proposed to discriminate its five botanical origins and to quantify its characteristic components in the chromatogram. The characteristic chromatogram with respect to the components of Uncaria stem with hooks with the five botanical origins was established using 0.02% diethylamine and acetonitrile as the mobile phase. The total analysis time was 50 min and the detection wavelength was 245 nm. Using the same chromatogram parameters, the single standard to determine multicomponents method was validated to simultaneously quantify nine indole alkaloids, including vincosamide, 3 α -dihydrocadambine, isocorynoxeine, corynoxeine, isorhynchophylline, rhynchophylline, hirsuteine, hirsutine, and geissoschizine methyl ether. The results showed that only the Uncaria stem with hooks from Uncaria rhynchophylla , the most widely used in the herbal market, showed the presence of these nine alkaloids. The conversion factors were 1.27, 2.32, 0.98, 1.04, 1.00, 1.02, 1.26, 1.33, and 1.25, respectively. The limits of quantitation were lower than 700 ng/mL. The total contents of 31 batches of Uncaria stem with hooks were in the range of 0.1 - 0.6%, except for Uncaria hirsuta Havil and Uncaria sinensis (Oliv.) Havil. The results also showed that the total content of indole alkaloids tended to decrease with an increase in the hook diameter. This showed that the characteristic chromatogram is practical for controlling the quality of traditional Chinese medicines with multiple botanical origins. Georg Thieme Verlag KG Stuttgart · New York.

Comparison of Anorectic Potencies of the Trichothecenes T-2 Toxin, HT-2 Toxin and Satratoxin G to the Ipecac Alkaloid Emetine.

PubMed

Wu, Wenda; Zhou, Hui-Ren; Pan, Xiao; Pestka, James J

Trichothecene mycotoxins, potent translational inhibitors that are associated with human food poisonings and damp-building illnesses, are of considerable concern to animal and human health. Food refusal is a hallmark of exposure of experimental animals to deoxynivalenol (DON) and other Type B trichothecenes but less is known about the anorectic effects of foodborne Type A trichothecenes (e.g., T-2 toxin, HT-2 toxin), airborne Type D trichothecenes (e.g. satratoxin G [SG]) or functionally analogous metabolites that impair protein synthesis. Here, we utilized a well-described mouse model of food intake to compare the anorectic potencies of T-2 toxin, HT-2 toxin, and SG to that of emetine, a medicinal alkaloid derived from ipecac that inhibits translation. Intraperitoneal (IP) administration with T-2 toxin, HT-2 toxin, emetine and SG evoked anorectic responses that occurred within 0.5 h that lasted up to 96, 96, 3 and 96 h, respectively, with lowest observed adverse effect levels (LOAELs) being 0.1, 0.1, 2.5 and 0.25 mg/kg BW, respectively. When delivered via natural routes of exposure, T-2 toxin, HT-2 toxin, emetine (oral) and SG (intranasal) induced anorectic responses that lasted up to 48, 48, 3 and 6 h, respectively with LOAELs being 0.1, 0.1, 0.25, and 0.5 mg/kg BW, respectively. All four compounds were generally much more potent than DON which was previously observed to have LOAELs of 1 and 2.5 mg/kg BW after IP and oral dosing, respectively. Taken together, these anorectic potency data will be valuable in discerning the relative risks from trichothecenes and other translational inhibitors of natural origin.

Rotational spectra of tetracyclic quinolizidine alkaloids: does a water molecule flip sparteine?

PubMed

Lesarri, Alberto; Pinacho, Ruth; Enríquez, Lourdes; Rubio, José E; Jaraíz, Martín; Abad, José L; Gigosos, Marco A

2017-07-21

Sparteine is a quinolizidine alkaloid used as a chiral auxiliary in asymmetric synthesis. We examine whether hydration by a single molecule can flip sparteine from the most stable trans conformation to the bidentate cis arrangement observed in catalytic complexation to a metal center. Sparteine and the sparteine-water dimer were generated in a supersonic jet expansion with H 2 16 O and H 2 18 O, and characterized by broadband chirped-pulse microwave spectroscopy. Even though the bidentate water dimer was predicted with larger binding energy, a single isomer was observed for the monohydrated cluster, with sparteine retaining the trans conformation observed for the free molecule. The absence of the bidentate dimer is attributed to the kinetic control of cluster formation, favoring the pre-expansion most abundant monomer. The structural properties of the O-HN hydrogen bond in the dimer are compared with those of complexes of other secondary and tertiary amines.

A novel and general synthetic pathway to strychnos indole alkaloids: total syntheses of (-)-tubifoline, (-)-dehydrotubifoline, and (-)-strychnine using palladium-catalyzed asymmetric allylic substitution.

PubMed

Mori, Miwako; Nakanishi, Masato; Kajishima, Daisuke; Sato, Yoshihiro

2003-08-13

A method of palladium-catalyzed asymmetric allylic substitution for synthesizing 2-substituted cyclohexenylamine derivatives was established. Treatment of a 2-silyloxymethylcyclohexenol derivative with ortho-bromo-N-tosylaniline in the presence of Pd(2)dba(3).CHCl(3) and (S)-BINAPO in THF afforded a cyclohexenylamine derivative with 84% ee in 80% yield. The Heck reaction was carried out to produce an indolenine derivative in good yield. Using this method, we synthesized indolenine derivative 7, which was recrystallized from EtOH to give an optically pure compound. From this compound, tetracyclic ketone 13, which should be a useful intermediate for the synthesis of indole alkaloids, could be synthesized. The total syntheses of (-)-dehydrotubifoline, (-)-tubifoline, and (-)-strychnine were achieved from 13. All ring constructions for the syntheses of these natural products were achieved using a palladium catalyst.

Synthesis of novel flavonoid alkaloids as α-glucosidase inhibitors.

PubMed

Zhen, Jing; Dai, Yujie; Villani, Tom; Giurleo, Daniel; Simon, James E; Wu, Qingli

2017-10-15

A series of novel flavonoid alkaloids were synthesized with different flavonoids and attached nitrogen-containing moieties. These new compounds were screened for inhibitory activity of α-glucosidase, among which compound 23 was found to show the lowest IC 50 of 4.13μM. Kinetic analysis indicates that the synthesized compounds 15 and 23 inhibit the enzyme in a non-competitive model with Ki value of 37.8±0.8μM and 13.2±0.6μM. Further docking studies suggest that the preferred binding pocket is close to the catalytic center, correlating to the experimental results. Structure activity relationship studies (SAR) indicate that 4'-hyroxyl group and the 4-position carbonyl group in the flavonoid structure are important for this biological activity. Addition of extra hydrogen bonding and hydrophobic groups on ring A would increase the inhibitory activity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Natural products with hypoglycemic, hypotensive, hypocholesterolemic, antiatherosclerotic and antithrombotic activities.

PubMed

Wang, H X; Ng, T B

1999-01-01

This article reviews compounds of botanical origin which are capable of lowering plasma levels of glucose and cholesterol and blood pressure, as well as compounds inhibiting atherosclerosis and thrombosis. Hypoglycemic natural products comprise flavonoids, xanthones, triterpenoids, alkaloids, glycosides, alkyldisulfides, aminobutyric acid derivatives, guanidine, polysaccharides and peptides. Hypotensive compounds include flavonoids, diterpenes, alkaloids, glycosides, polysaccharides and proteins. Among natural products with hypocholesterolemic activity are beta-carotene, lycopene, cycloartenol, beta-sitosterol, sitostanol, saponin, soybean protein, indoles, dietary fiber, propionate, mevinolin (beta-hydroxy-beta-methylglutaryl coenzyme A reductase inhibitor) and polysaccharides. Heparins, flavonoids, tocotrienols, beta-hydroxy-beta-methylglutaryl coenzyme A reductase inhibitors (statins), garlic compounds and fungal proteases exert antithrombotic action. Statins and garlic compounds also possess antiatherosclerotic activity.

In-vivo genotoxicity of the alkaloid drug pilocarpine nitrate in bone marrow cells and male germ cells of mice.

PubMed

Hegde, M J; Sujatha, T V

1995-10-01

Pilocarpine nitrate, an alkaloid drug of plant origin induces spindle disfunction in bone marrow cells of mice. Further studies were carried out to investigate its mutagenic effects in somatic and germ cells of mice by assessing chromosome aberrations at mitotic metaphase and as micronuclei in bone marrow cells and sperm-shape abnormality in cauda epididymides. The dose and time yield effects of the drug were investigated. The statistically significant results that were obtained for both chromosomal aberrations and micronucleus test but not for the sperm-shape abnormality test, indicated the genotoxicity of this compound in somatic cells but not in germ cells.

Nature as a source of metabolites with cholinesterase-inhibitory activity: an approach to Alzheimer's disease treatment.

PubMed

Pinho, Brígida R; Ferreres, Federico; Valentão, Patrícia; Andrade, Paula B

2013-12-01

Alzheimer's disease (AD) is the most common cause of dementia, being responsible for high healthcare costs and familial hardships. Despite the efforts of researchers, no treatment able to delay or stop AD progress exists. Currently, the available treatments are only symptomatic, cholinesterase inhibitors being the most widely used drugs. Here we describe several natural compounds with anticholinesterase (acetylcholinesterase and butyrylcholinesterase) activity and also some synthetic compounds whose structures are based on those of natural compounds. Galantamine and rivastigmine are two cholinesterase inhibitors used in therapeutics: galantamine is a natural alkaloid that was extracted for the first time from Galanthus nivalis L., while rivastigmine is a synthetic alkaloid, the structure of which is modelled on that of natural physostigmine. Alkaloids include a high number of compounds with anticholinesterases activity at the submicromolar range. Quinones and stilbenes are less well studied regarding cholinesterase inhibition, although some of them, such as sargaquinoic acid or (+)-α-viniferin, show promising activity. Among flavonoids, flavones and isoflavones are the most potent compounds. Xanthones and monoterpenes are generally weak cholinesterase inhibitors. Nature is an almost endless source of bioactive compounds. Several natural compounds have anticholinesterase activity and others can be used as leader compounds for the synthesis of new drugs. © 2013 Royal Pharmaceutical Society.

Studies of a Diazo Cyclopropanation Strategy for the Total Synthesis of (-)-Lundurine A.

PubMed

Huang, Hong-Xiu; Jin, Shuai-Jiang; Gong, Jin; Zhang, Dan; Song, Hao; Qin, Yong

2015-09-14

The bioactive Kopsia alkaloids lundurines A-D are the only natural products known to contain indolylcyclopropane. Achieving their syntheses can provide important insights into their biogenesis, as well as novel synthetic routes for complex natural products. Asymmetric total synthesis of (-)-lundurine A has previously been achieved through a Simmons-Smith cyclopropanation strategy. Here, the total synthesis of (-)-lundurine A was carried out using a metal-catalyzed diazo cyclopropanation strategy. In order to avoid a carbene CH insertion side reaction during cyclopropanation of α-diazo- carboxylates or cyanides, a one-pot, copper-catalyzed Bamford-Stevens diazotization/diazo decomposition/cyclopropanation cascade was developed, involving hydrazone. This approach simultaneously generates the C/D/E ring system and the two chiral quaternary centers at C2 and C7. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gold-Catalyzed Cyclization Leads to a Bridged Tetracyclic Indolenine that Represses β-Lactam Resistance.

PubMed

Xu, Wenqing; Wang, Wei; Wang, Xiang

2015-08-10

A gold-catalyzed desilylative cyclization was developed for facile synthesis of bridged tetracyclic indolenines, a common motif in many natural indole alkaloids. An antimicrobial screen of the cyclization products identified one compound which selectively potentiates β-lactam antibiotics in methicillin-resistant S. aureus (MRSA), and re-sensitizes a variety of MRSA strains to β-lactams. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Total synthesis of (+)-batzelladine A and (-)-batzelladine D via [4 + 2]-annulation of vinyl carbodiimides with N-alkyl imines.

PubMed

Arnold, Michael A; Day, Kenneth A; Durón, Sergio G; Gin, David Y

2006-10-11

A diastereoselective [4 + 2]-annulation of vinyl carbodiimides with chiral N-alkyl imines has been developed to access the stereochemically rich polycyclic guanidine cores of the batzelladine alkaloids. Application of this strategy, together with additional key steps such as long-range directed hydrogenation and diastereoselective intramolecular iodo-amination, led to highly convergent total syntheses of (-)-batzelladine D and (+)-batzelladine A with excellent stereocontrol.

Protein kinase inhibitory properties of extracts derived from Bocconia frutescens and Gomphocarpus physocarpus

USDA-ARS?s Scientific Manuscript database

Bocconia frutescens is an invasive shrub originally introduced to Hawaii as an ornamental plant. Gomphocarpus physocarpus is a shrub that is native to southern Africa, also introduced to Hawaii. These two plants were selected for study due to the possibility of alkaloid contents and biological activ...

Molecular Architecture of Strictosidine Glucosidase: The Gateway to the Biosynthesis of the Monoterpenoid Indole Alkaloid Family[W

PubMed Central

Barleben, Leif; Panjikar, Santosh; Ruppert, Martin; Koepke, Juergen; Stöckigt, Joachim

2007-01-01

Strictosidine β-d-glucosidase (SG) follows strictosidine synthase (STR1) in the production of the reactive intermediate required for the formation of the large family of monoterpenoid indole alkaloids in plants. This family is composed of ∼2000 structurally diverse compounds. SG plays an important role in the plant cell by activating the glucoside strictosidine and allowing it to enter the multiple indole alkaloid pathways. Here, we report detailed three-dimensional information describing both native SG and the complex of its inactive mutant Glu207Gln with the substrate strictosidine, thus providing a structural characterization of substrate binding and identifying the amino acids that occupy the active site surface of the enzyme. Structural analysis and site-directed mutagenesis experiments demonstrate the essential role of Glu-207, Glu-416, His-161, and Trp-388 in catalysis. Comparison of the catalytic pocket of SG with that of other plant glucosidases demonstrates the structural importance of Trp-388. Compared with all other glucosidases of plant, bacterial, and archaeal origin, SG's residue Trp-388 is present in a unique structural conformation that is specific to the SG enzyme. In addition to STR1 and vinorine synthase, SG represents the third structural example of enzymes participating in the biosynthetic pathway of the Rauvolfia alkaloid ajmaline. The data presented here will contribute to deciphering the structure and reaction mechanism of other higher plant glucosidases. PMID:17890378

A novel synthesis of octahydropyrido[3,2-c]carbazole framework of aspidospermidine alkaloids and a combined computational, FT-IR, NMR, NBO, NLO, FMO, MEP study of the cis-4a-Ethyl-1-(2hydroxyethyl)-2,3,4,4a,5,6,7,11c-octahydro-1H-pyrido[3,2-c]carbazole

NASA Astrophysics Data System (ADS)

Uludağ, Nesimi; Serdaroğlu, Goncagul; Yinanc, Abdullah

2018-06-01

In this study, we performed a novel synthesis of the octahydropyrido[3,2-c]carbazole derivative 6 from 1 in five steps with a 34% overall yield. We also developed a unique compound 2 by a cyclization reaction from the cyanoethylation of compound 1, which is an intermediate step in the synthesis of Aspidospermidine. The parent compound of Aspidospermidine alkaloids, comprise a large family of diverse structures. As a result, we obtained octahydropyrido[3,2-c]carbazole (6)and the proposed method may be applicable to other alkaloids. All quantum chemical calculations of the cis-4a-Ethyl-1-(2-hydroxyethyl)-2,3,4,4a,5,6,7,11c-octahydro-1H-pyrido[3,2-c]carbazole have been performed with the DFT/B3LYP and HF methods by using the Gaussian 09W software package. The most stable conformer obtained from the Potential Energy Surface (PES) scan analysis at the B3LYP/6-31G** level of theory in the gas phase was used as the starting structure of the title compound to further computational analysis. The Natural Bond Orbital (NBO) and NLO analyses were performed to evaluate the intra-molecular interactions contributing to the molecular stability and to predict the optical properties of the title compound, respectively. Gauge-Independent Atomic Orbital (GIAO) approach was used to determine the 1H and 1C NMR chemical shifts of the title compound by subtracting the shielding constants of TMS at both methods. The calculated vibrational frequencies of the title compound were assigned by using the VEDA program and were scaled down by using the scaling factor 0.9668 for B3LYP/6-311++G(d, p) and 0.9050 for HF/6-311++G(d, p) to improve the calculated vibrational frequencies. The FMO (frontier molecular orbital) analysis was evaluated to predict the chemical and physical properties of the title compound and the HOMO, LUMO, and MEP diagrams were visualized by GaussView 4.1 program to present the reactive site of the title compound.

hERG Blockade by Iboga Alkaloids.

PubMed

Alper, Kenneth; Bai, Rong; Liu, Nian; Fowler, Steven J; Huang, Xi-Ping; Priori, Silvia G; Ruan, Yanfei

2016-01-01

The iboga alkaloids are a class of naturally occurring and synthetic compounds, some of which modify drug self-administration and withdrawal in humans and preclinical models. Ibogaine, the prototypic iboga alkaloid that is utilized clinically to treat addictions, has been associated with QT prolongation, torsades de pointes and fatalities. hERG blockade as IKr was measured using the whole-cell patch clamp technique in HEK 293 cells. This yielded the following IC50 values: ibogaine manufactured by semisynthesis via voacangine (4.09 ± 0.69 µM) or by extraction from T. iboga (3.53 ± 0.16 µM); ibogaine's principal metabolite noribogaine (2.86 ± 0.68 µM); and voacangine (2.25 ± 0.34 µM). In contrast, the IC50 of 18-methoxycoronaridine, a product of rational synthesis and current focus of drug development was >50 µM. hERG blockade was voltage dependent for all of the compounds, consistent with low-affinity blockade. hERG channel binding affinities (K i) for the entire set of compounds, including 18-MC, ranged from 0.71 to 3.89 µM, suggesting that 18-MC binds to the hERG channel with affinity similar to the other compounds, but the interaction produces substantially less hERG blockade. In view of the extended half-life of noribogaine, these results may relate to observations of persistent QT prolongation and cardiac arrhythmia at delayed intervals of days following ibogaine ingestion. The apparent structure-activity relationships regarding positions of substitutions on the ibogamine skeleton suggest that the iboga alkaloids might provide an informative paradigm for investigation of the structural biology of the hERG channel.

Total Synthesis of (+)-Batzelladine A and (−)-Batzelladine D via [4 + 2]-Annulation of Vinyl Carbodiimides with N-Alkyl Imines

PubMed Central

Arnold, Michael A.; Day, Kenneth A.; Durón, Sergio G.; Gin, David Y.

2008-01-01

A diastereoselective [4 + 2]-annulation of vinyl carbodiimides with chiral N-alkyl imines has been developed to access the stereochemically rich polycyclic guanidine cores of the batzelladine alkaloids. Application of this strategy, together with additional key steps such as long-range directed hydrogenation and diastereoselective intramolecular iodo-amination, led to highly convergent total syntheses of (−)-batzelladine D and (+)-batzelladine A with excellent stereocontrol. PMID:17017806

Stereoselective Synthesis of Tetrahydroindolizines through the Catalytic Formation of Pyridinium Ylides from Diazo Compounds.

PubMed

Day, Jonathan; McKeever-Abbas, Ben; Dowden, James

2016-05-04

Commercially available iron(III) and copper(I) complexes catalyzed multicomponent cycloaddition reactions between diazo compounds, pyridines, and electrophilic alkenes to give alkaloid-inspired tetrahydroindolizidines in high yield with high diastereoselectivity. Hitherto, the catalytic formation of versatile pyridinium ylides from metal carbenes has been poorly developed; the broad utility demonstrated herein sets the stage for the invention of further multicomponent reactions in future. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Bio-inspired synthesis yields a tricyclic indoline that selectively resensitizes methicillin-resistant Staphylococcus aureus (MRSA) to β-lactam antibiotics

PubMed Central

Podoll, Jessica D.; Liu, Yongxiang; Chang, Le; Walls, Shane; Wang, Wei; Wang, Xiang

2013-01-01

The continuous emergence of resistant bacteria has become a major worldwide health threat. The current development of new antibacterials has lagged far behind. To discover reagents to fight against resistant bacteria, we initiated a chemical approach by synthesizing and screening a small molecule library, reminiscent of the polycyclic indole alkaloids. Indole alkaloids are a class of structurally diverse natural products, many of which were isolated from plants that have been used as traditional medicine for millennia. Specifically, we adapted an evolutionarily conserved biosynthetic strategy and developed a concise and unified diversity synthesis pathway. Using this pathway, we synthesized 120 polycyclic indolines that contain 26 distinct skeletons and a wide variety of functional groups. A tricyclic indoline, Of1, was discovered to selectively potentiate the activity of β-lactam antibiotics in multidrug-resistant methicillin-resistant Staphylococcus aureus (MRSA), but not in methicillin-sensitive S. aureus. In addition, we found that Of1 itself does not have antiproliferative activity but can resensitize several MRSA strains to the β-lactam antibiotics that are widely used in the clinic, such as an extended-spectrum β-lactam antibiotic amoxicillin/clavulanic acid and a first-generation cephalosporin cefazolin. These data suggest that Of1 is a unique selective resistance-modifying agent for β-lactam antibiotics, and it may be further developed to fight against resistant bacteria in the clinic. PMID:24019472

Molecular design, synthesis and physical properties of novel Cytisine-derivatives - Experimental and theoretical study

NASA Astrophysics Data System (ADS)

Ivanova, Bojidarka; Spiteller, Michael

2013-02-01

The paper presented a comprehensive theoretical and experimental study on the molecular drugs-design, synthesis, isolation, physical spectroscopic and mass spectrometric elucidation of novel functionalization derivatives of Cytisine (Cyt), using nucleosidic residues. Since these alkaloids have established biochemical profile, related the binding affinity of the nicotinic acetylcholine receptors (nAChRs), particularly α7 sub-type, the presented correlation between the molecular structure and properties allowed to evaluated the highlights of the biochemical hypothesises related the Schizophrenia. The anticancer activity of α7 subtype agonists and the crucial role of the nucleoside-based medications in the cancer therapy provided opportunity for further study on the biochemical relationship between Schizophrenia and few kinds of cancers, which has been hypothesized recently. The physical electronic absorptions (EAs), circular dichroic (CD) and Raman spectroscopic (RS) properties as well as mass spectrometric (MS) data, obtained using electrospray ionization (ESI) and atmospheric-pressure chemical ionization (APCI) methods under the positive single (MS) and tandem (MS/MS) modes of operation are discussed. Taking into account reports on a fatal intoxication of Cyt, the presented data would be of interest in the field of forensic chemistry, through development of highly selective and sensitive analytical protocols. Quantum chemical method is used to predict the physical properties of the isolated alkaloids, their affinity to the receptor loop and gas-phase stabilized species, observed mass spectrometrically.

Eco-friendly approach for nanoparticles synthesis and mechanism behind antibacterial activity of silver and anticancer activity of gold nanoparticles.

PubMed

Patil, Maheshkumar Prakash; Kim, Gun-Do

2017-01-01

This review covers general information about the eco-friendly process for the synthesis of silver nanoparticles (AgNP) and gold nanoparticles (AuNP) and focuses on mechanism of the antibacterial activity of AgNPs and the anticancer activity of AuNPs. Biomolecules in the plant extract are involved in reduction of metal ions to nanoparticle in a one-step and eco-friendly synthesis process. Natural plant extracts contain wide range of metabolites including carbohydrates, alkaloids, terpenoids, phenolic compounds, and enzymes. A variety of plant species and plant parts have been successfully extracted and utilized for AgNP and AuNP syntheses. Green-synthesized nanoparticles eliminate the need for a stabilizing and capping agent and show shape and size-dependent biological activities. Here, we describe some of the plant extracts involved in nanoparticle synthesis, characterization methods, and biological applications. Nanoparticles are important in the field of pharmaceuticals for their strong antibacterial and anticancer activity. Considering the importance and uniqueness of this concept, the synthesis, characterization, and application of AgNPs and AuNPs are discussed in this review.

Studies Toward the Total Synthesis of Eletefine

NASA Astrophysics Data System (ADS)

Rugg, Kyle William

Eletefine is a natural product of the stephaoxocane family of alkaloids. It possesses an isoquinoline moiety functionalized with three methoxy groups forming an electron rich aromatic system. Eletefine also possesses a ten-membered ring with a novel bridged vinyl ether functionality, and a remote chiral alcohol, making it a conspicuous and desirable target for the synthetic organic chemist. The plant from which eletefine was first isolated (Cissampelos glaberrima ) has been used in traditional medicine for the relief of symptoms from urinary tract infections and asthma. The proposed synthesis of eletefine is a convergent route which features a Sonogashira coupling and a novel alkyne hydration. Herein, methods towards the synthesis of the model system des-hydroxyeletefine are described, in particular attempts towards formation of the AB ring system of des-hydroxyeletefine, as well as C8-C9 bond formation methodology via acylation and Sonogashira coupling.

Optimization and stabilization of gold nanoparticles by using herbal plant extract with microwave heating

NASA Astrophysics Data System (ADS)

Yasmin, Akbar; Ramesh, Kumaraswamy; Rajeshkumar, Shanmugam

2014-04-01

In this study, we have synthesized the gold nanoparticles by using Hibiscus rosa-sinensis, a medicinal plant. The gold nanoparticles were synthesized rapidly by the involvement of microwave heating. By changing of plant extract concentration, gold solution concentration, microwave heating time and power of microwave heating the optimized condition was identified. The surface Plasmon resonance found at 520 nm confirmed the gold nanoparticles synthesis. The spherical sized nanoparticles in the size range of 16-30 nm were confirmed by Transmission Electron Microscope (TEM). The stability of the nanoparticles is very well proved in the invitro stability tests. The biochemical like alkaloids and flavonoids play a vital role in the nanoparticles synthesis was identified using the Fourier Transform Infrared Spectroscopy (FTIR). Combining the phytochemical and microwave heating, the rapid synthesis of gold nanoparticles is the novel process for the medically applicable gold nanoparticles production.

Some Medicinal Plants Used in Chinese Medicine.

DTIC Science & Technology

1960-09-27

plant, widely grown in China, probably of hybrid origin. The plant is a source for high-grade mint oil and menthol which are exported. In the world...1.8-2$ while the menthol content is 86-92$. Plants Used as Anodynes Some alkaloid plants have found wide use in Chinese medicine as anodynes. Fang

The effect of 7, 8-methylenedioxylycoctonine-type diterpenoid alkaloids on the toxicity of tall larkspur (Delphinium spp.) in cattle.

PubMed

Welch, K D; Green, B T; Gardner, D R; Cook, D; Pfister, J A; Panter, K E

2012-07-01

Delphinium spp. contain numerous norditerpenoid alkaloids which are structurally delineated as 7, 8-methylenedioxylycoctonine (MDL) and N-(methylsuccinimido) anthranoyllycoctonine (MSAL)-type alkaloids. The toxicity of many tall larkspur species has been primarily attributed to their increased concentration of MSAL-type alkaloids, such as methyllycaconitine (MLA), which are typically 20 times more toxic than MDL-type alkaloids. However, the less toxic MDL-type alkaloids are often more abundant than MSAL-type alkaloids in most Delphinium barbeyi and Delphinium occidentale populations. Previous research demonstrated that MDL-type alkaloids increase the acute toxicity of MSAL-type alkaloids. In this study, we examined the role of MDL-type alkaloids on the overall toxicity of tall larkspur plants to cattle while controlling for the exact dose of MSAL-type alkaloids. Cattle were dosed with plant material from 2 different populations of tall larkspur containing either almost exclusively MDL- or MSAL-type alkaloids. These 2 plant populations were combined to create mixtures with ratios of 0.3:1, 1:1, 5:1, and 10:1 MDL- to MSAL-type alkaloids. The dose that elicited similar clinical signs of poisoning in mice and cattle was determined for each mixture on the basis of the MSAL-type alkaloid content. As the ratio of MDL- to MSAL-type alkaloids increased, the amount of MSAL-type alkaloids required to elicit clinical signs decreased. These results indicate that the less toxic MDL-type alkaloids in tall larkspur exacerbate the toxicity of the MSAL-type alkaloids. Consequently, both the amount of MSAL-type alkaloids and the amount of total alkaloids should be fully characterized to determine more accurately the relative toxicity of tall larkspur plant material.

Endophytic Epichloë species and their grass hosts: from evolution to applications.

PubMed

Saikkonen, Kari; Young, Carolyn A; Helander, Marjo; Schardl, Christopher L

2016-04-01

The closely linked fitness of the Epichloë symbiont and the host grass is presumed to align the coevolution of the species towards specialization and mutually beneficial cooperation. Ecological observations demonstrating that Epichloë-grass symbioses can modulate grassland ecosystems via both above- and belowground ecosystem processes support this. In many cases the detected ecological importance of Epichloë species is directly or indirectly linked to defensive mutualism attributable to alkaloids of fungal-origin. Now, modern genetic and molecular techniques enable the precise studies on evolutionary origin of endophytic Epichloë species, their coevolution with host grasses and identification the genetic variation that explains phenotypic diversity in ecologically relevant characteristics of Epichloë-grass associations. Here we briefly review the most recent findings in these areas of research using the present knowledge of the genetic variation that explains the biosynthetic pathways driving the diversity of alkaloids produced by the endophyte. These findings underscore the importance of genetic interplay between the fungus and the host in shaping their coevolution and ecological role in both natural grass ecosystems, and in the agricultural arena.

Quantitative and qualitative transcriptome analysis of four industrial strains of Claviceps purpurea with respect to ergot alkaloid production.

PubMed

Majeská Čudejková, Mária; Vojta, Petr; Valík, Josef; Galuszka, Petr

2016-09-25

The fungus Claviceps purpurea is a biotrophic phytopathogen widely used in the pharmaceutical industry for its ability to produce ergot alkaloids (EAs). The fungus attacks unfertilized ovaries of grasses and forms sclerotia, which represent the only type of tissue where the synthesis of EAs occurs. The biosynthetic pathway of EAs has been extensively studied; however, little is known concerning its regulation. Here, we present the quantitative transcriptome analysis of the sclerotial and mycelial tissues providing a comprehensive view of transcriptional differences between the tissues that produce EAs and those that do not produce EAs and the pathogenic and non-pathogenic lifestyle. The results indicate metabolic changes coupled with sclerotial differentiation, which are likely needed as initiation factors for EA biosynthesis. One of the promising factors seems to be oxidative stress. Here, we focus on the identification of putative transcription factors and regulators involved in sclerotial differentiation, which might be involved in EA biosynthesis. To shed more light on the regulation of EA composition, whole transcriptome analysis of four industrial strains differing in their alkaloid spectra was performed. The results support the hypothesis proposing the composition of the amino acid pool in sclerotia to be an important factor regulating the final structure of the ergopeptines produced by Claviceps purpurea. Copyright © 2016 Elsevier B.V. All rights reserved.

Dendrobium nobile Lindl. alkaloids regulate metabolism gene expression in livers of mice.

PubMed

Xu, Yun-Yan; Xu, Ya-Sha; Wang, Yuan; Wu, Qin; Lu, Yuan-Fu; Liu, Jie; Shi, Jing-Shan

2017-10-01

In our previous studies, Dendrobium nobile Lindl. alkaloids (DNLA) has been shown to have glucose-lowering and antihyperlipidaemia effects in diabetic rats, in rats fed with high-fat diets, and in mice challenged with adrenaline. This study aimed to examine the effects of DNLA on the expression of glucose and lipid metabolism genes in livers of mice. Mice were given DNLA at doses of 10-80 mg/kg, po for 8 days, and livers were removed for total RNA and protein isolation to perform real-time RT-PCR and Western blot analysis. Dendrobium nobile Lindl. alkaloids increased PGC1α at mRNA and protein levels and increased glucose metabolism gene Glut2 and FoxO1 expression. DNLA also increased the expression of fatty acid β-oxidation genes Acox1 and Cpt1a. The lipid synthesis regulator Srebp1 (sterol regulatory element-binding protein-1) was decreased, while the lipolysis gene ATGL was increased. Interestingly, DNLA increased the expression of antioxidant gene metallothionein-1 and NADPH quinone oxidoreductase-1 (Nqo1) in livers of mice. Western blot on selected proteins confirmed these changes including the increased expression of GLUT4 and PPARα. DNLA has beneficial effects on liver glucose and lipid metabolism gene expressions, and enhances the Nrf2-antioxidant pathway gene expressions, which could play integrated roles in regulating metabolic disorders. © 2017 Royal Pharmaceutical Society.

Programmed serial stereochemical relay and its application in the synthesis of morphinans† †Electronic supplementary information (ESI) available. CCDC 1526432. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7sc03189k Click here for additional data file. Click here for additional data file.

PubMed Central

Ho (Kenny) Park, Kun; Chen, Rui

2017-01-01

Herein we report a rationally designed, serial point-to-axial and axial-to-point stereoinduction and its integration into multi-step and target-oriented organic synthesis. In this proof-of-concept study, the configurational stability of several carefully designed atropisomeric intermediates and the fidelity of their unconventional stereoinductions were systematically investigated. The highly functionalized prepared synthetic intermediate was further applied in a novel chemical method to access the morphinans and it is potentially applicable to other structurally related alkaloids. PMID:29147530

Palladium-catalyzed reactions in the synthesis of 3- and 4-substituted indoles. 4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hegedus, L.S.; Sestrick, M.R.; Michaelson, E.T.

1989-08-18

4-Bromo-1-tosylindole (1) was converted to tricyclic indole enone 11, a potential intermediate in the synthesis of tetracyclic ergot alkaloids, by a series of palladium-catalyzed processes. Attempts to construct the ergot D ring by the hetero-Diels-Alder reaction of enone 11 and 1-azabutadiene 12 produced not the expected (4 + 2) adduct 13 but the benz(cd)indoline derivative 14 resulting from attack of the aza diene at the indole 2-position. The thermodynamic stability of the naphthol nucleus makes enone 11 generally susceptible to attack at the indole 2-position, as evidenced by the attack of hydride and methyl cuprate nucleophiles at this portion formingmore » indolines 16 and 17, respectively.« less

A Highly Active System for the Metal-Free Aerobic Photocyanation of Tertiary Amines with Visible Light: Application to the Synthesis of Tetraponerines and Crispine A.

PubMed

Orejarena Pacheco, Julio Cesar; Lipp, Alexander; Nauth, Alexander M; Acke, Fabian; Dietz, Jule-Philipp; Opatz, Till

2016-04-04

A highly efficient metal-free catalytic system for the aerobic photocyanation of tertiary amines with visible light is reported. The use of air as terminal oxidant offers an improved safety profile compared with pure oxygen, the used compact fluorescent lamp (CFL) light sources are highly economical, and no halogenated solvents are required. This system not only proves to be effective for a wide variety of trialkylamines, pharmaceuticals, and alkaloids but remarkably also allows the lowest catalyst loading (0.00001 mol% or 0.1 ppm) ever reported for an organic dye. Bruylants reactions and C-alkylation/decyanations were performed on the obtained α-aminonitriles to demonstrate the postfunctionalization of complex molecules. The catalytic system is furthermore applied in the short and effective syntheses of the alkaloids (±)-crispine A and the tetraponerines T7 and T8. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis of berberine loaded polymeric nanoparticles by central composite design

NASA Astrophysics Data System (ADS)

Mehra, Meenakshi; Sheorain, Jyoti; Kumari, Santosh

2016-04-01

Berberine is an isoquinoline alkaloid which is extracted from bark and roots of Berberis vulgaris plant. It has been used in ayurvedic medicine as it possess antimicrobial, antidiabetic, anticancer, antioxidant properties etc. But poor solubility of berberine leads to poor stability and bioavailability in medical formulations decreasing its efficacy. Hence nanoformulations of berberine can help in removing the limiting factors of alkaloid enhancing its utilization in pharmaceutical industry. Sodium alginate polymer was used to encapsulate berberine within nanoparticles by emulsion solvent evaporation method using tween 80 as a surfactant. Two factors and three level in central composite design was used to study the formulation. The optimized formulation (1% v/v of Tween 80 and 0.01% w/v of sodium alginate) of polymeric nanoparticles was taken for further evaluations. The size of synthesized nanoparticles was found to be 71.18 nm by particle size analysis (PSA). The berberine loaded polymeric nanoparticles showed better antibacterial activity compared to aqueous solution of berberine by well diffusion assay.

The Effects of Lasiocarpine, Retrorsine and Retronecine Pyrrole on Human Embryo Lung and Liver Cells in Culture

PubMed Central

Armstrong, Sylvia J.; Zuckerman, A. J.

1972-01-01

Retronecine pyrrole induces toxic changes both in human liver and lung cells. Lasiocarpine and retrorsine are toxic to liver cells but not to lung cells, which are unable to metabolize the pyrrolizidine alkaloids to pyrroles. The application of lasiocarpine to human liver cells in culture is followed by inhibition of DNA, RNA and protein synthesis; vacuolation of the cells, the prevention of mitosis and the formation of giant cells (“megalocytes”). PMID:5032089

An Efficient, Optimized Synthesis of Fentanyl and Related Analogs

DOE PAGES

Valdez, Carlos A.; Leif, Roald N.; Mayer, Brian P.; ...

2014-09-18

The alternate and optimized syntheses of the parent opioid fentanyl and its analogs are described. The routes presented exhibit high-yielding transformations leading to these powerful analgesics after optimization studies were carried out for each synthetic step. The general three-step strategy produced a panel of four fentanyls in excellent yields (73–78%) along with their more commonly encountered hydrochloride and citric acid salts. In conclusion, the following strategy offers the opportunity for the gram-scale, efficient production of this interesting class of opioid alkaloids.

An Efficient, Optimized Synthesis of Fentanyl and Related Analogs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Valdez, Carlos A.; Leif, Roald N.; Mayer, Brian P.

The alternate and optimized syntheses of the parent opioid fentanyl and its analogs are described. The routes presented exhibit high-yielding transformations leading to these powerful analgesics after optimization studies were carried out for each synthetic step. The general three-step strategy produced a panel of four fentanyls in excellent yields (73–78%) along with their more commonly encountered hydrochloride and citric acid salts. In conclusion, the following strategy offers the opportunity for the gram-scale, efficient production of this interesting class of opioid alkaloids.

Co2(CO)8-catalyzed intramolecular hetero-Pauson-Khand reaction of alkynecarbodiimide: synthesis of (+/-)-physostigmine.

PubMed

Mukai, Chisato; Yoshida, Tatsunori; Sorimachi, Mao; Odani, Akira

2006-01-05

[reaction: see text] Herein we describe a novel Co(2)(CO)(8)-catalyzed intramolecular aza-Pauson-Khand-type reaction of alkynecarbodiimide derivatives affords pyrrolo[2,3-b]indol-2-one ring systems in reasonable yields. This is the first reported Co(2)(CO)(8) successfully applied in the hetero-Pauson-Khand reaction. Significantly, the transformation of one of our pyrrolo[2,3-b]indol-2-one derivatives into the indole alkaloid, (+/-)-physostigmine, was completed in a highly stereoselective manner.

Alkaloids in Marine Algae

PubMed Central

Güven, Kasım Cemal; Percot, Aline; Sezik, Ekrem

2010-01-01

This paper presents the alkaloids found in green, brown and red marine algae. Algal chemistry has interested many researchers in order to develop new drugs, as algae include compounds with functional groups which are characteristic from this particular source. Among these compounds, alkaloids present special interest because of their pharmacological activities. Alkaloid chemistry has been widely studied in terrestrial plants, but the number of studies in algae is insignificant. In this review, a detailed account of macro algae alkaloids with their structure and pharmacological activities is presented. The alkaloids found in marine algae may be divided into three groups: 1. Phenylethylamine alkaloids, 2. Indole and halogenated indole alkaloids, 3. Other alkaloids. PMID:20390105

Veno-occlusive disease and primary hepatic vein thrombosis in Israeli Arabs.

PubMed

Ghanem, J; Hershko, C

1981-05-01

In a survey of nine major Israeli hospitals, 29 patients diagnosed between 1955 and 1975 as suffering from hepatic vein thrombosis were identified. Fifteen of the patients were Jews and 14 were Arabs. In contrast to the Jewish patients, all of whom were adults, the majority of the Arab patients were children below 10 years of age. Primary hepatic vein occlusion was 2.4 times more common among Arab than among Jewish patients. Of the 11 Arab patients with primary hepatic vein occlusion, three had histological changes typical of veno-occlusive disease; whereas in five others, thrombotic occlusion of large hepatic veins or of the vena cava was documented. Although no plant alkaloids could be directly implicated in any of the Arab patients, circumstantial evidence strongly supports such an etiology. All of our Arab patients originated from small agricultural communities where ancient methods of winnowing, which expose the home-ground wheat to a high risk of contamination by grains containing pyrrolizidine alkaloids, are still in use. This report confirms the world-wide distribution of veno-occlusive disease, and under-lines the need for a systematic search for possible sources of poisoning by pyrrolizidine alkaloids.

Phylogeography of the wild and cultivated stimulant plant qat (Catha edulis, Celastraceae) in areas of historic cultivation1

USDA-ARS?s Scientific Manuscript database

Qat (Catha edulis, Celastraceae) is a woody plant species cultivated for its stimulant alkaloids. Qat is important to the economy and culture in large regions of Ethiopia, Kenya, and Yemen. Despite the importance of this species, the wild origins and dispersal of cultivars have only been described i...

Biparental defensive endowment of eggs with acquired plant alkaloid in the moth Utetheisa ornatrix.

PubMed Central

Dussourd, D E; Ubik, K; Harvis, C; Resch, J; Meinwald, J; Eisner, T

1988-01-01

The eggs of Utetheisa ornatrix contain pyrrolizidine alkaloids. These compounds are contributed by both parents, who sequester them as larvae from their food plants. Females receive alkaloid from the males at mating, apparently by seminal infusion, and transmit this alkaloid together with alkaloid of their own to the eggs. Field and laboratory tests showed that the alkaloids protect eggs from predators. The alkaloidal contribution of the male, although smaller than that of the female, itself provides significant egg protection. A previously identified pheromone, derived by the male from the alkaloid and emitted during precopulatory behavior, may announce the male alkaloidal worth to the female. PMID:3413071

Current Status and Future Prospects of Marine Natural Products (MNPs) as Antimicrobials.

PubMed

Choudhary, Alka; Naughton, Lynn M; Montánchez, Itxaso; Dobson, Alan D W; Rai, Dilip K

2017-08-28

The marine environment is a rich source of chemically diverse, biologically active natural products, and serves as an invaluable resource in the ongoing search for novel antimicrobial compounds. Recent advances in extraction and isolation techniques, and in state-of-the-art technologies involved in organic synthesis and chemical structure elucidation, have accelerated the numbers of antimicrobial molecules originating from the ocean moving into clinical trials. The chemical diversity associated with these marine-derived molecules is immense, varying from simple linear peptides and fatty acids to complex alkaloids, terpenes and polyketides, etc. Such an array of structurally distinct molecules performs functionally diverse biological activities against many pathogenic bacteria and fungi, making marine-derived natural products valuable commodities, particularly in the current age of antimicrobial resistance. In this review, we have highlighted several marine-derived natural products (and their synthetic derivatives), which have gained recognition as effective antimicrobial agents over the past five years (2012-2017). These natural products have been categorized based on their chemical structures and the structure-activity mediated relationships of some of these bioactive molecules have been discussed. Finally, we have provided an insight into how genome mining efforts are likely to expedite the discovery of novel antimicrobial compounds.

Chemical and molecular aspects on interactions of galanthamine and its derivatives with cholinesterases.

PubMed

Gulcan, Hayrettin O; Orhan, Ilkay E; Sener, Bilge

2015-01-01

Dual action of galanthamine as potent cholinesterase inhibitor and nicotinic modulator has attracted a great attention to be used in the treatment of AD. Consequently, galanthamine, a natural alkaloid isolated from a Galanthus species (snowdrop, Amaryllidaceae), has become an attractive model compound for synthesis of its novel derivatives to discover new drug candidates. Numerous studies have been done to elucidate interactions between galanthamine and its different derivatives and the enzymes; acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) using in vitro and in silico experimental models. The in vitro studies revealed that galanthamine inhibits AChE in strong, competitive, long-acting, and reversible manner as well as BChE, although its selectivity towards AChE is much higher than BChE. The in silico studies carried out by employing molecular docking experiments as well as molecular dynamics simulations pointed out to existence of strong interactions of galanthamine with the active gorge of AChE, mostly of Torpedo californica (the Pasific electric ray) origin. In this review, we evaluate the mainstays of cholinesterase inhibitory action of galanthamine and its various derivatives from the point of view of chemical and molecular aspects.

Frog skin opioid peptides: a case for environmental mimicry.

PubMed Central

Lazarus, L H; Bryant, S D; Attila, M; Salvadori, S

1994-01-01

Naturally occurring environmental substances often mimic endogenous substances found in mammals and are capable of interacting with specific proteins, such as receptors, with a high degree of fidelity and selectivity. Narcotic alkaloids and amphibian skin secretions, introduced into human society through close association with plants and animals through folk medicine and religious divination practices, were incorporated into the armamentarium of the early pharmacopoeia. These skin secretions contain a myriad of potent bioactive substances, including alkaloids, biogenic amines, peptides, enzymes, mucus, and toxins (noxious compounds notwithstanding); each class exhibits a broad range of characteristic properties. One specific group of peptides, the opioids, containing the dermorphins (dermal morphinelike substances) and the deltorphins (delta-selective opioids), display remarkable analgesic properties and include an amino acid with the rare (in a mammalian context) D-enantiomer in lieu of the normal L-isomer. Synthesis of numerous stereospecific analogues and conformational analyses of these peptides provided essential insights into the tertiary composition and microenvironment of the receptor "pocket" and the optimal interactions between receptor and ligand that trigger a biological response; new advances in the synthesis and receptor-binding properties of the deltorphins are discussed in detail. These receptor-specific opioid peptides act as more than mimics of endogenous opioids: their high selectivity for either the mu or delta receptor makes them formidable environmentally derived agents in the search for new antagonists for treating opiate addiction and in the treatment of a wide variety of human disorders. Images p648-a Figure 2. Figure 3. PMID:7895704

Synthetic versatility of 2-substituted-6-methyl 2,3-dihydropyridinones in the synthesis of polyfunctional piperidine-based compounds and related β amino acid derivatives.

PubMed

Yang, Yang; Hardman, Clayton

2017-10-18

Chiral 2-substituted-6-methyl 2,3-dihydropyidinones 9, which can be facilely obtained from an asymmetric vinylogous Mannich reaction (VMR) with 1,3-bis-trimethysily enol ether, were used as versatile intermediates in constructing chiral polyfunctional piperidine-based compounds. The 6-methyl group of such compounds can be conveniently functionalized via alkylation and acylation reactions to provide efficient entries to the synthesis of a variety of chiral multi-substituted piperidine-based compounds. Further elaboration of the corresponding intermediates also provided access to polyfunctional indolizidine-based compounds. These methods were showcased in an asymmetric synthesis of 2,6-di-substituted piperidine compound 13, reported as the key intermediate in the synthesis of (+)-calvine and a natural alkaloid (-)-indolizidine 209D. Furthermore, selective C5 iodination of compound 9 enabled the installation of additional functional groups at this position. Finally, we demonstrated that the oxidative cleavage of 2-substituted-6-methyl-2,3-dihydropyidinones is a practical and efficient method for the enantioselective synthesis of β-amino acids, which can undergo further intra-molecular cyclization to give the corresponding chiral four-membered β-lactam derivatives.

Plants to Polyelectrolytes: Theophylline Polymers and Their Microsphere Synthesis.

PubMed

Guterman, Ryan; Antonietti, Markus; Yuan, Jiayin

2017-04-01

To extend fossil oil supplies, sustainable feed stocks for the production of useful reagents and polymers should be harnessed. In this regard, chemicals derived from plants are excellent candidates. While the vast majority of plant sources used for polymer science only contain C x H y O z , alkaloids such as caffeine, nicotine, and theophylline possess nitrogen functionality that can provide new functions for bioderived polymers and their synthesis. In this context, the chemistry of theophylline, a natural product found in chocolate and tea, is exploited to create a cationic "poly(theophylline)" in a straightforward fashion for the first time. This work demonstrates how this new polymer can be synthesized and used for the creation of narrowly disperse cationic microspheres. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cascade oxime formation, cyclization to a nitrone, and intermolecular dipolar cycloaddition.

PubMed

Furnival, Rachel C; Saruengkhanphasit, Rungroj; Holberry, Heather E; Shewring, Jonathan R; Guerrand, Hélène D S; Adams, Harry; Coldham, Iain

2016-11-22

Simple haloaldehydes, including enolisable aldehydes, were found to be suitable for the formation of cyclic products by cascade (domino) condensation, cyclisation, dipolar cycloaddition chemistry. This multi-component reaction approach to heterocyclic compounds was explored by using hydroxylamine, a selection of aldehydes, and a selection of activated dipolarophiles. Initial condensation gives intermediate oximes that undergo cyclisation with displacement of halide to give intermediate nitrones; these nitrones undergo in situ intermolecular dipolar cycloaddition reactions to give isoxazolidines. The cycloadducts from using dimethyl fumarate were treated with zinc/acetic acid to give lactam products and this provides an easy way to prepare pyrrolizinones, indolizinones, and pyrrolo[2,1-a]isoquinolinones. The chemistry is illustrated with a very short synthesis of the pyrrolizidine alkaloid macronecine and a formal synthesis of petasinecine.

Organocatalytic, enantioselective synthesis of benzoxaboroles via Wittig/oxa-Michael reaction Cascade of α-formyl boronic acids† †Electronic supplementary information (ESI) available. CCDC 1487136. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c6sc04522g Click here for additional data file. Click here for additional data file.

PubMed Central

Hazra, Gurupada; Maity, Sanjay; Bhowmick, Sudipto

2017-01-01

An unprecedented enantioselective synthesis of 3-substituted benzoxaboroles has been developed. An in situ generated ortho-boronic acid containing chalcone provides the chiral benzoxaboroles via an asymmetric oxa-Michael addition of hydroxyl group attached to the boronic acid triggered by the cinchona alkaloid based chiral amino-squaramide catalysts. In general, good yields with good to excellent enantioselectivities (up to 99%) were obtained. The resulting benzoxaboroles were converted to the corresponding chiral β-hydroxy ketones without affecting the enantioselectivity. PMID:28451370

[Effects of steaming and baking on content of alkaloids in Aconite Lateralis Radix (Fuzi)].

PubMed

Yang, Chang-lin; Huang, Zhi-fang; Zhang, Yi-han; Liu, Yu-hong; Liu, Yun-huan; Chen, Yan; Yi, Jin-hai

2014-12-01

To study the effect of steaming and baking process on contents of alkaloids in Aconite Lateralis Radix (Fuzi), 13 alkaloids were analyzed by UPLC-MS/MS equipped with ESI ion source in MRM mode. In steaming process, the contents of diester-diterpenoid alkaloids decreased rapidly, the contents of monoester-diterpenoid alkaloids firstly increased, reached the peak at 40 min, and then deceased gradually. The contents of aconine alkaloids (mesaconine, aconine and hypaconine) increased all the time during processing, while the contents of fuziline, songorine, karacoline, salsolionl were stable or slightly decreased. In baking process, dynamic variations of alkaloids were different from that in the steaming process. Diester-diterpenoid alkaloids were degraded slightly slower than in steaming process. Monoester-diterpenoid alkaloids, aconine alkaloids and the total alkaloids had been destroyed at different degrees, their contents were significantly lower than the ones in steaming Fuzi at the same processing time. This experiment revealed the dynamic variations of alkaloids in the course of steaming and baking. Two processing methods which can both effectively remove the toxic ingredients and retain the active ingredients are simple and controllable, and are valuable for popularization and application.

Alteration of the Alkaloid Profile in Genetically Modified Tobacco Reveals a Role of Methylenetetrahydrofolate Reductase in Nicotine N-Demethylation1[C][W][OA

PubMed Central

Hung, Chiu-Yueh; Fan, Longjiang; Kittur, Farooqahmed S.; Sun, Kehan; Qiu, Jie; Tang, She; Holliday, Bronwyn M.; Xiao, Bingguang; Burkey, Kent O.; Bush, Lowell P.; Conkling, Mark A.; Roje, Sanja; Xie, Jiahua

2013-01-01

Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme of the tetrahydrofolate (THF)-mediated one-carbon (C1) metabolic network. This enzyme catalyzes the reduction of 5,10-methylene-THF to 5-methyl-THF. The latter donates its methyl group to homocysteine, forming methionine, which is then used for the synthesis of S-adenosyl-methionine, a universal methyl donor for numerous methylation reactions, to produce primary and secondary metabolites. Here, we demonstrate that manipulating tobacco (Nicotiana tabacum) MTHFR gene (NtMTHFR1) expression dramatically alters the alkaloid profile in transgenic tobacco plants by negatively regulating the expression of a secondary metabolic pathway nicotine N-demethylase gene, CYP82E4. Quantitative real-time polymerase chain reaction and alkaloid analyses revealed that reducing NtMTHFR expression by RNA interference dramatically induced CYP82E4 expression, resulting in higher nicotine-to-nornicotine conversion rates. Conversely, overexpressing NtMTHFR1 suppressed CYP82E4 expression, leading to lower nicotine-to-nornicotine conversion rates. However, the reduced expression of NtMTHFR did not affect the methionine and S-adenosyl-methionine levels in the knockdown lines. Our finding reveals a new regulatory role of NtMTHFR1 in nicotine N-demethylation and suggests that the negative regulation of CYP82E4 expression may serve to recruit methyl groups from nicotine into the C1 pool under C1-deficient conditions. PMID:23221678

Low‑dose halofuginone inhibits the synthesis of type I collagen without influencing type II collagen in the extracellular matrix of chondrocytes.

PubMed

Li, Zeng; Fei, Hao; Wang, Zhen; Zhu, Tianyi

2017-09-01

Full‑thickness and large area defects of articular cartilage are unable to completely repair themselves and require surgical intervention, including microfracture, autologous or allogeneic osteochondral grafts, and autologous chondrocyte implantation. A large proportion of regenerative cartilage exists as fibrocartilage, which is unable to withstand impacts in the same way as native hyaline cartilage, owing to excess synthesis of type I collagen in the matrix. The present study demonstrated that low‑dose halofuginone (HF), a plant alkaloid isolated from Dichroa febrifuga, may inhibit the synthesis of type I collagen without influencing type II collagen in the extracellular matrix of chondrocytes. In addition, HF was revealed to inhibit the phosphorylation of mothers against decapentaplegic homolog (Smad)2/3 and promoted Smad7 expression, as well as decrease the synthesis of type I collagen synthesis. Results from the present study indicated that HF treatment suppressed the synthesis of type I collagen by inhibiting the transforming growth factor‑β signaling pathway in chondrocytes. These results may provide an alternative solution to the problems associated with fibrocartilage, and convert fibrocartilage into hyaline cartilage at the mid‑early stages of cartilage regeneration. HF may additionally be used to improve monolayer expansion or 3D cultures of seed cells for the tissue engineering of cartilage.

Non-statistical 13C Fractionation Distinguishes Co-incident and Divergent Steps in the Biosynthesis of the Alkaloids Nicotine and Tropine.

PubMed

Romek, Katarzyna M; Remaud, Gérald S; Silvestre, Virginie; Paneth, Piotr; Robins, Richard J

2016-08-05

During the biosynthesis of natural products, isotopic fractionation occurs due to the selectivity of enzymes for the heavier or lighter isotopomers. As only some of the positions in the molecule are implicated in a given reaction mechanism, position-specific fractionation occurs, leading to a non-statistical distribution of isotopes. This can be accessed by isotope ratio monitoring (13)C NMR spectrometry. The solanaceous alkaloids S-(-)-nicotine and hyoscyamine (atropine) are related in having a common intermediate, but downstream enzymatic steps diverge, providing a relevant test case to: (a) elucidate the isotopic affiliation between carbon atoms in the alkaloids and those in the precursors; (b) obtain information about the kinetic isotope effects of as yet undescribed enzymes, thus to make predictions as to their possible mechanism(s). We show that the position-specific (13)C/(12)C ratios in the different moieties of these compounds can satisfactorily be related to their known precursors and to the known kinetic isotope effects of enzymes involved in their biosynthesis, or to similar reaction mechanisms. Thus, the pathway to the common intermediate, N-methyl-Δ(1)-pyrrolinium, is seen to introduce similar isotope distribution patterns in the two alkaloids independent of plant species, whereas the remaining atoms of each target compound, which are of different origins, reflect their specific metabolic ancestry. We further demonstrate that the measured (13)C distribution pattern can be used to deduce aspects of the reaction mechanism of enzymes still to be identified. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Non-statistical 13C Fractionation Distinguishes Co-incident and Divergent Steps in the Biosynthesis of the Alkaloids Nicotine and Tropine*

PubMed Central

Romek, Katarzyna M.; Remaud, Gérald S.; Silvestre, Virginie; Paneth, Piotr; Robins, Richard J.

2016-01-01

During the biosynthesis of natural products, isotopic fractionation occurs due to the selectivity of enzymes for the heavier or lighter isotopomers. As only some of the positions in the molecule are implicated in a given reaction mechanism, position-specific fractionation occurs, leading to a non-statistical distribution of isotopes. This can be accessed by isotope ratio monitoring 13C NMR spectrometry. The solanaceous alkaloids S-(−)-nicotine and hyoscyamine (atropine) are related in having a common intermediate, but downstream enzymatic steps diverge, providing a relevant test case to: (a) elucidate the isotopic affiliation between carbon atoms in the alkaloids and those in the precursors; (b) obtain information about the kinetic isotope effects of as yet undescribed enzymes, thus to make predictions as to their possible mechanism(s). We show that the position-specific 13C/12C ratios in the different moieties of these compounds can satisfactorily be related to their known precursors and to the known kinetic isotope effects of enzymes involved in their biosynthesis, or to similar reaction mechanisms. Thus, the pathway to the common intermediate, N-methyl-Δ1-pyrrolinium, is seen to introduce similar isotope distribution patterns in the two alkaloids independent of plant species, whereas the remaining atoms of each target compound, which are of different origins, reflect their specific metabolic ancestry. We further demonstrate that the measured 13C distribution pattern can be used to deduce aspects of the reaction mechanism of enzymes still to be identified. PMID:27288405

Biosynthesis and Regulation of Bioprotective Alkaloids in the Gramineae Endophytic Fungi with Implications for Herbivores Deterrents.

PubMed

Luo, Hongping; Xie, Longxiang; Zeng, Jie; Xie, Jianping

2015-12-01

Four kinds of bioprotective alkaloids-peramine, loline, ergot alkaloid, indole-diterpenes, produced by grass-fungal endophyte symbioses, are deterrents or toxic to vertebrate and invertebrate herbivores. Ergot alkaloids have pharmacological properties and widely are used clinically. The regulation of alkaloids biosynthesis is under intensive study to improve the yield for better agricultural and medicinal application. In this paper, we summarize the structure, related genes, regulation, and toxicity of alkaloids. We focus on the biosynthesis and the regulation network of alkaloids.

Genetic variation of piperidine alkaloids in Pinus ponderosa: a common garden study.

PubMed

Gerson, Elizabeth A; Kelsey, Rick G; St Clair, J Bradley

2009-02-01

Previous measurements of conifer alkaloids have revealed significant variation attributable to many sources, environmental and genetic. The present study takes a complementary and intensive, common garden approach to examine genetic variation in Pinus ponderosa var. ponderosa alkaloid production. Additionally, this study investigates the potential trade-off between seedling growth and alkaloid production, and associations between topographic/climatic variables and alkaloid production. Piperidine alkaloids were quantified in foliage of 501 nursery seedlings grown from seed sources in west-central Washington, Oregon and California, roughly covering the western half of the native range of ponderosa pine. A nested mixed model was used to test differences among broad-scale regions and among families within regions. Alkaloid concentrations were regressed on seedling growth measurements to test metabolite allocation theory. Likewise, climate characteristics at the seed sources were also considered as explanatory variables. Quantitative variation from seedling to seedling was high, and regional variation exceeded variation among families. Regions along the western margin of the species range exhibited the highest alkaloid concentrations, while those further east had relatively low alkaloid levels. Qualitative variation in alkaloid profiles was low. All measures of seedling growth related negatively to alkaloid concentrations on a natural log scale; however, coefficients of determination were low. At best, annual height increment explained 19.4 % of the variation in ln(total alkaloids). Among the climate variables, temperature range showed a negative, linear association that explained 41.8 % of the variation. Given the wide geographic scope of the seed sources and the uniformity of resources in the seedlings' environment, observed differences in alkaloid concentrations are evidence for genetic regulation of alkaloid secondary metabolism in ponderosa pine. The theoretical trade-off with seedling growth appeared to be real, however slight. The climate variables provided little evidence for adaptive alkaloid variation, especially within regions.

Tropine Forming Tropinone Reductase Gene from Withania somnifera (Ashwagandha): Biochemical Characteristics of the Recombinant Enzyme and Novel Physiological Overtones of Tissue-Wide Gene Expression Patterns

PubMed Central

Kushwaha, Amit Kumar; Sangwan, Neelam Singh; Trivedi, Prabodh Kumar; Negi, Arvind Singh; Misra, Laxminarain; Sangwan, Rajender Singh

2013-01-01

Withania somnifera is one of the most reputed medicinal plants of Indian systems of medicine synthesizing diverse types of secondary metabolites such as withanolides, alkaloids, withanamides etc. Present study comprises cloning and E. coli over-expression of a tropinone reductase gene (WsTR-I) from W. somnifera, and elucidation of biochemical characteristics and physiological role of tropinone reductase enzyme in tropane alkaloid biosynthesis in aerial tissues of the plant. The recombinant enzyme was demonstrated to catalyze NADPH-dependent tropinone to tropine conversion step in tropane metabolism, through TLC, GC and GC-MS-MS analyses of the reaction product. The functionally active homodimeric ∼60 kDa enzyme catalyzed the reaction in reversible manner at optimum pH 6.7. Catalytic kinetics of the enzyme favoured its forward reaction (tropine formation). Comparative 3-D models of landscape of the enzyme active site contours and tropinone binding site were also developed. Tissue-wide and ontogenic stage-wise assessment of WsTR-I transcript levels revealed constitutive expression of the gene with relatively lower abundance in berries and young leaves. The tissue profiles of WsTR-I expression matched those of tropine levels. The data suggest that, in W. somnifera, aerial tissues as well possess tropane alkaloid biosynthetic competence. In vivo feeding of U-[14C]-sucrose to orphan shoot (twigs) and [14C]-chasing revealed substantial radiolabel incorporation in tropinone and tropine, confirming the de novo synthesizing ability of the aerial tissues. This inherent independent ability heralds a conceptual novelty in the backdrop of classical view that these tissues acquire the alkaloids through transportation from roots rather than synthesis. The TR-I gene expression was found to be up-regulated on exposure to signal molecules (methyl jasmonate and salicylic acid) and on mechanical injury. The enzyme's catalytic and structural properties as well as gene expression profiles are discussed with respect to their physiological overtones. PMID:24086372

Tropine forming tropinone reductase gene from Withania somnifera (Ashwagandha): biochemical characteristics of the recombinant enzyme and novel physiological overtones of tissue-wide gene expression patterns.

PubMed

Kushwaha, Amit Kumar; Sangwan, Neelam Singh; Trivedi, Prabodh Kumar; Negi, Arvind Singh; Misra, Laxminarain; Sangwan, Rajender Singh

2013-01-01

Withania somnifera is one of the most reputed medicinal plants of Indian systems of medicine synthesizing diverse types of secondary metabolites such as withanolides, alkaloids, withanamides etc. Present study comprises cloning and E. coli over-expression of a tropinone reductase gene (WsTR-I) from W. somnifera, and elucidation of biochemical characteristics and physiological role of tropinone reductase enzyme in tropane alkaloid biosynthesis in aerial tissues of the plant. The recombinant enzyme was demonstrated to catalyze NADPH-dependent tropinone to tropine conversion step in tropane metabolism, through TLC, GC and GC-MS-MS analyses of the reaction product. The functionally active homodimeric ~60 kDa enzyme catalyzed the reaction in reversible manner at optimum pH 6.7. Catalytic kinetics of the enzyme favoured its forward reaction (tropine formation). Comparative 3-D models of landscape of the enzyme active site contours and tropinone binding site were also developed. Tissue-wide and ontogenic stage-wise assessment of WsTR-I transcript levels revealed constitutive expression of the gene with relatively lower abundance in berries and young leaves. The tissue profiles of WsTR-I expression matched those of tropine levels. The data suggest that, in W. somnifera, aerial tissues as well possess tropane alkaloid biosynthetic competence. In vivo feeding of U-[(14)C]-sucrose to orphan shoot (twigs) and [(14)C]-chasing revealed substantial radiolabel incorporation in tropinone and tropine, confirming the de novo synthesizing ability of the aerial tissues. This inherent independent ability heralds a conceptual novelty in the backdrop of classical view that these tissues acquire the alkaloids through transportation from roots rather than synthesis. The TR-I gene expression was found to be up-regulated on exposure to signal molecules (methyl jasmonate and salicylic acid) and on mechanical injury. The enzyme's catalytic and structural properties as well as gene expression profiles are discussed with respect to their physiological overtones.

Alkaloids in bufonid toads (melanophryniscus): temporal and geographic determinants for two argentinian species.

PubMed

Daly, J W; Wilham, J M; Spande, T F; Garraffo, H M; Gil, R R; Silva, G L; Vaira, M

2007-04-01

Bufonid toads of the genus Melanophryniscus represent one of several lineages of anurans with the ability to sequester alkaloids from dietary arthropods for chemical defense. The alkaloid profile for Melanophryniscus stelzneri from a location in the province of Córdoba, Argentina, changed significantly over a 10-year period, probably indicating changes in availability of alkaloid-containing arthropods. A total of 29 alkaloids were identified in two collections of this population. Eight alkaloids were identified in M. stelzneri from another location in the province of Córdoba. The alkaloid profiles of Melanophryniscus rubriventris collected from four locations in the provinces of Salta and Jujuy, Argentina, contained 44 compounds and differed considerably between locations. Furthermore, alkaloid profiles of M. stelzneri and M. rubriventris strongly differed, probably reflecting differences in the ecosystem and hence in availability of alkaloid-containing arthropods.

Alkaloids in the human food chain--natural occurrence and possible adverse effects.

PubMed

Koleva, Irina I; van Beek, Teris A; Soffers, Ans E M F; Dusemund, Birgit; Rietjens, Ivonne M C M

2012-01-01

Alkaloid-containing plants are an intrinsic part of the regular Western diet. The present paper summarizes the occurrence of alkaloids in the food chain, their mode of action and possible adverse effects including a safety assessment. Pyrrolizidine alkaloids are a reason for concern because of their bioactivation to reactive alkylating intermediates. Several quinolizidine alkaloids, β-carboline alkaloids, ergot alkaloids and steroid alkaloids are active without bioactivation and mostly act as neurotoxins. Regulatory agencies are aware of the risks and have taken or are considering appropriate regulatory actions for most alkaloids. These vary from setting limits for the presence of a compound in feed, foods and beverages, trying to define safe upper limits, advising on a strategy aiming at restrictions in use, informing the public to be cautious or taking specific plant varieties from the market. For some alkaloids known to be present in the modern food chain, e.g., piperine, nicotine, theobromine, theophylline and tropane alkaloids risks coming from the human food chain are considered to be low if not negligible. Remarkably, for many alkaloids that are known constituents of the modern food chain and of possible concern, tolerable daily intake values have so far not been defined. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

BREEDING EXPERIMENTS ON MEDICINAL PLANTS. 27. ROENTGEN MUTATIONS AND ACTIVE SUBSTANCE CONTENT IN DATURA (in German)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steinegger, E.; Zbinden, F.

1961-10-01

The changes in alkaloid content of the Datura stramonium var. godronii are considered. About 1000 plants cultivated from irradiated and nonlrradiated seeds were examined for changes in total alkaloid content. In about 1.5% of the plants the alknloid content changed considerably, the decreases being more marked than the increases. Completely alkaloid-free plants, however, were not produced, in spite of the fact that occasionally the alkaloid content was so low that it could no longer be determined. There were two groups of mutants with increased alkaloid content. Some pharmaceutically important plants with higher total alkaloid production per plant and with loweredmore » alkaloid drug yield had double chromosome numbers and proved to be autotetraploid. However, the alkaloid contents of these plants were not higher than those of the artificially cultivated polyploids. The alkaloid content was evaluated by paper chromatography, which made possible the extraction of minute amounts of water- soluble basic amines as well as preventing the secondary changes of alkaloids. New alkaloids were not detected. Scopolamine content was found to decrease with age of the plant. In some mutants a reciprocal change in the amounts of some alkaloids could be demonstrated. A mutant containing a large amount of cuskohygrine was detected. (BBB)« less

Synthetic study toward the misassigned (±)-tronoharine.

PubMed

Zhong, Xue; Li, You; Zhang, Jing; Han, Fu-She

2015-02-06

The synthesis of a pentacyclic indole compound corresponding to the core structure of the misassigned indole alkaloid, tronoharine (1), is presented. The key reactions were a formal [3 + 3] cycloaddition of an indol-2-yl carbinol with an azadiene for the construction of the 6/5/6/6 tetracyclic system containing an all-carbon quaternary center and an intramolecular substitution reaction of an amine and a triflate for the creation of the bridged azepine ring. In addition, some other interesting transformations discovered during the synthetic studies are also discussed.

Catharanthus alkaloids XXXII: isolation of alkaloids from Catharanthus trichophyllus roots and structure elucidation of cathaphylline.

PubMed

Cordell, G A; Farnsworth, N R

1976-03-01

Further examination of the cytotoxic alkaloid fractions of Catharanthus trichophyllus roots afforded nine alkaloids. Two of these alkaloids, lochnericine and horhammericine, are responsible for part of the cytotoxic activity. The structure elucidation of cathaphylline, a new beta-anilino acrylate derivative, is described.

Isolation, Identification, and Xanthine Oxidase Inhibition Activity of Alkaloid Compound from Peperomia pellucida

NASA Astrophysics Data System (ADS)

Fachriyah, E.; Ghifari, M. A.; Anam, K.

2018-04-01

The research of the isolation and xanthine oxidation inhibition activity of alkaloid compound from Peperomia pellucida has been carried out. Alkaloid extract is isolated by column chromatography and preparative TLC. Alkaloid isolate is identified spectroscopically by UV-Vis spectrophotometer, FT-IR, and LC-MS/MS. Xanthine oxidase inhibition activity is carried out by in vitro assay. The result showed that the alkaloid isolated probably has piperidine basic structure. The alkaloid isolate has N-H, C-H, C = C, C = O, C-N, C-O-C groups and the aromatic ring. The IC50 values of ethanol and alkaloid extract are 71.6658 ppm and 76.3318 ppm, respectively. Alkaloid extract of Peperomia pellucida showed higher activity than ethanol extract.

Tachykinin-independent activity of capsaicin on in-vitro lamb detrusor.

PubMed

Tucci, Paolo; Evandri, Maria Grazia; Bolle, Paola

2002-08-01

The capsicum alkaloid capsaicin is an afferent fibre exciter. In the vesical bladder, capsaicin acts by releasing peptides stored in afferent fibres. The aim of this work was to verify the activity of capsaicin on in-vitro lamb urinary bladder and to ascertain whether this alkaloid evokes peptide release. Capsaicin relaxed about 80% of the lamb detrusor muscle preparations tested and contracted about 20%. Whereas neurokinin A and substance P antagonists, administered alone or together, left the contractile responses to capsaicin unchanged, atropine and tetrodotoxin totally inhibited contraction. Ruthenium red and indometacin abolished contractions and relaxation. The substance P and neurokinin A antagonists and the NO-synthesis inhibitor N omega-nitro-L-arginine methyl ester (L-NAME) left relaxation unchanged; conversely, the calcitonin gene-related peptide antagonist alpha h-CGRP (8-37) abolished this response. These results suggest that capsaicin relaxes lamb detrusor muscle not through tachykinins but by releasing CGRP from afferent fibres. Our observation that indometacin blocks the capsaicin response in in-vitro lamb urinary bladder also suggests a role of prostanoids.

Alkaloids as Cyclooxygenase Inhibitors in Anticancer Drug Discovery.

PubMed

Hashmi, Muhammad Ali; Khan, Afsar; Farooq, Umar; Khan, Sehroon

2018-01-01

Cancer is the leading cause of death worldwide and anticancer drug discovery is a very hot area of research at present. There are various factors which control and affect cancer, out of which enzymes like cyclooxygenase-2 (COX-2) play a vital role in the growth of tumor cells. Inhibition of this enzyme is a very useful target for the prevention of various types of cancers. Alkaloids are a diverse group of naturally occurring compounds which have shown great COX-2 inhibitory activity both in vitro and in vivo. In this mini-review, we have discussed different alkaloids with COX-2 inhibitory activities and anticancer potential which may act as leads in modern anticancer drug discovery. Different classes of alkaloids including isoquinoline alkaloids, indole alkaloids, piperidine alkaloids, quinazoline alkaloids, and various miscellaneous alkaloids obtained from natural sources have been discussed in detail in this review. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Establishment of a search library about benzylisoquinoline alkaloids based on selective separation on the binaphthyl column and standard analysis on C18 column.

PubMed

Liu, Qiaoxia; Zhou, Binbin; Wang, Xinliang; Ke, Yanxiong; Jin, Yu; Yin, Lihui; Liang, Xinmiao

2012-12-01

A search library about benzylisoquinoline alkaloids was established based on preparation of alkaloid fractions from Rhizoma coptidis, Cortex phellodendri, and Rhizoma corydalis. In this work, two alkaloid fractions from each herbal medicine were first prepared based on selective separation on the "click" binaphthyl column. And then these alkaloid fractions were analyzed on C18 column by liquid chromatography coupled with tandem mass spectrometry. Many structure-related compounds were included in these alkaloids fractions, which led to easy separation and good MS response in further work. Therefore, a search library of 52 benzylisoquinoline alkaloids was established, which included eight aporphine, 19 tetrahydroprotoberberine, two protopine, two benzyltetrahydroisoquinoline, and 21 protoberberine alkaloids. The information of the search library contained compound names, structures, retention times, accurate masses, fragmentation pathways of benzylisoquionline alkaloids, and their sources from three herbal medicines. Using such a library, the alkaloids, especially those trace and unknown components in some herbal medicine could be accurately and quickly identified. In addition, the distribution of benzylisoquinoline alkaloids in the herbal medicines could be also summarized by searching the source samples in the library. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dietary alkaloid sequestration in a poison frog: an experimental test of alkaloid uptake in Melanophryniscus stelzneri (Bufonidae).

PubMed

Hantak, Maggie M; Grant, Taran; Reinsch, Sherri; McGinnity, Dale; Loring, Marjorie; Toyooka, Naoki; Saporito, Ralph A

2013-12-01

Several lineages of brightly colored anurans independently evolved the ability to secrete alkaloid-containing defensive chemicals from granular glands in the skin. These species, collectively referred to as 'poison frogs,' form a polyphyletic assemblage that includes some species of Dendrobatidae, Mantellidae, Myobatrachidae, Bufonidae, and Eleutherodactylidae. The ability to sequester alkaloids from dietary arthropods has been demonstrated experimentally in most poison frog lineages but not in bufonid or eleutherodactylid poison frogs. As with other poison frogs, species of the genus Melanophryniscus (Bufonidae) consume large numbers of mites and ants, suggesting they might also sequester defensive alkaloids from dietary sources. To test this hypothesis, fruit flies dusted with alkaloid/nutritional supplement powder were fed to individual Melanophryniscus stelzneri in two experiments. In the first experiment, the alkaloids 5,8-disubstituted indolizidine 235B' and decahydroquinoline were administered to three individuals for 104 days. In the second experiment, the alkaloids 3,5-disubstituted indolizidine 239Q and decahydroquinoline were given to three frogs for 153 days. Control frogs were fed fruit flies dusted only with nutritional supplement. Gas chromatography/mass spectrometry analyses revealed that skin secretions of all experimental frogs contained alkaloids, whereas those of all control frogs lacked alkaloids. Uptake of decahydroquinoline was greater than uptake of 5,8-disubstituted indolizidine, and uptake of 3,5-disubstituted indolizidine was greater than uptake of decahydroquinoline, suggesting greater uptake efficiency of certain alkaloids. Frogs in the second experiment accumulated a greater amount of alkaloid, which corresponds to the longer duration and greater number of alkaloid-dusted fruit flies that were consumed. These findings provide the first experimental evidence that bufonid poison frogs sequester alkaloid-based defenses from dietary sources.

An integrated strategy for the systematic characterization and discovery of new indole alkaloids from Uncaria rhynchophylla by UHPLC/DAD/LTQ-Orbitrap-MS.

PubMed

Pan, Huiqin; Yang, Wenzhi; Zhang, Yibei; Yang, Min; Feng, Ruihong; Wu, Wanying; Guo, Dean

2015-08-01

The exploration of new chemical entities from herbal medicines may provide candidates for the in silico screening of drug leads. However, this significant work is hindered by the presence of multiple classes of plant metabolites and many re-discovered structures. This study presents an integrated strategy that uses ultrahigh-performance liquid chromatography/linear ion-trap quadrupole/Orbitrap mass spectrometry (UHPLC/LTQ-Orbitrap-MS) coupled with in-house library data for the systematic characterization and discovery of new potentially bioactive molecules. Exploration of the indole alkaloids from Uncaria rhynchophylla (UR) is presented as a model study. Initially, the primary characterization of alkaloids was achieved using mass defect filtering and neutral loss filtering. Subsequently, phytochemical isolation obtained 14 alkaloid compounds as reference standards, including a new one identified as 16,17-dihydro-O-demethylhirsuteine by NMR analyses. The direct-infusion fragmentation behaviors of these isolated alkaloids were studied to provide diagnostic structural information facilitating the rapid differentiation and characterization of four different alkaloid subtypes. Ultimately, after combining the experimental results with a survey of an in-house library containing 129 alkaloids isolated from the Uncaria genus, a total of 92 alkaloids (60 free alkaloids and 32 alkaloid O-glycosides) were identified or tentatively characterized, 56 of which are potential new alkaloids for the Uncaria genus. Hydroxylation on ring A, broad variations in the C-15 side chain, new N-oxides, and numerous O-glycosides, represent the novel features of the newly discovered indole alkaloid structures. These results greatly expand our knowledge of UR chemistry and are useful for the computational screening of potentially bioactive molecules from indole alkaloids. Graphical Abstract A four-step integrated strategy for the systematic characterization and efficient discovery of new indole alkaloids from Uncaria rhynchophylla.

Alkaloid concentration of the invasive plant species Ulex europaeus in relation to geographic origin and herbivory

NASA Astrophysics Data System (ADS)

Hornoy, Benjamin; Atlan, Anne; Tarayre, Michèle; Dugravot, Sébastien; Wink, Michael

2012-11-01

In the study of plant defense evolution, invasive plant species can be very insightful because they are often introduced without their enemies, and traits linked to defense can be released from selective pressures and evolve. Further, studying plant defense evolution in invasive species is important for biological control and use of these species. In this study, we investigated the evolution of the defensive chemicals quinolizidine alkaloids (QAs) in the invasive species gorse, Ulex europaeus. Using a common garden experiment, our goals were to characterize the role of QAs relative to specialist enemies of gorse and to investigate if QA concentration evolved in invaded regions, where gorse was introduced without these enemies. Our results showed that pod infestation rate by the seed predator Exapion ulicis and infestation by the rust pathogen Uromyces genistae-tinctoriae were negatively correlated to concentration of the QA lupanine. Quinolizidine alkaloid concentration was very variable between individuals, both within and among populations, but it was not different between native and invaded regions, suggesting that no evolution of decreased resistance occurred after gorse lost its enemies. Our study also suggests that QA concentrations are traits integrated into seed predation avoidance strategies of gorse, with plants that mass-fruit in spring but do not escape pod infestation in time being richer in QAs.

Alkaloid concentration of the invasive plant species Ulex europaeus in relation to geographic origin and herbivory.

PubMed

Hornoy, Benjamin; Atlan, Anne; Tarayre, Michèle; Dugravot, Sébastien; Wink, Michael

2012-11-01

In the study of plant defense evolution, invasive plant species can be very insightful because they are often introduced without their enemies, and traits linked to defense can be released from selective pressures and evolve. Further, studying plant defense evolution in invasive species is important for biological control and use of these species. In this study, we investigated the evolution of the defensive chemicals quinolizidine alkaloids (QAs) in the invasive species gorse, Ulex europaeus. Using a common garden experiment, our goals were to characterize the role of QAs relative to specialist enemies of gorse and to investigate if QA concentration evolved in invaded regions, where gorse was introduced without these enemies. Our results showed that pod infestation rate by the seed predator Exapion ulicis and infestation by the rust pathogen Uromyces genistae-tinctoriae were negatively correlated to concentration of the QA lupanine. Quinolizidine alkaloid concentration was very variable between individuals, both within and among populations, but it was not different between native and invaded regions, suggesting that no evolution of decreased resistance occurred after gorse lost its enemies. Our study also suggests that QA concentrations are traits integrated into seed predation avoidance strategies of gorse, with plants that mass-fruit in spring but do not escape pod infestation in time being richer in QAs.

Chemical defense: Bestowal of a nuptial alkaloidal garment by a male moth on its mate

PubMed Central

Conner, William E.; Boada, Ruth; Schroeder, Frank C.; González, Andrés; Meinwald, Jerrold; Eisner, Thomas

2000-01-01

Males of the moth Cosmosoma myrodora (Arctiidae) acquire pyrrolizidine alkaloid by feeding on the excrescent fluids of certain plants (for instance, Eupatorium capillifolium). They incorporate the alkaloid systemically and as a result are protected against spiders. The males have a pair of abdominal pouches, densely packed with fine cuticular filaments, which in alkaloid-fed males are alkaloid laden. The males discharge the filaments on the female in bursts during courtship, embellishing her with alkaloid as a result. The topical investiture protects the female against spiders. Alkaloid-free filaments, from alkaloid-deprived males, convey no such protection. The males also transmit alkaloid to the female by seminal infusion. The systemic alkaloid thus received, which itself may contribute to the female's defense against spiders, is bestowed in part by the female on the eggs. Although paternal contribution to egg defense had previously been demonstrated for several arctiid moths, protective nuptial festooning of a female by its mate, such as is practiced by C. myrodora, appears to be without parallel among insects. PMID:11114202

Genetic variation of piperidine alkaloids in Pinus ponderosa: a common garden study

PubMed Central

Gerson, Elizabeth A.; Kelsey, Rick G.; St Clair, J. Bradley

2009-01-01

Background and Aims Previous measurements of conifer alkaloids have revealed significant variation attributable to many sources, environmental and genetic. The present study takes a complementary and intensive, common garden approach to examine genetic variation in Pinus ponderosa var. ponderosa alkaloid production. Additionally, this study investigates the potential trade-off between seedling growth and alkaloid production, and associations between topographic/climatic variables and alkaloid production. Methods Piperidine alkaloids were quantified in foliage of 501 nursery seedlings grown from seed sources in west-central Washington, Oregon and California, roughly covering the western half of the native range of ponderosa pine. A nested mixed model was used to test differences among broad-scale regions and among families within regions. Alkaloid concentrations were regressed on seedling growth measurements to test metabolite allocation theory. Likewise, climate characteristics at the seed sources were also considered as explanatory variables. Key Results Quantitative variation from seedling to seedling was high, and regional variation exceeded variation among families. Regions along the western margin of the species range exhibited the highest alkaloid concentrations, while those further east had relatively low alkaloid levels. Qualitative variation in alkaloid profiles was low. All measures of seedling growth related negatively to alkaloid concentrations on a natural log scale; however, coefficients of determination were low. At best, annual height increment explained 19·4 % of the variation in ln(total alkaloids). Among the climate variables, temperature range showed a negative, linear association that explained 41·8 % of the variation. Conclusions Given the wide geographic scope of the seed sources and the uniformity of resources in the seedlings' environment, observed differences in alkaloid concentrations are evidence for genetic regulation of alkaloid secondary metabolism in ponderosa pine. The theoretical trade-off with seedling growth appeared to be real, however slight. The climate variables provided little evidence for adaptive alkaloid variation, especially within regions. PMID:19010800

Repeated Evolution of the Pyrrolizidine Alkaloid–Mediated Defense System in Separate Angiosperm LineagesW⃞

PubMed Central

Reimann, Andreas; Nurhayati, Niknik; Backenköhler, Anita; Ober, Dietrich

2004-01-01

Species of several unrelated families within the angiosperms are able to constitutively produce pyrrolizidine alkaloids as a defense against herbivores. In pyrrolizidine alkaloid (PA) biosynthesis, homospermidine synthase (HSS) catalyzes the first specific step. HSS was recruited during angiosperm evolution from deoxyhypusine synthase (DHS), an enzyme involved in the posttranslational activation of eukaryotic initiation factor 5A. Phylogenetic analysis of 23 cDNA sequences coding for HSS and DHS of various angiosperm species revealed at least four independent recruitments of HSS from DHS: one within the Boraginaceae, one within the monocots, and two within the Asteraceae family. Furthermore, sequence analyses indicated elevated substitution rates within HSS-coding sequences after each gene duplication, with an increased level of nonsynonymous mutations. However, the contradiction between the polyphyletic origin of the first enzyme in PA biosynthesis and the structural identity of the final biosynthetic PA products needs clarification. PMID:15466410

N-Methyl Inversion and Accurate Equilibrium Structures in Alkaloids: Pseudopelletierine.

PubMed

Vallejo-López, Montserrat; Écija, Patricia; Vogt, Natalja; Demaison, Jean; Lesarri, Alberto; Basterretxea, Francisco J; Cocinero, Emilio J

2017-11-21

A rotational spectroscopy investigation has resolved the conformational equilibrium and structural properties of the alkaloid pseudopelletierine. Two different conformers, which originate from inversion of the N-methyl group from an axial to an equatorial position, have been unambiguously identified in the gas phase, and nine independent isotopologues have been recorded by Fourier-transform microwave spectroscopy in a jet expansion. Both conformers share a chair-chair configuration of the two bridged six-membered rings. The conformational equilibrium is displaced towards the axial form, with a relative population in the supersonic jet of N axial /N equatorial ≈2/1. An accurate equilibrium structure has been determined by using the semiexperimental mixed-estimation method and alternatively computed by quantum-chemical methods up to the coupled-cluster level of theory. A comparison with the N-methyl inversion equilibria in related tropanes is also presented. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chemoselective reductive nucleophilic addition to tertiary amides, secondary amides, and N-methoxyamides.

PubMed

Nakajima, Minami; Oda, Yukiko; Wada, Takamasa; Minamikawa, Ryo; Shirokane, Kenji; Sato, Takaaki; Chida, Noritaka

2014-12-22

As the complexity of targeted molecules increases in modern organic synthesis, chemoselectivity is recognized as an important factor in the development of new methodologies. Chemoselective nucleophilic addition to amide carbonyl centers is a challenge because classical methods require harsh reaction conditions to overcome the poor electrophilicity of the amide carbonyl group. We have successfully developed a reductive nucleophilic addition of mild nucleophiles to tertiary amides, secondary amides, and N-methoxyamides that uses the Schwartz reagent [Cp2 ZrHCl]. The reaction took place in a highly chemoselective fashion in the presence of a variety of sensitive functional groups, such as methyl esters, which conventionally require protection prior to nucleophilic addition. The reaction will be applicable to the concise synthesis of complex natural alkaloids from readily available amide groups. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Function-Oriented Synthesis of Marine Phidianidine Derivatives as Potential PTP1B Inhibitors with Specific Selectivity.

PubMed

Liu, Jin; Chen, Yu; Li, Jing-Ya; Luo, Cheng; Li, Jia; Chen, Kai-Xian; Li, Xu-Wen; Guo, Yue-Wei

2018-03-20

Phidianidines A and B are two novel marine indole alkaloids bearing an uncommon 1,2,4-oxadiazole ring and exhibiting various biological activities. Our previous research showed that the synthesized phidianidine analogs had the potential to inhibit the activity of protein tyrosine phosphatase 1B (PTP1B), a validated target for Type II diabetes, which indicates that these analogs are worth further structural modification. Therefore, in this paper, a series of phidianidine derivatives were designed and rapidly synthesized with a function-oriented synthesis (FOS) strategy. Their inhibitory effects on PTP1B and T-cell protein tyrosine phosphatase (TCPTP) were evaluated, and several compounds displayed significant inhibitory potency and specific selectivity over PTP1B. The structure-activity relationship (SAR) and molecular docking analyses are also described.

Function-Oriented Synthesis of Marine Phidianidine Derivatives as Potential PTP1B Inhibitors with Specific Selectivity

PubMed Central

Liu, Jin; Chen, Yu; Li, Jing-Ya; Luo, Cheng; Li, Jia; Chen, Kai-Xian; Li, Xu-Wen

2018-01-01

Phidianidines A and B are two novel marine indole alkaloids bearing an uncommon 1,2,4-oxadiazole ring and exhibiting various biological activities. Our previous research showed that the synthesized phidianidine analogs had the potential to inhibit the activity of protein tyrosine phosphatase 1B (PTP1B), a validated target for Type II diabetes, which indicates that these analogs are worth further structural modification. Therefore, in this paper, a series of phidianidine derivatives were designed and rapidly synthesized with a function-oriented synthesis (FOS) strategy. Their inhibitory effects on PTP1B and T-cell protein tyrosine phosphatase (TCPTP) were evaluated, and several compounds displayed significant inhibitory potency and specific selectivity over PTP1B. The structure–activity relationship (SAR) and molecular docking analyses are also described. PMID:29558377

Enhanced antimicrobial activity in biosynthesized ZnO nanoparticles

NASA Astrophysics Data System (ADS)

Kumari, Niraj; Kumari, Priti; Jha, Anal K.; Prasad, K.

2018-05-01

Biological synthesis of different metallic and/or oxide nanoparticles and their applications especially in agriculture and biomedical sciences are gaining prominence nowadays due to their handy and reproducible synthetic protocols which are cost-effective and eco-friendly. In this work, green synthesis of zinc oxide nanoparticles (ZnO NPs) using the alcoholic extract of Azadirachta indica as a reducing and stabilizing agent has been presented. Formation of ZnO NPs was confirmed by X-ray diffraction, scanning and transmission electron microscopy techniques. The phytochemicals responsible for nano-transformation were principally alkaloids, flavanoids, terpenoids, tannins and organic acids present in the Azadirachta indica leaves. The synthesized ZnO NPs were used for antimicrobial assays by disc diffusion method against Staphylococcus aureus and Candida albicans. Results showed that ZnO NPs may act as antimicrobial agent especially against skin infections.

Influence of grass pellet production on pyrrolizidine alkaloids occurring in Senecio aquaticus-infested grassland.

PubMed

Gottschalk, Christoph; Ostertag, Johannes; Meyer, Karsten; Gehring, Klaus; Thyssen, Stefan; Gareis, Manfred

2018-04-01

1,2-Dehydro-pyrrolizidine alkaloids (PA) and their N-oxides (PANO) exhibit acute and chronic toxic effects on the liver and other organs and therefore are a hazard for animal and human health. In certain regions of Germany, an increasing spread of Senecio spp. (ragwort) on grassland and farmland areas has been observed during the last years leading to a PA/PANO-contamination of feed and food of animal and plant origin. This project was carried out to elucidate whether the process of grass pellet production applying hot air drying influences the content of PA and PANO. Samples of hay (n = 22) and grass pellets (n = 28) originated from naturally infested grassland (around 10% and 30% dominance of Senecio aquaticus) and from a trial plot with around 50% dominance. Grass pellets were prepared from grass originating from exactly the same plots as the hay samples. The samples were analysed by liquid chromatography-tandem mass spectrometry for PA/PANO typically produced by this weed. The results of the study revealed that PA/PANO levels (predominantly sum of senecionine, seneciphylline, erucifoline and their N-oxides) in hay ranged between 2.1 and 12.6 mg kg -1 dry matter in samples with 10% and 30% dominance of S. aquaticus, respectively. Samples from the trial plot (50% dominance) had levels of up to 52.9 mg kg -1 . Notably, the hot air drying process during the production of grass pellets did not lead to a reduction of PA/PANO levels. Instead, the levels in grass pellets with 10% and 30% S. aquaticus ranged from 3.1 to 55.1 mg kg -1 . Grass pellets from the trial plot contained up to 96.8 mg kg -1 . In conclusion, hot air drying and grass pellet production did not affect PA/PANO contents in plant material and therefore, heat-dried products cannot be regarded as safe in view of the toxic potential of 1,2-dehydro-pyrrolizidine alkaloids.

Alkaloids from single skins of the Argentinian toad Melanophryniscus rubriventris (ANURA, BUFONIDAE): An unexpected variability in alkaloid profiles and a profusion of new structures.

PubMed

Garraffo, H Martin; Andriamaharavo, Nirina R; Vaira, Marcos; Quiroga, María F; Heit, Cecilia; Spande, Thomas F

2012-12-01

GC-MS analysis of single-skins of ten Melanophryniscus rubriventris toads (five collections of two toads each) captured during their breeding season in NW Argentina has revealed a total of 127 alkaloids of which 56 had not been previously detected in any frog or toad. Included among these new alkaloids are 23 new diastereomers of previously reported alkaloids. What is particularly distinguishing about the alkaloid profiles of these ten collections is the occurrence of many of the alkaloids, whether known or new to us, in only one of the ten skins sampled, despite two skins being obtained from each breeding site of the five populations. Many of the alkaloids are of classes known to have structures with branched-chains (e.g. pumiliotoxins and tricyclic structures) that are considered to derive from dietary mites. A large number of previously reported and new alkaloids are also of unclassified structures. Only a very few 3,5-disubstituted-indolizidine or -pyrrolizidine alkaloids are observed that have a straight-chain carbon skeleton and are likely derived from ant prey. The possible relationship of these collections made during the toad's brief breeding episodes to sequestration of dietary arthropods and individual alkaloid profiles is discussed.

Ergot Alkaloids Produced by Endophytic Fungi of the Genus Epichloë

PubMed Central

Guerre, Philippe

2015-01-01

The development of fungal endophytes of the genus Epichloë in grasses results in the production of different groups of alkaloids, whose mechanism and biological spectrum of toxicity can differ considerably. Ergot alkaloids, when present in endophyte-infected tall fescue, are responsible for “fescue toxicosis” in livestock, whereas indole-diterpene alkaloids, when present in endophyte-infected ryegrass, are responsible for “ryegrass staggers”. In contrast, peramine and loline alkaloids are deterrent and/or toxic to insects. Other toxic effects in livestock associated with the consumption of endophyte-infected grass that contain ergot alkaloids include the “sleepy grass” and “drunken horse grass” diseases. Although ergovaline is the main ergopeptine alkaloid produced in endophyte-infected tall fescue and is recognized as responsible for fescue toxicosis, a number of questions still exist concerning the profile of alkaloid production in tall fescue and the worldwide distribution of tall fescue toxicosis. The purpose of this review is to present ergot alkaloids produced in endophyte-infected grass, the factors of variation of their level in plants, and the diseases observed in the mammalian species as relate to the profiles of alkaloid production. In the final section, interactions between ergot alkaloids and drug-metabolizing enzymes are presented as mechanisms that could contribute to toxicity. PMID:25756954

[Comparative study on alkaloids of tissue-culture seedling and wild plant of Dendrobium huoshanense ].

PubMed

Chen, Nai-dong; Gao, Feng; Lin, Xin; Jin, Hui

2014-06-01

To compare the composition and content of alkaloid of Dendrobium huoshanense tissue-culture seedling and wild plant. A comparative evaluation on the quality was carried out by HPLC and TLC methods including the composition and the content of alkaloids. Remarkable variation existed in the two kinds of Dendrobium huoshanense. For the tissue-culture plant, only two alkaloids were checked out by both HPLC and TLC while four alkaloids were observed in the wild plant. The alkaloid content of tissue-culture seedling and wild plant was(0. 29 ± 0. 11)%o and(0. 43 ± 0. 15) %o,respectively. Distinguished difference is observed in both composition and content of alkaloids from the annual shoots of different provenances of Dendrobium huoshanense. It suggested that the quality of tissue-culture seedling of Dendrobium huoshanense might be inconsistent with the wild plant. Furthermore, the established alkaloids-knock-out HPLC method would provide a new research tool on quality control of Chinese medicinal materials which contain unknown alkaloids.

[Exploration of toxicity reducing mechanism of aconite alkaloids during decoction process using liquid chromatography-mass spectrometry].

PubMed

Chen, Ping; Chen, Yimin; Chen, Jia; Tong, Hongbin; Xu, Zhiliang

2013-11-01

A high performance liquid chromatography-electrospray ionization mass spectrometry method was developed for the determination of aconite alkaloids. It was used to investigate the degradation of alkaloids of Radix Aconiti Lateralis Preparata during decoction. Six alkaline degradation products were identified, and the degradation regularity of diester-diterpenoid alkaloids was confirmed during the test using standards. The dynamic changes of the amount of aconite alkaloids in the decoction of Radix Aconiti Lateralis Preparata were supervised. Along with the increase of decoction time, the concentrations of diester-diterpenoid alkaloids and lipo-alkaloid decreased significantly. The results can provide a scientific basis for the safety use of aconite.

Risk assessment of buckwheat flour contaminated by thorn-apple (Datura stramonium L.) alkaloids: a case study from Slovenia.

PubMed

Perharič, Lucija; Koželj, Gordana; Družina, Branko; Stanovnik, Lovro

2013-01-01

In Slovenia, a mass poisoning incident involving 73 consumers with symptoms such as dry mouth, hot red skin, blurred vision, tachycardia, urinary retention, ataxia, speech disturbance, disorientation and visual hallucinations occurred in 2003. In all cases, consumers had eaten buckwheat flour food products within the last few hours. Investigations by responsible authorities identified the contamination of a range of buckwheat food products with thorn-apple (Datura stramonium L.) seeds containing toxic alkaloids, atropine and scopolamine. To ensure the safe consumption of buckwheat food products, we carried out risk characterisation and proposed provisional maximum residue levels (MRLs) of atropine and scopolamine mixture in buckwheat flour. In the absence of critical "no observed adverse effect levels" for atropine and scopolamine, we based our estimation of the acute reference doses on the lowest recommended therapeutic doses. Taking into account the additive effect of the two alkaloids, we calculated acute reference doses of the mixture, that is 0.05 µg/kg of body mass for atropine and 0.03 µg/kg of body mass for scopolamine. MRLs for atropine and scopolamine mixture in buckwheat flour were estimated in a worst-case scenario, that is consumption of 100 g of flour by a child weighing 10 kg and taking into account a range of atropine/scopolamine ratio in implicated food products, that is 0.85-3.3. We proposed the national MRLs for atropine/scopolamine mixture in buckwheat food products: 4.0 µg/kg (atropine) and 2.0 µg/kg(scopolamine). However, in view of the large variability in the alkaloid content, depending on the origin of the Datura, we propose that risk assessment should be carried out on a case-by-case basis, taking into account the ratio between atropine and scopolamine content in a particular sample.

Dynamic pH junction high-speed counter-current chromatography coupled with microwave-assisted extraction for online separation and purification of alkaloids from Stephania cepharantha.

PubMed

Yuan, Zhiquan; Xiao, Xiaohua; Li, Gongke

2013-11-22

A simple and efficient dynamic pH junction high-speed counter-current chromatography method was developed and further applied to the online extraction, separation and purification of alkaloids from Stephania cepharantha by coupling with microwave-assisted extraction. Mineral acid and organic base were added into the mobile phase and the sample solution, respectively, leading to the formation of a dynamic pH junction in the column and causing focus of alkaloids. Selective focus of analytes can be achieved on the basis of velocity changes of the pH junction through appropriate selection of solvent systems and optimization of additive concentrations. The extract can be directly introduced into the HSCCC for the online extraction, separation and purification of alkaloids from S. cepharantha. Continuous separation can be easily achieved with the same solvent system. Under the optimum conditions, 6.0 g original sample was extracted with 60 mL of the upper phase of hexane-ethyl acetate-methanol-water (1:1:1:1, v/v/v/v) containing 10% triethylamine under 50 °C and 400 W irradiation power for 10 min, the extracts were directly separated and purified by high-speed counter-current chromatography. A total of 5.7 mg sinomenine, 8.3mg 6,7-di-O-acetylsinococuline, 17.9 mg berbamine, 12.7 mg isotetrandrine and 14.6 mg cepharanthine were obtained with purities of 96.7%, 93.7%, 98.7%, 97.3% and 99.3%, respectively. The online method provides good selectivity to ionizable compounds and improves the separation and purification efficiency of the high-speed counter-current chromatography technique. It has good potential for separation and purification of effective compounds from natural products. Copyright © 2013 Elsevier B.V. All rights reserved.

Capsaicin Synthesis Requires in Situ Phenylalanine and Valine Formation in in Vitro Maintained Placentas from Capsicum chinense.

PubMed

Baas-Espinola, Fray M; Castro-Concha, Lizbeth A; Vázquez-Flota, Felipe A; Miranda-Ham, María L

2016-06-21

Capsaicinoids (CAP) are nitrogenous metabolites formed from valine (Val) and phenylalanine (Phe) in the placentas of hot Capsicum genotypes. Placentas of Habanero peppers can incorporate inorganic nitrogen into amino acids and have the ability to secure the availability of the required amino acids for CAP biosynthesis. In order to determine the participation of the placental tissue as a supplier of these amino acids, the effects of blocking the synthesis of Val and Phe by using specific enzyme inhibitors were analyzed. Isolated placentas maintained in vitro were used to rule out external sources' participation. Blocking Phe synthesis, through the inhibition of arogenate dehydratase, significantly decreased CAP accumulation suggesting that at least part of Phe required in this process has to be produced in situ. Chlorsulfuron inhibition of acetolactate synthase, involved in Val synthesis, decreased not only Val accumulation but also that of CAP, pointing out that the requirement for this amino acid can also be fulfilled by this tissue. The presented data demonstrates that CAP accumulation in in vitro maintained placentas can be accomplished through the in situ availability of Val and Phe and suggests that the synthesis of the fatty acid chain moiety may be a limiting factor in the biosynthesis of these alkaloids.

Ergot alkaloid transport across ruminant gastric tissues.

PubMed

Hill, N S; Thompson, F N; Stuedemann, J A; Rottinghaus, G W; Ju, H J; Dawe, D L; Hiatt, E E

2001-02-01

Ergot alkaloids cause fescue toxicosis when livestock graze endophyte-infected tall fescue. It is generally accepted that ergovaline is the toxic component of endophyte-infected tall fescue, but there is no direct evidence to support this hypothesis. The objective of this study was to examine relative and potential transport of ergoline and ergopeptine alkaloids across isolated gastric tissues in vitro. Sheep ruminal and omasal tissues were surgically removed and placed in parabiotic chambers. Equimolar concentrations of lysergic acid, lysergol, ergonovine, ergotamine, and ergocryptine were added to a Kreb's Ringer phosphate (KRP) solution on the mucosal side of the tissue. Tissue was incubated in near-physiological conditions for 240 min. Samples were taken from KRP on the serosal side of the chambers at times 0, 30, 60, 120, 180, and 240 min and analyzed for ergot alkaloids by competitive ELISA. The serosal KRP remaining after incubation was freeze-dried and the alkaloid species quantified by HPLC. The area of ruminal and omasal tissues was measured and the potential transportable alkaloids calculated by multiplying the moles of transported alkaloids per square centimeter of each tissue type by the surface area of the tissue. Studies were conducted to compare alkaloid transport in reticular, ruminal, and omasal tissues and to determine whether transport was active or passive. Ruminal tissue had greater ergot alkaloid transport potential than omasal tissue (85 vs 60 mmol) because of a larger surface area. The ruminal posterior dorsal sac had the greatest potential for alkaloid transport, but the other ruminal tissues were not different from one another. Alkaloid transport was less among reticular tissues than among ruminal tissues. Transport of alkaloids seemed to be an active process. The alkaloids with greatest transport potential were lysergic acid and lysergol. Ergopeptine alkaloids tended to pass across omasal tissues in greater quantities than across ruminal tissues, but their transport was minimal compared to lysergic acid and lysergol.

Temporal and spatial variation in alkaloid levels in Achnatherum robustum, a native grass infected with the endophyte Neotyphodium.

PubMed

Faeth, Stanley H; Gardner, Dale R; Hayes, Cinnamon J; Jani, Andrea; Wittlinger, Sally K; Jones, Thomas A

2006-02-01

The native North American perennial grass Achnatherum robustum (Vasey) Barkworth [= Stipa robusta (Vasey) Scribn.] or sleepygrass is toxic and narcotic to livestock. The causative agents are alkaloidal mycotoxins produced from infections by a systemic and asexual Neotyphodium endophyte. Recent studies suggest that toxicity is limited across the range of sleepygrass in the Southwest USA. We sampled 17 populations of sleepygrass with varying distance from one focal population known for its high toxicity levels near Cloudcroft, NM, USA. For some, we sampled individual plants twice within the same growing season and over successive years (2001-2004). We also determined infection levels in each population. In general, all populations were highly infected, but infection levels were more variable near the focal population. Only infected plants within populations near the Cloudcroft area produced alkaloids. The ergot alkaloid, ergonovine, comprised the bulk of the alkaloids, with lesser amounts of lysergic and isolysergic acid amides and ergonovinine alkaloids. Levels of all alkaloids were positively correlated among individual plants within and between growing seasons. Infected plants that produced no alkaloids in 1 yr did not produce any alkaloids within the same growing season or in other years. Levels of alkaloids in sleepygrass populations declined with distance from the Cloudcroft population, although infection levels increased. Infected plants in populations in northern New Mexico and southern Colorado produced no alkaloids at all despite 100% infectivity. Our results suggest that only specific Neotyphodium haplotypes or specific Neotyphodium-grass combinations produce ergot alkaloids in sleepygrass. The Neotyphodium haplotype or host-endophyte combination that produces toxic levels of alkaloids appears restricted to one locality across the range of sleepygrass. Because of the wide variation in alkaloid levels among populations, interactions between the endophyte and host, and consequences for herbivores, competitors, and pathogens and other components of the community, are likely to vary widely across the geographic range of this native grass.

Design and Stereoselective Preparation of a New Class of Chiral Olefin Metathesis Catalysts and Application to Enantioselective Synthesis of Quebrachamine: Catalyst Development Inspired by Natural Product Synthesis

PubMed Central

Sattely, Elizabeth S.; Meek, Simon J.; Malcolmson, Steven J.; Schrock, Richard R.; Hoveyda, Amir H.

2010-01-01

A total synthesis of the Aspidosperma alkaloid quebrachamine in racemic form is first described. A key catalytic ring-closing metathesis of an achiral triene is used to establish the all-carbon quaternary stereogenic center and the tetracyclic structure of the natural product; the catalytic transformation proceeds with reasonable efficiency through the use of existing achiral Ru or Mo catalysts. Ru- or Mo-based chiral olefin metathesis catalysts have proven to be inefficient and entirely nonselective in cases where the desired product is observed. In the present study, the synthesis route thus serves as a platform for the discovery of new olefin metathesis catalysts that allow for efficient completion of an enantioselective synthesis of quebrachamine. Accordingly, on the basis of mechanistic principles, stereogenic-at-Mo complexes bearing only monodentate ligands have been designed. The new catalysts provide significantly higher levels of activity than observed with the previously reported Ru- or Mo-based complexes. Enantiomerically enriched chiral alkylidenes are generated through diastereoselective reactions involving achiral Mo-based bispyrrolides and enantiomerically pure silyl-protected binaphthols. Such chiral catalysts initiate the key enantioselective ring-closing metathesis step in the total synthesis of quebrachamine efficiently (1 mol % loading, 22 °C, 1 h, >98% conversion, 84% yield) and with high selectivity (98:2 er, 96% ee). PMID:19113867

The effect of body condition on disposition of alkaloids from silvery lupine (Lupinus argenteus pursh) in sheep.

PubMed

Lopez-Ortiz, S; Panter, K E; Pfister, J A; Launchbaugh, K L

2004-09-01

Several species of lupine (Lupinus spp.) are poisonous to livestock, producing death in sheep and "crooked calf disease" in cattle. Range livestock cope with poisonous plants through learned foraging strategies or mechanisms affecting toxicant disposition. When a toxic plant is eaten, toxicant clearance may be influenced by the animal's nutritional and/or physiological status. This research was conducted to determine whether differences in body condition or short-term nutritional supplementation of sheep altered the disposition of lupine alkaloids given as a single oral dose of ground silvery lupine (Lupinus argenteus) seed. Ewes in average body condition (ABC, n = 9) and low body condition (LBC, n = 10) received a single dose of ground lupine seeds including pods (8.5 g/kg BW) via gavage on the first day of the experiment, and were then randomly assigned to one of two nutritional supplement treatments. Blood samples were taken 0 to 60 h after dosing to compare blood alkaloid concentration and to evaluate alkaloid absorption and elimination profiles. Concentrations of total alkaloid and anagyrine, 5,6 dehydrolupanine, lupanine, and alkaloid E were measured in serum. These four alkaloids constituted 78 and 75% of the total alkaloid concentration in serum for LBC vs. ABC groups, respectively. Initial analysis indicated that short-term supplementation had no effect on alkaloid disposition, and supplementation was removed from the statistical model. The highest concentration of total alkaloids was observed 2 h after dosing. Overall, serum total alkaloid and anagyrine levels (area under the curve) were higher (P < 0.01) for sheep in the LBC group. Serum peak concentrations of total alkaloid and anagyrine were higher in LBC vs. ABC groups (P < 0.05). Serum elimination of anagyrine, unknown alkaloid E, and lupanine was decreased in LBC vs. ABC treatments (P < 0.05). These results demonstrate that body condition is important in the disposition of lupine alkaloids; however, further research is needed to determine the potential benefit, if any, that short-term nutritional supplementation might have on alkaloid disposition.

Survival and development of Heliothis virescens (Lepidoptera: Noctuidae) larvae on isogenic tobacco lines with different levels of alkaloids.

PubMed

Jackson, D Michael; Johnson, A W; Stephenson, M G

2002-12-01

Levels of pyridine alkaloids were measured in 18 tobacco, Nicotiana tabacum L., entries from three parental isolines ('NC 95', 'SC 58', and 'Coker 139'), grown at Tifton, GA, Florence, SC, and Oxford, NC, in 1991. Levels of alkaloids in bud leaves (first fully unfolded leaf below the apical leaf bud) were negatively correlated to natural infestation ratings of tobacco budworm larvae, Heliothis virescens (F.), 7 wk after transplanting. For artificially infested bud leaves at Oxford, there was a significant negative correlation between levels of total alkaloids and larval weights after 1 wk of feeding. In 1992, four entries from the 'NC 95' isoline were grown at Oxford, and samples for alkaloid analyses were taken every 2 wk at several leaf positions on each plant. During weeks 4, 8, 12, and 16, second instar tobacco budworms were caged on individual, intact leaves inside perforated plastic bags in the field. The survival and development of tobacco budworm larvae after 1 wk were negatively correlated with levels of alkaloids at the various leaf positions. Larvae survived better and grew faster on the bud leaves of each entry where alkaloid levels were lower than they did on leaves further down the stalk where alkaloid levels were higher. More larvae survived on the lower leaves of the low alkaloid lines than on the lower leaves of the high alkaloid lines. Even moderate increases in pyridine alkaloids had negative effects on tobacco budworm survival and development. Nicotine constituted >97% of the pyridine alkaloids in the 'NC95' isoline each year.

Qualitative and quantitative analysis of an alkaloid fraction from Piper longum L. using ultra-high performance liquid chromatography-diode array detector-electrospray ionization mass spectrometry.

PubMed

Li, Kuiyong; Fan, Yunpeng; Wang, Hui; Fu, Qing; Jin, Yu; Liang, Xinmiao

2015-05-10

In a previous research, an alkaloid fraction and 18 alkaloid compounds were prepared from Piper longum L. by series of purification process. In this paper, a qualitative and quantitative analysis method using ultra-high performance liquid chromatography-diode array detector-mass spectrometry (UHPLC-DAD-MS) was developed to evaluate the alkaloid fraction. Qualitative analysis of the alkaloid fraction was firstly completed by UHPLC-DAD method and 18 amide alkaloid compounds were identified. A further qualitative analysis of the alkaloid fraction was accomplished by UHPLC-MS/MS method. Another 25 amide alkaloids were identified according to their characteristic ions and neutral losses. At last, a quantitative method for the alkaloid fraction was established using four marker compounds including piperine, pipernonatine, guineensine and N-isobutyl-2E,4E-octadecadienamide. After the validation of this method, the contents of above four marker compounds in the alkaloid fraction were 57.5mg/g, 65.6mg/g, 17.7mg/g and 23.9mg/g, respectively. Moreover, the relative response factors of other three compounds to piperine were calculated. A comparative study between external standard quantification and relative response factor quantification proved no remarkable difference. UHPLC-DAD-MS method was demonstrated to be a powerful tool for the characterization of the alkaloid fraction from P. longum L. and the result proved that the quality of alkaloid fraction was efficiently improved after appropriate purification. Copyright © 2015. Published by Elsevier B.V.

Comparative study of fourteen alkaloids from Uncaria rhynchophylla hooks and leaves using HPLC-diode array detection-atmospheric pressure chemical ionization/MS method.

PubMed

Qu, Jialin; Gong, Tianxing; Ma, Bin; Zhang, Lin; Kano, Yoshihiro; Yuan, Dan

2012-01-01

The purpose of the study is to compare alkaloid profile of Uncaria rhynchophylla hooks and leaves. Ten oxindole alkaloids and four glycosidic indole alkaloids were identified using HPLC-diode array detection (DAD) or LC-atmospheric pressure chemical ionization (APCI)-MS method, and a HPLC-UV method for simultaneous quantification of major alkaloids was validated. The hooks are characterized by high levels of four oxindole alkaloids rhynchophylline (R), isorhynchophylline (IR), corynoxeine (C) and isocorynoxeine (IC), while the leaves contained high level of two glycosidic indole alkaloids vincoside lactam (VL) and strictosidine (S). The presented methods have proven its usefulness in chemical characterization of U. rhynchophylla hooks and leaves.

Total alkaloid content in various fractions of Tabernaemonata sphaerocarpa Bl. (Jembirit) leaves

NASA Astrophysics Data System (ADS)

Salamah, N.; Ningsih, D. S.

2017-11-01

Tabernaemontana sphaerocarpa Bl. (Jembirit) is one of the Apocynaceae family plants containing alkaloid compound. Traditionally, it is used as an anti-inflammatory medicine. It is found to have a new bisindole alkaloid compound that shows a potent cytotoxic activity in human cancer. This study aimed to know the total alkaloid content in some fractions of ethanolic extract of T. sphaerocarpa Bl. leaf powder was extracted by maceration method in 70% ethanol solvent. Then, the extract was fractionated in a separatory funnel using water, ethyl acetate, and hexane. The total alkaloid content in each fraction was analyzed with visible spectrophotometric methods based on the reaction with Bromocresol Green (BCG). The total alkaloids in water fraction and ethyl acetate fraction were (0.0312±0.0009)% and (0.0281±0.0014)%, respectively. Meanwhile, the total alkaloid content in hexane was not detected. The statistical analysis, performed in SPSS, resulted in a significant difference between the total alkaloids in water fraction and ethyl acetate fraction. The total alkaloid in water fraction of T. sphaerocarpa Bl. was higher than the one in ethyl acetate fraction.

Claviceps cyperi, a new cause of severe ergotism in dairy cattle consuming maize silage and teff hay contaminated with ergotised Cyperus esculentus (nut sedge) on the Highveld of South Africa.

PubMed

Naudè, T W; Botha, C J; Vorster, J H; Roux, C; Van der Linde, E J; Van der Walt, S I; Rottinghaus, G E; Van Jaarsveld, L; Lawrence, A N

2005-03-01

During December/January 1996/97 typical summer syndrome (hyperthermia and a 30% drop in milk yield) occurred in succession in two Holstein dairy herds (n=240 and n=150 milking cows, respectively) on the South African Highveld. These farms are situated in the midst of the prime maize and dairy farming areas of South Africa where this condition had never been diagnosed before. The individual components of the concentrate on both farms were negative for ergot alkaloids. Endophytic fungi and/or ergot infestation of teff and other grasses fed to the cows were then suspected of being involved, but neither endophytes nor ergot alkaloids could be implicated from these sources. By measuring the serum prolactin levels of groups of sheep (n=5) fed the first farm's total mixed ration (TMR) or its three individual fibre components for a period of 11 days, the source of the ergot alkaloids was identified. A statistically significant decrease in the level of this hormone occurred only in the group on maize silage (which constituted 28% on dry matter base of the TMR). The involvement of the maize silage was further chemically confirmed by the high levels of total ergot alkaloids, predominantly ergocryptine, found by LC-MS in the silage as well as in the TMR (115-975 ppb and 65-300 ppb, respectively). The ergot alkaloid content (mainly ergocryptine) of the maize silage on the second affected farm was 875 ppb. Withdrawal of contaminated silage resulted in gradual recovery of stock on both farms. Nut sedge (Cyperus esculentus and Cyperus rotundus of the family Cyperaceae) has a world-wide distribution and is a common weed in annual crops, and can be parasitized by Claviceps cyperi. Careful examination of the maize silage from both farms revealed that it was heavily contaminated with nut sedge and that it contained minute sclerotia, identified as those of Claviceps cyperi, originating from the latter. Nut sedge was abundant on both farms and it is believed that late seasonal rain had resulted in mature, heavily ergotised nut sedge being cut with the silage. Claviceps cyperi sclerotia, collected on the affected fields in the following autumn contained 3600-4000 ppm ergocryptine. That the dominant alkaloid produced by this particular fungus was indeed ergocryptine, was confirmed by negative ion chemical ionization MS/MS. In one further outbreak in another Holstein herd, teff hay contaminated with ergotised nut sedge and containing 1200 ppb alkaloids, was incriminated as the cause of the condition. This is the first report of bovine ergotism not associated with the Poaceae infected with Claviceps purpureum or endophytes but with the family Cyperaceae and this particular fungal phytopathogen.

[Alkaloids of Pausinystalia macroceras].

PubMed

Leboef, M; Cavé, A; Mangeney, P; Bouquet, A

1981-04-01

A study of the alkaloidal content of trunk-barks of Pausinystalia macroceras (K. Schum.) Pierre, Rubiaceae, resulted in the isolation of six alkaloids, five of which are indole alkaloids that belong to the yohimbane and heteroyohimbane groups; among them, yohimbine was found in major amount. Moreover, the levorotatory isomer of calycanthine, a quinoline dimeric tryptophane derived base, has been isolated for the first time. The phytochemical significance of calycanthine and related alkaloids is discussed.

Identification of Oxygenated Fatty Acid as a Side Chain of Lipo-Alkaloids in Aconitum carmichaelii by UHPLC-Q-TOF-MS and a Database.

PubMed

Liang, Ying; Wu, Jian-Lin; Leung, Elaine Lai-Han; Zhou, Hua; Liu, Zhongqiu; Yan, Guanyu; Liu, Ying; Liu, Liang; Li, Na

2016-03-31

Lipo-alkaloid is a kind of C19-norditerpenoid alkaloid usually found in Aconitum species. Structurally, they contain an aconitane skeleton and one or two fatty acid moieties of 3-25 carbon chains with 1-6 unsaturated degrees. Analysis of the lipo-alkaloids in roots of Aconitum carmichaelii resulted in the isolation of six known pure lipo-alkaloids (A1-A6) and a lipo-alkaloid mixture (A7). The mixture shared the same aconitane skeleton of 14-benzoylmesaconine, but their side chains were determined to be 9-hydroxy-octadecadienoic acid, 13-hydroxy-octadecadienoic acid and 10-hydroxy-octadecadienoic acid, respectively, by MS/MS analysis after alkaline hydrolysis. To our knowledge, this is the first time of the reporting of the oxygenated fatty acids as the side chains in naturally-occurring lipo-alkaloids. In order to identify more lipo-alkaloids, a compound database was established based on various combinations between the aconitane skeleton and the fatty acid chain, and then, the identification of lipo-alkaloids was conducted using the database, UHPLC-Q-TOF-MS and MS/MS. Finally, 148 lipo-alkaloids were identified from A. carmichaelii after intensive MS/MS analysis, including 93 potential new compounds and 38 compounds with oxygenated fatty acid moieties.

Assessing the Regioselectivity of OleD-Catalyzed Glycosylation with a Diverse Set of Acceptors

PubMed Central

Zhou, Maoquan; Hamza, Adel; Zhan, Chang-Guo; Thorson, Jon S.

2013-01-01

To explore the acceptor regioselectivity of OleD-catalyzed glucosylation, the products of OleD-catalyzed reactions with the six structurally diverse acceptors - flavones (daidzein), isoflavones (flavopiridol), stilbenes (resveratrol), indole alkaloids (10-hydroxycamptothecin), and steroids (2-methoxyestradiol) - were determined. This study highlights the first synthesis of flavopiridol and 2-methoxyestradiol glucosides and confirms the ability of OleD to glucosylate both aromatic and aliphatic nucleophiles. In all cases, molecular dynamics simulations were consistent with the determined product distribution and suggest the potential to develop a virtual screening model to identify additional OleD substrates. PMID:23360118

Pd-Catalyzed regioselective intramolecular dehydrogenative C-5 cross coupling in an N-substituted pyrrole-azole system.

PubMed

Tripathi, Krishna N; Ray, Devalina; Singh, Ravi P

2017-12-06

Functionalized polycyclic pyrrole-azole structures possessing fused six membered and seven membered rings were directly synthesized via ligand-enabled, Pd-catalyzed, site selective, intramolecular cross couplings of N-substituted pyrrole-azoles. C5-H activation in the presence of a reactive C2-H remains a challenge that needs to be addressed and this was targeted to be resolved through the present approach by specifically generating the cyclized products with 83-100% selectivity. The featured methodology provides a novel disconnection for the synthesis of pyrrole containing alkaloids and medicinal compounds.

A room-temperature protocol to access isoquinolines through Ag(I) catalysed annulation of o-(1-alkynyl)arylaldehydes and ketones with NH4OAc: elaboration to berberine and palmatine.

PubMed

Reddy, Virsinha; Jadhav, Abhijeet S; Vijaya Anand, Ramasamy

2015-03-28

An efficient and mild protocol for the direct construction of aryl- and alkyl-substituted isoquinolines has been realized through silver nitrate catalyzed aromatic annulation of o-(1-alkynyl)arylaldehydes and ketones with ammonium acetate. The salient feature of this methodology is that this annulation could be effected at room temperature leading to a wide range of isoquinoline derivatives in good to excellent yields. Additionally, this approach has been employed to the synthesis of biologically important isoquinoline alkaloids such as berberine and palmatine.

Structure–Activity Relationship Studies of the Tricyclic Indoline Resistance-Modifying Agent

PubMed Central

2015-01-01

Previously we discovered a tricyclic indoline, N-[2-(6-bromo-4-methylidene-2,3,4,4a,9,9a-hexahydro-1H-carbazol-4a-yl)ethyl]-4-chlorobenzene-1-sulfonamide (1, Of1), from bioinspired synthesis of a highly diverse polycyclic indoline alkaloid library, that selectively resensitizes methicillin-resistant Staphylococcus aureus strains to β-lactam antibiotics. Herein, we report a thorough structure–activity relationship investigation of 1, which identified regions of 1 that tolerate modifications without compromising activity and afforded the discovery of a more potent analogue with reduced mammalian toxicity. PMID:24694192

CAPSAICIN: ITS BIOLOGICAL ACTIVITIES AND IN SILICO TARGET FISHING.

PubMed

Akhtar, Fahad; Muhammad Sharif, Hajra; Arshad Mallick, Muhammad; Zahoor, Fareeha; Abdulmalik, Attiya; Baig, Warda; Shujaat, Nodia; Gul, Sundas; Bibi, Gulfam; Ramzan, Rahdia; Murtaza, Ghulam

2017-03-01

Capsicum annuum L. is a rich source of capsaicin, an alkaloid, which is a very pungent compound. Due to ever growing need of capsaicin, an extensive research on its efficient cultivation as well as chemical synthesis is underway. Owing to the pungent nature of capsaicin, its analogous molecules without pungent effect are being explored. The objective of this descriptive review is to comprehensively present the updates on the bioactivities of capsaicin. Additionally, the in silico target fishing approach has been used to identify the possible protein targets of capsaicin. This article will definitely provide future perspectives of research on capsaicin.

Current Status and Future Prospects of Marine Natural Products (MNPs) as Antimicrobials

PubMed Central

Choudhary, Alka; Naughton, Lynn M.; Montánchez, Itxaso

2017-01-01

The marine environment is a rich source of chemically diverse, biologically active natural products, and serves as an invaluable resource in the ongoing search for novel antimicrobial compounds. Recent advances in extraction and isolation techniques, and in state-of-the-art technologies involved in organic synthesis and chemical structure elucidation, have accelerated the numbers of antimicrobial molecules originating from the ocean moving into clinical trials. The chemical diversity associated with these marine-derived molecules is immense, varying from simple linear peptides and fatty acids to complex alkaloids, terpenes and polyketides, etc. Such an array of structurally distinct molecules performs functionally diverse biological activities against many pathogenic bacteria and fungi, making marine-derived natural products valuable commodities, particularly in the current age of antimicrobial resistance. In this review, we have highlighted several marine-derived natural products (and their synthetic derivatives), which have gained recognition as effective antimicrobial agents over the past five years (2012–2017). These natural products have been categorized based on their chemical structures and the structure-activity mediated relationships of some of these bioactive molecules have been discussed. Finally, we have provided an insight into how genome mining efforts are likely to expedite the discovery of novel antimicrobial compounds. PMID:28846659

Phytochemical and pharmacological investigation of Spiraea chamaedryfolia: a contribution to the chemotaxonomy of Spiraea genus.

PubMed

Kiss, Tivadar; Cank, Kristóf Bence; Orbán-Gyapai, Orsolya; Liktor-Busa, Erika; Zomborszki, Zoltán Péter; Rutkovska, Santa; Pučka, Irēna; Németh, Anikó; Csupor, Dezső

2017-12-21

Diterpene alkaloids are secondary plant metabolites and chemotaxonomical markers with a strong biological activity. These compounds are characteristic for the Ranunculaceae family, while their occurrence in other taxa is rare. Several species of the Spiraea genus (Rosaceae) are examples of this rarity. Screening Spiraea species for alkaloid content is a chemotaxonomical approach to clarify the classification and phylogeny of the genus. Novel pharmacological findings make further investigations of Spiraea diterpene alkaloids promising. Seven Spiraea species were screened for diterpene alkaloids. Phytochemical and pharmacological investigations were performed on Spiraea chamaedryfolia, the species found to contain diterpene alkaloids. Its alkaloid-rich fractions were found to exert a remarkable xanthine-oxidase inhibitory activity and a moderate antibacterial activity. The alkaloid distribution within the root was clarified by microscopic techniques.

Four new diterpenoid alkaloids from Aconitum japonicum subsp. subcuneatum.

PubMed

Yamashita, Hiroshi; Takeda, Keiko; Haraguchi, Machiko; Abe, Yuki; Kuwahara, Natsumi; Suzuki, Shota; Terui, Ayaka; Masaka, Takumi; Munakata, Naoko; Uchida, Mariko; Nunokawa, Masashi; Kaneda, Kyousuke; Goto, Masuo; Lee, Kuo-Hsiung; Wada, Koji

2018-01-01

Diterpenoid alkaloids with remarkable chemical properties and biological activities are frequently found in plants of the genera Aconitum, Delphinium, and Garrya. Accordingly, several diterpenoid alkaloid constituents of Aconitum and Delphinium plants as well as their derivatives exhibited cytotoxic activity against lung, prostate, nasopharyngeal, and vincristine-resistant nasopharyngeal cancer cell lines. Four new C 19 -diterpenoid alkaloids, 14-anisoyllasianine (1), 14-anisoyl-N-deethylaconine (2), N-deethylaljesaconitine A (3), and N-deethylnevadensine (4), together with 17 known C 19 - and C 20 -diterpenoid alkaloids, were isolated in a phytochemical investigation of rhizoma of Aconitum japonicum THUNB. subsp. subcuneatum (NAKAI) KADOTA. Their structures were elucidated by extensive spectroscopic methods including NMR (1D and 2D), IR, and MS (HRMS). Eight known diterpenoid alkaloids, lipoaconitine, lipomesaconitine, aconine, nevadenine, talatisamine, nevadensine, ryosenamine, and dehydrolucidusculine, were isolated the first time from A. japonicum subsp. subcuneatum. Three of the new C 19 -diterpenoid alkaloids (1, 3, 4) and six of the known diterpenoid alkaloids were evaluated for cytotoxic activity against five human tumor cell lines.

Differential effects of sugar-mimic alkaloids in mulberry latex on sugar metabolism and disaccharidases of Eri and domesticated silkworms: enzymatic adaptation of Bombyx mori to mulberry defense.

PubMed

Hirayama, Chikara; Konno, Kotaro; Wasano, Naoya; Nakamura, Masatoshi

2007-12-01

Mulberry leaves (Morus spp.) exude latex rich in sugar-mimic alkaloids, 1,4-dideoxy-1,4-imino-d-arabinitol (d-AB1) and 1-deoxynojirimycin (DNJ), as a defense against herbivorous insects. Sugar-mimic alkaloids are inhibitors of sugar-metabolizing enzymes, and are toxic to the Eri silkworm, Samia ricini, a generalist herbivore, but not at all to the domesticated silkworm, Bombyx mori, a mulberry specialist. To address the phenomena, we fed both larvae diets containing different sugar sources (sucrose, glucose or none) with or without sugar-mimic alkaloids from mulberry latex. In S. ricini, addition of sugar-mimic alkaloids to the sucrose (the major sugar in mulberry leaves) diet reduced both growth and the absorption ratio of sugar, but it reduced neither in B. mori. The midgut soluble sucrase activity of S. ricini was low and inhibited by very low concentrations of sugar-mimic alkaloids (IC(50)=0.9-8.2microM), but that of B. mori was high and not inhibited even by very high concentrations (IC(50)>1000microM) of sugar-mimic alkaloids. In S. ricini, the addition of sugar-mimic alkaloids to the glucose diet still had considerable negative effects on growth, although it did not reduce the absorption ratio of glucose. The hemolymph of S. ricini fed sugar-mimic alkaloids contained sugar-mimic alkaloids. The trehalose concentration in the hemolymph increased significantly in S. ricini fed sugar-mimic alkaloids, but not in B. mori. The trehalase activities of S. ricini were lower and inhibited by lower concentrations of sugar-mimic alkaloids than those of B. mori. These results suggest that sugar-mimic alkaloids in mulberry latex exert toxicity to S. ricini larvae first by inhibiting midgut sucrase and digestion of sucrose, and secondly, after being absorbed into hemolymph, by inhibiting trehalase and utilization of trehalose, the major blood sugar. Further, our results reveal that B. mori larvae evolved enzymatic adaptation to mulberry defense by developing sucrase and trehalase that are insensitive to sugar-mimic alkaloids.

Catalyst-controlled oligomerization for the collective synthesis of polypyrroloindoline natural products.

PubMed

Jamison, Christopher R; Badillo, Joseph J; Lipshultz, Jeffrey M; Comito, Robert J; MacMillan, David W C

2017-12-01

In nature, many organisms generate large families of natural product metabolites that have related molecular structures as a means to increase functional diversity and gain an evolutionary advantage against competing systems within the same environment. One pathway commonly employed by living systems to generate these large classes of structurally related families is oligomerization, wherein a series of enzymatically catalysed reactions is employed to generate secondary metabolites by iteratively appending monomers to a growing serial oligomer chain. The polypyrroloindolines are an interesting class of oligomeric natural products that consist of multiple cyclotryptamine subunits. Herein we describe an iterative application of asymmetric copper catalysis towards the synthesis of six distinct oligomeric polypyrroloindoline natural products: hodgkinsine, hodgkinsine B, idiospermuline, quadrigemine H and isopsychotridine B and C. Given the customizable nature of the small-molecule catalysts employed, we demonstrate that this strategy is further amenable to the construction of quadrigemine H-type alkaloids not isolated previously from natural sources.

Catalyst-controlled oligomerization for the collective synthesis of polypyrroloindoline natural products

NASA Astrophysics Data System (ADS)

Jamison, Christopher R.; Badillo, Joseph J.; Lipshultz, Jeffrey M.; Comito, Robert J.; MacMillan, David W. C.

2017-12-01

In nature, many organisms generate large families of natural product metabolites that have related molecular structures as a means to increase functional diversity and gain an evolutionary advantage against competing systems within the same environment. One pathway commonly employed by living systems to generate these large classes of structurally related families is oligomerization, wherein a series of enzymatically catalysed reactions is employed to generate secondary metabolites by iteratively appending monomers to a growing serial oligomer chain. The polypyrroloindolines are an interesting class of oligomeric natural products that consist of multiple cyclotryptamine subunits. Herein we describe an iterative application of asymmetric copper catalysis towards the synthesis of six distinct oligomeric polypyrroloindoline natural products: hodgkinsine, hodgkinsine B, idiospermuline, quadrigemine H and isopsychotridine B and C. Given the customizable nature of the small-molecule catalysts employed, we demonstrate that this strategy is further amenable to the construction of quadrigemine H-type alkaloids not isolated previously from natural sources.

Theophylline-assisted, eco-friendly synthesis of PtAu nanospheres at reduced graphene oxide with enhanced catalytic activity towards Cr(VI) reduction.

PubMed

Hu, Ling-Ya; Chen, Li-Xian; Liu, Meng-Ting; Wang, Ai-Jun; Wu, Lan-Ju; Feng, Jiu-Ju

2017-05-01

Theophylline as a naturally alkaloid is commonly employed to treat asthma and chronic obstructive pulmonary disorder. Herein, a facile theophylline-assisted green approach was firstly developed for synthesis of PtAu nanospheres/reduced graphene oxide (PtAu NSs/rGO), without any surfactant, polymer, or seed involved. The obtained nanocomposites were applied for the catalytic reduction and removal of highly toxic chromium (VI) using formic acid as a model reductant at 50°C, showing the significantly enhanced catalytic activity and improved recyclability when compared with commercial Pt/C (50%) and home-made Au nanocrystals supported rGO (Au NCs/rGO). It demonstrates great potential applications of the catalyst in wastewater treatment and environmental protection. The eco-friendly route provides a new platform to fabricate other catalysts with enhanced catalytic activity. Copyright © 2016 Elsevier Inc. All rights reserved.

Effect of feeding fescue seed containing ergot alkaloid toxins on stallion spermatogenesis and sperm cells.

PubMed

Fayrer-Hosken, R; Stanley, A; Hill, N; Heusner, G; Christian, M; De La Fuente, R; Baumann, C; Jones, L

2012-12-01

The cellular effects of tall fescue grass-associated toxic ergot alkaloids on stallion sperm and colt testicular tissue were evaluated. This was a continuation of an initial experiment where the effects of toxic ergot alkaloids on the stallion spermiogram were investigated. The only spermiogram parameter in exposed stallions that was affected by the toxic ergot alkaloids was a decreased gel-free volume of the ejaculate. This study examined the effect of toxic ergot alkaloids on chilling and freezing of the stallion sperm cells. The effect of toxic ergot alkaloids on chilled extended sperm cells for 48 h at 5°C was to make the sperm cells less likely to undergo a calcium ionophore-induced acrosome reaction. The toxic ergot alkaloids had no effect on the freezability of sperm cells. However, if yearling colts were fed toxic ergot alkaloids, then the cytological analysis of meiotic chromosome synapsis revealed a significant increase in the proportion of pachytene spermatocytes showing unpaired sex chromosomes compared to control spermatocytes. There was little effect of ergot alkaloids on adult stallions, but there might be a significant effect on yearling colts. © 2012 Blackwell Verlag GmbH.

Effect of Feeding Fescue Seed Containing Ergot Alkaloid Toxins on Stallion Spermatogenesis and Sperm Cells

PubMed Central

Fayrer-Hosken, R; Stanley, A; Hill, N; Heusner, G; Christian, M; Fuente, R De La; Baumann, C; Jones, L

2012-01-01

Contents The cellular effects of tall fescue grass–associated toxic ergot alkaloids on stallion sperm and colt testicular tissue were evaluated. This was a continuation of an initial experiment where the effects of toxic ergot alkaloids on the stallion spermiogram were investigated. The only spermiogram parameter in exposed stallions that was affected by the toxic ergot alkaloids was a decreased gel-free volume of the ejaculate. This study examined the effect of toxic ergot alkaloids on chilling and freezing of the stallion sperm cells. The effect of toxic ergot alkaloids on chilled extended sperm cells for 48 h at 5 °C was to make the sperm cells less likely to undergo a calcium ionophore–induced acrosome reaction. The toxic ergot alkaloids had no effect on the freezability of sperm cells. However, if yearling colts were fed toxic ergot alkaloids, then the cytological analysis of meiotic chromosome synapsis revealed a significant increase in the proportion of pachytene spermatocytes showing unpaired sex chromosomes compared to control spermatocytes. There was little effect of ergot alkaloids on adult stallions, but there might be a significant effect on yearling colts. PMID:22524585

Clavine Alkaloids Gene Clusters of Penicillium and Related Fungi: Evolutionary Combination of Prenyltransferases, Monooxygenases and Dioxygenases

PubMed Central

Martín, Juan F.; Liras, Paloma

2017-01-01

The clavine alkaloids produced by the fungi of the Aspergillaceae and Arthrodermatacea families differ from the ergot alkaloids produced by Claviceps and Neotyphodium. The clavine alkaloids lack the extensive peptide chain modifications that occur in lysergic acid derived ergot alkaloids. Both clavine and ergot alkaloids arise from the condensation of tryptophan and dimethylallylpyrophosphate by the action of the dimethylallyltryptophan synthase. The first five steps of the biosynthetic pathway that convert tryptophan and dimethylallyl-pyrophosphate (DMA-PP) in chanoclavine-1-aldehyde are common to both clavine and ergot alkaloids. The biosynthesis of ergot alkaloids has been extensively studied and is not considered in this article. We focus this review on recent advances in the gene clusters for clavine alkaloids in the species of Penicillium, Aspergillus (Neosartorya), Arthroderma and Trychophyton and the enzymes encoded by them. The final products of the clavine alkaloids pathways derive from the tetracyclic ergoline ring, which is modified by late enzymes, including a reverse type prenyltransferase, P450 monooxygenases and acetyltransferases. In Aspergillus japonicus, a α-ketoglutarate and Fe2+-dependent dioxygenase is involved in the cyclization of a festuclavine-like unknown type intermediate into cycloclavine. Related dioxygenases occur in the biosynthetic gene clusters of ergot alkaloids in Claviceps purpurea and also in the clavine clusters in Penicillium species. The final products of the clavine alkaloid pathway in these fungi differ from each other depending on the late biosynthetic enzymes involved. An important difference between clavine and ergot alkaloid pathways is that clavine producers lack the enzyme CloA, a P450 monooxygenase, involved in one of the steps of the conversion of chanoclavine-1-aldehyde into lysergic acid. Bioinformatic analysis of the sequenced genomes of the Aspergillaceae and Arthrodermataceae fungi showed the presence of clavine gene clusters in Arthroderma species, Penicillium roqueforti, Penicillium commune, Penicillium camemberti, Penicillium expansum, Penicillium steckii and Penicillium griseofulvum. Analysis of the gene clusters in several clavine alkaloid producers indicates that there are gene gains, gene losses and gene rearrangements. These findings may be explained by a divergent evolution of the gene clusters of ergot and clavine alkaloids from a common ancestral progenitor six genes cluster although horizontal gene transfer of some specific genes may have occurred more recently. PMID:29186777

Alkaloid profiles of Mimosa tenuiflora and associated methods of analysis

USDA-ARS?s Scientific Manuscript database

The alkaloid contents of the leaves and seeds of M. tenuiflora collected from northeastern Brazil were studied. Alkaloids were isolated by classical acid/base extraction procedures and by cation exchange solid phase extraction. The crude alkaloid fractions were then analysed by thin layer chromatogr...

The serum concentrations of lupine alkaloids in orally-dosed Holstein cattle

USDA-ARS?s Scientific Manuscript database

Teratogenic alkaloid-containing Lupinus spp. cause significant losses to the cattle industry. Previous research has suggested that Holstein cattle clear toxic Delphinium alkaloids from their serum at a greater rate than beef cattle. The toxicokinetics of lupine alkaloids in Holsteins are not known...

Secondary and tertiary isoquinoline alkaloids from Xylopia parviflora.

PubMed

Nishiyama, Yumi; Moriyasu, Masataka; Ichimaru, Momoyo; Iwasa, Kinuko; Kato, Atsushi; Mathenge, Simon G; Chalo Mutiso, Patrick B; Juma, Francis D

2006-12-01

From the secondary and tertiary alkaloidal fractions of the root and the bark of Xylopia parviflora (Annonaceae), the isoquinoline alkaloids, 10,11-dihydroxy-1,2-dimethoxynoraporphine and parvinine were isolated, along with 39 known alkaloids. Their structures were determined on the basis of analysis of spectroscopic data.

Analysis of Alkaloids from Physalis peruviana by Capillary GC, Capillary GC-MS, and GC-FTIR.

PubMed

Kubwabo, C; Rollmann, B; Tilquin, B

1993-04-01

The alkaloid composition of the aerial parts and roots of PHYSALIS PERUVIANA was analysed by capillary GC (GC (2)), GC (2)-MS and GC (2)-FTIR. Eight alkaloids were identified, three of those alkaloids are 3beta-acetoxytropane and two N-methylpyrrolidinylhygrine isomers, which were not previously found in the genus PHYSALIS. A reproduction of the identification of alkaloids detected in the plant by the use of retention indices has been proposed.

Highly efficient molybdenum-based catalysts for enantioselective alkene metathesis

PubMed Central

Malcolmson, Steven J.; Meek, Simon J.; Sattely, Elizabeth S.; Schrock, Richard R.; Hoveyda, Amir H.

2009-01-01

Discovery of efficient catalysts is one of the most compelling objectives of modern chemistry. Chiral catalysts are in particularly high demand, as they facilitate synthesis of enantiomerically enriched small molecules that are critical to developments in medicine, biology and materials science1. Especially noteworthy are catalysts that promote—with otherwise inaccessible efficiency and selectivity levels—reactions demonstrated to be of great utility in chemical synthesis. Here we report a class of chiral catalysts that initiate alkene metathesis1 with very high efficiency and enantioselectivity. Such attributes arise from structural fluxionality of the chiral catalysts and the central role that enhanced electronic factors have in the catalytic cycle. The new catalysts have a stereogenic metal centre and carry only monodentate ligands; the molybdenum-based complexes are prepared stereoselectively by a ligand exchange process involving an enantiomerically pure aryloxide, a class of ligands scarcely used in enantioselective catalysis2,3. We demonstrate the application of the new catalysts in an enantioselective synthesis of the Aspidosperma alkaloid, quebrachamine, through an alkene metathesis reaction that cannot be promoted by any of the previously reported chiral catalysts. PMID:19011612

Parasitic fungus Claviceps as a source for biotechnological production of ergot alkaloids.

PubMed

Hulvová, Helena; Galuszka, Petr; Frébortová, Jitka; Frébort, Ivo

2013-01-01

Ergot alkaloids produced by the fungus Claviceps parasitizing on cereals, include three major groups: clavine alkaloids, d-lysergic acid and its derivatives and ergopeptines. These alkaloids are important substances for the pharmatech industry, where they are used for production of anti-migraine drugs, uterotonics, prolactin inhibitors, anti-Parkinson agents, etc. Production of ergot alkaloids is based either on traditional field cultivation of ergot-infected rye or on submerged cultures of the fungus in industrial fermentation plants. In 2010, the total production of these alkaloids in the world was about 20,000 kg, of which field cultivation contributed about 50%. This review covers the recent advances in understanding of the genetics and regulation of biosynthesis of ergot alkaloids, focusing on possible applications of the new knowledge to improve the production yield. Copyright © 2012 Elsevier Inc. All rights reserved.

Alkaloid profiling of the traditional Chinese medicine Rhizoma corydalis using high performance liquid chromatography-tandem quadrupole time-of-flight mass spectrometry

PubMed Central

Sun, Mingqian; Liu, Jianxun; Lin, Chengren; Miao, Lan; Lin, Li

2014-01-01

Since alkaloids are the major active constituents of Rhizoma corydalis (RC), a convenient and accurate analytical method is needed for their identification and characterization. Here we report a method to profile the alkaloids in RC based on liquid chromatography-tandem quadrupole time-of-flight mass spectrometry (LC–Q-TOF-MS/MS). A total of 16 alkaloids belonging to four different classes were identified by comparison with authentic standards. The fragmentation pathway of each class of alkaloid was clarified and their differences were elucidated. Furthermore, based on an analysis of fragmentation pathways and alkaloid profiling, a rapid and accurate method for the identification of unknown alkaloids in RC is proposed. The method could also be useful for the quality control of RC. PMID:26579385

Eating chemically defended prey: alkaloid metabolism in an invasive ladybird predator of other ladybirds (Coleoptera: Coccinellidae).

PubMed

Sloggett, J J; Davis, A J

2010-01-15

By comparison with studies of herbivore physiological adaptation to plant allelochemicals, work on predator physiological adaptation to potentially toxic prey has been very limited. Such studies are important in understanding how evolution could shape predator diets. An interesting question is the specificity of predator adaptation to prey allelochemicals, given that many predators consume diverse prey with different chemical defences. The ladybird Harmonia axyridis, an invasive species in America, Europe and Africa, is considered a significant predatory threat to native invertebrates, particularly other aphid-eating ladybirds of which it is a strong intraguild predator. Although ladybirds possess species-specific alkaloid defences, H. axyridis exhibits high tolerance for allospecific ladybird prey alkaloids. Nonetheless, it performs poorly on species with novel alkaloids not commonly occurring within its natural range. We examined alkaloid fate in H. axyridis larvae after consumption of two other ladybird species, one containing an alkaloid historically occurring within the predator's native range (isopropyleine) and one containing a novel alkaloid that does not (adaline). Our results indicate that H. axyridis rapidly chemically modifies the alkaloid to which it has been historically exposed to render it less harmful: this probably occurs outside of the gut. The novel, more toxic alkaloid persists in the body unchanged for longer. Our results suggest metabolic alkaloid specialisation, in spite of the diversity of chemically defended prey that the predator consumes. Physiological adaptations appear to have made H. axyridis a successful predator of other ladybirds; however, limitations are imposed by its physiology when it eats prey with novel alkaloids.

Recent investigations of ergot alkaloids incorporated into plant and/or animal systems

USDA-ARS?s Scientific Manuscript database

Ergot alkaloids produced by fungi have a basic chemical structure but different chemical moieties at substituent sites resulting in various forms of alkaloids that are distinguishable from one another. Since the ergoline ring structure found in ergot alkaloids is similar to that of biogenic amines (...

New alkaloids of the sarpagine group from Rauvolfia serpentina hairy root culture.

PubMed

Sheludko, Yuri; Gerasimenko, Irina; Kolshorn, Heinz; Stöckigt, Joachim

2002-07-01

Three new monoterpenoid indole alkaloids, 19(S),20(R)-dihydroperaksine (1), 19(S),20(R)-dihydroperaksine-17-al (2), and 10-hydroxy-19(S),20(R)-dihydroperaksine (3), along with 16 known alkaloids 4-19 were isolated from hairy root culture of Rauvolfia serpentina, and their structures were elucidated by 1D and 2D NMR analyses. Taking into account the stereochemistry of the new alkaloids and results of preliminary enzymatical studies, the putative biosynthetical relationships between the novel alkaloids are discussed.

Isolation and structure elucidation of a new indole alkaloid from Rauvolfia serpentina hairy root culture: the first naturally occurring alkaloid of the raumacline group.

PubMed

Sheludko, Yuri; Gerasimenko, Irina; Kolshorn, Heinz; Stöckigt, Joachim

2002-05-01

A new monoterpenoid indole alkaloid, 10-hydroxy- N(alpha)-demethyl-19,20-dehydroraumacline ( 1), was isolated as a mixture of E- and Z-isomers from hairy root culture of Rauvolfia serpentina Benth. ex Kurz (Apocynaceae) and the structure was determined by 1D and 2D NMR analyses. The new indole alkaloid represents the first naturally occurring alkaloid of the raumacline group and its putative biosynthetical pathway is discussed.

Quinolizidine alkaloids from Lupinus lanatus

NASA Astrophysics Data System (ADS)

Neto, Alexandre T.; Oliveira, Carolina Q.; Ilha, Vinicius; Pedroso, Marcelo; Burrow, Robert A.; Dalcol, Ionara I.; Morel, Ademir F.

2011-10-01

In this study, one new quinolizidine alkaloid, lanatine A ( 1), together with three other known alkaloids, 13-α- trans-cinnamoyloxylupanine ( 2), 13-α-hydroxylupanine ( 3), and (-)-multiflorine ( 4) were isolated from the aerial parts of Lupinus lanatus (Fabaceae). The structures of alkaloids 1- 4 were elucidated by spectroscopic data analysis. The stereochemistry of 1 was determined by single crystal X-ray analysis. Bayesian statistical analysis of the Bijvoet differences suggests the absolute stereochemistry of 1. In addition, the antimicrobial potential of alkaloids 1- 4 is also reported.

Estimation of total alkaloid in Chitrakadivati by UV-Spectrophotometer.

PubMed

Ajanal, Manjunath; Gundkalle, Mahadev B; Nayak, Shradda U

2012-04-01

Herbal formulation standardization by adopting newer technique is need of the hour in the field of Ayurvedic pharmaceutical industry. As very few reports exist. These kind of studies would certainly widen the herbal research area. Chitrakadivati is one such popular herbal formulation used in Ayurveda. Many of its ingredients are known for presence of alkaloids. Presence of alkaloid was tested qualitatively by Dragondroff's method then subjected to quantitative estimation by UV-Spectrophotometer. This method is based on the reaction between alkaloid and bromocresol green (BCG). Study discloses that out of 16 ingredients, 9 contain alkaloid. Chitrakadivati has shown 0.16% of concentration of alkaloid and which is significantly higher than it's individual ingredients.

An In-Silico Investigation of Phytochemicals as Antiviral Agents Against Dengue Fever.

PubMed

Powers, Chelsea N; Setzer, William N

2016-01-01

A virtual screening analysis of our library of phytochemical structures with dengue virus protein targets has been carried out using a molecular docking approach. A total of 2194 plant-derived secondary metabolites have been docked. This molecule set comprised of 290 alkaloids (68 indole alkaloids, 153 isoquinoline alkaloids, 5 quinoline alkaloids, 13 piperidine alkaloids, 14 steroidal alkaloids, and 37 miscellaneous alkaloids), 678 terpenoids (47 monoterpenoids, 169 sesquiterpenoids, 265 diterpenoids, 81 steroids, and 96 triterpenoids), 20 aurones, 81 chalcones, 349 flavonoids, 120 isoflavonoids, 74 lignans, 58 stilbenoids, 169 miscellaneous polyphenolic compounds, 100 coumarins, 28 xanthones, 67 quinones, and 160 miscellaneous phytochemicals. Dengue virus protein targets examined included dengue virus protease (NS2B-NS3pro), helicase (NS3 helicase), methyltransferase (MTase), RNA-dependent RNA polymerase (RdRp), and the dengue virus envelope protein. Polyphenolic compounds, flavonoids, chalcones, and other phenolics were the most numerous of the strongly docking ligands for dengue virus protein targets.

Analysis and modification of ergot alkaloid profiles in fungi.

PubMed

Panaccione, Daniel G; Ryan, Katy L; Schardl, Christopher L; Florea, Simona

2012-01-01

The ergot alkaloids are a family of secondary metabolites produced by a phylogenetically discontinuous group of fungi. Various members of the family are important in agriculture, where they accumulate in grain crops or forage grasses and adversely affect humans or animals who consume them. Other ergot alkaloids have been used clinically to treat a variety of diseases. Because of their significance in agriculture and medicine, the ability to detect and quantify these alkaloids from a variety of substrates is important. The primary analytical approach for these purposes has been high performance liquid chromatography. The ability to manipulate ergot alkaloid production in fungi, by transformation-mediated approaches, has been useful for studies on the biosynthesis of these alkaloids and may have practical application in agriculture and medicine. Such modifications have been informed by comparative genomic approaches, which have provided information on the gene clusters associated with ergot alkaloid biosynthesis. Copyright © 2012 Elsevier Inc. All rights reserved.

Genome mining of ascomycetous fungi reveals their genetic potential for ergot alkaloid production.

PubMed

Gerhards, Nina; Matuschek, Marco; Wallwey, Christiane; Li, Shu-Ming

2015-06-01

Ergot alkaloids are important as mycotoxins or as drugs. Naturally occurring ergot alkaloids as well as their semisynthetic derivatives have been used as pharmaceuticals in modern medicine for decades. We identified 196 putative ergot alkaloid biosynthetic genes belonging to at least 31 putative gene clusters in 31 fungal species by genome mining of the 360 available genome sequences of ascomycetous fungi with known proteins. Detailed analysis showed that these fungi belong to the families Aspergillaceae, Clavicipitaceae, Arthrodermataceae, Helotiaceae and Thermoascaceae. Within the identified families, only a small number of taxa are represented. Literature search revealed a large diversity of ergot alkaloid structures in different fungi of the phylum Ascomycota. However, ergot alkaloid accumulation was only observed in 15 of the sequenced species. Therefore, this study provides genetic basis for further study on ergot alkaloid production in the sequenced strains.

Toxicosis by Plant Alkaloids in Humans and Animals in Colombia

PubMed Central

Diaz, Gonzalo J.

2015-01-01

Due to its tropical location, chains of mountains, inter-Andean valleys, Amazon basin area, eastern plains and shores on both the Atlantic and Pacific Oceans, Colombia has many ecosystems and the second largest plant biodiversity in the world. Many plant species, both native and naturalized, are currently recognized as toxic for both animals and humans, and some of them are known to cause their toxic effects due to their alkaloid content. Among these, there are plants containing the hepatotoxic pyrrolizidine alkaloids, neurotoxins such as the indolizidine alkaloid swainsonine and the piperidine alkaloids coniine and γ-coniceine and tropane alkaloids. Unfortunately, the research in toxic plants in Colombia is not nearly proportional to its plant biodiversity and the scientific information available is only very scarce. The present review aims at summarizing the scarce information about plant alkaloid toxicosis in animals and humans in Colombia. PMID:26690479

Overexpression of tropinone reductases alters alkaloid composition in Atropa belladonna root cultures.

PubMed

Richter, Ute; Rothe, Grit; Fabian, Anne-Katrin; Rahfeld, Bettina; Dräger, Birgit

2005-02-01

The medicinally applied tropane alkaloids hyoscyamine and scopolamine are produced in Atropa belladonna L. and in a small number of other Solanaceae. Calystegines are nortropane alkaloids that derive from a branching point in the tropane alkaloid biosynthetic pathway. In A. belladonna root cultures, calystegine molar concentration is 2-fold higher than that of hyoscyamine and scopolamine. In this study, two tropinone reductases forming a branching point in the tropane alkaloid biosynthesis were overexpressed in A. belladonna. Root culture lines with strong overexpression of the transcripts contained more enzyme activity of the respective reductase and enhanced enzyme products, tropine or pseudotropine. High pseudotropine led to an increased accumulation of calystegines in the roots. Strong expression of the tropine-forming reductase was accompanied by 3-fold more hyoscyamine and 5-fold more scopolamine compared with control roots, and calystegine levels were decreased by 30-90% of control. In some of the transformed root cultures, an increase of total tropane alkaloids was observed. Thus, transformation with cDNA of tropinone reductases successfully altered the ratio of tropine-derived alkaloids versus pseudotropine-derived alkaloids.

Towards a Molecular Understanding of the Biosynthesis of Amaryllidaceae Alkaloids in Support of Their Expanding Medical Use

PubMed Central

Takos, Adam M.; Rook, Fred

2013-01-01

The alkaloids characteristically produced by the subfamily Amaryllidoideae of the Amaryllidaceae, bulbous plant species that include well know genera such as Narcissus (daffodils) and Galanthus (snowdrops), are a source of new pharmaceutical compounds. Presently, only the Amaryllidaceae alkaloid galanthamine, an acetylcholinesterase inhibitor used to treat symptoms of Alzheimer’s disease, is produced commercially as a drug from cultivated plants. However, several Amaryllidaceae alkaloids have shown great promise as anti-cancer drugs, but their further clinical development is restricted by their limited commercial availability. Amaryllidaceae species have a long history of cultivation and breeding as ornamental bulbs, and phytochemical research has focussed on the diversity in alkaloid content and composition. In contrast to the available pharmacological and phytochemical data, ecological, physiological and molecular aspects of the Amaryllidaceae and their alkaloids are much less explored and the identity of the alkaloid biosynthetic genes is presently unknown. An improved molecular understanding of Amaryllidaceae alkaloid biosynthesis would greatly benefit the rational design of breeding programs to produce cultivars optimised for the production of pharmaceutical compounds and enable biotechnology based approaches. PMID:23727937

Comparison of Ergot Alkaloid Biosynthesis Gene Clusters in Claviceps Species Indicates Loss of Late Pathway Steps in Evolution of C. fusiformis▿

PubMed Central

Lorenz, Nicole; Wilson, Ella V.; Machado, Caroline; Schardl, Christopher L.; Tudzynski, Paul

2007-01-01

The grass parasites Claviceps purpurea and Claviceps fusiformis produce ergot alkaloids (EA) in planta and in submerged culture. Whereas EA synthesis (EAS) in C. purpurea proceeds via clavine intermediates to lysergic acid and the complex ergopeptines, C. fusiformis produces only agroclavine and elymoclavine. In C. purpurea the EAS gene (EAS) cluster includes dmaW (encoding the first pathway step), cloA (elymoclavine oxidation to lysergic acid), and the lpsA/lpsB genes (ergopeptine formation). We analyzed the corresponding C. fusiformis EAS cluster to investigate the evolutionary basis for chemotypic differences between the Claviceps species. Other than three peptide synthetase genes (lpsC and the tandem paralogues lpsA1 and lpsA2), homologues of all C. purpurea EAS genes were identified in C. fusiformis, including homologues of lpsB and cloA, which in C. purpurea encode enzymes for steps after clavine synthesis. Rearrangement of the cluster was evident around lpsB, which is truncated in C. fusiformis. This and several frameshift mutations render CflpsB a pseudogene (CflpsBΨ). No obvious inactivating mutation was identified in CfcloA. All C. fusiformis EAS genes, including CflpsBΨ and CfcloA, were expressed in culture. Cross-complementation analyses demonstrated that CfcloA and CflpsBΨ were expressed in C. purpurea but did not encode functional enzymes. In contrast, CpcloA catalyzed lysergic acid biosynthesis in C. fusiformis, indicating that C. fusiformis terminates its EAS pathway at elymoclavine because the cloA gene product is inactive. We propose that the C. fusiformis EAS cluster evolved from a more complete cluster by loss of some lps genes and by rearrangements and mutations inactivating lpsB and cloA. PMID:17720822

Combinatorial assembly of simple and complex D-lysergic acid alkaloid peptide classes in the ergot fungus Claviceps purpurea.

PubMed

Ortel, Ingo; Keller, Ullrich

2009-03-13

The ergot fungus Claviceps purpurea produces both ergopeptines and simple d-lysergic acid alkylamides. In the ergopeptines, such as ergotamine, d-lysergic acid is linked to a bicyclic tripeptide in amide-like fashion, whereas in the d-lysergylalkanolamides it is linked to an amino alcohol derived from alanine. We show here that these compound classes are synthesized by a set of three non-ribosomal lysergyl peptide synthetases (LPSs), which interact in a combinatorial fashion for synthesis of the relevant product. The trimodular LPS1 assembles with LPS2, the d-lysergic acid recruiting module, to synthesize the d-lysergyltripeptide precursors of ergopeptines from d-lysergic acid and the three amino acids of the peptide chain. Alternatively, LPS2 can assemble with a distinct monomodular non-ribosomal peptide synthetase (NRPS) subunit (ergometrine synthetase) to synthesize the d-lysergic acid alkanolamide ergometrine from d-lysergic acid and alanine. The synthesis proceeds via covalently bound d-lysergyl alanine and release of dipeptide as alcohol with consumption of NADPH. Enzymatic and immunochemical analyses showed that ergometrine synthetase is most probably the enzyme LPS3 whose gene had been identified previously as part of the ergot alkaloid biosynthesis gene cluster in C. purpurea. Inspections of all LPS sequences showed no recognizable peptide linkers for their protein-protein interactions as in NRPS subunits of bacteria. Instead, they all carry conserved N-terminal domains (C0-domains) with similarity to the C-terminal halves of NRPS condensation domains pointing to an alternative mechanism of subunit-subunit interactions in fungal NRPS systems. Phylogenetic analysis of LPS modules and the C0-domains suggests that these enzyme systems most probably evolved by module duplications and rearrangements from a bimodular ancestor.

Combinatorial Assembly of Simple and Complex d-Lysergic Acid Alkaloid Peptide Classes in the Ergot Fungus Claviceps purpurea*S⃞

PubMed Central

Ortel, Ingo; Keller, Ullrich

2009-01-01

The ergot fungus Claviceps purpurea produces both ergopeptines and simple d-lysergic acid alkylamides. In the ergopeptines, such as ergotamine, d-lysergic acid is linked to a bicyclic tripeptide in amide-like fashion, whereas in the d-lysergylalkanolamides it is linked to an amino alcohol derived from alanine. We show here that these compound classes are synthesized by a set of three non-ribosomal lysergyl peptide synthetases (LPSs), which interact in a combinatorial fashion for synthesis of the relevant product. The trimodular LPS1 assembles with LPS2, the d-lysergic acid recruiting module, to synthesize the d-lysergyltripeptide precursors of ergopeptines from d-lysergic acid and the three amino acids of the peptide chain. Alternatively, LPS2 can assemble with a distinct monomodular non-ribosomal peptide synthetase (NRPS) subunit (ergometrine synthetase) to synthesize the d-lysergic acid alkanolamide ergometrine from d-lysergic acid and alanine. The synthesis proceeds via covalently bound d-lysergyl alanine and release of dipeptide as alcohol with consumption of NADPH. Enzymatic and immunochemical analyses showed that ergometrine synthetase is most probably the enzyme LPS3 whose gene had been identified previously as part of the ergot alkaloid biosynthesis gene cluster in C. purpurea. Inspections of all LPS sequences showed no recognizable peptide linkers for their protein-protein interactions as in NRPS subunits of bacteria. Instead, they all carry conserved N-terminal domains (C0-domains) with similarity to the C-terminal halves of NRPS condensation domains pointing to an alternative mechanism of subunit-subunit interactions in fungal NRPS systems. Phylogenetic analysis of LPS modules and the C0-domains suggests that these enzyme systems most probably evolved by module duplications and rearrangements from a bimodular ancestor. PMID:19139103

Comparison of ergot alkaloid biosynthesis gene clusters in Claviceps species indicates loss of late pathway steps in evolution of C. fusiformis.

PubMed

Lorenz, Nicole; Wilson, Ella V; Machado, Caroline; Schardl, Christopher L; Tudzynski, Paul

2007-11-01

The grass parasites Claviceps purpurea and Claviceps fusiformis produce ergot alkaloids (EA) in planta and in submerged culture. Whereas EA synthesis (EAS) in C. purpurea proceeds via clavine intermediates to lysergic acid and the complex ergopeptines, C. fusiformis produces only agroclavine and elymoclavine. In C. purpurea the EAS gene (EAS) cluster includes dmaW (encoding the first pathway step), cloA (elymoclavine oxidation to lysergic acid), and the lpsA/lpsB genes (ergopeptine formation). We analyzed the corresponding C. fusiformis EAS cluster to investigate the evolutionary basis for chemotypic differences between the Claviceps species. Other than three peptide synthetase genes (lpsC and the tandem paralogues lpsA1 and lpsA2), homologues of all C. purpurea EAS genes were identified in C. fusiformis, including homologues of lpsB and cloA, which in C. purpurea encode enzymes for steps after clavine synthesis. Rearrangement of the cluster was evident around lpsB, which is truncated in C. fusiformis. This and several frameshift mutations render CflpsB a pseudogene (CflpsB(Psi)). No obvious inactivating mutation was identified in CfcloA. All C. fusiformis EAS genes, including CflpsB(Psi) and CfcloA, were expressed in culture. Cross-complementation analyses demonstrated that CfcloA and CflpsB(Psi) were expressed in C. purpurea but did not encode functional enzymes. In contrast, CpcloA catalyzed lysergic acid biosynthesis in C. fusiformis, indicating that C. fusiformis terminates its EAS pathway at elymoclavine because the cloA gene product is inactive. We propose that the C. fusiformis EAS cluster evolved from a more complete cluster by loss of some lps genes and by rearrangements and mutations inactivating lpsB and cloA.

Lactam ergot alkaloids (ergopeptams) as predominant alkaloids in sclerotia of Claviceps purpurea from Norwegian wild grasses.

PubMed

Uhlig, Silvio; Petersen, Dirk

2008-07-01

Four major alkaloids in the extracts from sclerotia of Claviceps purpurea, picked from wild grasses, have been identified as lactam (non-cyclol) ergot alkaloids. The structural information was obtained from ion trap MS and NMR spectroscopy. The data for one of the lactam ergot alkaloids were coinciding with ergocristam [N-(lysergyl-valyl)-cyclo(phenylalanyl-prolyl)]. The structural information of two further lactam alkaloids was suggestive of either alpha- or beta-ergocryptam [N-(lysergyl-valyl)-cyclo(leucyl-prolyl) or N-(lysergyl-valyl)-cyclo(isoleucyl-prolyl)] and ergoannam [N-(lysergyl-leucyl)-cyclo(leucyl-prolyl) or N-(lysergyl-isoleucyl)-cyclo(isoleucyl-prolyl)]. The constitution of the fourth lactam ergot alkaloid corresponded to N-(lysergyl-isoleucyl)-cyclo(phenylalanyl-prolyl), a new ergopeptam, which has not been described before. Additionally, the cyclol-analogue of the new ergopeptam was detected in the extracts and has been identified on the basis of its product ion spectrum from fragmentation of [M+H](+). The study described in this paper shows that lactam ergot alkaloids may not only be minor products of ergopeptine biosynthesis, as has been suggested hitherto, but may be major biosynthetic endproducts for some ergot strains. This is also the first report demonstrating the production of an ergot alkaloid that contains isoleucine as the second amino acid, i.e. the N-(lysergyl-isoleucyl)-moiety, by parasitic, naturally growing C. purpurea. This unusual type of ergot alkaloid has so far only been found in saprophytic cultures of C. purpurea.

Detection of Total Ergot Alkaloids in Cereal Flour and in Bread by a Generic Enzyme Immunoassay Method.

PubMed

Gross, Madeleine; Curtui, Valeriu; Usleber, Ewald

2018-05-01

Four sets of polyclonal antibodies against ergot alkaloids ergometrine, ergotamine, α-ergocryptine, and ergocornine were produced and characterized in a competitive direct or indirect enzyme immunoassay (EIA). Standard curve LODs were 0.03 ng/mL (ergometrine EIA) to 2.0 ng/mL (ergocornine EIA). Three EIAs were highly specific, whereas the ergometrine EIA had a broad specificity pattern and reacted, albeit weakly, with all seven major ergot alkaloids and their epimeric forms. Using the ergometrine EIA, a generic test system was established in which total ergot alkaloids are quantified by a standard curve for a toxin mixture composed of three alkaloids that matched the ergot alkaloid composition in naturally contaminated rye and wheat products. Sample extraction with acetonitrile-phosphate-buffered saline at pH 6.0 without further cleanup was sufficient for EIA analysis. The LODs for total ergot alkaloids were 20 ng/g in rye and wheat flour and 14 ng/g in bread. Recoveries were 85-110% (RSDs of 0.1-11.7%) at a concentration range of 50-1000 ng/g. The total ergot alkaloid EIA was validated by comparison with HPLC-fluorescence detection. Although some under- and overestimation by the total ergot alkaloid EIA was observed, it was suitable for the reliable identification of positive samples at 10-20 ng/g and for the determination of total ergot alkaloids in a concentration range between 100 and 1000 ng/g.

Tandem Mass Spectrometry for Structural Identification of Sesquiterpene Alkaloids from the Stems of Dendrobium nobile Using LC-QToF.

PubMed

Wang, Yan-Hong; Avula, Bharathi; Abe, Naohito; Wei, Feng; Wang, Mei; Ma, Shuang-Cheng; Ali, Zulfiqar; Elsohly, Mahmoud A; Khan, Ikhlas A

2016-05-01

Dendrobium nobile is one of the fundamental herbs in traditional Chinese medicine. Sesquiterpene alkaloids are the main active components in this plant. Due to weak ultraviolet absorption and low content in D. nobile, these sesquiterpene alkaloids have not been extensively studied using chromatographic methods. Herein, tandem mass spectrometry combined with liquid chromatography separation provides a tool for the identification and characterization of the alkaloids from D. nobile. A total of nine sesquiterpene alkaloids were characterized by ultrahigh-performance liquid chromatography tandem mass spectrometry. These alkaloids can be classified into two subgroups that are represented by dendrobine and nobilonine. Tandem mass spectrometric studies revealed the fragmentation pathways of these two subgroup alkaloids that were used for the identification and characterization of other alkaloids in D. nobile. Characterization of these alkaloids using accurate mass and diagnostic fragments provided a reliable methodology for the analysis of D. nobile by ultrahigh-performance liquid chromatography tandem mass spectrometry. The limit of detection was defined as the signal-to-noise ratio equal to 3 : 1. Limits of detection of dendrobine and nobilonine were less than 30 ng/mL. The developed method was applied for the analysis of various Dendrobium species and related dietary supplements. Alkaloids were identified from D. nobile, but not detected from commercial samples including 13 other Dendrobium species and the 7 dietary supplements. Georg Thieme Verlag KG Stuttgart · New York.

Digital Gene Expression Analysis Provides Insight into the Transcript Profile of the Genes Involved in Aporphine Alkaloid Biosynthesis in Lotus (Nelumbo nucifera)

PubMed Central

Yang, Mei; Zhu, Lingping; Li, Ling; Li, Juanjuan; Xu, Liming; Feng, Ji; Liu, Yanling

2017-01-01

The predominant alkaloids in lotus leaves are aporphine alkaloids. These are the most important active components and have many pharmacological properties, but little is known about their biosynthesis. We used digital gene expression (DGE) technology to identify differentially-expressed genes (DEGs) between two lotus cultivars with different alkaloid contents at four leaf development stages. We also predicted potential genes involved in aporphine alkaloid biosynthesis by weighted gene co-expression network analysis (WGCNA). Approximately 335 billion nucleotides were generated; and 94% of which were aligned against the reference genome. Of 22 thousand expressed genes, 19,000 were differentially expressed between the two cultivars at the four stages. Gene Ontology (GO) enrichment analysis revealed that catalytic activity and oxidoreductase activity were enriched significantly in most pairwise comparisons. In Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, dozens of DEGs were assigned to the categories of biosynthesis of secondary metabolites, isoquinoline alkaloid biosynthesis, and flavonoid biosynthesis. The genes encoding norcoclaurine synthase (NCS), norcoclaurine 6-O-methyltransferase (6OMT), coclaurine N-methyltransferase (CNMT), N-methylcoclaurine 3′-hydroxylase (NMCH), and 3′-hydroxy-N-methylcoclaurine 4′-O-methyltransferase (4′OMT) in the common pathways of benzylisoquinoline alkaloid biosynthesis and the ones encoding corytuberine synthase (CTS) in aporphine alkaloid biosynthetic pathway, which have been characterized in other plants, were identified in lotus. These genes had positive effects on alkaloid content, albeit with phenotypic lag. The WGCNA of DEGs revealed that one network module was associated with the dynamic change of alkaloid content. Eleven genes encoding proteins with methyltransferase, oxidoreductase and CYP450 activities were identified. These were surmised to be genes involved in aporphine alkaloid biosynthesis. This transcriptomic database provides new directions for future studies on clarifying the aporphine alkaloid pathway. PMID:28197160

Poor permeability and absorption affect the activity of four alkaloids from Coptis.

PubMed

Cui, Han-Ming; Zhang, Qiu-Yan; Wang, Jia-Long; Chen, Jian-Long; Zhang, Yu-Ling; Tong, Xiao-Lin

2015-11-01

Coptidis rhizoma (Coptis) and its alkaloids exert various pharmacological functions in cells and tissues; however, the oral absorption of these alkaloids requires further elucidation. The present study aimed to examine the mechanism underlying the poor absorption of alkaloids, including berberine (BER), coptisine (COP), palmatine (PAL) and jatrorrhizine (JAT). An ultra‑performance liquid chromatography (UPLC) method was validated for the determination of BER, COP, PAL and JAT in the above experimental medium. In addition, the apparent oil‑water partition coefficient (Po/w); apparent permeability coefficient (Papp), determined using a parallel artificial membrane permeability assay (PAMPA) plate; membrane retention coefficient (R %); and effect of P‑glycoprotein (P‑gp) inhibitor on the Papp of the four alkaloids were investigated. The intestinal absorption rate constant (Ka) and absorption percentage (A %) of the four alkaloids were also determined. The results of the present study demonstrated that the Po/w of the four alkaloids in 0.1 mol·l‑1 HCl medium was significantly higher (P<0.01), compared with those of the alkaloids in phosphate buffer (pH 7.4). The Papp of BER was 1.0‑1.2x10‑6 cm·s‑1, determined using a PAMPA plate, and the Papp of BER, COP, PAL and JAT decreased sequentially. The concentrations of the four alkaloids on the apical‑to‑basolateral (AP‑BL) surface and the basolateral‑to‑apical (BL‑AP) surface increased in a linear manner, with increasing concentrations between 10 and 100 µmol. In addition, the transportation of BER on the BL‑AP surface was significantly faster (P<0.01), compared with that on the AP‑BL surface and, following the addition of verpamil (a P‑gp inhibitor), the Papp (AP‑BL) of the four alkaloids increased, whereas the Papp (BL‑AP) was significantly decreased (P<0.01). The rat intestinal perfusion experiment demonstrated that the four alkaloids were poorly absorbed; however, the Ka of BER was significantly higher, compared with the three other alkaloids. Furthermore, the A % and Ka provided evidence that the absorption of BER was increased in the jejunum, compared with in the ileum. In conclusion, the four alkaloids from Coptis appeared to be poorly absorbed, determined using a shake flask, pre‑coated PAMPA plates, a Caco‑2 cell monolayer model and intestinal perfusion; however, absorption was higher in the jejunum than in the ileum. Among the four alkaloids, the permeability of BER was markedly higher than the others, and P‑gp efflux had a significant effect on the absorption of those alkaloids.

Identification and characterization of the ergochrome gene cluster in the plant pathogenic fungus Claviceps purpurea.

PubMed

Neubauer, Lisa; Dopstadt, Julian; Humpf, Hans-Ulrich; Tudzynski, Paul

2016-01-01

Claviceps purpurea is a phytopathogenic fungus infecting a broad range of grasses including economically important cereal crop plants. The infection cycle ends with the formation of the typical purple-black pigmented sclerotia containing the toxic ergot alkaloids. Besides these ergot alkaloids little is known about the secondary metabolism of the fungus. Red anthraquinone derivatives and yellow xanthone dimers (ergochromes) have been isolated from sclerotia and described as ergot pigments, but the corresponding gene cluster has remained unknown. Fungal pigments gain increasing interest for example as environmentally friendly alternatives to existing dyes. Furthermore, several pigments show biological activities and may have some pharmaceutical value. This study identified the gene cluster responsible for the synthesis of the ergot pigments. Overexpression of the cluster-specific transcription factor led to activation of the gene cluster and to the production of several known ergot pigments. Knock out of the cluster key enzyme, a nonreducing polyketide synthase, clearly showed that this cluster is responsible for the production of red anthraquinones as well as yellow ergochromes. Furthermore, a tentative biosynthetic pathway for the ergot pigments is proposed. By changing the culture conditions, pigment production was activated in axenic culture so that high concentration of phosphate and low concentration of sucrose induced pigment syntheses. This is the first functional analysis of a secondary metabolite gene cluster in the ergot fungus besides that for the classical ergot alkaloids. We demonstrated that this gene cluster is responsible for the typical purple-black color of the ergot sclerotia and showed that the red and yellow ergot pigments are products of the same biosynthetic pathway. Activation of the gene cluster in axenic culture opened up new possibilities for biotechnological applications like the dye production or the development of new pharmaceuticals.

Regulation of neurosteroid allopregnanolone biosynthesis in the rat spinal cord by glycine and the alkaloidal analogs strychnine and gelsemine.

PubMed

Venard, C; Boujedaini, N; Belon, P; Mensah-Nyagan, A G; Patte-Mensah, C

2008-04-22

The neurosteroid allopregnanolone (3alpha,5alpha-THP) is well characterized as a potentially therapeutic molecule which exerts important neurobiological actions including neuroprotective, antidepressant, anxiolytic, anesthetic and analgesic effects. We have recently observed that neurons and glial cells of the rat spinal cord (SC) contain various key steroidogenic enzymes such as 5alpha-reductase and 3alpha-hydroxysteroid oxido-reductase which are crucial for 3alpha,5alpha-THP biosynthesis. Furthermore, we demonstrated that the rat SC actively produces 3alpha,5alpha-THP. As the key factors regulating neurosteroid production by nerve cells are unknown and because glycine is one of the pivotal inhibitory neurotransmitters in the SC, we investigated glycine effects on 3alpha,5alpha-THP biosynthesis in the rat SC. Glycine markedly stimulated [(3)H]-progesterone conversion into [(3)H]3alpha,5alpha-THP by SC slices. The alkaloid strychnine, well-known as a glycine receptor (Gly-R) antagonist, blocked glycine stimulatory effect on 3alpha,5alpha-THP formation. Gelsemine, another alkaloid containing the same functional groups as strychnine, increased 3alpha,5alpha-THP synthesis. The stimulatory effects of glycine and gelsemine on 3alpha,5alpha-THP production were additive when the two drugs were combined. These results demonstrate that glycine and gelsemine, acting via Gly-R, upregulate 3alpha,5alpha-THP biosynthesis in the SC. The data also revealed a structure-activity relationship of the analogs strychnine and gelsemine on neurosteroidogenesis. Possibilities are opened for glycinergic agents and gelsemine utilization to stimulate selectively 3alpha,5alpha-THP biosynthetic pathways in diseases evoked by a decreased neurosteroidogenic activity of nerve cells.

Isolation of Araguspongine M, a New Stereoisomer of an Araguspongine/Xestospongin alkaloid, and Dopamine from the Marine Sponge Neopetrosia exigua Collected in Palau

PubMed Central

Liu, Hongwei; Mishima, Yuri; Fujiwara, Takeshi; Nagai, Hiroshi; Kitazawa, Akira; Mine, Yuji; Kobayashi, Hisayoshi; Yao, Xinsheng; Yamada, Junko; Oda, Taiko; Namikoshi, Michio

2004-01-01

A new stereoisomer of an araguspongine/xestospongin alkaloid, named araguspongine M (1), has been isolated together with 12 known compounds, araguspongines B (2) and D (3), dopamine, three galactosyl diacylglycerols, 24-methyl cholesterol, 5,6-dihydrocholesterol, β-sitosterol, and three 5α,8α-epidioxy sterols (11–13), from the marine sponge Neopetrosia exigua (formerly Xestospongia exigua) collected in Palau. The structure of 1 was assigned on the basis of its spectral data analysis. This is the first report on the isolation of dopamine from a marine sponge. This compound may be produced by an endosymbiotic Synechococcus-like cyanobacterium. Compounds 1–3 and 11–13 showed cytotoxicity against HL-60 at IC50’s of 5.5, 5.5, 5.9, 22.4, 9.5, and 9.6 μM, respectively. The possible biosynthesis origin of the isolated metabolites is discussed.

Nauclea latifolia: biological activity and alkaloid phytochemistry of a West African tree.

PubMed

Boucherle, Benjamin; Haudecoeur, Romain; Queiroz, Emerson Ferreira; De Waard, Michel; Wolfender, Jean-Luc; Robins, Richard J; Boumendjel, Ahcène

2016-09-25

Covering up to 2016Nauclea latifolia (syn. Sarcocephalus latifolius, Rubiaceae), commonly called the African pincushion tree, is a plant widely used in folk medicine in different regions of Africa for treating a variety of illnesses, including malaria, epilepsy and pain. N. latifolia has not only drawn the interest of traditional healers but also of phytochemists, who have identified a range of bioactive indole alkaloids in its tissue. More recently, following up on the traditional use of extracts in pain management, a bio-guided purification from the roots of the tree led to the identification of the active ingredient as tramadol, available as a synthetic analgesic since the 1970s. The discovery of this compound as a natural phytochemical was highlighted worldwide. This review focuses on the correlation between extracted compounds and pharmacological activities, paying special attention to infectious diseases and neurologically-related disorders. A critical analysis of the data reported so far on the natural origin of tramadol and its proposed biosynthesis is also presented.

Death related to consumption of Rauvolfia sp. powder mislabeled as Tabernanthe iboga.

PubMed

Gicquel, Thomas; Hugbart, Chloé; Le Devehat, Françoise; Lepage, Sylvie; Baert, Alain; Bouvet, Renaud; Morel, Isabelle

2016-09-01

Powdered roots of iboga (Tabernanthe iboga) contain ibogaine, an alkaloid that has been used to treat addictions. We report the case of a 30-year-old woman who died after ingesting a powder labeled as Tabernanthe iboga she had bought online. Analysis of the powder revealed the absence of ibogaine but the presence of toxic alkaloids (ajmaline, yohimbine and reserpine) found in Rauvolfia sp. plant species. An original and specific LC-MS/MS method developed to quantify ajmaline, yohimbine and reserpine showed respective concentrations of 109.1ng/mL, 98.2ng/mL and 30.8ng/mL in blood, and 1528.2ng/mL, 914.2ng/mL and 561.2ng/mL in bile. Moreover, systematic toxicological analyses of biological samples showed the presence of oxazepam at therapeutic concentration and cannabinoids. Death could be attributed to ingestion of a substantial quantity of crushed roots of Rauvolfia in association with concomitant drug withdrawal. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Quantification of the antiplasmodial alkaloid carpaine in papaya (Carica papaya) leaves.

PubMed

Julianti, Tasqiah; Oufir, Mouhssin; Hamburger, Matthias

2014-08-01

Daily consumption of papaya (Carica papaya) leaves as greens and an herbal infusion is common in some parts of Indonesia as a means for preventing malaria. Antiplasmodial activity of the leaf extracts and of the main alkaloid carpaine were recently confirmed. A quantitative assay for determination of carpaine in papaya leaves was developed and validated. The assay involved pressurized liquid extraction and quantification with the aid of ultrahigh-performance liquid chromatography-tandem mass spectroscopy. Extraction conditions were optimized with respect to solvent, temperature, and number of extraction cycles. The ultrahigh-performance liquid chromatography-tandem mass spectroscopy assay was validated over a range of 20-5000 ng/mL (R(2) of 0.9908). A total of 29 papaya leaf samples were analyzed, and carpaine concentration in dry leaves was found to range from 0.02 to 0.31%. No obvious dependence on geographic origin and leaf maturity was observed. Georg Thieme Verlag KG Stuttgart · New York.

Pyrrolizidine Alkaloids: Potential Role in the Etiology of Cancers, Pulmonary Hypertension, Congenital Anomalies, and Liver Disease.

PubMed

Edgar, John A; Molyneux, Russell J; Colegate, Steven M

2015-01-20

Large outbreaks of acute food-related poisoning, characterized by hepatic sinusoidal obstruction syndrome, hemorrhagic necrosis, and rapid liver failure, occur on a regular basis in some countries. They are caused by 1,2-dehydropyrrolizidine alkaloids contaminating locally grown grain. Similar acute poisoning can also result from deliberate or accidental consumption of 1,2-dehydropyrrolizidine alkaloid-containing herbal medicines, teas, and spices. In recent years, it has been confirmed that there is also significant, low-level dietary exposure to 1,2-dehydropyrrolizidine alkaloids in many countries due to consumption of common foods such as honey, milk, eggs, salads, and meat. The level of 1,2-dehydropyrrolizidine alkaloids in these foods is generally too low and too intermittent to cause acute toxicity. However, these alkaloids are genotoxic and can cause slowly developing chronic diseases such as pulmonary arterial hypertension, cancers, cirrhosis, and congenital anomalies, conditions unlikely to be easily linked with dietary exposure to 1,2-dehydropyrrolizidine alkaloids, especially if clinicians are unaware that such dietary exposure is occurring. This Perspective provides a comprehensive review of the acute and chronic toxicity of 1,2-dehydropyrrolizidine alkaloids and their potential to initiate certain chronic diseases, and suggests some associative considerations or indicators to assist in recognizing specific cases of diseases that may have resulted from dietary exposure to these hazardous natural substances. If it can be established that low-level dietary exposure to 1,2-dehydropyrrolizidine alkaloids is a significant cause of some of these costly and debilitating diseases, then this should lead to initiatives to reduce the level of these alkaloids in the food chain.

Sodium ion channel alkaloid resistance does not vary with toxicity in aposematic Dendrobates poison frogs: An examination of correlated trait evolution

PubMed Central

Wang, Ian J.

2018-01-01

Spatial heterogeneity in the strength or agents of selection can lead to geographic variation in ecologically important phenotypes. Many dendrobatid frogs sequester alkaloid toxins from their diets and often exhibit fixed mutations at NaV1.4, a voltage-gated sodium ion channel associated with alkaloid toxin resistance. Yet previous studies have noted an absence of resistance mutations in individuals from several species known to sequester alkaloid toxins, suggesting possible intraspecific variation for alkaloid resistance in these species. Toxicity and alkaloid profiles vary substantially between populations in several poison frog species (genus Dendrobates) and are correlated with variation in a suite of related traits such as aposematic coloration. If resistance mutations are costly, due to alterations of channel gating properties, we expect that low toxicity populations will have reduced frequencies and potentially even the loss of resistance alleles. Here, we examine whether intraspecific variation in toxicity in three dendrobatid frogs is associated with intraspecific variation in alleles conferring toxin resistance. Specifically, we examine two species that display marked variation in toxicity throughout their native ranges (Dendrobates pumilio and D. granuliferus) and one species with reduced toxicity in its introduced range (D. auratus). However, we find no evidence for population-level variation in alkaloid resistance at NaV1.4. In fact, contrary to previous studies, we found that alkaloid resistance alleles were not absent in any populations of these species. All three species exhibit fixed alkaloid resistance mutations throughout their ranges, suggesting that these mutations are maintained even when alkaloid sequestration is substantially reduced. PMID:29534110

Comparison of a specific HPLC determination of toxic aconite alkaloids in processed Radix aconiti with a titration method of total alkaloids.

PubMed

Csupor, Dezso; Borcsa, Botond; Heydel, Barbara; Hohmann, Judit; Zupkó, István; Ma, Yan; Widowitz, Ute; Bauer, Rudolf

2011-10-01

In traditional Chinese medicine, Aconitum (Ranunculaceae) roots are only applied after processing. Nevertheless, several cases of poisoning by improperly processed aconite roots have been reported. The aim of this study was to develop a reliable analytical method to assess the amount of toxic aconite alkaloids in commercial aconite roots, and to compare this method with the commonly used total alkaloid content determination by titration. The content of mesaconitine, aconitine, and hypaconitine in 16 commercial samples of processed aconite roots was determined by an HPLC method and the total alkaloid content by indirect titration. Five samples were selected for in vivo toxicological investigation. In most of the commercial samples, toxic alkaloids were not detectable, or only traces were found. In four samples, we could detect >0.04% toxic aconite alkaloids, the highest with a content of 0.16%. The results of HPLC analysis were compared with the results obtained by titration, and no correlation was found between the two methods. The in vivo results reassured the validity of the HPLC determination. Samples with mesaconitine, aconitine, and hypaconitine content below the HPLC detection limit still contained up to 0.2% alkaloids determined by titration. Since titration of alkaloids gives no information selectively on the aconitine-type alkaloid content and toxicity of aconite roots this method is not appropriate for safety assessment. The HPLC method developed by us provides a quick and reliable assessment of toxicity and should be considered as a purity test in pharmacopoeia monographs.

Diterpenoid alkaloids from the roots of Aconitum brachypodum Diels.

PubMed

Yang, Li-Guo; Zhang, Ying-Jie; Xie, Jia-Ying; Xia, Wei-Jun; Zhang, Hai-Yuan; Tang, Meng-Yun; Mei, Shuang-Xi; Cui, Tao; Wang, Jing-Kun; Zhu, Zhao-Yun

2016-09-01

A new diterpenoid alkaloid, named bullatine H (1), along with 10 known diterpenoid alkaloids were isolated from the roots of Aconitum brachypodum Diels (Ranunculaceae). The structure of 1 was elucidated by analysis of its spectroscopic data. It should be noted that compound 1 is the first example with 11, 13-dioxygenated denudatine-type diterpenoid alkaloid isolated from Aconitum brachypodum.

Analgesic activity of diterpene alkaloids from Aconitum baikalensis.

PubMed

Nesterova, Yu V; Povet'yeva, T N; Suslov, N I; Zyuz'kov, G N; Pushkarskii, S V; Aksinenko, S G; Schultz, E E; Kravtsova, S S; Krapivin, A V

2014-08-01

We compared analgesic activities of individual alkaloids extracted from Baikal aconite (Aconitum baikalensis): napelline, hypaconitine, songorine, mesaconitine, 12-epinapelline N-oxide. The detected analgesic activity was comparable to that of sodium metamizole. The mechanisms of analgesia were different in diterpene alkaloids of different structure. The antinociceptive effect of atisine alkaloids (12-epinapelline N-oxide, songorine) was naloxonedependent and realized via opioid receptor modulation.

[Isolation of the ergot (Claviceps purpurea (Fr.) Tul., strain VKM-F-366D), producing the lactamic alkaloid ergocornam].

PubMed

Komarova, E L; Shain, S S; Sheĭchenko, V I

2002-01-01

A new ergot strain VKM-F-3662D producing lactamic alkaloid ergocornam with concomitant alkaloids valinamide and ergometrine was isolated during selective works with sclerotium MS-462, which was obtained from ergocryptine ergot strain VKM-F-2642D. The structure of these alkaloids was determined by 1H and 13C NMR.

Application of Liquid Chromatography/Ion Trap Mass Spectrometry Technique to Determine Ergot Alkaloids in Grain Products

PubMed Central

Szymczyk, Krystyna; Jędrzejczak, Renata; Roszko, Marek

2015-01-01

Summary A liquid chromatography/ion trap mass spectrometry-based method to determine six ergot alkaloids and their isomers is presented. The samples were cleaned on neutral alumina-based solid-phase extraction cartridges. The following method parameters were obtained (depending on the analyte and spiking level): method recovery from 63.0 to 104.6%, relative standard deviation below 18%, linear range from 1 to 325 µg/kg, linear correlation coefficient not less than 0.98. The developed analytical procedure was applied to determine the levels of ergot alkaloids in 65 samples of selected rye-based food products (flour – 34 samples, bran – 12 samples, rye – 18 samples, flakes – 1 sample). Measurable levels of alkaloids were found in majority of the analysed samples, particularly in rye flour. Additionally, alkaloids were determined in ergot sclerotia isolated from rye grains. Total content was nearly 0.01% (97.9 mg/kg). However, the alkaloid profile was dominated by ergocristine at 45.6% (44.7 mg/kg), an alkaloid not commonly found in the tested food products. Ergocorninine at 0.2% (0.2 mg/kg) was the least abundant alkaloid. PMID:27904328

Lolitrem B and Indole Diterpene Alkaloids Produced by Endophytic Fungi of the Genus Epichloë and Their Toxic Effects in Livestock.

PubMed

Philippe, Guerre

2016-02-15

Different group of alkaloids are produced during the symbiotic development of fungal endophytes of the genus Epichloë in grass. The structure and toxicity of the compounds vary considerably in mammalian herbivores and in crop pests. Alkaloids of the indole-diterpene group, of which lolitrem B is the most toxic, were first characterized in endophyte-infected perennial ryegrass, and are responsible for "ryegrass staggers." Ergot alkaloids, of which ergovaline is the most abundant ergopeptide alkaloid produced, are also found in ryegrass, but generally at a lower rate than lolitrem B. Other alkaloids such as lolines and peramine are toxic for crop pests but have weak toxicological properties in mammals. The purpose of this review is to present indole-diterpene alkaloids produced in endophyte infected ryegrass from the first characterization of ryegrass staggers to the determination of the toxicokinetics of lolitrem B and of their mechanism of action in mammals, focusing on the different factors that could explain the worldwide distribution of the disease. Other indole diterpene alkaloids than lolitrem B that can be found in Epichloë infected ryegrass, and their tremorgenic properties, are presented in the last section of this review.

An In-Silico Investigation of Phytochemicals as Antiviral Agents Against Dengue Fever

PubMed Central

Powers, Chelsea N.; Setzer, William N.

2016-01-01

Abstract: A virtual screening analysis of our library of phytochemical structures with dengue virus protein targets has been carried out using a molecular docking approach. A total of 2194 plant-derived secondary metabolites have been docked. This molecule set comprised of 290 alkaloids (68 indole alkaloids, 153 isoquinoline alkaloids, 5 quinoline alkaloids, 13 piperidine alkaloids, 14 steroidal alkaloids, and 37 miscellaneous alkaloids), 678 terpenoids (47 monoterpenoids, 169 sesquiterpenoids, 265 diterpenoids, 81 steroids, and 96 triterpenoids), 20 aurones, 81 chalcones, 349 flavonoids, 120 isoflavonoids, 74 lignans, 58 stilbenoids, 169 miscellaneous polyphenolic compounds, 100 coumarins, 28 xanthones, 67 quinones, and 160 miscellaneous phytochemicals. Dengue virus protein targets examined included dengue virus protease (NS2B-NS3pro), helicase (NS3 helicase), methyltransferase (MTase), RNA-dependent RNA polymerase (RdRp), and the dengue virus envelope protein. Polyphenolic compounds, flavonoids, chalcones, and other phenolics were the most numerous of the strongly docking ligands for dengue virus protein targets. PMID:27151482

Anticholinesterase inhibitory activity of quaternary alkaloids from Tinospora crispa.

PubMed

Yusoff, Mashitah; Hamid, Hazrulrizawati; Houghton, Peter

2014-01-20

Quaternary alkaloids are the major alkaloids isolated from Tinospora species. A previous study pointed to the necessary presence of quaternary nitrogens for strong acetylcholinesterase (AChE) inhibitory activity in such alkaloids. Repeated column chromatography of the vine of Tinospora crispa extract led to the isolation of one new protoberberine alkaloid, 4,13-dihydroxy-2,8,9-trimethoxydibenzo[a,g]quinolizinium (1), along with six known alkaloids-dihydrodiscretamine (2), columbamine (3), magnoflorine (4), N-formylannonaine (5), N-formylnornuciferine (6), and N-trans-feruloyltyramine (7). The seven compounds were isolated and structurally elucidated by spectroscopic analysis. Two known alkaloids, namely, dihydrodiscretamine and columbamine are reported for the first time for this plant. The compounds were tested for AChE inhibitory activity using Ellman's method. In the AChE inhibition assay, only columbamine (3) showed strong activity with IC50 48.1 µM. The structure-activity relationships derived from these results suggest that the quaternary nitrogen in the skeleton has some effect, but that a high degree of methoxylation is more important for acetylcholinesterase inhibition.

Ergot Alkaloids and their Hallucinogenic Potential in Morning Glories.

PubMed

Steiner, Ulrike; Leistner, Eckhard

2018-03-02

Naturally occurring and semisynthetic ergot alkaloids play a role in health care or as recreational drugs in Western and indigenous Mexican societies. Evidence is summarized that ergot alkaloids present in Central American Convolvulaceae like Turbina corymbosa, Ipomoea violacea , and Ipomoea asarifolia are colonized by different species of a newly described clavicipitaceous fungal genus named Periglandula . The fungi are associated with peltate glandular trichomes on the adaxial leaf surface of its host plants. The Periglandula fungi are not yet culturable in vitro but were demonstrated to have the capacity to synthesize ergot alkaloids. The alkaloids do not remain in the fungal mycelium but are translocated via the glandular trichomes into their plant host. Both fungi and host benefit from a symbiotic lifestyle. In evolutionary terms the alkaloid biosynthetic gene cluster in the Periglandula/Ipomoea symbiosis is likely to have a conserved (basic) structure while biosynthetic ergot gene clusters within the genera Claviceps and Epichloe were under ecological selection for alkaloid diversification. Georg Thieme Verlag KG Stuttgart · New York.

Occurrence of Ergot and Ergot Alkaloids in Western Canadian Wheat and Other Cereals.

PubMed

Tittlemier, Sheryl A; Drul, Dainna; Roscoe, Mike; McKendry, Twylla

2015-07-29

A new method was developed to analyze 10 ergot alkaloids in cereal grains. Analytes included both "ine" and "inine" type ergot alkaloids. Validation of the method showed it performed with good accuracy and precision and that minor enhancement due to matrix effects was present during LC-MS/MS analysis, but was mitigated by use of an internal standard. The method was used to survey durum and wheat harvested in 2011, a year in which ergot infection was particularly widespread in western Canada. A strong linear relationship between the concentration of ergot alkaloids and the presence of ergot sclerotia was observed. In addition, shipments of cereals from 2010-2012 were also monitored for ergot alkaloids. Concentrations of total ergot alkaloids in shipments were lower than observed in harvest samples, and averaged from 0.065 mg/kg in barley to 1.14 mg/kg in rye. In shipments, the concentration of ergot alkaloids was significantly lower in wheat of higher grades.

[Analysis of effect of topographical conditions on content of total alkaloid in Coptidis Rhizoma in Chongqin, China].

PubMed

Liu, Xin; Huang, He; Yang, Yan-fang; Wu, He-zhen

2014-12-01

To study ecology suitability rank dividing of the total alkaloid content of Coptis Rhizoma for selecting artificial planting base and high-quality industrial raw material in Chongqing province. Based on the investigation of PCB and DEM data of Chongqing province, the relationship between the total alkaloid content in Coptis Rhizoma and topographical conditions was analyzed by statistical analysis. The geographic information systems (GIS)-based assessment and landscape ecological principles were applied to assess eco logy suitability areas of Coptis Rhizoma in Chongqing. slope, aspect and altitude are main topographical factors that affect the content of the total alkaloid content in Coptis Rhizoma The total alkaloid content in Coptis Rhizoma is higher in the lower altitude, shady slope and bigger slope areas. The total alkaloid content is higher in the south areas of Chongqing province and lower in the northeast. Terrain conditions of the southern region of Chongqing are most suitable for The accumulated of total alkaloid Coptis Rhizoma content.

Piperidine alkaloids: human and food animal teratogens.

PubMed

Green, Benedict T; Lee, Stephen T; Panter, Kip E; Brown, David R

2012-06-01

Piperidine alkaloids are acutely toxic to adult livestock species and produce musculoskeletal deformities in neonatal animals. These teratogenic effects include multiple congenital contracture (MCC) deformities and cleft palate in cattle, pigs, sheep, and goats. Poisonous plants containing teratogenic piperidine alkaloids include poison hemlock (Conium maculatum), lupine (Lupinus spp.), and tobacco (Nicotiana tabacum) [including wild tree tobacco (Nicotiana glauca)]. There is abundant epidemiological evidence in humans that link maternal tobacco use with a high incidence of oral clefting in newborns; this association may be partly attributable to the presence of piperidine alkaloids in tobacco products. In this review, we summarize the evidence for piperidine alkaloids that act as teratogens in livestock, piperidine alkaloid structure-activity relationships and their potential implications for human health. Copyright © 2012 Elsevier Ltd. All rights reserved.

Bioactive alkaloids produced by fungi. I. Updates on alkaloids from the species of the genera Boletus, Fusarium and psilocybe.

PubMed

Mahmood, Zafar Alam; Ahmed, Syed Waseemuddin; Azhar, Iqbal; Sualeh, Mohammad; Baig, Mirza Tasawer; Zoha, Sms

2010-07-01

Fungi, in particular, are able in common with the higher plants and bacteria, to produce metabolites, including alkaloids. Alkaloids, along with other metabolites are the most important fungal metabolites from pharmaceutical and industrial point of view. Based on this observation, the authors of this review article have tried to provide an information on the alkaloids produced by the species of genera: Boletus, Fusarium and Psilocybef from 1981-2009. Thus the review would be helpful and provides valuable information for the researchers of the same field.

Antimicrobial and Antimycobacterial Activity of Cyclostellettamine Alkaloids from Sponge Pachychalina sp.

PubMed Central

de Oliveira, Jaine H. H. L.; Seleghim, Mirna H. R.; Timm, Christoph; Grube, Achim; Köck, Matthias; Nascimento, Gislene G.F.; Martins, Ana Claudia T.; Silva, Elissa G. O.; de Souza, Ana Olívia; Minarini, Paulo R. R.; Galetti, Fabio C. S.; Silva, Célio L.; Hajdu, Eduardo; Berlinck, Roberto G. S.

2006-01-01

Cyclostellettamines A – F (1 – 6) isolated from the sponge Pachychalina sp. and cyclostellettamines G - I, K and L (7 – 11) obtained by synthesis were evaluated in bioassays of antimicrobial activity against susceptible and antibiotic-resistant Staphylococcus aureus, Pseudomonas aeruginosa and antibiotic-susceptible Escherichia coli and Candida albicans, as well as in antimycobacterial activity against Mycobacterium tuberculosis H37Rv bioassays. The results obtained indicated that cyclostellettamines display different antimicrobial activity depending on the alkyl-chain size, suggesting that, if a mechanism-of action is implied, it is dependent on the distance between the two pyridinium moieties of cyclostellettamines.

5-(Methylthio)tetrazoles as Versatile Synthons in the Stereoselective Synthesis of Polycyclic Pyrazolines via Photoinduced Intramolecular Nitrile Imine–Alkene 1,3-Dipolar Cycloaddition

PubMed Central

Pla, Daniel; Tan, Derek S.; Gin, David Y.

2014-01-01

A key thioether substituent in readily accessible 2-alkyl-5-(methylthio)tetrazoles enables facile photoinduced denitrogenation and intramolecular nitrile imine 1,3-dipolar cycloaddition to afford a wide range of polycyclic pyrazoline products with excellent diastereoselectivity. The methylthio group red-shifts the UV absorbance of the tetrazole, obviating the requirement in all previous substrate systems for at least one aryl substituent, and can subsequently be converted into a variety of other functionalities. This synthetic platform has been applied to the concise total syntheses of the alkaloid natural products (±)-newbouldine and withasomnine. PMID:25114776

The different conformations and crystal structures of dihydroergocristine

NASA Astrophysics Data System (ADS)

Mönch, B.; Kraus, W.; Köppen, R.; Emmerling, F.

2016-02-01

The identification of different forms of dihydroergocristine (DHEC) was carried out by crystallization from different organic solvents. DHEC was identified as potential template for molecularly imprinted polymers (MIPs) for the epimeric specific analysis of ergot alkaloids (EAs) in food. DHEC was crystallized from different solvents in order to mimic the typical MIP synthesis conditions. Four new solvatomorphs of DHEC were obtained. All solvatomorphs contain a water molecule in the crystal structure, whereas three compounds contain an additional solvent molecule. Based on the conformation of DHEC a comparison with typical EA molecules was possible. The analysis showed that DHEC is a suitable template for MIPs for EAs.

Ring-rearrangement metathesis of nitroso Diels-Alder cycloadducts.

PubMed

Vincent, Guillaume; Kouklovsky, Cyrille

2011-03-01

Strained nitroso Diels-Alder bicyclo[2.2.1] or [2.2.2] adducts functionalized with alkene side chains of diverse length undergo a ring-rearrangement metathesis process with external alkenes and Grubbs II or Hoveyda-Grubbs II ruthenium catalysts, under microwave irradiation or classical heating, to deliver cis-fused bicycles of various ring sizes, which contain a N-O bond. These scaffolds are of synthetic relevance for the generation of molecular diversity and to the total synthesis of alkaloids. The observation of unexpected reactions, such as epimerization or one-carbon homologation of the alkene side chain, is also reported. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis and Evaluation of Strychnos Alkaloids as MDR Reversal Agents for Cancer Cell Eradication

DTIC Science & Technology

2014-01-01

followed by magnesium in MeOH to afford 11 in 75% yield (one-pot). Alkylation with (Z)-2-iodobutenyl bromide23 and acyla- tion with bromoacetyl chloride...eluting with MeOH/CH2Cl2 (0.4:9.6? 1:9). The material was washed with a solution of 25% aq NaOH (10 mL), which afforded 24 mg (71%) of Table 2...with MeOH/CH2Cl2 (0.4:9.6? 1:9). The material was washed with a solution of 25% aq NaOH (10 mL), which afforded 90 mg (86%) of 2 as yellow liquid

Cytotoxicity and accumulation of ergot alkaloids in human primary cells.

PubMed

Mulac, Dennis; Humpf, Hans-Ulrich

2011-04-11

Ergot alkaloids are secondary metabolites produced by fungi of the species Claviceps. Toxic effects after consumption of contaminated grains are described since mediaeval times. Of the more than 40 known ergot alkaloids six are found predominantly. These are ergotamine, ergocornine, ergocryptine, ergocristine, ergosine and ergometrine, along with their corresponding isomeric forms (-inine-forms). Toxic effects are known to be induced by an interaction of the ergot alkaloids as neurotransmitters, like dopamine or serotonin. Nevertheless data concerning cytotoxic effects are missing and therefore a screening of the six main ergot alkaloids was performed in human primary cells in order to evaluate the toxic potential. As it is well known that ergot alkaloids isomerize easily the stability was tested in the cell medium. Based on these results factors were calculated to correct the used concentration values to the biologically active lysergic (-ine) form. These factors range from 1.4 for the most stable compound ergometrine to 5.0 for the most unstable ergot alkaloid ergocristine. With these factors, reflecting the instability, several controverse literature data concerning the toxicity could be explained. To evaluate the cytotoxic effects of ergot alkaloids, human cells in primary culture were used. These cells remain unchanged in contrast to cell lines and the data allow a better comparison to the in vivo situation than using immortalized cell lines. To characterize the effects on primary cells, renal proximal tubule epithelial cells (RPTEC) and normal human astrocytes (NHA) were used. The parameters necrosis (LDH-release) and apoptosis (caspase-3-activation, DNA condensation and fragmentation) were distinguished. The results show that depending on the individual structure of the peptide ergot alkaloids the toxic properties change. While ergometrine as a lysergic acid amide did not show any effect, the peptide ergot alkaloids revealed a different toxic potential. Of all tested ergot alkaloids ergocristine was the most cytotoxic compound inducing apoptosis in human kidney cells starting at a concentration of 1μM in RPTEC. Uptake studies underline the cytotoxic properties, with an accumulation of peptide ergot alkaloids and no uptake of ergometrine. The results represent a new description of effects of ergot alkaloids regarding cytotoxicity and accumulation in human primary cells. For the first time apoptosis has been identified besides well described receptor effects. This gives a hint for a more complex mode of action of ergot alkaloids than described in literature so far. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

The effect of 7,8-methylenedioxylycoctonine-type diterpenoid alkaloids on the toxicity of methyllycaconitine in mice.

PubMed

Welch, K D; Panter, K E; Gardner, D R; Green, B T; Pfister, J A; Cook, D; Stegelmeier, B L

2008-10-01

Larkspur plants contain numerous norditerpenoid alkaloids, which include the 7,8-methylenedioxylycoctonine (MDL)-type alkaloids and the N-(methylsuccinimido)anthranoyllycoctonine (MSAL)-type alkaloids. The MSAL-type alkaloids are generally much more toxic (typically >20 times). Toxicity of many tall larkspurs, such as Delphinium barbeyi, has been attributed to its large concentration of MSAL-type alkaloids, including methyllycaconitine (MLA). However, the norditerpenoid alkaloids found in the greatest concentrations in most D. barbeyi populations are either deltaline or 14-O-acetyldictyocarpine (14-OAD), both less toxic MDL-type alkaloids. Although the individual toxicities of MLA, 14-OAD, and deltaline have been determined, the impact (additive or antagonistic) that large concentrations of deltaline or 14-OAD in the plant have on the toxicity of MLA is unknown. Consequently, the effect of MDL-type alkaloids on the toxicity of MLA was compared by using median lethal dose (LD(50)) and toxicokinetic profiles of the brainand muscle from mice receiving i.v. administration of these alkaloids, individually or in combination, at ratios of 1:1, 1:5, and 1:25 MLA to MDL-type alkaloids. The LD(50) for MLA alone was 4.4 +/- 0.7 mg/kg of BW, whereas the coadministration of MLA and deltaline at 1:1, 1:5, and 1:25 resulted in an LD(50) of 2.7, 2.5, and 1.9 mg/kg of BW, respectively. Similarly, the coadministration of MLA and 14-OAD at 1:1, 1:5, and 1:25 resulted in an LD(50) of 3.1, 2.2, and 1.5 mg/kg of BW, respectively. Coadministration of mixtures did not result in increased MLA bioavailability or alterations in clearance from the brain and muscle. Consequently, the increased toxicity of the mixtures was not a result of increased MLA bioavailability (based on the maximum concentrations observed) or alterations in MLA clearance from the brain and muscle, because these were unchanged. These results demonstrate that MDL-type alkaloids have an additive effect on MLA toxicity in mice and may also play a role in the overall toxicity of tall larkspur plants in cattle.

Plant-symbiotic fungi as chemical engineers: multi-genome analysis of the clavicipitaceae reveals dynamics of alkaloid loci.

PubMed

Schardl, Christopher L; Young, Carolyn A; Hesse, Uljana; Amyotte, Stefan G; Andreeva, Kalina; Calie, Patrick J; Fleetwood, Damien J; Haws, David C; Moore, Neil; Oeser, Birgitt; Panaccione, Daniel G; Schweri, Kathryn K; Voisey, Christine R; Farman, Mark L; Jaromczyk, Jerzy W; Roe, Bruce A; O'Sullivan, Donal M; Scott, Barry; Tudzynski, Paul; An, Zhiqiang; Arnaoudova, Elissaveta G; Bullock, Charles T; Charlton, Nikki D; Chen, Li; Cox, Murray; Dinkins, Randy D; Florea, Simona; Glenn, Anthony E; Gordon, Anna; Güldener, Ulrich; Harris, Daniel R; Hollin, Walter; Jaromczyk, Jolanta; Johnson, Richard D; Khan, Anar K; Leistner, Eckhard; Leuchtmann, Adrian; Li, Chunjie; Liu, JinGe; Liu, Jinze; Liu, Miao; Mace, Wade; Machado, Caroline; Nagabhyru, Padmaja; Pan, Juan; Schmid, Jan; Sugawara, Koya; Steiner, Ulrike; Takach, Johanna E; Tanaka, Eiji; Webb, Jennifer S; Wilson, Ella V; Wiseman, Jennifer L; Yoshida, Ruriko; Zeng, Zheng

2013-01-01

The fungal family Clavicipitaceae includes plant symbionts and parasites that produce several psychoactive and bioprotective alkaloids. The family includes grass symbionts in the epichloae clade (Epichloë and Neotyphodium species), which are extraordinarily diverse both in their host interactions and in their alkaloid profiles. Epichloae produce alkaloids of four distinct classes, all of which deter insects, and some-including the infamous ergot alkaloids-have potent effects on mammals. The exceptional chemotypic diversity of the epichloae may relate to their broad range of host interactions, whereby some are pathogenic and contagious, others are mutualistic and vertically transmitted (seed-borne), and still others vary in pathogenic or mutualistic behavior. We profiled the alkaloids and sequenced the genomes of 10 epichloae, three ergot fungi (Claviceps species), a morning-glory symbiont (Periglandula ipomoeae), and a bamboo pathogen (Aciculosporium take), and compared the gene clusters for four classes of alkaloids. Results indicated a strong tendency for alkaloid loci to have conserved cores that specify the skeleton structures and peripheral genes that determine chemical variations that are known to affect their pharmacological specificities. Generally, gene locations in cluster peripheries positioned them near to transposon-derived, AT-rich repeat blocks, which were probably involved in gene losses, duplications, and neofunctionalizations. The alkaloid loci in the epichloae had unusual structures riddled with large, complex, and dynamic repeat blocks. This feature was not reflective of overall differences in repeat contents in the genomes, nor was it characteristic of most other specialized metabolism loci. The organization and dynamics of alkaloid loci and abundant repeat blocks in the epichloae suggested that these fungi are under selection for alkaloid diversification. We suggest that such selection is related to the variable life histories of the epichloae, their protective roles as symbionts, and their associations with the highly speciose and ecologically diverse cool-season grasses.

Development and Validation of a HPLC-ESI-MS/MS Method for Simultaneous Quantification of Fourteen Alkaloids in Mouse Plasma after Oral Administration of the Extract of Corydalis yanhusuo Tuber: Application to Pharmacokinetic Study.

PubMed

Du, Weijuan; Jin, Lisha; Li, Liping; Wang, Wei; Zeng, Su; Jiang, Huidi; Zhou, Hui

2018-03-21

The tuber of Corydalis yanhusuo is a famous traditional Chinese medicine and found to have potent pharmacological effects, such as antinociceptive, antitumor, antibacterial, anti-inflammatory, and anti-depressive activities. Although there are several methods to be developed for the analysis and detection of the bioactive ingredients' alkaloids, so far, only few prominent alkaloids could be quantified, and in vitro and in vivo changes of comprehensive alkaloids after oral administration are still little known. In this study, we first developed a simple and sensitive high-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (HPLC-ESI-MS/MS) method to quantify the comprehensive alkaloids of extracts of C. yanhusuo in mouse plasma, using nitidine chloride as an internal standard. As results, at least fourteen alkaloids, including an aporphine (oxoglaucine), a protopine (protopine), five tertiary alkaloids (corydaline, tetrahydroberberine, tetrahydropalmatine, tetrahydrocolumbamine, and tetrahydrocoptisine) and seven quaternary alkaloids (columbamine, palmatine, berberine, epiberberine, coptisine, jatrorrhizine, and dehydrocorydaline) could be well quantified simultaneously in mouse plasma. The lower limits of quantification were greater than, or equal to, 0.67 ng/mL, and the average matrix effects ranged from 96.4% to 114.3%. The mean extraction recoveries of quality control samples were over 71.40%, and the precision and accuracy were within the acceptable limits. All the analytes were shown to be stable under different storage conditions. Then the established method was successfully applied to investigate the pharmacokinetics of these alkaloids after oral administration of the extract of Corydalis yanhusuo in mice. To the best of our knowledge, this is the first document to report the comprehensive and simultaneous analyses of alkaloids of C. yanhusuo in mouse plasma. It was efficient and useful for comprehensive pharmacokinetic and metabolomic analyses of these complex alkaloids after drug administration.

Integration of Transcriptome, Proteome and Metabolism Data Reveals the Alkaloids Biosynthesis in Macleaya cordata and Macleaya microcarpa

PubMed Central

Liu, Fuqing; Huang, Peng; Zhu, Pengcheng; Chen, Jinjun; Shi, Mingming; Guo, Fang; Cheng, Pi; Zeng, Jing; Liao, Yifang; Gong, Jing; Zhang, Hong-Mei; Wang, Depeng; Guo, An-Yuan; Xiong, Xingyao

2013-01-01

Background The Macleaya spp., including Macleaya cordata and Macleaya microcarpa, are traditional anti-virus, inflammation eliminating, and insecticide herb medicines for their isoquinoline alkaloids. They are also known as the basis of the popular natural animal food addictive in Europe. However, few studies especially at genomics level were conducted on them. Hence, we performed the Macleaya spp. transcriptome and integrated it with iTRAQ proteome analysis in order to identify potential genes involved in alkaloids biosynthesis. Methodology and Principal Findings We elaborately designed the transcriptome, proteome and metabolism profiling for 10 samples of both species to explore their alkaloids biosynthesis. From the transcriptome data, we obtained 69367 and 78255 unigenes for M. cordata and M. microcarpa, in which about two thirds of them were similar to sequences in public databases. By metabolism profiling, reverse patterns for alkaloids sanguinarine, chelerythrine, protopine, and allocryptopine were observed in different organs of two species. We characterized the expressions of enzymes in alkaloid biosynthesis pathways. We also identified more than 1000 proteins from iTRAQ proteome data. Our results strongly suggest that the root maybe the organ for major alkaloids biosynthesis of Macleaya spp. Except for biosynthesis, the alkaloids storage and transport were also important for their accumulation. The ultrastructure of laticifers by SEM helps us to prove the alkaloids maybe accumulated in the mature roots. Conclusions/Significance To our knowledge this is the first study to elucidate the genetic makeup of Macleaya spp. This work provides clues to the identification of the potential modulate genes involved in alkaloids biosynthesis in Macleaya spp., and sheds light on researches for non-model medicinal plants by integrating different high-throughput technologies. PMID:23326424

Protective effects on vascular endothelial cell in N'-nitro-L-arginine (L-NNA)-induced hypertensive rats from the combination of effective components of Uncaria rhynchophylla and Semen Raphani.

PubMed

Li, Yunlun; Yang, Wenqing; Zhu, Qingjun; Yang, Jinguo; Wang, Zhen

2015-08-01

Endothelial dysfunction is closely associated with hypertension. Protection of vascular endothelial cell is the key to prevention and treatment of hypertension. Uncaria rhynchophylla total alkaloids and Semen Raphani soluble alkaloid, isolated from traditional Chinese medicine Uncaria rbyncbopbylla and Semen Raphani respectively, exhibit properties of anti-hypertension and protection of blood vessels. In the present study, we observed the protective effect of the combined use of Uncaria rhynchophylla total alkaloids and Semen Raphani soluble alkaloid to the vascular endothelial cell in N'-nitro-L-arginine-induced hypertensive rats and investigate the preliminary mechanism. Blood pressure was detected by non-invasive rats tail method to observe the anti-hypertension effect of drugs. Scanning electron microscopy was used to observe the integrity or shedding state of vascular endothelial cell. The amount of circulating endothelial cells and CD54 and CD62P expression on circulating endothelial cells were tested to evaluate the endothelium function. In this study, we found that the Uncaria rhynchophylla total alkaloids and Semen Raphani soluble alkaloid compatibility can effectively lower the blood pressure, improve the structural integrity of vascular endothelium, and significantly reduce the number of circulating endothelial cells. Furthermore, the mean fluorescence intensity of CD54 and CD62P expressed showed decrease after the intervention of Uncaria rhynchophylla total alkaloids and Semen Raphani soluble alkaloid compatibility. In conclusion, the combination of effective components of the Uncaria rhynchophylla total alkaloids and Semen Raphani soluble alkaloid demonstrated good antihypertension effect and vascular endothelium protective effect. The preliminary mechanism of the protective effect may attribute to relieve the overall low-grade inflammation.

Fingerprinting and simultaneous determination of alkaloids in Picrasma quassioides from different locations by high performance liquid chromatography with photodiode array detection.

PubMed

Liao, Hui-Jun; Lai, Zheng-Quan; Su, Ji-Yan; Yi, Yu-Yang; Li, Yu-Cui; Lai, Xiao-Ping; Su, Zi-Ren; Lin, Zhi-Xiu

2012-09-01

A simple and sensitive method was developed and validated for profiling and simultaneous quantitation of seven alkaloids (6-hydroxy-β-carboline-1-carboxylic acid, β-carboline-1-carboxylic acid, β-carboline-1-propanoic acid, 3-methylcanthin-5,6-dione, 5-hydroxy-4-methoxycanthin-6-one, 1-methoxycarbony-β-carboline, and 4,5-dimethoxycanthin-6-one) in Picrasma quassioide grown in different locations by high-performance liquid chromatography with photodiode array detection. The analysis was conducted on a Phenomenex Gemini C(18) column at 35°C with mobile phase of 25 mM aqueous ammonium acetate (pH 4.0, adjusted by glacial acetate acid) and acetonitrile. A common fingerprint chromatograph under 254 nm consisting of 27 peaks was constructed for the evaluation of the similarities among 31 P. quassioide samples. Samples from Guangdong and Guangxi Provinces were found to be within group linkage and showed significant difference from that of Jiangxi Province origin by using principal component analysis and hierarchical clustering analysis. In addition, the seven alkaloids were identified by electrospray ionization mass spectrometry and comparing with reference standards and literature data. All of them were determined simultaneously using the established HPLC method. This rapid and effective analytical method could be employed for quality assessment of P. quassioide, as well as pharmaceutical products containing this herbal material. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Alkaloids in plants and root cultures of Atropa belladonna overexpressing putrescine N-methyltransferase.

PubMed

Rothe, Grit; Hachiya, Akira; Yamada, Yasuyuki; Hashimoto, Takashi; Dräger, Birgit

2003-09-01

Putrescine N-methyltransferase (PMT) is the first alkaloid-specific enzyme for nicotine and tropane alkaloid formation. The pmt gene from Nicotiana tabacum was fused to the CaMV 35S promoter and integrated into the Atropa belladonna genome. Transgenic plants and derived root cultures were analysed for gene expression and for levels of alkaloids and their precursors. Scopolamine, hyoscyamine, tropine, pseudotropine, tropinone, and calystegines were found unaltered or somewhat decreased in pmt-overexpressing lines compared to controls. When root cultures were treated with 5% sucrose, calystegine levels were elevated in control roots, but were not affected in pmt-overexpressing roots. 1 microM auxin reduced calystegine levels in control roots, while in pmt-overexpressing roots all alkaloids remained unaltered. Expression level of pmt alone is apparently not limiting for tropane alkaloid formation in A. belladonna.

Probing the transcriptome of Aconitum carmichaelii reveals the candidate genes associated with the biosynthesis of the toxic aconitine-type C19-diterpenoid alkaloids.

PubMed

Zhao, Dake; Shen, Yong; Shi, Yana; Shi, Xingqiao; Qiao, Qin; Zi, Shuhui; Zhao, Erqiang; Yu, Diqiu; Kennelly, Edward J

2018-05-11

Aconitum carmichaelii has long been used as a traditional Chinese medicine, and its processed lateral roots are known commonly as fuzi. Aconitine-type C 19 -diterpenoid alkaloids accumulating in the lateral roots are some of the main toxicants of this species, yet their biosynthesis remains largely unresolved. As a first step towards understanding the biosynthesis of aconitine-type C 19 -diterpenoid alkaloids, we performed de novo transcriptome assembly and analysis of rootstocks and leaf tissues of Aconitum carmichaelii by next-generation sequencing. A total of 525 unigene candidates were identified as involved in the formation of C 19 -diterpenoid alkaloids, including those encoding enzymes in the early steps of diterpenoid alkaloids scaffold biosynthetic pathway, such as ent-copalyl diphosphate synthases, ent-kaurene synthases, kaurene oxidases, cyclases, and key aminotransferases. Furthermore, candidates responsible for decorating of diterpenoid alkaloid skeletons were discovered from transcriptome sequencing of fuzi, such as monooxygenases, methyltransferase, and BAHD acyltransferases. In addition, 645 differentially expressed genes encoding transcription factors potentially related to diterpenoid alkaloids accumulation underground were documented. Subsequent modular domain structure phylogenetics and differential expression analysis led to the identification of BAHD acyltransferases possibly involved in the formation of acetyl and benzoyl esters of diterpenoid alkaloids, associated with the acute toxicity of fuzi. The transcriptome data provide the foundation for future research into the molecular basis for aconitine-type C 19 -diterpenoid alkaloids biosynthesis in A. carmichaelii. Copyright © 2018. Published by Elsevier Ltd.

[Effects of Total Alkaloids of Harmaline on Learning and Memory in Vascular Dementia Rats].

PubMed

Zhang, Xiao-shuang; Sun, Jian-ning; Yu, Hui-ling

2015-11-01

To investigate the effects of total alkaloids of harmaline on learning and memory in vascular dementia rats, and its mechanism. The model rats of vascular dementia were established with bilateral carotid artery ligation. After 30 days, the model rats were randomly divided into six groups: sham group, model group, nicergoline tablets 7 mg/kg group, and 25, 12.5 and 6.25 mg/kg dose groups of total alkaloids of harmaline, the rats were given medicine for 30 days. Learning and memory abilities were tested by Morris water maze, histomorphology in hippocampal CA1 area were observed by HE staining, BAX and BCL-2 protein expression in hippocampal CA1 area were detected by immunohistochemistry. Compared with model group, 25 mg/kg group of total alkaloids of harmaline shortened the incubation period in the third and fourth day significantly, 12.5 mg/kg group of total alkaloids of harmaline shortened the incubation period in the fourth day. 25 and 12.5 mg/kg groups of total alkaloids of harmaline significantly increased the times crossing the target. Total alkaloids of harmaline improved the neurons pathological changes of rat in the hippocampus CA1 area, 25 and 12.5 mg/kg of total alkaloids of harmaline downregulated the expression of apoptosis proteins BAX, upregulated the protein expression of BCL-2. Total alkaloids of harmaline can improve the learning and memory abilities in vascular dementia rats, which probably is related to inhibiting apoptosis of hippocampus cell.

In Situ Histochemical Localisation of Alkaloids and Acetogenins in the Endosperm and Embryonic Axis of Annona Macroprophyllata Donn. Sm. Seeds During Germination

PubMed Central

Brechú-Franco, A.E.; Laguna-Hernández, G.; De la Cruz-Chacón, I.; González-Esquinca, A.R.

2016-01-01

Currently, the Annonaceae family is characterised by the production of acetogenins (ACGs), and also by the biosynthesis of alkaloids, primarily benzylisoquinolines derived from tyrosine. The objective of this study was to confirm the presence of alkaloids and acetogenins in the idioblasts of the endosperm and the embryonic axis of A. macroprophyllata seeds in germination. The Dragendorff, Dittmar, Ellram, and Lugol reagents were used to test for alkaloids, and Kedde’s reagent was used to determine the presence of acetogenins in fresh sections of the endosperm and embryonic axis of seeds after twelve days of germination. A positive reaction was observed for all the reagents, and the presence of alkaloids and acetogenins was confirmed in the idioblasts of the endosperm and those involved in the differentiation of the embryonic axis of the developing seedling. We concluded that the idioblasts store both metabolites, acetogenins and alkaloids. Beginning at differentiation, the idioblasts of the embryonic axis simultaneously biosynthesise acetogenins and alkaloids that are characteristic of the species during the development of the seedling. The method used here can be applied to histochemically confirm the presence of acetogenins and alkaloids in tissues and structures of the plant in different stages of its life cycle. PMID:26972713

Ameliorative effect of alkaloid extract of Cyclea peltata (Poir.) Hook. f. & Thoms. roots (ACP) on APAP/CCl4 induced liver toxicity in Wistar rats and in vitro free radical scavenging property.

PubMed

Shine, Varghese Jancy; Latha, Panikamparambil Gopalakrishnan; Suja, Somasekharan Nair Rajam; Anuja, Gangadharan Indira; Raj, Gopan; Rajasekharan, Sreedharan Nair

2014-02-01

To evaluate the hepatoprotective and antioxidant properties of alkaloid extract of Cyclea peltata (C. peltata) against paracetamol/carbon tetra chloride induced liver damage in Wistar rats. In vivo paracetamol/carbon tetrachloride induced liver damage in Wistar rats, in vitro free radical scavenging studies, HPTLC estimation of tetrandrine and direct analysis in real time- mass spectrometry of alkaloid extract of C. peltata were used for the validation. The results showed that pretreatment with alkaloid extract of C. peltata caused significant reduction of serum glutamate pyruvate transaminase, serum glutamate oxaloacetate transaminase, serum alkaline phosphatase, serum cholesterol, liver malondialdehyde levels. The reduced glutathione, catalase, superoxide dismutase levels in liver were increased with alkaloid extract of C. peltata treatment. These results were almost comparable to silymarin and normal control. Histopathological studies also substantiated the biochemical findings. The in vitro hydroxyl, superoxide and DPPH scavenging study of alkaloid extract of C. peltata showed significant free radical scavenging property. The hepatoprotective property of alkaloid extract of C. peltata against paracetamol/carbon tetrachloride may be due the synergistic action of alkaloids especially tetrandrine, fangchinoline through free radical scavenging and thus preventing oxidative stress.

Drug Delivery Systems and Combination Therapy by Using Vinca Alkaloids

PubMed Central

Lee, Chun-Ting; Huang, Yen-Wei; Yang, Chih-Hui; Huang, Keng-Shiang

2015-01-01

Developing new methods for chemotherapy drug delivery has become a topic of great concern. Vinca alkaloids are among the most widely used chemotherapy reagents for tumor therapy; however, their side effects are particularly problematic for many medical doctors. To reduce the toxicity and enhance the therapeutic efficiency of vinca alkaloids, many researchers have developed strategies such as using liposome-entrapped drugs, chemical- or peptide-modified drugs, polymeric packaging drugs, and chemotherapy drug combinations. This review mainly focuses on the development of a vinca alkaloid drug delivery system and the combination therapy. Five vinca alkaloids (eg, vincristine, vinblastine, vinorelbine, vindesine, and vinflunine) are reviewed. PMID:25877096

[Relativity among starch quantity, polysaccharides content and total alkaloid content of Dendrobium loddigesii].

PubMed

Zhu, Hua; Teng, Jianbei; Cai, Yi; Liang, Jie; Zhu, Yilin; Wei, Tao

2011-12-01

To find out the relativity among starch quantity, polysaccharides content and total alkaloid content of Dendrobium loddigesii. Microscopy-counting process was applied to starch quantity statistics, sulfuric acid-anthrone colorimetry was used to assay polysaccharides content and bromocresol green colorimetry was used to assay alkaloid content. Pearson product moment correlation analysis, Kendall's rank correlation analysis and Spearman's concordance coefficient analysis were applied to study their relativity. Extremely significant positive correlation was found between starch quantity and polysaccharides content, and significant negative correlation between alkaloid content and starch quantity was discovered, as well was between alkaloid content and polysaccharides content.

Alkaloid diversity in the leaves of Australian Flindersia (Rutaceae) species driven by adaptation to aridity.

PubMed

Robertson, Luke P; Hall, Casey R; Forster, Paul I; Carroll, Anthony R

2018-05-04

The genus Flindersia (Rutaceae) comprises 17 species of mostly Australian endemic trees. Although most species are restricted to rainforests, four have evolved to grow in semi-arid and arid environments. In this study, the leaf alkaloid diversity of rainforest and semi-arid/arid zone adapted Australian Flindersia were compared by LC/MS-MS and NMR spectroscopy. Contrary to expectations, Flindersia alkaloid diversity was strongly correlated with environmental aridity, where species predominating in drier regions produced more alkaloids than their wet rainforest congenerics. Rainforest species were also more chemically similar to each other than were the four semi-arid/arid zone species. There was a significant relationship between the presence of alkaloid structural classes and phylogenetic distance, suggesting that alkaloid profiles are influenced by both genetic and environmental factors. The results suggest that the radiation of Flindersia species out of the rainforest and into drier environments has promoted the evolution of unique alkaloid diversity. Plants growing in arid and semi-arid regions of Australia may represent an untapped source of undescribed specialised metabolites. Copyright © 2018 Elsevier Ltd. All rights reserved.

Alkaloids as important scaffolds in therapeutic drugs for the treatments of cancer, tuberculosis, and smoking cessation.

PubMed

Kittakoop, Prasat; Mahidol, Chulabhorn; Ruchirawat, Somsak

2014-01-01

Alkaloid molecules can act, depending on a type of amine functionality present in alkalods, as either hydrogenacceptor or hydrogen-donor for hydrogen bonding that is critically important for the interaction (binding) between targets (enzymes, proteins and receptors) and drugs (ligands). Because of this unique property, alkaloid scaffolds are therefore present in several drugs and lead compounds. This review highlights alkaloid scaffolds in drugs, particularly those recently approved in 2012; it also covers the scaffolds in leads and drug candidates which are in clinical trials and preclinical pipeline. The review focuses on three therapeutic areas including treatments of cancer, tuberculosis, and tobacco cessation. Alkaloid scaffolds in drugs and leads are inspired by those of naturally occurring alkaloids, and these scaffolds include pyridine, piperidine, quinoline, quinolinone, quinazoline, isoquinoline, indole, indolinone, isoindole, isoxazole, imidazole, indazole, thiazole, pyrazole, oxazolidinone, oxadiazole, and benzazepine. In addition to medicinal chemistry aspects, natural products possessing an individual alkaloid scaffold, as well as the mechanism of action of drugs and leads, are also discussed in this review.

Alkaloid Profiling as an Approach to Differentiate Lupinus garfieldensis, Lupinus sabinianus and Lupinus sericeus.

PubMed

Cook, Daniel; Lee, Stephen T; Pfister, James A; Stonecipher, Clint A; Welch, Kevin D; Green, Benedict T; Panter, Kip E

2012-01-01

Many species in the Lupinus genus are poorly defined morphologically, potentially resulting in improper taxonomic identification. Lupine species may contain quinolizidine and/or piperidine alkaloids that can be acutely toxic and/or teratogenic, the latter resulting in crooked calf disease. To identify characteristic alkaloid profiles of Lupinus sabinianus, L. garfieldensis and L. sericeus which would aid in discriminating these species from each other and from L. sulphureus. Quinolizidine and piperidine alkaloids were extracted from herbarium specimens and recent field collections of L. sabinianus, L. garfieldensis and L. sericeus. The alkaloid composition of each species was defined using GC-FID and GC-MS and compared using multivariate statistics. Each of the three species investigated contained a diagnostic chemical fingerprint composed of quinolizidine and/or piperidine alkaloids. The alkaloid profiles of Lupinus sabinianus, L. garfieldensis and L. sericeus can be used as a tool to discriminate these species from each other and L. sulphureus as long as one considers locality of the collection in the case of L. sabinianus. Published 2011. This article is a US Government work and is in the public domain in the USA.

Maternally derived chemical defences are an effective deterrent against some predators of poison frog tadpoles (Oophaga pumilio).

PubMed

Stynoski, Jennifer L; Shelton, Georgia; Stynoski, Peter

2014-05-01

Parents defend their young in many ways, including provisioning chemical defences. Recent work in a poison frog system offers the first example of an animal that provisions its young with alkaloids after hatching or birth rather than before. But it is not yet known whether maternally derived alkaloids are an effective defence against offspring predators. We identified the predators of Oophaga pumilio tadpoles and conducted laboratory and field choice tests to determine whether predators are deterred by alkaloids in tadpoles. We found that snakes, spiders and beetle larvae are common predators of O. pumilio tadpoles. Snakes were not deterred by alkaloids in tadpoles. However, spiders were less likely to consume mother-fed O. pumilio tadpoles than either alkaloid-free tadpoles of the red-eyed treefrog, Agalychnis callidryas, or alkaloid-free O. pumilio tadpoles that had been hand-fed with A. callidryas eggs. Thus, maternally derived alkaloids reduce the risk of predation for tadpoles, but only against some predators. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

Rapid Screening of Ergot Alkaloids in Sclerotia by MALDI-TOF Mass Spectrometry.

PubMed

Sivagnanam, Kumaran; Komatsu, Emy; Patrick, Susan; Rampitsch, Christoph; Perreault, Hélène; Gräfenhan, Tom

2016-07-01

Ergot is a common disease of wheat and other cereal grains that is predominantly caused by Claviceps purpurea in the field, often affecting crop yield in addition to the environment. Infected grain can be contaminated with dark sclerotia, which contain fungal metabolites such as ergot alkaloids. The occurrence of ergot alkaloids in cereal grain is a major health concern for humans and livestock. Effective and rapid screening of these mycotoxins is crucial for producers, processors, and consumers of cereal-based food and feed grain. Established methods of ergot alkaloid screening based on LC-MS or GC-MS require laborious processes. A novel method using matrix-assisted laser desorption ionization (MALDI)-time-of-flight (TOF) MS was developed to identify four ergot alkaloids. Using dihydroxybenzoic acid as the matrix, ergosine, ergocornine, ergocryptine, and ergocristine were readily detected in individual sclerotia of C. purpurea. The accuracy of the identified ergot alkaloids was further confirmed by tandem MS analysis. MALDI-TOF MS is suitable for high-throughput screening of ergot alkaloids because it permits rapid and accurate identification, simple sample preparation, and no derivatization or chromatographic separation.

[Study on the separation process of pharmacological active total alkaloids from Chelidonium majus L. growing in Georgia].

PubMed

Bozhadze, A D; Vachnadze, V Iu; Dzhokhadze, M S; Berashvili, D T; Bakuridze, A Dzh

2013-04-01

In present article was studied the separation process of pharmacological active total alkaloids from Chelidonium majus L. growing in Georgia. Alkaloids were extracted from medicinal herbal material and separated by liquid extraction, diluents gas and a microfiltration through membrane equipment. The obtained A1, A2, A3 fractions were analyzed by GC/MS method; in all cases separation proceeds by the principle of extraction of the target alkaloids. It was concluded that the A1 is enriched with α and β cryptopins, and protopin, but homochelidonine and chelidonine are in low contents. As accompanying alkaloid is identified dihydrosanguinarine as an artifact; the A2 is enriched with the maximum contents of stylopine and protopin, but the poor contents of chelidonine and homochelidonine; the A3 is enriched with α and β cryptopins and maximum content of chelidonine. Extraction of alkaloids from Chelidonium majus L. proceeds selectively, but depending on a way of separation of the total alkaloids allows varying qualitative and quantitative consistence of the final product.

Poisonous plants contaminating edible ones and toxic substances in plant foods. Part 3. Pyrrolizidine alkaloids from Heliotropium digynum Forssk. (= H. luteum, Poir.).

PubMed

Hammouda, F M; Rizk, A M; Ismail, S I; Atteya, S Z; Ghaleb, H A; Madkour, M K; Pohland, A E; Wood, G

1984-10-01

Investigation of the alkaloidal constituents of Heliotropium digynum resulted in the isolation of four alkaloids viz. heliotrine, europine, lasiocarpine and 7-angelylheliotrine. Moreover, HPLC and GLC showed the probable presence of heliotridine and some other unidentified minor constituents. A summary of the pharmacotoxicity and biological activity of the ethanolic extract, total alkaloids with special reference to heliotrine is presented.

Five New Alkaloids from the Roots of Sophora flavescens.

PubMed

Zhang, Sheng-Yuan; Li, Wen; Nie, Hua; Liao, Mei; Qiu, Bo; Yang, Ya-Li; Chen, Yan-Fen

2018-03-01

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. © 2018 Wiley-VHCA AG, Zurich, Switzerland.

Antimicrobial Resistance and the Alternative Resources with Special Emphasis on Plant-Based Antimicrobials—A Review

PubMed Central

Chandra, Harish; Bishnoi, Parul; Yadav, Archana; Patni, Babita; Mishra, Abhay Prakash; Nautiyal, Anant Ram

2017-01-01

Indiscriminate and irrational use of antibiotics has created an unprecedented challenge for human civilization due to microbe’s development of antimicrobial resistance. It is difficult to treat bacterial infection due to bacteria’s ability to develop resistance against antimicrobial agents. Antimicrobial agents are categorized according to their mechanism of action, i.e., interference with cell wall synthesis, DNA and RNA synthesis, lysis of the bacterial membrane, inhibition of protein synthesis, inhibition of metabolic pathways, etc. Bacteria may become resistant by antibiotic inactivation, target modification, efflux pump and plasmidic efflux. Currently, the clinically available treatment is not effective against the antibiotic resistance developed by some bacterial species. However, plant-based antimicrobials have immense potential to combat bacterial, fungal, protozoal and viral diseases without any known side effects. Such plant metabolites include quinines, alkaloids, lectins, polypeptides, flavones, flavonoids, flavonols, coumarin, terpenoids, essential oils and tannins. The present review focuses on antibiotic resistance, the resistance mechanism in bacteria against antibiotics and the role of plant-active secondary metabolites against microorganisms, which might be useful as an alternative and effective strategy to break the resistance among microbes. PMID:28394295

Engineering an enantioselective amine oxidase for the synthesis of pharmaceutical building blocks and alkaloid natural products.

PubMed

Ghislieri, Diego; Green, Anthony P; Pontini, Marta; Willies, Simon C; Rowles, Ian; Frank, Annika; Grogan, Gideon; Turner, Nicholas J

2013-07-24

The development of cost-effective and sustainable catalytic methods for the production of enantiomerically pure chiral amines is a key challenge facing the pharmaceutical and fine chemical industries. This challenge is highlighted by the estimate that 40-45% of drug candidates contain a chiral amine, fueling a demand for broadly applicable synthetic methods that deliver target structures in high yield and enantiomeric excess. Herein we describe the development and application of a "toolbox" of monoamine oxidase variants from Aspergillus niger (MAO-N) which display remarkable substrate scope and tolerance for sterically demanding motifs, including a new variant, which exhibits high activity and enantioselectivity toward substrates containing the aminodiphenylmethane (benzhydrylamine) template. By combining rational structure-guided engineering with high-throughput screening, it has been possible to expand the substrate scope of MAO-N to accommodate amine substrates containing bulky aryl substituents. These engineered MAO-N biocatalysts have been applied in deracemization reactions for the efficient asymmetric synthesis of the generic active pharmaceutical ingredients Solifenacin and Levocetirizine as well as the natural products (R)-coniine, (R)-eleagnine, and (R)-leptaflorine. We also report a novel MAO-N mediated asymmetric oxidative Pictet-Spengler approach to the synthesis of (R)-harmicine.

Transcriptome analysis of 20 taxonomically related benzylisoquinoline alkaloid-producing plants.

PubMed

Hagel, Jillian M; Morris, Jeremy S; Lee, Eun-Jeong; Desgagné-Penix, Isabel; Bross, Crystal D; Chang, Limei; Chen, Xue; Farrow, Scott C; Zhang, Ye; Soh, Jung; Sensen, Christoph W; Facchini, Peter J

2015-09-18

Benzylisoquinoline alkaloids (BIAs) represent a diverse class of plant specialized metabolites sharing a common biosynthetic origin beginning with tyrosine. Many BIAs have potent pharmacological activities, and plants accumulating them boast long histories of use in traditional medicine and cultural practices. The decades-long focus on a select number of plant species as model systems has allowed near or full elucidation of major BIA pathways, including those of morphine, sanguinarine and berberine. However, this focus has created a dearth of knowledge surrounding non-model species, which also are known to accumulate a wide-range of BIAs but whose biosynthesis is thus far entirely unexplored. Further, these non-model species represent a rich source of catalyst diversity valuable to plant biochemists and emerging synthetic biology efforts. In order to access the genetic diversity of non-model plants accumulating BIAs, we selected 20 species representing 4 families within the Ranunculales. RNA extracted from each species was processed for analysis by both 1) Roche GS-FLX Titanium and 2) Illumina GA/HiSeq platforms, generating a total of 40 deep-sequencing transcriptome libraries. De novo assembly, annotation and subsequent full-length coding sequence (CDS) predictions indicated greater success for most species using the Illumina-based platform. Assembled data for each transcriptome were deposited into an established web-based BLAST portal ( www.phytometasyn.ca) to allow public access. Homology-based mining of libraries using BIA-biosynthetic enzymes as queries yielded ~850 gene candidates potentially involved in alkaloid biosynthesis. Expression analysis of these candidates was performed using inter-library FPKM normalization methods. These expression data provide a basis for the rational selection of gene candidates, and suggest possible metabolic bottlenecks within BIA metabolism. Phylogenetic analysis was performed for each of 15 different enzyme/protein groupings, highlighting many novel genes with potential involvement in the formation of one or more alkaloid types, including morphinan, aporphine, and phthalideisoquinoline alkaloids. Transcriptome resources were used to design and execute a case study of candidate N-methyltransferases (NMTs) from Glaucium flavum, which revealed predicted and novel enzyme activities. This study establishes an essential resource for the isolation and discovery of 1) functional homologues and 2) entirely novel catalysts within BIA metabolism. Functional analysis of G. flavum NMTs demonstrated the utility of this resource and underscored the importance of empirical determination of proposed enzymatic function. Publically accessible, fully annotated, BLAST-accessible transcriptomes were not previously available for most species included in this report, despite the rich repertoire of bioactive alkaloids found in these plants and their importance to traditional medicine. The results presented herein provide essential sequence information and inform experimental design for the continued elucidation of BIA metabolism.

Design and synthesis of novel C14-urea-tetrandrine derivatives with potent anti-cancer activity.

PubMed

Lan, Junjie; Huang, Lan; Lou, Huayong; Chen, Chao; Liu, Tangjingjun; Hu, Shengcao; Yao, Yao; Song, Junrong; Luo, Jun; Liu, Yazhou; Xia, Bin; Xia, Lei; Zeng, Xueyi; Ben-David, Yaacov; Pan, Weidong

2018-01-01

Tetrandrine is a dibenzyltetrahydroisoquinoline alkaloid, isolated from traditional Chinese medicinal plant Stephania tetrandra, with anti-tumor activity. Our previous study identified several derivatives of tetrandrine showing better activities than parental compound against human hepatocellular carcinoma cells. To increase diversity and cytotoxic activities of the original compound, a series of novel 14-urea-tetrandrine derivatives were synthesized through structural modification of tetrandrine. These derivaties demonstrated a moderate to strong anti-proliferative activities against human cell lines HEL and K562 (Leukemia), prostate (PC3), breast (MDA-MB-231) and melanoma (WM9). Compound 4g showed strongest cytotoxic effect against PC3 cells with IC 50 value of 0.64 μM, which was 12-fold, 31-fold and 26-fold lower than the parental tetrandrine, 5-fluorouracil and cisplatin, respectively. Preliminary structure-activity relationship study indicated that urea subsititution was the key pharmacophore for the enhancement of their antitumor activities. Induction of apoprosis by 4g was associated with the activation of pro-apoptotic protein BAX and inhibition of antiapoptosis proteins survivin as well as Bcl-2. Moreover, activation of caspases led to increase cleavage of PARP, which further accelerates apoptotic cell death. These results reveal that the compound 4g may be used as a potential anticancer drug candidate. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Lysergic acid amide as chemical marker for the total ergot alkaloids in rye flour - Determination by high-performance thin-layer chromatography-fluorescence detection.

PubMed

Oellig, Claudia

2017-07-21

Ergot alkaloids are generally determined by high-performance liquid chromatography (HPLC) coupled to fluorescence detection (FLD) or mass selective detection, analyzing the individual compounds. However, fast and easy screening methods for the determination of the total ergot alkaloid content are more suitable, since for monitoring only the sum of the alkaloids is relevant. The herein presented screening uses lysergic acid amide (LSA) as chemical marker, formed from ergopeptine alkaloids, and ergometrine for the determination of the total ergot alkaloids in rye with high-performance thin-layer chromatography-fluorescence detection (HPTLC-FLD). An ammonium acetate buffered extraction step was followed by liquid-liquid partition for clean-up before the ergopeptine alkaloids were selectively transformed to LSA and analyzed by HPTLC-FLD on silica gel with isopropyl acetate/methanol/water/25% ammonium hydroxide solution (80:10:3.8:1.1, v/v/v/v) as the mobile phase. The enhanced native fluorescence of LSA and unaffected ergometrine was used for quantitation without any interfering matrix. Limits of detection and quantitation were 8 and 26μg LSA/kg rye, which enables the determination of the total ergot alkaloids far below the applied quality criterion limit for rye. Close to 100% recoveries for different rye flours at relevant spiking levels were obtained. Thus, reliable results were guaranteed, and the fast and efficient screening for the total ergot alkaloids in rye offers a rapid alternative to the HPLC analysis of the individual compounds. Copyright © 2017 Elsevier B.V. All rights reserved.

[Analysis and evaluation of alkaloids and flavonoids in flower of Sophora flavescens from Shanxi province].

PubMed

Zhang, Huang-Qin; Zhu, Zhen-Hua; Qian, Da-Wei; Weng, Ze-Bin; Guo, Sheng; Duan, Jin-Ao; Lei, Zhen-Hong; Li, An-Ping

2016-12-01

This study intends to explore the potential resource-orientedutilization value of the flower of Sophora flavescents by analyzing alkaloids and flavonoids in the flower of S. flavescens from Shanxi province. This study established a rapid UPLC-TQ-MS/MS method that is used for determination of seven alkaloids and seven flavonoids in the flower of S.flavescens. The different florescences all have the seven detected alkaloids such as cytisine, oxy-matrine, oxy-sophocarpine, sophoridine, N-methylcytisine, matrine, sophocarpine.The total contents of detected alkaloids are as follows: flower buds 1.47%, primal flowers 1.34%, full bloomed flowers 1.17%, faded flowers 1.01%. The top three contents of alkaloids are N-methylcytisine , oxy-sophocarpine and oxymatrine, accounting for about 83% of the total amount of detected alkaloids. All the samples in different florescences have the seven detected flavonoids such as rutin, luteolin, quercetin, isoquercitrin, trifolirhizin, kurarinone, and kushenol I. The total contents of detected alkaloids are as follows: flower buds 495.2 μg•g⁻¹, primal flowers 313.7 μg•g⁻¹, faded flowers 224.2 μg•g⁻¹, full bloomed flowers 193.0 μg•g⁻¹. The content of luteolinis relatively higher than other detected flavonoids, accounting for about 89%-94% of the total amount of detected flavonoids. The results indicated that the flower of S.flavescens could be an important material resource to obtain the resourceful alkaloids. This result can provide scientific basis for resource-oriented utilization and industrial development of the flower of S. flavescens. Copyright© by the Chinese Pharmaceutical Association.

Influence of 7,8-methylenedioxylycoctonine-type alkaloids on the toxic effects associated with ingestion of tall larkspur (Delphinium spp) in cattle.

PubMed

Welch, Kevin D; Green, Benedict T; Gardner, Dale R; Cook, Daniel; Pfister, James A; Stegelmeier, Bryan L; Panter, Kip E; Davis, T Zane

2010-04-01

To determine the contribution of 7,8-methylenedioxylycoctonine (MDL)-type alkaloids to the toxic effects of tall larkspur (Delphinium spp) consumption in cattle. Sixteen 2-year-old Angus steers. Plant material from 3 populations of tall larkspur that contained different concentration ratios of MDL-type-to-N-(methylsuccinimido) anthranoyllycoctonine (MSAL)-type alkaloids was collected, dried, and finely ground. For each plant population, a dose of ground plant material that would elicit similar clinical signs of toxicosis in cattle after oral administration was determined on the basis of the plants' MSAL-type alkaloid concentration. Cattle were treated via oral gavage with single doses of ground plant material from each of the 3 populations of tall larkspur; each animal underwent 1 to 3 single-dose treatments (> or = 21-day interval between treatments). Heart rate was recorded immediately before (baseline) and 24 hours after each larkspur treatment. Tall larkspur populations with a lower MDL-type-to-MSAL-type alkaloid concentration ratio required a greater amount of MSAL-type alkaloids to cause the expected clinical signs of toxicosis (including increased heart rate) in cattle. Results indicated that the typically less toxic MDL-type alkaloids contributed in a significant manner to the toxic effects of tall larkspur in steers. Consequently, both the concentration of MSAL-type alkaloids and the total concentration of MSAL- and MDL-type alkaloids should be determined when assessing the relative toxicity of tall larkspur populations. These results provide valuable information to determine the risk of toxicosis in cattle grazing on tall larkspur-infested rangelands.

Larkspur (Delphinium spp.) poisoning in livestock.

PubMed

Pfister, J A; Gardner, D R; Panter, K E; Manners, G D; Ralphs, M H; Stegelmeier, B L; Schoch, T K

1999-02-01

Larkspurs (Delphinium spp.) are toxic plants that contain numerous diterpenoid alkaloids which occur as one of two structural types: (1) lycotonine, and (2) 7,8-methylenedioxylycoctonine (MDL-type). Among the lycoctonine type alkaloids are three N-(methylsuccinimido) anthranoyllycoctonine (MSAL-type) alkaloids which appear to be most toxic: methyllycaconitine (MLA), 14-deacetylnudicauline (DAN), and nudicauline. An ester function at C-18 is an important structural requirement for toxicity. Intoxication results from neuromuscular paralysis, as nicotinic acetylcholine receptors in the muscle and brain are blocked by toxic alkaloids. Clinical signs include labored breathing, rapid and irregular heartbeat, muscular weakness, and collapse. Toxic alkaloid concentration generally declines in tall larkspurs with maturation, but alkaloid concentration varies over years and from plant to plant, and is of little use for predicting consumption by cattle. Knowledge of toxic alkaloid concentration is valuable for management purposes when cattle begin to eat larkspur. Cattle generally begin consuming tall larkspur after flowering racemes are elongated, and consumption increases as larkspur matures. Weather is also a major factor in cattle consumption, as cattle tend to eat more larkspur during or just after summer storms. Management options that may be useful for livestock producers include conditioning cattle to avoid larkspur (food aversion learning), grazing tall larkspur ranges before flowering (early grazing) and after seed shatter (late grazing), grazing sheep before cattle, herbicidal control of larkspur plants, and drug therapy for intoxicated animals. Some potentially fruitful research avenues include examining alkaloid chemistry in low and plains larkspurs, developing immunologic methods for analyzing larkspur alkaloids, developing drug therapy, and devising grazing regimes specifically for low and plains larkspur.

Oxindole: A chemical prism carrying plethora of therapeutic benefits.

PubMed

Kaur, Maninder; Singh, Manjinder; Chadha, Navriti; Silakari, Om

2016-11-10

Oxindole has emerged as a valuable scaffold in medicinal chemistry possessing diverse range of pharmacological activities. Its value has further been increased by its natural occurrence as alkaloids in variety of plants. It was first extracted from the cat claw's plant Uncaria tomentosa found in the Amazon rainforest and other tropical areas of South and Central America. Traditionally as well as present emerging therapeutic potential of oxindole nucleus has captured the interest of medicinal chemists to synthesize novel oxindole derivatives. In the present review the authors have integrated its chemistry and synthetic strategies developed after 1945. Also the information of naturally occurring oxindole alkaloids has been incorporated. The detailed pharmacological activities including anti-cancer, anti-HIV, antidiabetic, antibacterial, antioxidant, kinase inhibitory, AChE inhibitory, anti-leishmanial, β3 adrenergic receptor agonistic, phosphatase inhibitory, analgesic, spermicidal, vasopressin antagonists, progesterone antagonists, neuroprotection, and NMDA blocker activities of oxindole derivatives alongwith their SAR has also been discussed in detail. Additionally, information regarding the oxindole derivatives in clinical trials has been incorporated. Thus, this review will provide insights for the synthetic as well as medicinal chemist for the designing and synthesis of novel oxindole derivatives with novel improved range of pharmacological implications. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Biochemical changes during the development of witches' broom: the most important disease of cocoa in Brazil caused by Crinipellis perniciosa.

PubMed

Scarpari, L M; Meinhardt, L W; Mazzafera, P; Pomella, A W V; Schiavinato, M A; Cascardo, J C M; Pereira, G A G

2005-03-01

Witches' broom disease (WBD) is caused by the hemibiotrophic basidiomycete fungus Crinipellis perniciosa, which is one of the most important diseases of cocoa in the western hemisphere. In this study, the contents of soluble sugars, amino acids, alkaloids, ethylene, phenolics, tannins, flavonoids, pigments, malondialdehyde (MDA), glycerol, and fatty acids were analysed in cocoa (Theobroma cacao) shoots during the infection and development of WBD. Alterations were observed in the content of soluble sugars (sucrose, glucose, and fructose), asparagine and alkaloids (caffeine and theobromine), ethylene, and tannins. Ethylene and tannins increased prior to symptom development and declined with the death of the infected tissues. Furthermore, MDA and glycerol concentrations were higher in infected tissue than in the controls, while fatty acid composition changed in the infected tissues. Chlorophylls a and b were lower throughout the development of the disease while carotenoids and xanthophylls dropped in the infected tissue by the time of symptom development. These results show co-ordinated biochemical alterations in the infected tissues, indicating major stress responses with the production of ethylene. Ethylene levels are hypothesized to play a key role in broom development. Some of the other biochemical alterations are directly associated with ethylene synthesis and may be important for the modification of its effect on the infected tissues.

Synergistic effects on enantioselectivity of zwitterionic chiral stationary phases for separations of chiral acids, bases, and amino acids by HPLC.

PubMed

Hoffmann, Christian V; Pell, Reinhard; Lämmerhofer, Michael; Lindner, Wolfgang

2008-11-15

In an attempt to overcome the limited applicability scope of earlier proposed Cinchona alkaloid-based chiral weak anion exchangers (WAX) and recently reported aminosulfonic acid-based chiral strong cation exchangers (SCX), which are conceptionally restricted to oppositely charged solutes, their individual chiral selector (SO) subunits have been fused in a combinatorial synthesis approach into single, now zwitterionic, chiral SO motifs. The corresponding zwitterionic ion-exchange-type chiral stationary phases (CSPs) in fact combined the applicability spectra of the parent chiral ion exchangers allowing for enantioseparations of chiral acids and amine-type solutes in liquid chromatography using polar organic mode with largely rivaling separation factors as compared to the parent WAX and SCX CSPs. Furthermore, the application spectrum could be remarkably expanded to various zwitterionic analytes such as alpha- and beta-amino acids and peptides. A set of structurally related yet different CSPs consisting of either a quinine or quinidine alkaloid moiety as anion-exchange subunit and various chiral or achiral amino acids as cation-exchange subunits enabled us to derive structure-enantioselectivity relationships, which clearly provided strong unequivocal evidence for synergistic effects of the two oppositely charged ion-exchange subunits being involved in molecular recognition of zwitterionic analytes by zwitterionic SOs driven by double ionic coordination.

Alkaloid profiles and acetylcholinesterase inhibitory activities of Fumaria species from Bulgaria.

PubMed

Vrancheva, Radka Z; Ivanov, Ivan G; Aneva, Ina Y; Dincheva, Ivayla N; Badjakov, Ilian K; Pavlov, Atanas I

2016-01-01

GC-MS analysis of alkaloid profiles of five Fumaria species, naturally grown in Bulgaria (F. officinalis, F. thuretii, F. kralikii, F. rostellata and F. schrammii) and analysis of acetylcholinesterase inhibitory activity of alkaloid extracts were performed. Fourteen isoquinoline alkaloids were identified, with the principle ones being protopine, cryptopine, sinactine, parfumine, fumariline, fumarophycine, and fumaritine. Protopine contents, defined by HPLC analysis varied between 210.6 ± 8.8 μg/g DW (F. schrammii) and 334.5 ± 7.1 μg/g DW. (F. rostellata). While all of the investigated alkaloid extracts significantly inhibited acetylcholinesterase activity, the F. kralikii demonstrated the highest level of inhibition (IC(50) 0.13 ± 0.01 mg extract/mL).

Green synthesis of magnetite (Fe3O4) nanoparticles using Graptophyllum pictum leaf aqueous extract

NASA Astrophysics Data System (ADS)

Sari, I. P.; Yulizar, Y.

2017-04-01

Magnetite nanoparticles (MNPs) attracted the attention of many researchers due to their unique properties. In this research, nanoscale magnetite particles have been successfully synthesized through an environmentally friendly method using aqueous extract of Graptophyllum pictum leaf (GPLE). In MNPs formation, GPLE acted as a base source and capping agent. Alkaloids in GPLE were hydrolyzed in water and hydroxilated Fe2+ to form Fe3O4 nanoparticles powder through calcination. After the addition of leaf extract, MNPs formation was observed by color change from pale yellow to dark brown. The synthesized nanoparticles were characterized using UV-Vis spectrophotometer, X-Ray diffraction (XRD), and Fourier transform infra red (FTIR) spectroscopy. The results confirmed that MNPs formation indicated the surface plasmon resonance at a maximum wavelength, λmax 291 nm. The average crystallite size is 23.17 nm. The formed MNPs through green synthesis method promise in various medical applications such as drug carrier and targeted therapy.

Total Synthesis of Natural Products Using Hypervalent Iodine Reagents

NASA Astrophysics Data System (ADS)

Maertens, Gaetan; L'homme, Chloe; Canesi, Sylvain

2014-12-01

We present a review of natural product syntheses accomplished in our laboratory during the last five years. Each synthetic route features a phenol dearomatization promoted by an environmentally benign hypervalent iodine reagent. The dearomatizations demonstrate the “aromatic ring umpolung” concept, and involve stereoselective remodeling of the inert unsaturations of a phenol into a highly functionalized key intermediate that may contain a quaternary carbon center and a prochiral dienone system. Several new oxidative strategies were employed, including transpositions (1,3-alkyl shift and Prins-pinacol), a polycyclization, an ipso rearrangement, and direct nucleophilic additions at the phenol para position. Several alkaloids, heterocyclic compounds, and a polycyclic core have been achieved, including sceletenone (a serotonin reuptake inhibitor), acetylaspidoalbidine (an antitumor agent), fortucine (antiviral and antitumor), erysotramidine (curare-like effect), platensimycin (an antibiotic), and the main core of a kaurane diterpene (immunosuppressive agent and stimulator of apoptosis). These concise and in some cases enantioselective syntheses effectively demonstrate the importance of hypervalent iodine reagents in the total synthesis of bioactive natural products.

Discoipyrroles A-D: Isolation, Structure Determination and Synthesis of Potent Migration Inhibitors from Bacillus hunanensis

PubMed Central

Hu, Youcai; Potts, Malia B.; Colosimo, Dominic; Herrera-Herrera, Mireya L.; Legako, Aaron G.; Yousufuddin, Muhammed; White, Michael A.; MacMillan, John B.

2013-01-01

Discoidin domain receptor 2 (DDR2) is a receptor tyrosine kinase involved in a variety of cellular response pathways, including regulation of cell growth, proliferation and motility. Using a newly developed platform to identify the signaling pathway/molecular target of natural products, we identified a family of alkaloid natural products, discoipyrroles A–D (1–4), from Bacillus hunanensis that inhibit the DDR2 signaling pathway. The structure of 1–4, determined by detailed 2D NMR methods and confirmed by X-ray crystallographic analysis has an unusual 3H-benzo[ d]pyrrolo][1,3]oxazine-3,5-dione core. Discoipyrroles A–D potently inhibit DDR2 dependent migration of BR5 fibroblasts and show selective cytotoxicity to DDR2 mutant cell lung cancer cell lines (IC50 120–400 nM). Examination of the biosynthesis has led to the conclusion that the discoipyrroles are formed through a non-enzymatic process, leading to a one-pot total synthesis of 1. PMID:23984625

Concise Total Synthesis of (-)-Affinisine Oxindole, (+)-Isoalstonisine, (+)-Alstofoline, (-)-Macrogentine, (+)-Na -Demethylalstonisine, (-)-Alstonoxine A, and (+)-Alstonisine.

PubMed

Stephen, Michael Rajesh; Rahman, M Toufiqur; Tiruveedhula, V V N Phani Babu; Fonseca, German O; Deschamps, Jeffrey R; Cook, James M

2017-11-07

A highly enantio- and diastereoselective strategy to access any member of the sarpagine/macroline family of oxindole alkaloids via internal asymmetric induction was developed from readily available d-(+)-tryptophan. At the center of this approach was the diastereospecific generation of the spiro[pyrrolidine-3,3'-oxindole] moiety at an early stage via a tert-butyl hypochlorite-promoted oxidative rearrangement of a chiral tetrahydro-β-carboline derivative. This key branching point determined the spatial configuration at the C-7 spiro center to be entirely 7R or 7S. Other key stereospecific processes were the asymmetric Pictet-Spengler reaction and Dieckmann cyclization, which were scalable to the 600 and 150 gram levels, respectively. Execution of this approach resulted in first enantiospecific total synthesis of (+)-isoalstonisine and (-)-macrogentine from the chitosenine series (7R), as well as (+)-alstonisine, (+)-alstofoline, (-)-alstonoxine A and (+)-N a -demethylalstonisine from the alstonisine series (7S). © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Axinellamines as Broad-Spectrum Antibacterial Agents: Scalable Synthesis and Biology

PubMed Central

2015-01-01

Antibiotic-resistant bacteria present an ongoing challenge to both chemists and biologists as they seek novel compounds and modes of action to out-maneuver continually evolving resistance pathways, especially against Gram-negative strains. The dimeric pyrrole–imidazole alkaloids represent a unique marine natural product class with diverse primary biological activity and chemical architecture. This full account traces the strategy used to develop a second-generation route to key spirocycle 9, culminating in a practical synthesis of the axinellamines and enabling their discovery as broad-spectrum antibacterial agents, with promising activity against both Gram-positive and Gram-negative bacteria. While their detailed mode of antibacterial action remains unclear, the axinellamines appear to cause secondary membrane destabilization and impart an aberrant cellular morphology consistent with the inhibition of normal septum formation. This study serves as a rare example of a natural product initially reported to be devoid of biological activity surfacing as an active antibacterial agent with an intriguing mode of action. PMID:25328977

Metabolic engineering of microorganisms for the synthesis of plant natural products.

PubMed

Marienhagen, Jan; Bott, Michael

2013-01-20

Of more than 200,000 plant natural products known to date, many demonstrate important pharmacological activities or are of biotechnological significance. However, isolation from natural sources is usually limited by low abundance and environmental, seasonal as well as regional variation, whereas total chemical synthesis is typically commercially unfeasible considering the complex structures of most plant natural products. With advances in DNA sequencing and recombinant DNA technology many of the biosynthetic pathways responsible for the production of these valuable compounds have been elucidated, offering the opportunity of a functional integration of biosynthetic pathways in suitable microorganisms. This approach offers promise to provide sufficient quantities of the desired plant natural products from inexpensive renewable resources. This review covers recent advancements in the metabolic engineering of microorganisms for the production of plant natural products such as isoprenoids, phenylpropanoids and alkaloids, and highlights general approaches and strategies to gain access to the rich biochemical diversity of plants by employing the biosynthetic power of microorganisms. Copyright © 2012 Elsevier B.V. All rights reserved.

Alkaloids as a source of potential anticholinesterase inhibitors for the treatment of Alzheimer's disease.

PubMed

Konrath, Eduardo Luis; Passos, Carolina dos Santos; Klein, Luiz Carlos; Henriques, Amélia T

2013-12-01

The inhibition of acetylcholinesterase (AChE), the key enzyme in the breakdown of acetylcholine, is currently the main pharmacological strategy available for Alzheimer's disease (AD). In this sense, many alkaloids isolated from natural sources, such as physostigmine, have been long recognized as acetyl- and butyrylcholinesterase (BChE) inhibitors. Since the approval of galantamine for the treatment of AD patients, the search for new anticholinesterase alkaloids has escalated, leading to promising candidates such as huperzine A. This review aims to summarize recent advances in current knowledge on alkaloids as AChE and BChE inhibitors, highlighting structure-activity relationship (SAR) and docking studies. Natural alkaloids belonging to the steroidal/triterpenoidal, quinolizidine, isoquinoline and indole classes, mainly distributed within Buxaceae, Amaryllidaceae and Lycopodiaceae, are considered important sources of alkaloids with anti-enzymatic properties. Investigations into the possible SARs for some active compounds are based on molecular modelling studies, predicting the mode of interaction of the molecules with amino acid residues in the active site of the enzymes. Following this view, an increasing interest in achieving more potent and effective analogues makes alkaloids good chemical templates for the development of new cholinesterase inhibitors. The anticholinesterase activity of alkaloids, together with their structural diversity and physicochemical properties, makes them good candidate agents for the treatment of AD. © 2013 Royal Pharmaceutical Society.

Enrichment and purification of six Aconitum alkaloids from Aconiti kusnezoffii radix by macroporous resins and quantification by HPLC-MS.

PubMed

Liu, Jingjing; Li, Qing; Liu, Ran; Yin, Yidi; Chen, Xiaohui; Bi, Kaishun

2014-06-01

Aconitine, mesaconitine, hypaconitine, benzoylaconine, benzoylmesaconine and benzoylhypaconine are six main Aconitum alkaloids from traditional Chinese medicine, Aconiti kusnezoffii radix, which possess highly bioactive as well as highly toxic character for medicinal use. In the present study, for the purpose of better utilizing the toxic herbal material, the performance characteristics of NKA-II, D101, X-5, AB-8, S-8, HPD722 and HPD750 macroporous resins for the enrichment and purification of these six Aconitum alkaloids were critically evaluated. Results showed that NKA-II offered the best adsorption and desorption capacities for six Aconitum alkaloids among the seven macroporous resins tested, which were affected significantly by the pH value. Subsequently, dynamic adsorption and desorption experiments had been carried out with the column packed by NKA-II resin to optimize the separation process of six Aconitum alkaloids. After one run treatment with NKA-II resin, the content of total six Aconitum alkaloids were increased from 5.87% to 60.3%, the recovery was 75.8%. Meanwhile, a validated HPLC-MS method had been developed to qualitative and quantitative these six Aconitum alkaloids. This method would provide scientific references to the large-scale production of six Aconitum alkaloids from Aconiti kusnezoffii radix or other plants and might also expand the secure application of these highly toxic components for pharmacy. Copyright © 2014 Elsevier B.V. All rights reserved.

A new benzylisoquinoline alkaloid from Leontice altaica.

PubMed

Jenis, Janar; Nugroho, Alfarius Eko; Hashimoto, Akiyo; Deguchi, Jun; Hirasawa, Yusuke; Wong, Chin Piow; Kaneda, Toshio; Shirota, Osamu; Morita, Hiroshi

2015-02-01

A new benzylisoquinoline alkaloid, lincangenine-4-β-D-glucopyranoside (1), has been isolated from the roots of Leontice altaica, together with 5 known alkaloids. Its structure was elucidated on the basis of 1D and 2D NMR data, and chemical means.

Actions of Piperidine Alkaloid Teratogens at Fetal Nicotinic Acetylcholine Receptors.

USDA-ARS?s Scientific Manuscript database

Teratogenic alkaloids are found in many species of plants including Conium maculatum L., Nicotiana glauca, Nicotiana tabaccum, and multiple Lupinus spp. Fetal musculoskeletal defects produced by alkaloids from these plants include arthrogyropisis, scoliosis, torticollis, kyposis, lordosis, and clef...

Structure-Activity Relationship of Benzophenanthridine Alkaloids from Zanthoxylum rhoifolium Having Antimicrobial Activity

PubMed Central

Tavares, Luciana de C.; Zanon, Graciane; Weber, Andréia D.; Neto, Alexandre T.; Mostardeiro, Clarice P.; Da Cruz, Ivana B. M.; Oliveira, Raul M.; Ilha, Vinicius; Dalcol, Ionara I.; Morel, Ademir F.

2014-01-01

Zanthoxylum rhoifolium (Rutaceae) is a plant alkaloid that grows in South America and has been used in Brazilian traditional medicine for the treatment of different health problems. The present study was designed to evaluate the antimicrobial activity of the steam bark crude methanol extract, fractions, and pure alkaloids of Z. rhoifolium. Its stem bark extracts exhibited a broad spectrum of antimicrobial activity, ranging from 12.5 to 100 µg/mL using bioautography method, and from 125 to 500 µg/mL in the microdilution bioassay. From the dichloromethane basic fraction, three furoquinoline alkaloids (1–3), and nine benzophenanthridine alkaloids (4–12) were isolated and the antimicrobial activity of the benzophenanthridine alkaloids is discussed in terms of structure-activity relationships. The alkaloid with the widest spectrum of activity was chelerythrine (10), followed by avicine (12) and dihydrochelerythrine (4). The minimal inhibitory concentrations of chelerythrine, of 1.50 µg/mL for all bacteria tested, and between 3.12 and 6.25 µg/mL for the yeast tested, show this compound to be a more powerful antimicrobial agent when compared with the other active alkaloids isolated from Z. rhoifolium. To verify the potential importance of the methylenedioxy group (ring A) of these alkaloids, chelerythrine was selected to represent the remainder of the benzophenanthridine alkaloids isolated in this work and was subjected to a demethylation reaction giving derivative 14. Compared to chelerythrine, the derivative (14) was less active against the tested bacteria and fungi. Kinetic measurements of the bacteriolytic activities of chelerythrine against the bacteria Bacillus subtilis (Gram-positive) and Escherichia coli (Gram-negative) were determined by optical density based on real time assay, suggesting that its mechanism of action is not bacteriolytic. The present study did not detect hemolytic effects of chelerythrine on erythrocytes and found a protective effect considering the decrease in TBARS and AOPP (advanced oxidized protein products) levels when compared to the control group. PMID:24824737

Plant-Symbiotic Fungi as Chemical Engineers: Multi-Genome Analysis of the Clavicipitaceae Reveals Dynamics of Alkaloid Loci

PubMed Central

Schardl, Christopher L.; Young, Carolyn A.; Hesse, Uljana; Amyotte, Stefan G.; Andreeva, Kalina; Calie, Patrick J.; Fleetwood, Damien J.; Haws, David C.; Moore, Neil; Oeser, Birgitt; Panaccione, Daniel G.; Schweri, Kathryn K.; Voisey, Christine R.; Farman, Mark L.; Jaromczyk, Jerzy W.; Roe, Bruce A.; O'Sullivan, Donal M.; Scott, Barry; Tudzynski, Paul; An, Zhiqiang; Arnaoudova, Elissaveta G.; Bullock, Charles T.; Charlton, Nikki D.; Chen, Li; Cox, Murray; Dinkins, Randy D.; Florea, Simona; Glenn, Anthony E.; Gordon, Anna; Güldener, Ulrich; Harris, Daniel R.; Hollin, Walter; Jaromczyk, Jolanta; Johnson, Richard D.; Khan, Anar K.; Leistner, Eckhard; Leuchtmann, Adrian; Li, Chunjie; Liu, JinGe; Liu, Jinze; Liu, Miao; Mace, Wade; Machado, Caroline; Nagabhyru, Padmaja; Pan, Juan; Schmid, Jan; Sugawara, Koya; Steiner, Ulrike; Takach, Johanna E.; Tanaka, Eiji; Webb, Jennifer S.; Wilson, Ella V.; Wiseman, Jennifer L.; Yoshida, Ruriko; Zeng, Zheng

2013-01-01

The fungal family Clavicipitaceae includes plant symbionts and parasites that produce several psychoactive and bioprotective alkaloids. The family includes grass symbionts in the epichloae clade (Epichloë and Neotyphodium species), which are extraordinarily diverse both in their host interactions and in their alkaloid profiles. Epichloae produce alkaloids of four distinct classes, all of which deter insects, and some—including the infamous ergot alkaloids—have potent effects on mammals. The exceptional chemotypic diversity of the epichloae may relate to their broad range of host interactions, whereby some are pathogenic and contagious, others are mutualistic and vertically transmitted (seed-borne), and still others vary in pathogenic or mutualistic behavior. We profiled the alkaloids and sequenced the genomes of 10 epichloae, three ergot fungi (Claviceps species), a morning-glory symbiont (Periglandula ipomoeae), and a bamboo pathogen (Aciculosporium take), and compared the gene clusters for four classes of alkaloids. Results indicated a strong tendency for alkaloid loci to have conserved cores that specify the skeleton structures and peripheral genes that determine chemical variations that are known to affect their pharmacological specificities. Generally, gene locations in cluster peripheries positioned them near to transposon-derived, AT-rich repeat blocks, which were probably involved in gene losses, duplications, and neofunctionalizations. The alkaloid loci in the epichloae had unusual structures riddled with large, complex, and dynamic repeat blocks. This feature was not reflective of overall differences in repeat contents in the genomes, nor was it characteristic of most other specialized metabolism loci. The organization and dynamics of alkaloid loci and abundant repeat blocks in the epichloae suggested that these fungi are under selection for alkaloid diversification. We suggest that such selection is related to the variable life histories of the epichloae, their protective roles as symbionts, and their associations with the highly speciose and ecologically diverse cool-season grasses. PMID:23468653

An efficient and target-oriented sample enrichment method for preparative separation of minor alkaloids by pH-zone-refining counter-current chromatography.

PubMed

Feng, Rui-Hong; Hou, Jin-Jun; Zhang, Yi-Bei; Pan, Hui-Qin; Yang, Wenzhi; Qi, Peng; Yao, Shuai; Cai, Lu-Ying; Yang, Min; Jiang, Bao-Hong; Liu, Xuan; Wu, Wan-Ying; Guo, De-An

2015-08-28

An efficient and target-oriented sample enrichment method was established to increase the content of the minor alkaloids in crude extract by using the corresponding two-phase solvent system applied in pH-zone-refining counter-current chromatography. The enrichment and separation of seven minor indole alkaloids from Uncaria rhynchophylla (Miq.) Miq. ex Havil(UR) were selected as an example to show the advantage of this method. An optimized two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (3:7:1:9, v/v) was used in this study, where triethylamine (TEA) as the retainer and hydrochloric acid (HCl) as the eluter were added at the equimolar of 10mM. Crude alkaloids of UR dissolved in the corresponding upper phase (containing 10mM TEA) were extracted twice with lower phase (containing 10mM TEA) and lower phase (containing 10mM HCl), respectively, the second lower phase extract was subjected to pH-zone-refining CCC separation after alkalization and desalination. Finally, from 10g of crude alkaloids, 4g of refined alkaloids was obtained and the total content of seven target indole alkaloids was increased from 4.64% to 15.78%. Seven indole alkaloids, including 54mg isocorynoxeine, 21mg corynoxeine, 46mg isorhynchophylline, 35mg rhynchophylline, 65mg hirsutine, 51mg hirsuteine and 27mg geissoschizine methylether were all simultaneously separated from 2.5g of refined alkaloids, with the purity of 86.4%, 97.5%, 90.3%, 92.1%, 98.5%, 92.3%, and 92.8%, respectively. The total content and purities of the seven minor indole alkaloids were tested by HPLC and their chemical structures were elucidated by ESI-HRMS and (1)H NMR. Copyright © 2015 Elsevier B.V. All rights reserved.

Development and validation of a rapid capillary zone electrophoresis method for the determination of aconite alkaloids in aconite roots.

PubMed

Song, Jing-Zheng; Han, Quan-Bin; Qiao, Chun-Feng; But, Paul Pui-Hay; Xu, Hong-Xi

2010-01-01

Aconites, with aconite alkaloids as the major therapeutic and toxic components, are used for the treatment of analgesic, antirheumatic and neurological symptoms. Quantification of the aconite alkaloids is important for the quality control of aconite-containing drugs. To establish a validated capillary zone electrophoresis (CZE) method for the simultaneous determination of six major alkaloids, namely aconitine, mesaconitine, hypaconitine, benzoylaconine, benzoylmesaconine and benzoylhypaconine, in crude and processed aconite roots. The CZE method was optimised and validated using a stability-indicating method. The optimised running buffer was a mixture of 200 mm Tris, 150 mm perchloric acid and 40% 1,4-dioxane (pH 7.8) with the capillary thermostated at 25 degrees C. Using the optimised method, six aconite alkaloids were well separated. The established method showed good precision, accuracy and recovery. Contents of these alkaloids in crude and processed aconites were determined and it was observed that the levels of individual alkaloids varied between samples. The developed CZE method was reliable for the quality control of aconites contained in herbal medicines. The method could also be used as an approach for toxicological studies.

Genetics, Genomics and Evolution of Ergot Alkaloid Diversity

PubMed Central

Young, Carolyn A.; Schardl, Christopher L.; Panaccione, Daniel G.; Florea, Simona; Takach, Johanna E.; Charlton, Nikki D.; Moore, Neil; Webb, Jennifer S.; Jaromczyk, Jolanta

2015-01-01

The ergot alkaloid biosynthesis system has become an excellent model to study evolutionary diversification of specialized (secondary) metabolites. This is a very diverse class of alkaloids with various neurotropic activities, produced by fungi in several orders of the phylum Ascomycota, including plant pathogens and protective plant symbionts in the family Clavicipitaceae. Results of comparative genomics and phylogenomic analyses reveal multiple examples of three evolutionary processes that have generated ergot-alkaloid diversity: gene gains, gene losses, and gene sequence changes that have led to altered substrates or product specificities of the enzymes that they encode (neofunctionalization). The chromosome ends appear to be particularly effective engines for gene gains, losses and rearrangements, but not necessarily for neofunctionalization. Changes in gene expression could lead to accumulation of various pathway intermediates and affect levels of different ergot alkaloids. Genetic alterations associated with interspecific hybrids of Epichloë species suggest that such variation is also selectively favored. The huge structural diversity of ergot alkaloids probably represents adaptations to a wide variety of ecological situations by affecting the biological spectra and mechanisms of defense against herbivores, as evidenced by the diverse pharmacological effects of ergot alkaloids used in medicine. PMID:25875294

Measurement of antiphotooxidative properties of isoquinoline alkaloids using transient thermal lens spectroscopy

NASA Astrophysics Data System (ADS)

Hung, J.; Castillo, J.; Laboren, I.; Rodríguez, M.; Hassegawa, M.

2005-11-01

The antiphotooxidative properties of boldine and chloride berberine were studied by time-resolved thermal lensing technique. These compounds belong to isoquinoline alkaloids possessing interesting biological activity (e.g. antibacterial, antimalarial, antitumor). Antiphotooxidative properties of the alkaloids were studied by mechanism of energy transference between powerful oxidizing agents such as singlet oxygen. Singlet oxygen was produced by energy transfer from chlorophyll-sensitized photooxidation of oil by exposure of high light intensities like laser. The lifetimes of singlet oxygen in dimethylsulfoxide, methanol and water were determined to confirm the assignment of the singlet molecular oxygen O II (1Δ g) in the experiments. In order to understand the effect of the alkaloids on active oxygen species, we carried out in detail an analysis of the thermal lensing signal. It was shown that the alkaloids can act as quenchers of singlet oxygen. To demonstrate the ability of the alkaloids to act efficient singlet oxygen acceptors, we have measured the fluorescence spectra of the studied alkaloids in the presence and in the absence of singlet oxygen. The antiphotooxidative activity of boldine and chloride berberine can be explained by the ability to quench singlet oxygen.

Trichloroacetimidates as Alkylating Reagents and Their Application in the Synthesis of Pyrroloindoline Natural Products and Synthesis of Small Molecule Inhibitors of Src Homology 2 Domain-Containing Inositol Phosphatase (SHIP)

NASA Astrophysics Data System (ADS)

Adhikari, Arijit A.

Trichloroacetimidates are known to be excellent alkylating agents when activated by a catalytic amount of a Bronsted or Lewis acid. Work described herein involved taking advantage of the favorable reactivity of trichloroacetimidates to establish several different synthetic protocols, including the application of these reagents in the synthesis of pyrroloindoline based natural products, 3,3'-disubstituted indolenines and benzylic trichloroacetamides. Initial investigations on the utilization of the reactivity of trichloroacetimidates found that diphenylmethyl trichloroacetimidate, which is a precursor to a highly stabilized carbocation, undergoes facile displacement with carboxylic acids providing the ester product without the need of any exogenous catalyst. Both hindered and unhindered carboxylic acids were esterified with high yields, with no preference for aromatic or aliphatic carboxylic acids. Carboxylic acids with unprotected hydroxyl groups or beta-lactam rings were esterified efficiently. Substrates that are highly prone to elimination or retro-aldol were also esterified in high yields. Carboxylic acids with highly enolizable alpha-stereocenters were esterified without any racemization. Mechanistic studies indicate that the carboxylic acid substrate itself is acidic enough to be effective at promoting the esterification reaction. During our studies on esterification with imidates it was found that these imidates also showed a tendency to undergo rearrangement to the corresponding trichloroacetamides. Two different sets of conditions, thermal and Lewis acid catalyzed, were established which provided these rearranged products with high yields. Various benzylic trichloroacetimidates were shown to undergo these transformations under the established conditions. Based on the observations discussed in this work a cationic mechanism is proposed. After the preliminary studies on alkylation of benzylic trichloroacetimidate with different nucleophiles, this chemistry was applied towards the synthesis of natural products and their analogs. The pyrroloindoline ring system is found in many alkaloids and cyclic peptides which mainly differ in the substitution at the C3a position. To provide rapid access to these natural products a diversity-oriented strategy was established via displacement of C3a-trichloroacetimidate pyrroloindoline. Carbon, oxygen, sulfur and nitrogen nucleophiles were all shown to undergo substitution reactions with these trichloroacetimidates in the presence of a Lewis acid catalyst. In order to demonstrate the utility of this new method it was applied towards the synthesis of arundinine and a formal synthesis of psychotriasine. Current investigations involve the application of this method towards the synthesis of a complex pyrroloindoline natural product kapakahine C and the progress made therein has been discussed. The reactivity of trichloroacetimidates was also investigated for the selective C3-alkylation of 2,3-disubstituted indoles to provide indolenines. Indolenines serve as useful intermediates in the synthesis of many complex alkaloids. Different benzylic and allylic trichloroacetimidates were shown to provide 3,3'-disubstituted indolenines with high yields in the presence of catalytic amounts of Lewis acids. Various substituted indoles were evaluated under these reaction conditions. This methodology was also applied towards the synthesis of the core tetracyclic ring system found in communesin natural products. In addition to the above work, synthesis of small molecule inhibitors of Src Homology 2 Domain-Containing Inositol Phosphatase (SHIP) has also been described. Aberrations in the phosphoinositide 3-kinase (PI3K) cellular signaling pathway can lead to diseased cellular states like cancer. Herein we have reported stereoselective synthesis of two quinoline based small molecule SHIP inhibitors. The lead compounds and their analogs were tested for their activities against SHIP by Malachite green assay and the discoveries made therein are discussed. In addition to this synthesis of a tryptamine based SHIP inhibitor has also been reported.

Bovine lateral saphenous veins exposed to ergopeptine alkaloids do not relax

USDA-ARS?s Scientific Manuscript database

The ergot alkaloid ergovaline has demonstrated a persistent and sustained contractile response in several different vascular models. It was hypothesized that different alkaloids isolated from tall fescue (Lolium arundinaceum) will contribute to this contractile response differently. The objective wa...

Bovine lateral saphenous veins exposed to ergopeptine alkaloids do not relax

USDA-ARS?s Scientific Manuscript database

The ergot alkaloid, ergovaline has demonstrated a persistent binding and sustained contractile response in several vascular models. It was hypothesized that different alkaloids isolated from tall fescue (Lolium arundinaceum) will contribute to this response differently. The objective was to compare ...

Tall fescue seed extraction and partial purification of ergot alkaloids

USDA-ARS?s Scientific Manuscript database

Many substances in the tall fescue/endophyte association (Schedonorus arundinaceus/Epichloë coenophiala) have biological activity. Of these compounds only the ergot alkaloids are known to have significant mammalian toxicity and the predominant ergot alkaloids are ergovaline and ergovalinine. Because...

Bisindole alkaloids from Tabernaemontana corymbosa.

PubMed

Zhang, Bing-Jie; Lu, Jing-Song; Bao, Mei-Fen; Zhong, Xiu-Hong; Ni, Ling; Wu, Jing; Cai, Xiang-Hai

2018-05-11

Continued study in bioactive monoterpenoid alkaloids led to the isolation of nine undescribed alkaloids, taberyunines A-I, together with 32 known ones from the aerial parts of Tabernaemontana corymbosa Roxb. ex Wall (Apocynaceae). Among the undescribed alkaloids, taberyunines A-G and H-I were assigned to Aspidosperma-Aspidosperma and Vobasinyl-Ibogan type bisindoles, respectively. Their structures were determined by NMR spectra, MS data and X-ray diffraction. Taberyunine B showed significant cytotoxicity against three cancer cell lines. Copyright © 2018 Elsevier Ltd. All rights reserved.

Detection of Pyrrolizidine Alkaloid DNA Adducts in Livers of Cattle Poisoned with Heliotropium europaeum.

PubMed

Fu, Peter P; Xia, Qingsu; He, Xiaobo; Barel, Shimon; Edery, Nir; Beland, Frederick A; Shimshoni, Jakob A

2017-03-20

Pyrrolizidine alkaloids are among the most common poisonous plants affecting livestock, wildlife, and humans. Exposure of humans and livestock to toxic pyrrolizidine alkaloids through the intake of contaminated food and feed may result in poisoning, leading to devastating epidemics. During February 2014, 73 mixed breed female beef cows from the Galilee region of Israel were accidently fed pyrrolizidine alkaloid contaminated hay for 42 days, resulting in the sudden death of 24 cows over a period of 63 days. The remaining cows were slaughtered 2.5 months after the last ingestion of the contaminated hay. In this study, we report the histopathological analysis of the livers from five of the slaughtered cows and quantitation of pyrrolizidine alkaloid-derived DNA adducts from their livers and three livers of control cows fed with feed free of weeds producing pyrrolizidine alkaloids. Histopathological examination revealed that the five cows suffered from varying degrees of bile duct proliferation, fibrosis, and megalocytosis. Selected reaction monitoring HPLC-ES-MS/MS analysis indicated that (±)-6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP)-derived DNA adducts were formed in all five livers. The livers from the three control cows did not have any liver damage nor any indication of DHP-DNA adduct formed. These results confirm that the toxicity observed in these cattle was caused by pyrrolizidine alkaloid poisoning and that pyrrolizidine alkaloid-derived DNA adducts could still be detected and quantified in the livers of the chronically poisoned cows 2.5 months after their last exposure to the contaminated feed, suggesting that DHP-derived DNA adducts can serve as biomarkers for pyrrolizidine alkaloid exposure and poisoning.

Fire ant alarm pheromone and venom alkaloids act in concert to attract parasitic phorid flies, Pseudacteon spp.

PubMed

Sharma, Kavita R; Fadamiro, Henry Y

2013-11-01

Pseudacteon tricuspis, Pseudacteon obtusus and Pseudacteon curvatus are three species of parasitic phorid flies (Diptera: Phoridae), which have been introduced as classical biological control agents of imported, Solenopsis fire ants (Hymenoptera: Formicidae) in the southern USA. Previous studies demonstrated the behavioral response of P. tricuspis to the venom alkaloids and alarm pheromone of the fire ant, S. invicta. In the present study, we compared the responses of P. tricuspis, P. obtusus and P. curvatus to Solenopsis invicta alarm pheromone, venom alkaloids, or a mixture of both chemicals in four-choice olfactometer bioassays. The main hypothesis tested was that the fire ant alarm pheromone and venom alkaloids act in concert to attract Pseudacteon phorid flies. Both sexes of all three Pseudacteon species were attracted to low doses of the fire ant alarm pheromone or venom alkaloids (i.e. 1 ant worker equivalent) alone. However, the flies were significantly more attracted to a mixture of both chemicals (i.e., 1:1 mixture of alarm pheromone+alkaloids) than to either chemical. The results suggest an additive rather than a synergistic effect of combining both chemicals. Comparing the fly species, P. tricuspis showed relatively greater attraction to cis alkaloids, whereas the alkaloid mixture (cis+trans) was preferred by P. obtusus and P. curvatus. In general, no key sexual differences were recorded, although females of P. tricuspis and P. obtusus showed slightly higher response than conspecific males to lower doses of the alarm pheromone. The ecological significance of these findings is discussed, and a host location model is proposed for parasitic phorid flies involving the use of fire ant alarm pheromone and venom alkaloids as long range and short range attractants, respectively. Published by Elsevier Ltd.

Evidence for an ergot alkaloid gene cluster in Claviceps purpurea.

PubMed

Tudzynski, P; Hölter, K; Correia, T; Arntz, C; Grammel, N; Keller, U

1999-02-01

A gene (cpd1) coding for the dimethylallyltryptophan synthase (DMATS) that catalyzes the first specific step in the biosynthesis of ergot alkaloids, was cloned from a strain of Claviceps purpurea that produces alkaloids in axenic culture. The derived gene product (CPD1) shows only 70% similarity to the corresponding gene previously isolated from Claviceps strain ATCC 26245, which is likely to be an isolate of C. fusiformis. Therefore, the related cpd1 most probably represents the first C. purpurea gene coding for an enzymatic step of the alkaloid biosynthetic pathway to be cloned. Analysis of the 3'-flanking region of cpd1 revealed a second, closely linked ergot alkaloid biosynthetic gene named cpps1, which codes for a 356-kDa polypeptide showing significant similarity to fungal modular peptide synthetases. The protein contains three amino acid-activating modules, and in the second module a sequence is found which matches that of an internal peptide (17 amino acids in length) obtained from a tryptic digest of lysergyl peptide synthetase 1 (LPS1) of C. purpurea, thus confirming that cpps1 encodes LPS1. LPS1 activates the three amino acids of the peptide portion of ergot peptide alkaloids during D-lysergyl peptide assembly. Chromosome walking revealed the presence of additional genes upstream of cpd1 which are probably also involved in ergot alkaloid biosynthesis: cpox1 probably codes for an FAD-dependent oxidoreductase (which could represent the chanoclavine cyclase), and a second putative oxidoreductase gene, cpox2, is closely linked to it in inverse orientation. RT-PCR experiments confirm that all four genes are expressed under conditions of peptide alkaloid biosynthesis. These results strongly suggest that at least some genes of ergot alkaloid biosynthesis in C. purpurea are clustered, opening the way for a detailed molecular genetic analysis of the pathway.

Enhancing Tropane Alkaloid Production Based on the Functional Identification of Tropine-Forming Reductase in Scopolia lurida, a Tibetan Medicinal Plant.

PubMed

Zhao, Kaihui; Zeng, Junlan; Zhao, Tengfei; Zhang, Haoxing; Qiu, Fei; Yang, Chunxian; Zeng, Lingjiang; Liu, Xiaoqiang; Chen, Min; Lan, Xiaozhong; Liao, Zhihua

2017-01-01

Scopolia lurida , a native herbal plant species in Tibet, is one of the most effective producers of tropane alkaloids. However, the tropane alkaloid biosynthesis in this plant species of interest has yet to be studied at the molecular, biochemical, and biotechnological level. Here, we report on the isolation and characterization of a putative short chain dehydrogenase (SDR) gene. Sequence analysis showed that SlTRI belonged to the SDR family. Phylogenetic analysis revealed that SlTRI was clustered with the tropine-forming reductases. SlTRI and the other TA-biosynthesis genes, including putrescine N-methyltransferase ( SlPMT ) and hyoscyamine 6 β -hydroxylase ( SlH6H ), were preferably or exclusively expressed in the S . lurida roots. The tissue profile of SlTRI suggested that this gene might be involved in tropane alkaloid biosynthesis. By using GC-MS, SlTRI was shown to catalyze the tropinone reduction to yield tropine, the key intermediate of tropane alkaloids. With the purified recombinant SlTRI from Escherichia coli , an enzymatic assay was carried out; its result indicated that SlTRI was a tropine-forming reductase. Finally, the role of SlTRI in promoting the tropane alkaloid biosynthesis was confirmed through metabolic engineering in S . lurida . Specifically, hairy root cultures of S . lurida were established to investigate the effects of SlTRI overexpression on tropane alkaloid accumulation. In the SlTRI -overexpressing root cultures, the hyoscyamine contents were 1.7- to 2.9-fold higher than those in control while their corresponding scopolamine contents were likewise elevated. In summary, this functional identification of SlTRI has provided for a better understanding of tropane alkaloid biosynthesis. It also provides a candidate gene for enhancing tropane alkaloid biosynthesis in S . lurida via metabolic engineering.

Enhancing Tropane Alkaloid Production Based on the Functional Identification of Tropine-Forming Reductase in Scopolia lurida, a Tibetan Medicinal Plant

PubMed Central

Zhao, Kaihui; Zeng, Junlan; Zhao, Tengfei; Zhang, Haoxing; Qiu, Fei; Yang, Chunxian; Zeng, Lingjiang; Liu, Xiaoqiang; Chen, Min; Lan, Xiaozhong; Liao, Zhihua

2017-01-01

Scopolia lurida, a native herbal plant species in Tibet, is one of the most effective producers of tropane alkaloids. However, the tropane alkaloid biosynthesis in this plant species of interest has yet to be studied at the molecular, biochemical, and biotechnological level. Here, we report on the isolation and characterization of a putative short chain dehydrogenase (SDR) gene. Sequence analysis showed that SlTRI belonged to the SDR family. Phylogenetic analysis revealed that SlTRI was clustered with the tropine-forming reductases. SlTRI and the other TA-biosynthesis genes, including putrescine N-methyltransferase (SlPMT) and hyoscyamine 6β-hydroxylase (SlH6H), were preferably or exclusively expressed in the S. lurida roots. The tissue profile of SlTRI suggested that this gene might be involved in tropane alkaloid biosynthesis. By using GC-MS, SlTRI was shown to catalyze the tropinone reduction to yield tropine, the key intermediate of tropane alkaloids. With the purified recombinant SlTRI from Escherichia coli, an enzymatic assay was carried out; its result indicated that SlTRI was a tropine-forming reductase. Finally, the role of SlTRI in promoting the tropane alkaloid biosynthesis was confirmed through metabolic engineering in S. lurida. Specifically, hairy root cultures of S. lurida were established to investigate the effects of SlTRI overexpression on tropane alkaloid accumulation. In the SlTRI-overexpressing root cultures, the hyoscyamine contents were 1.7- to 2.9-fold higher than those in control while their corresponding scopolamine contents were likewise elevated. In summary, this functional identification of SlTRI has provided for a better understanding of tropane alkaloid biosynthesis. It also provides a candidate gene for enhancing tropane alkaloid biosynthesis in S. lurida via metabolic engineering. PMID:29085381

Proapoptotic activity of Ukrain is based on Chelidonium majus L. alkaloids and mediated via a mitochondrial death pathway

PubMed Central

Habermehl, Daniel; Kammerer, Bernd; Handrick, René; Eldh, Therese; Gruber, Charlotte; Cordes, Nils; Daniel, Peter T; Plasswilm, Ludwig; Bamberg, Michael; Belka, Claus; Jendrossek, Verena

2006-01-01

Background The anticancer drug Ukrain (NSC-631570) which has been specified by the manufacturer as semisynthetic derivative of the Chelidonium majus L. alkaloid chelidonine and the alkylans thiotepa was reported to exert selective cytotoxic effects on human tumour cell lines in vitro. Few clinical trials suggest beneficial effects in the treatment of human cancer. Aim of the present study was to elucidate the importance of apoptosis induction for the antineoplastic activity of Ukrain, to define the molecular mechanism of its cytotoxic effects and to identify its active constituents by mass spectrometry. Methods Apoptosis induction was analysed in a Jurkat T-lymphoma cell model by fluorescence microscopy (chromatin condensation and nuclear fragmentation), flow cytometry (cellular shrinkage, depolarisation of the mitochondrial membrane potential, caspase-activation) and Western blot analysis (caspase-activation). Composition of Ukrain was analysed by mass spectrometry and LC-MS coupling. Results Ukrain turned out to be a potent inducer of apoptosis. Mechanistic analyses revealed that Ukrain induced depolarisation of the mitochondrial membrane potential and activation of caspases. Lack of caspase-8, expression of cFLIP-L and resistance to death receptor ligand-induced apoptosis failed to inhibit Ukrain-induced apoptosis while lack of FADD caused a delay but not abrogation of Ukrain-induced apoptosis pointing to a death receptor independent signalling pathway. In contrast, the broad spectrum caspase-inhibitor zVAD-fmk blocked Ukrain-induced cell death. Moreover, over-expression of Bcl-2 or Bcl-xL and expression of dominant negative caspase-9 partially reduced Ukrain-induced apoptosis pointing to Bcl-2 controlled mitochondrial signalling events. However, mass spectrometric analysis of Ukrain failed to detect the suggested trimeric chelidonine thiophosphortriamide or putative dimeric or monomeric chelidonine thiophosphortriamide intermediates from chemical synthesis. Instead, the Chelidonium majus L. alkaloids chelidonine, sanguinarine, chelerythrine, protopine and allocryptopine were identified as major components of Ukrain. Apart from sanguinarine and chelerythrine, chelidonine turned out to be a potent inducer of apoptosis triggering cell death at concentrations of 0.001 mM, while protopine and allocryptopine were less effective. Similar to Ukrain, apoptosis signalling of chelidonine involved Bcl-2 controlled mitochondrial alterations and caspase-activation. Conclusion The potent proapoptotic effects of Ukrain are not due to the suggested "Ukrain-molecule" but to the cytotoxic efficacy of Chelidonium majus L. alkaloids including chelidonine. PMID:16417634

Gastric and duodenal antiulcer activity of alkaloids: a review.

PubMed

de Sousa Falcão, Heloina; Leite, Jacqueline Alves; Barbosa-Filho, José Maria; de Athayde-Filho, Petrônio Filgueiras; de Oliveira Chaves, Maria Célia; Moura, Marcelo Dantas; Ferreira, Anderson Luiz; de Almeida, Ana Beatriz Albino; Souza-Brito, Alba Regina Monteiro; de Fátima Formiga Melo Diniz, Margareth; Batista, Leônia Maria

2008-12-17

Peptic ulcer disease is a deep gastrointestinal erosion disorder that involves the entire mucosal thickness and can even penetrate the muscular mucosa. Numerous natural products have been evaluated as therapeutics for the treatment of a variety of diseases, including this one. These products usually derive from plant and animal sources that contain active constituents such as alkaloids, flavonoids, terpenoids, tannins and others. The alkaloids are natural nitrogen-containing secondary metabolites mostly derived from amino acids and found in about 20% of plants. There has been considerable pharmacological research into the antiulcer activity of these compounds. In this work we review the literature on alkaloids with antiulcer activity, which covers about sixty-one alkaloids, fifty-five of which have activity against this disease when induced in animals.

Identification of the quinolizidine alkaloids in Sophora leachiana

USDA-ARS?s Scientific Manuscript database

Sophora is a diverse genus representing herbs, shrubs, and trees that occurs throughout the world, primarily in the northern hemisphere. Sophora species contain a variety of quinolizidine alkaloids that are toxic and potentially teratogenic. However, there are no previous reports on the alkaloid c...

21 CFR 119.1 - Dietary supplements containing ephedrine alkaloids.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Dietary supplements containing ephedrine alkaloids... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION DIETARY SUPPLEMENTS THAT PRESENT A SIGNIFICANT OR UNREASONABLE RISK § 119.1 Dietary supplements containing ephedrine alkaloids. Dietary supplements containing...

21 CFR 119.1 - Dietary supplements containing ephedrine alkaloids.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Dietary supplements containing ephedrine alkaloids... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION DIETARY SUPPLEMENTS THAT PRESENT A SIGNIFICANT OR UNREASONABLE RISK § 119.1 Dietary supplements containing ephedrine alkaloids. Dietary supplements containing...

21 CFR 119.1 - Dietary supplements containing ephedrine alkaloids.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Dietary supplements containing ephedrine alkaloids... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION DIETARY SUPPLEMENTS THAT PRESENT A SIGNIFICANT OR UNREASONABLE RISK § 119.1 Dietary supplements containing ephedrine alkaloids. Dietary supplements containing...

21 CFR 119.1 - Dietary supplements containing ephedrine alkaloids.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Dietary supplements containing ephedrine alkaloids... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION DIETARY SUPPLEMENTS THAT PRESENT A SIGNIFICANT OR UNREASONABLE RISK § 119.1 Dietary supplements containing ephedrine alkaloids. Dietary supplements containing...

Four alkaloids from Annona cherimola.

PubMed

Chen, C Y; Chang, F R; Pan, W B; Wu, Y C

2001-04-01

Four alkaloids, annocherine A, annocherine B, cherianoine, and romucosine H, along with one known alkaloid, artabonatine B, were isolated from the MeOH extract of the stems of Annona cherimola. Their structures were identified on the basis of both analysis of their spectral data and from chemical evidence.

21 CFR 119.1 - Dietary supplements containing ephedrine alkaloids.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Dietary supplements containing ephedrine alkaloids... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION DIETARY SUPPLEMENTS THAT PRESENT A SIGNIFICANT OR UNREASONABLE RISK § 119.1 Dietary supplements containing ephedrine alkaloids. Dietary supplements containing...

Recognition of pyrrolizidine alkaloid esters in the invasive aquatic plant Gymnocoronis spilanthoides (Asteraceae)

USDA-ARS?s Scientific Manuscript database

Introduction – The freshwater aquatic plant Gymnocoronis spilanthoides (Senegal tea plant, jazmín del bañado, Falscher Wasserfreund) is an invasive plant in many countries. Behavioural observations of pyrrolizidine alkaloid-pharmacophagous butterflies suggested the presence of pyrrolizidine alkaloid...

Metabolomics driven analysis of six Nigella species seeds via UPLC-qTOF-MS and GC-MS coupled to chemometrics.

PubMed

Farag, Mohamed A; Gad, Haidy A; Heiss, Andreas G; Wessjohann, Ludger A

2014-05-15

Nigella sativa, commonly known as black cumin seed, is a popular herbal supplement that contains numerous phytochemicals including terpenoids, saponins, flavonoids, alkaloids. Only a few of the ca. 15 species in the genus Nigella have been characterized in terms of phytochemical or pharmacological properties. Here, large scale metabolic profiling including UPLC-PDA-MS and GC-MS with further multivariate analysis was utilized to classify 6 Nigella species. Under optimized conditions, we were able to annotate 52 metabolites including 8 saponins, 10 flavonoids, 6 phenolics, 10 alkaloids, and 18 fatty acids. Major peaks in UPLC-MS spectra contributing to the discrimination among species were assigned as kaempferol glycosidic conjugates, with kaempferol-3-O-[glucopyranosyl-(1→2)-galactopyranosyl-(1→2)-glucopyranoside, identified as potential taxonomic marker for N. sativa. Compared with GC-MS, UPLC-MS was found much more efficient in Nigella sample classification based on genetic and geographical origin. Nevertheless, both GC-MS and UPLC-MS support the remote position of Nigella nigellastrum in relation to the other taxa. Copyright © 2013 Elsevier Ltd. All rights reserved.

Secondary metabolites from three Florida sponges with antidepressant activity.

PubMed

Kochanowska, Anna J; Rao, Karumanchi V; Childress, Suzanne; El-Alfy, Abir; Matsumoto, Rae R; Kelly, Michelle; Stewart, Gina S; Sufka, Kenneth J; Hamann, Mark T

2008-02-01

Brominated indole alkaloids are a common class of metabolites reported from sponges of the order Verongida. Herein we report the isolation, structure determination, and activity of metabolites from three Florida sponges, namely, Verongula rigida (order Verongida, family Aplysinidae), Smenospongia aurea, and S. cerebriformis (order Dictyoceratida, family Thorectidae). All three species were investigated chemically, revealing similarities in secondary metabolites. Brominated compounds, as well as sesquiterpene quinones and hydroquinones, were identified from both V. rigida and S. aurea despite their apparent taxonomic differences at the ordinal level. Similar metabolites found in these distinct sponge species of two different genera provide evidence for a microbial origin of the metabolites. Isolated compounds were evaluated in the Porsolt forced swim test (FST) and the chick anxiety-depression continuum model. Among the isolated compounds, 5,6-dibromo- N,N-dimethyltryptamine ( 1) exhibited significant antidepressant-like action in the rodent FST model, while 5-bromo- N,N-dimethyltryptamine ( 2) caused significant reduction of locomotor activity indicative of a potential sedative action. The current study provides ample evidence that marine natural products with the diversity of brominated marine alkaloids will provide potential leads for antidepressant and anxiolytic drugs.

Effects of tryptophan derivatives and β-carboline alkaloids on radiation- and peroxide-induced transformations of ethanol

NASA Astrophysics Data System (ADS)

Sverdlov, R. L.; Brinkevich, S. D.; Shadyro, O. I.

2014-05-01

The subject of this study was investigation of interactions of tryptophan and its derivatives, including structurally related β-carboline alkaloids with oxygen- and carbon-centered radicals being formed during radiation- and peroxide-induced transformations of ethanol. It was shown that the above named compounds suppressed recombination and disproportionation reactions of α-hydroxyethyl radicals. The inhibitory effects of tryptophan, 5-hydroxytryptophan and serotonin were mainly realized by means of reduction and addition reactions, while those of β-carboline alkaloids - harmine, harmane and harmaline - were due to oxidation reactions. Melatonin displayed low reactivity towards α-hydroxyethyl radicals. Tryptophan derivatives and β-carboline alkaloids were found to inhibit radiation-induced oxidation of ethanol while being virtually not used up. The low transformation yields of tryptophan, 5-hydroxytryptophan and serotonin, as well as β-carboline alkaloids, indicate their capability of regeneration, which could occur on interaction of tryptophan with О-2 and НО2, or on oxidation of α-hydroxyethyl radicals by β-carboline alkaloids.

Study on the Alkaloids in Tibetan Medicine Aconitum pendulum Busch by HPLC–MSn Combined with Column Chromatography

PubMed Central

Wang, Beibei; Dong, Jie; Ji, Jiaojiao; Yuan, Jiang; Wang, Jiali; Wu, Jiarui; Tan, Peng; Liu, Yonggang

2016-01-01

A rapid, convenient and effective identification method of alkaloids was established and an attempt on isolating and analyzing the alkaloids in Aconitum pendulum Busch was conducted successfully. In this article, four high-content components including deoxyaconitine, benzoylaconine, aconine and neoline were isolated by using column chromatography. HPLC–MSn was employed to deduce the regulations of fragmentation of diterpenoid alkaloids which displayed a characteristic behavior of loss of CO(28u), CH3COOH(60u), CH3OH(32u), H2O(18u) and C6H5COOH(122u). Then, according to fragmentation regulation of mass spectrometry, 42 alkaloids were found in A. pendulum. Among them, 38 compounds were identified and 29 alkaloids were reported for the first time for this herb. Therefore, this means that HPLC–MSn combined with column chromatography could work as an effective and reliable tool for rapid identification of the chemical components of herbal medicine. PMID:26896350

Report on maloine, a new alkaloid discovered from G. maloi: Structural characterization and biological activity

NASA Astrophysics Data System (ADS)

Çela, Dorisa; Nepravishta, Ridvan; Lazari, Diamanto; Gaziano, Roberta; Moroni, Gabriella; Pica, Francesca; Paci, Maurizio; Abazi, Sokol

2017-02-01

Gymnospermium maloi Kit Tan, & Shuka is a new endemic species of the genus Gymnospermium Spach which has been described recently from the southern part of Albania. The members of this genus are poorly studied for what it concern the secondary metabolites in general and the class of alkaloids in particular. In fact from Gymnospermium genus, there are only few alkaloids characterized, (namely albertramine, albertidine, and albertine) isolated from G. albertii. Until now the chemical composition and the structure elucidation of other possible secondary metabolites, especially alkaloids, remain largely unknown. Here we report, for the first time, the structure of a new alkaloid isolated from G. maloi, designated by us as maloine, and obtained by the use of 2D homonuclear and heteronuclear NMR spectroscopy, FTIR, UV, Fluorescence and HPLC/MS spectra. The biological activity of the crude extract of Gymnospermium maloi and of its alkaloid maloine, was evaluated in vitro on human chronic myeloid leukemia cell line K562 and results herewith reported.

Dynamic Variation Patterns of Aconitum Alkaloids in Daughter Root of Aconitum Carmichaelii (Fuzi) in the Decoction Process Based on the Content Changes of Nine Aconitum Alkaloids by HPLC- MS- MS

PubMed Central

Luo, Heng; Huang, Zhifang; Tang, Xiaolong; Yi, Jinhai; Chen, Shuiying; Yang, Andong; Yang, Jun

2016-01-01

The chemical components in the decoctions of Chinese herbal medicines are not always the same as those in the crude herbs because of the insolubility or instability of some compounds. In this work, a high-performance liquid chromatography (HPLC) coupled with electrospray ionization (ESI) tandem mass spectrometry method was developed to explore dynamic variation patterns of aconitum alkaloids in Fuzi during the process of decocting aconite root. The fragmentation patterns of aconitum alkaloids using ESI and collision-induced dissociation (CID) techniques were reported. This assay method was validated with respect to linearity (r2 > 0.9950), precision, repeatability, and accuracy (recovery rate between 94.6 and 107.9%).The result showed that the amounts of aconitum alkaloids in the decoction at different boiling time varied significantly. In the decoction process，the diester- type alkaloids in crude aconite roots have transformed into Benzoylaconines or aconines. PMID:27610167

Antiviral activity of aconite alkaloids from Aconitum carmichaelii Debx.

PubMed

Xu, Weiming; Zhang, Min; Liu, Hongwu; Wei, Kun; He, Ming; Li, Xiangyang; Hu, Deyu; Yang, Song; Zheng, Yuguo

2017-12-22

Four diterpenoid alkaloids, namely, (a) hypaconitine, (b) songorine, (c) mesaconitine and (d) aconitine, were isolated from the ethanol root extract of Aconitum carmichaelii Debx. The antiviral activities of these alkaloids against tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV) were evaluated. Antiviral activity test in vivo showed that compounds a and c, which were C19-diterpenoid alkaloids, showed inactivation efficacy values of 82.4 and 85.6% against TMV at 500 μg/mL, respectively. By contrast, compound c presented inactivation activity of 52.1% against CMV at 500 μg/mL, which was almost equal to that of the commercial Ningnanmycin (87.1% inactivation activity against TMV and 53.8% inactivation activity against CMV). C19-Diterpenoid alkaloids displayed moderate to high antiviral activity against TMV and CMV at 500 μg/mL, dosage plays an important role in antiviral activities. This paper is the first report on the evolution of aconite diterpenoid alkaloids for antiviral activity against CMV.

Dynamic Variation Patterns of Aconitum Alkaloids in Daughter Root of Aconitum Carmichaelii (Fuzi) in the Decoction Process Based on the Content Changes of Nine Aconitum Alkaloids by HPLC- MS- MS.

PubMed

Luo, Heng; Huang, Zhifang; Tang, Xiaolong; Yi, Jinhai; Chen, Shuiying; Yang, Andong; Yang, Jun

2016-01-01

The chemical components in the decoctions of Chinese herbal medicines are not always the same as those in the crude herbs because of the insolubility or instability of some compounds. In this work, a high-performance liquid chromatography (HPLC) coupled with electrospray ionization (ESI) tandem mass spectrometry method was developed to explore dynamic variation patterns of aconitum alkaloids in Fuzi during the process of decocting aconite root. The fragmentation patterns of aconitum alkaloids using ESI and collision-induced dissociation (CID) techniques were reported. This assay method was validated with respect to linearity (r(2) > 0.9950), precision, repeatability, and accuracy (recovery rate between 94.6 and 107.9%).The result showed that the amounts of aconitum alkaloids in the decoction at different boiling time varied significantly. In the decoction process，the diester- type alkaloids in crude aconite roots have transformed into Benzoylaconines or aconines.

Newly discovered ergot alkaloids in Sorghum ergot Claviceps africana occurring for the first time in Israel.

PubMed

Shimshoni, J A; Cuneah, O; Sulyok, M; Krska, R; Sionov, E; Barel, S; Meller Harel, Y

2017-03-15

Sorghum ergot is a disease caused commonly by C. africana. In 2015, ergot was identified for the first time in sorghum fields in Israel, leading to measures of eradication and quarantine. The aims of the study were to identify the ergot species by molecular and ergot alkaloid profile analysis, to determine the ergot alkaloid profile in pure honeydew and in infected sorghum silages and to estimate the safety of sorghum silages as a feed source. C. africana was rapidly and reliably identified by microscopical and molecular analysis. Dihydroergosine was identified as the major ergot alkaloid. Dihydrolysergol and dihydroergotamine were identified for the first time as significant ergot alkaloid components within the C. africana sclerotia, thereby providing for the first time a proof for the natural occurrence of dihydroergotamine. The sorghum silages were found to be safe for feed consumption, since the ergot alkaloids and the regulated mycotoxins were below their regulated limits. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthesis of substituted tetrahydroisoquinolines by lithiation then electrophilic quench.

PubMed

Talk, Ruaa A; Duperray, Alexia; Li, Xiabing; Coldham, Iain

2016-06-07

Substituted N-tert-butoxycarbonyl (Boc)-1,2,3,4-tetrahydroisoquinolines were prepared and treated with n-butyllithium in THF at -50 °C to test the scope of the metallation and electrophilic quench. The lithiation was optimised by using in situ ReactIR spectroscopy and the rate of rotation of the carbamate was determined. The 1-lithiated intermediates could be trapped with a variety of electrophiles to give good yields of 1-substituted tetrahydroisoquinoline products. Treatment with acid or reduction with LiAlH4 allows conversion to the N-H or N-Me compound. The chemistry was applied to the efficient total syntheses of the alkaloids (±)-crispine A and (±)-dysoxyline.

Synthesis and biological evaluation of febrifugine analogues as potential antimalarial agents.

PubMed

Zhu, Shuren; Zhang, Quan; Gudise, Chandrashekar; Wei, Lai; Smith, Erika; Zeng, Yuling

2009-07-01

Febrifugine is an alkaloid isolated from Dichroa febrifuga Lour as the active component against Plasmodium falciparum. Adverse side effects have precluded febrifugine as a potential clinical drug. In this study novel febrifugine analogues were designed and synthesized. Lower toxicity was achieved by reducing or eliminating the tendency of forming chemically reactive and toxic intermediates and metabolites. Synthesized compounds were evaluated for acute toxicity and in vitro and in vivo antimalarial efficacy. Some compounds are much less toxic than the natural product febrifugine and existing antimalarial drug chloroquine and are expected to possess wide therapeutic windows. These compounds, as well as the underlying design rationale, may find usefulness in the discovery and development of new antimalarial drugs.

Copper-catalyzed C(sp3)-OH cleavage with concomitant C-C coupling: synthesis of 3-substituted isoindolinones.

PubMed

Rao, H Surya Prakash; Rao, A Veera Bhadra

2015-02-06

Copper(II) trifluoromethanesulfonate (Cu(OTf)2) efficiently catalyzes the C-C coupling of 3-hydoxyisoindolinones with a variety of aryl-, heteroaryl-, and alkenylboronic acids to furnish C(3) aryl-, heteroaryl-, and alkenyl-substituted isoindolinones. The coupling reactions work smoothly in 1,2-dicholoroethane (DCE) reflux, to effect both inter- and intramolecular versions. This is the first report on C(sp(3))-OH cleavage with concomitant C-C coupling. The photolabile 2-nitrobenzyl protecting group is most appropriate for promotion of the coupling reaction and for deprotection. The tetracyclic ring motif of the alkaloid neuvamine was prepared by applying the newly developed copper-catalyzed C-C coupling.

Synthesis of febrifugine derivatives and development of an effective and safe tetrahydroquinazoline-type antimalarial.

PubMed

Kikuchi, Haruhisa; Horoiwa, Seiko; Kasahara, Ryota; Hariguchi, Norimitsu; Matsumoto, Makoto; Oshima, Yoshiteru

2014-04-09

Febrifugine, a quinazoline alkaloid isolated from Dichroa febrifuga roots, shows powerful antimalarial activity against Plasmodium falciparum. Although the use of ferifugine as an antimalarial drug has been precluded because of its severe side effects, its potent antimalarial activity has stimulated medicinal chemists to pursue its derivatives instead, which may provide valuable leads for novel antimalarial drugs. In the present study, we synthesized new derivatives of febrifugine and evaluated their in vitro and in vivo antimalarial activities to develop antimalarials that are more effective and safer. As a result, we proposed tetrahydroquinazoline-type derivative as a safe and effective antimalarial candidate. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Alkaloid production in Vernonia cinerea: Callus, cell suspension and root cultures.

PubMed

Maheshwari, Priti; Songara, Bharti; Kumar, Shailesh; Jain, Prachi; Srivastava, Kamini; Kumar, Anil

2007-08-01

Fast-growing callus, cell suspension and root cultures of Vernonia cinerea, a medicinal plant, were analyzed for the presence of alkaloids. Callus and root cultures were established from young leaf explants in Murashige and Skoog (MS) basal media supplemented with combinations of auxins and cytokinins, whereas cell suspension cultures were established from callus cultures. Maximum biomass of callus, cell suspension and root cultures were obtained in the medium supplemented with 1 mg/L alpha-naphthaleneacetic acid (NAA) and 5 mg/L benzylaminopurine (BA), 1.0 mg/L NAA and 0.1 mg/L BA and 1.5 mg/L NAA, respectively. The 5-week-old callus cultures resulted in maximum biomass and alkaloid contents (750 microg/g). Cell suspension growth and alkaloid contents were maximal in 20-day-old cultures and alkaloid contents were 1.15 mg/g. A 0.2-g sample of root tissue regenerated in semi-solid medium upon transfer to liquid MS medium containing 1.5 mg/L NAA regenerated a maximum increase in biomass of 6.3-fold over a period of 5 weeks. The highest root growth and alkaloid contents of 2 mg/g dry weight were obtained in 5-week-old cultures. Maximum alkaloid contents were obtained in root cultures in vitro compared to all others including the alkaloid content of in vivo obtained with aerial parts and roots (800 microg/g and 1.2 mg/g dry weight, respectively) of V. cinerea.

Employing Two-stage Derivatisation and GC-MS to Assay for Cathine and Related Stimulant Alkaloids across the Celastraceae.

PubMed

Tembrock, Luke R; Broeckling, Corey D; Heuberger, Adam L; Simmons, Mark P; Stermitz, Frank R; Uvarov, Jessica M

2017-07-01

Catha edulis (qat, khat, mirra) is a woody plant species that is grown and consumed in East Africa and Yemen for its stimulant alkaloids cathinone, cathine and norephedrine. Two Celastraceae species, in addition to qat, have been noted for their stimulant properties in ethnobotanical literature. Recent phylogenetic reconstructions place four genera in a clade sister to Catha edulis, and these genera are primary candidates to search for cathine and related alkaloids. Determine if cathine or related alkaloids are present in species of Celastraceae other than Catha edulis. Leaf samples from 43 Celastraceae species were extracted in water followed by basification of the aqueous extract and partitioning with methyl-t-butyl ether to provide an alkaloid-enriched fraction. The extract was derivatised in a two-stage process and analysed using GC-MS for the presence of cathine. Related alkaloids and other metabolites in this alkaloid-enriched fraction were tentatively identified. Cathinone, cathine and norephedrine were not detected in any of the 43 Celastraceae species assayed other than Catha edulis. However, the phenylalanine- or tyrosine-derived alkaloid phenylethylamine was identified in five species. Nine species were found to be enriched for numerous sterol- and terpene-like compounds. These results indicate that cathine is unique to Catha edulis, and not the compound responsible for the stimulant properties reported in related Celastraceae species. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Physiological Effects of Ergot Alkaloid and Indole-Diterpene Consumption on Sheep under Hot and Thermoneutral Ambient Temperature Conditions.

PubMed

Henry, Michelle L E; Kemp, Stuart; Dunshea, Frank R; Leury, Brian J

2016-06-02

A controlled feeding study was undertaken to determine the physiological and production effects of consuming perennial ryegrass alkaloids (fed via seed) under extreme heat in sheep. Twenty-four Merino ewe weaners (6 months; initial BW 30.8 ± 1.0 kg) were selected and the treatment period lasted 21 days following a 14 day acclimatisation period. Two levels of two factors were used. The first factor was alkaloid, fed at a nil (NilAlk) or moderate level (Alk; 80 μg/kg LW ergovaline and 20.5 μg/kg·LW lolitrem B). The second factor was ambient temperature applied at two levels; thermoneutral (TN; constant 21-22 °C) or heat (Heat; 9:00 AM-5:00 PM at 38 °C; 5:00 PM-9:00 AM at 21-22 °C), resulting in four treatments, NilAlk TN, NilAlk Heat, Alk TN and Alk Heat. Alkaloid consumption reduced dry matter intake ( p = 0.008), and tended to reduce liveweight ( p = 0.07). Rectal temperature and respiration rate were increased by both alkaloid and heat ( p < 0.05 for all). Respiration rate increased to severe levels when alkaloid and heat were combined, indicating the short term effects which may be occurring in perennial ryegrass toxicosis (PRGT) areas during severe weather conditions, a novel finding. When alkaloid ingestion and heat were administered separately, similar physiological responses occurred, indicating alkaloid ingestion causes a similar heat stress response to 38 °C heat.

Identification of Plant-derived Alkaloids with Therapeutic Potential for Myotonic Dystrophy Type I*

PubMed Central

Herrendorff, Ruben; Faleschini, Maria Teresa; Stiefvater, Adeline; Erne, Beat; Wiktorowicz, Tatiana; Kern, Frances; Hamburger, Matthias; Potterat, Olivier; Kinter, Jochen; Sinnreich, Michael

2016-01-01

Myotonic dystrophy type I (DM1) is a disabling neuromuscular disease with no causal treatment available. This disease is caused by expanded CTG trinucleotide repeats in the 3′ UTR of the dystrophia myotonica protein kinase gene. On the RNA level, expanded (CUG)n repeats form hairpin structures that sequester splicing factors such as muscleblind-like 1 (MBNL1). Lack of available MBNL1 leads to misregulated alternative splicing of many target pre-mRNAs, leading to the multisystemic symptoms in DM1. Many studies aiming to identify small molecules that target the (CUG)n-MBNL1 complex focused on synthetic molecules. In an effort to identify new small molecules that liberate sequestered MBNL1 from (CUG)n RNA, we focused specifically on small molecules of natural origin. Natural products remain an important source for drugs and play a significant role in providing novel leads and pharmacophores for medicinal chemistry. In a new DM1 mechanism-based biochemical assay, we screened a collection of isolated natural compounds and a library of over 2100 extracts from plants and fungal strains. HPLC-based activity profiling in combination with spectroscopic methods were used to identify the active principles in the extracts. The bioactivity of the identified compounds was investigated in a human cell model and in a mouse model of DM1. We identified several alkaloids, including the β-carboline harmine and the isoquinoline berberine, that ameliorated certain aspects of the DM1 pathology in these models. Alkaloids as a compound class may have potential for drug discovery in other RNA-mediated diseases. PMID:27298317

Effect of ensiling moist field bean (Vicia faba), pea (Pisum sativum) and lupine (Lupinus spp.) grains on the contents of alkaloids, oligosaccharides and tannins.

PubMed

Gefrom, A; Ott, E M; Hoedtke, S; Zeyner, A

2013-12-01

Ensiling legume grain may be an inexpensive and ecologically interesting method to produce a high-protein feed of local origin. The typically patchy maturation recommends harvesting and ensiling the seeds in moist condition. Developing a method for preserving legume grains harvested before maturation by lactic acid fermentation would have several advantages. Under laboratory conditions, crushed legume seeds of beans, peas and lupines with high moisture content of 35 % were ensiled with different additives (molasses and lactic acid bacteria). To characterize the final silages, contents of proximate nutrients and antinutritional factors (alkaloids, oligosaccharides, tannins) were analysed. The addition of lactic acid bacteria ensured a fast and pronounced lactic acid production and decreased contents of undesired fermentation products like ethanol. An additional use of molasses for ensilage did not provide a remarkable additional benefit. Excluding sugar and starch, the contents of proximate nutrients were not remarkably altered after ensiling. As an overall effect, lactic acid fermentation reduced tannins and oligosaccharides. It can be supposed that the oligosaccharides after breakdown of the complex molecules acted as a source of fermentable carbohydrates. A relevant reduction of alkaloids did not occur. The lactic acid fermentation of legume grains can be recommended as an appropriate method for conservation. With respect to the economic advantages and compared with methods of chemical preservation, the lactic acid fermentation of legume grains under anaerobic conditions is an environmentally compliant procedure and therefore also an option for organic farming. © 2012 Blackwell Verlag GmbH.

Messages from the Other Side: Parasites Receive Damage Cues from their Host Plants.

PubMed

Tjiurutue, Muvari Connie; Stevenson, Philip C; Adler, Lynn S

2016-08-01

As sessile organisms, plants rely on their environment for cues indicating imminent herbivory. These cues can originate from tissues on the same plant or from different individuals. Since parasitic plants form vascular connections with their host, parasites have the potential to receive cues from hosts that allow them to adjust defenses against future herbivory. However, the role of plant communication between hosts and parasites for herbivore defense remains poorly investigated. Here, we examined the effects of damage to lupine hosts (Lupinus texensis) on responses of the attached hemiparasite (Castilleja indivisa), and indirectly, on a specialist herbivore of the parasite, buckeyes (Junonia coenia). Lupines produce alkaloids that act as defenses against herbivores that can be taken up by the parasite. We found that damage to lupine host plants by beet armyworm (Spodoptera exigua) significantly increased jasmonic acid (JA) levels in both the lupine host and parasite, suggesting uptake of phytohormones or priming of parasite defenses by using host cues. However, lupine host damage did not induce changes in alkaloid levels in the hosts or parasites. Interestingly, the parasite had substantially higher concentrations of JA and alkaloids compared to lupine host plants. Buckeye herbivores consumed more parasite tissue when attached to damaged compared to undamaged hosts. We hypothesize that increased JA due to lupine host damage induced higher iridoid glycosides in the parasite, which are feeding stimulants for this specialist herbivore. Our results demonstrate that damage to hosts may affect both parasites and associated herbivores, indicating cascading effects of host damage on multiple trophic levels.

Geographically Sourcing Cocaine's Origin - Delineation of the Nineteen Major Coca Growing Regions in South America.

PubMed

Mallette, Jennifer R; Casale, John F; Jordan, James; Morello, David R; Beyer, Paul M

2016-03-23

Previously, geo-sourcing to five major coca growing regions within South America was accomplished. However, the expansion of coca cultivation throughout South America made sub-regional origin determinations increasingly difficult. The former methodology was recently enhanced with additional stable isotope analyses ((2)H and (18)O) to fully characterize cocaine due to the varying environmental conditions in which the coca was grown. An improved data analysis method was implemented with the combination of machine learning and multivariate statistical analysis methods to provide further partitioning between growing regions. Here, we show how the combination of trace cocaine alkaloids, stable isotopes, and multivariate statistical analyses can be used to classify illicit cocaine as originating from one of 19 growing regions within South America. The data obtained through this approach can be used to describe current coca cultivation and production trends, highlight trafficking routes, as well as identify new coca growing regions.

Geographically Sourcing Cocaine’s Origin - Delineation of the Nineteen Major Coca Growing Regions in South America

NASA Astrophysics Data System (ADS)

Mallette, Jennifer R.; Casale, John F.; Jordan, James; Morello, David R.; Beyer, Paul M.

2016-03-01

Previously, geo-sourcing to five major coca growing regions within South America was accomplished. However, the expansion of coca cultivation throughout South America made sub-regional origin determinations increasingly difficult. The former methodology was recently enhanced with additional stable isotope analyses (2H and 18O) to fully characterize cocaine due to the varying environmental conditions in which the coca was grown. An improved data analysis method was implemented with the combination of machine learning and multivariate statistical analysis methods to provide further partitioning between growing regions. Here, we show how the combination of trace cocaine alkaloids, stable isotopes, and multivariate statistical analyses can be used to classify illicit cocaine as originating from one of 19 growing regions within South America. The data obtained through this approach can be used to describe current coca cultivation and production trends, highlight trafficking routes, as well as identify new coca growing regions.

Livestock Poisoning with Pyrrolizidine Alkaloid Containing Plants (Senecio, Crotalaria, Cynoglossum, Amsinckia, Heliotropium and Echium spp.)

USDA-ARS?s Scientific Manuscript database

Pyrrolizidine alkaloids (PAs) are potent liver toxins that have been identified in over 6,000 plants throughout the world. Alkaloids are nitrogen-based compounds with potent biological activity. About half of the identified PAs are toxic and several cause cancer (carcinogenic). PA-containing plants...

Complete inhibition of fetal movement in the day 40 pregnant goat model by the piperidine alkaloid anabasine but not related alkaloids

USDA-ARS?s Scientific Manuscript database

Four chemically similar alkaloids, anabasine, anabaseine, epibatidine and dimethylphenylpiperazinium (DMPP), are potent nicotinic acetylcholine receptor agonists of fetal muscle nicotinic acetylcholine receptors in human TE-671 cells. Based on results with these cells, we hypothesized that these alk...

The Actions of Piperidine Alkaloids at Fetal Muscle-Type and Autonomic-Type Nicotinic Acetylcholine Receptors

USDA-ARS?s Scientific Manuscript database

Piperidine alkaloids are found in many species of plants including Conium maculatum, Nicotiana spp., and Lupinus spp. A pharmacodynamic comparison was made of the alkaloids ammodendrine, anabasine, anabaseine, and coniine in; SH-SY5Y cells which express autonomic-type nicotinic acetylcholine recept...

Plant alkaloids that cause developmental defects through the disruption of cholinergic neurotransmission

USDA-ARS?s Scientific Manuscript database

The exposure of a developing embryo or fetus to alkaloids from plants, plant products, or plant extracts has the potential to cause developmental defects in humans and animals. These defects may have multiple causes but those induced by piperidine and quinolizidine alkaloids arise from the inhibiti...

Studies on the teratogenicity of anabasine in a rat model

USDA-ARS?s Scientific Manuscript database

A number of plant toxins have been shown to be teratogenic to livestock. The teratogenic action of some of these alkaloids is mediated by nicotinic acetylcholine receptors (nAChR). However, for many of these alkaloids it is difficult to obtain sufficient quantities of individual alkaloids to perform...

Plant-symbiotic fungi as chemical engineers: multi-genome analysis of the Clavicipitaceae reveals dynamics of alkaloid loci

USDA-ARS?s Scientific Manuscript database

The fungal family Clavicipitaceae includes plant symbionts and pathogens that produce neurotropic alkaloids with diverse effects on vertebrate and invertebrate animals. For example, ergot alkaloids are historically linked to mass poisonings (St. Anthony's fire) and sociological effects such as the ...

The toxicity of Poison Dart Frog alkaloids against the Fire Ant (Solenopsis invicta)

USDA-ARS?s Scientific Manuscript database

Hundreds of alkaloids, representing over 20 structural classes, have been identified from the skin of neotropical poison frogs (Dendrobatidae). These alkaloids are derived from arthropod prey of the frogs, and are generally are believed to deter vertebrate predators. We developed a method to put ind...

Vasoconstrictive responses of the testicular and caudal arteries in bulls exposed to ergot alkaloids from tall fescue

USDA-ARS?s Scientific Manuscript database

Color Doppler ultasonography was used to evaluate vasoconstrictive responses of the testicular artery in yearling bulls to ergot alkaloids. Ergot alkaloid-induced constriction of the testicular artery could disrupt thermoregulation of the testes and reduce bull fertility. Luminal areas of the test...

Alkaloids from Isopyrum thalictroides L.

PubMed

Istatkova, Ralitsa; Philipov, Stefan

2004-06-01

Two new aporphine-benzylisoquinoline alkaloids thaliphine and isothaliphine with a new type of ether bridge were isolated from the roots and rhyzomes of Isopyrum thalictroides L. (Ranunculaceae). Their structures were established by physical and spectral analysis. The known alkaloid N-methylglaucine was isolated for the first time from a plant of the family Ranunculaceae.

A new strain of Claviceps purpurea accumulating tetracyclic clavine alkaloids.

PubMed

Schumann, B; Erge, D; Maier, W; Gröger, D

1982-05-01

A new strain of Claviceps was isolated from a blokked mutant of Claviceps purpurea. This strain accumulates substantial amounts of clavine alkaloids (2 g/l). The alkaloid fraction is composed of chanoclavine-I ( approximately 10%) and a mixture of agroclavine/elymoclavine (90%). Most suitable for alkaloid production in submerged culture is an ammoncitrate/sucrose medium. The genealogy of the new strain, designated Pepty 695/ch-I is the following one: Pepty 695/S (ergotoxine producer) --> Pepty 695/ch (secoergoline producer) --> Pepty 695/ch-I (tetracyclic clavine producer).

Ergot alkaloids produced by submerged cultures of Claviceps zizaniae.

PubMed

Kantorová, Michaela; Kolínská, Renata; Pazoutová, Sylvie; Honzátko, Ales; Havlícek, Vladimír; Flieger, Miroslav

2002-07-01

Two ergopeptine alkaloids, alpha-ergocryptine (1) and its C(8) epimer alpha-ergocryptinine, have been isolated from the mycelium and fermentation broth of submerged cultures of Claviceps zizaniae CCM 8240. The structure of 1 was determined by HPLC/positive ion APCI MS and NMR analysis. Alkaloid concentrations of 10 microg/mL in 14-day-old fermentation broth and 1 mg/g of dry mycelium mass were found. These results are of considerable biotechnological interest since these were the only detectable alkaloids produced. Toxicity of naturally occurring sclerotia of C. zizaniae cannot be excluded.

[Ibogaine--the substance for treatment of toxicomania. Neurochemical and pharmacological action].

PubMed

Kazlauskas, Saulius; Kontrimaviciūte, Violeta; Sveikata, Audrius

2004-01-01

The review of scientific literature, concerning the indol alkaloid Ibogaine, which is extracted from the bush Tabernanthe Iboga, is presented in this article. Used as a stimulating factor for hundred of years in non-traditional medicine, this alkaloid could be important for modern pharmacology because of potential anti-addictive properties. The mechanism of action of this alkaloid is closely related to different neurotransmitting systems. Studies with animals allow concluding that Ibogaine or medicines based on this alkaloid can be used for treatment of drug dependencies.

Metabolite fingerprinting of Camptotheca acuminata and the HPLC-ESI-MS/MS analysis of camptothecin and related alkaloids.

PubMed

Montoro, Paola; Maldini, Mariateresa; Piacente, Sonia; Macchia, Mario; Pizza, Cosimo

2010-01-20

The major phytochemical constituents, namely, alkaloids, flavonoids and ellagic acid derivatives, of leaves of Camptotheca acuminata were identified using high performance liquid chromatography (HPLC) coupled with electrospray mass spectrometry (ESI-MS) in extracts of plants cultivated in Italy and collected at different growth stages. Alkaloids related to camptothecin were identified and quantified by HPLC coupled with ESI-tandem mass spectrometry (MS/MS) employing, respectively, an ion trap and a triple quadrupole mass analyser. The fragmentation patterns of alkaloids related to camptothecin were analysed and a specific Multiple Reaction Monitoring HPLC-MS/MS method was developed for the quantitative determination of these constituents. The described method provides high sensitivity and specificity for the characterisation and quantitative determination of the alkaloids in C. acuminata.

Microcalorimetry studies of the antimicrobial actions of Aconitum alkaloids*

PubMed Central

Shi, Yan-bin; Liu, Lian; Shao, Wei; Wei, Ting; Lin, Gui-mei

2015-01-01

The metabolic activity of organisms can be measured by recording the heat output using microcalorimetry. In this paper, the total alkaloids in the traditional Chinese medicine Radix Aconiti Lateralis were extracted and applied to Escherichia coli and Staphylococcus aureus. The effect of alkaloids on bacteria growth was studied by microcalorimetry. The power-time curves were plotted with a thermal activity monitor (TAM) air isothermal microcalorimeter and parameters such as growth rate constant (μ), peak-time (Tm), inhibitory ratio (I), and enhancement ratio (E) were calculated. The relationships between the concentration of Aconitum alkaloids and μ of E. coli or S. aureus were discussed. The results showed that Aconitum alkaloids had little effect on E. coli and had a potentially inhibitory effect on the growth of S. aureus. PMID:26238544

Distinct sesquiterpene pyridine alkaloids from in Salvadoran and Peruvian Celastraceae species.

PubMed

Callies, Oliver; Núñez, Marvin J; Perestelo, Nayra R; Reyes, Carolina P; Torres-Romero, David; Jiménez, Ignacio A; Bazzocchi, Isabel L

2017-10-01

As part of a bioprospecting program aimed at the discovery of undescribed natural products from Salvadoran and Peruvian flora, the phytochemical investigations of four Celastraceae species, Celastrus vulcanicola, Maytenus segoviarum, Maytenus jeslkii, and Maytenus cuzcoina, were performed. The current study reports the isolation and structural characterization of five previously undescribed macrolide sesquiterpene pyridine alkaloids, named vulcanicoline-A, cuzcoinine, vulcanicoline-B, jelskiine, and vulcanicoline-C, along with sixteen known alkaloids. The structures of the alkaloids were established by spectrometric and extensive 1D and 2D NMR spectroscopic analysis, including COSY, HSQC, HMBC, and ROESY experiments. The absolute configurations of alkaloids were proposed based on optical rotation sign, and biogenetic considerations. This study represents the first phytochemical analysis of Maytenus segoviarum. Copyright © 2017 Elsevier Ltd. All rights reserved.

Analysis of the Impact of Isoquinoline Alkaloids, Derived from Macleaya cordata Extract, on the Development and Innate Immune Response in Swine and Poultry.

PubMed

Ni, Hengjia; Martínez, Yordan; Guan, Guiping; Rodríguez, Román; Más, Dairon; Peng, Hanhui; Valdivié Navarro, Manuel; Liu, Gang

2016-01-01

Medicinal extract has been chronicled extensively in traditional Chinese medicine. Isoquinoline alkaloids, extract of Macleaya cordata (Willd.) R. Br., have been used as feed additive in both swine and poultry. Dietary supplementation with isoquinoline alkaloids increases feed intake and weight gain. In addition, recent researches have demonstrated that isoquinoline alkaloids can regulate metabolic processes, innate immune system, and digestive functioning in animals. This review summarizes the latest scientific researches on isoquinoline alkaloids which are extracted from Macleaya cordata (Willd.) R. Br. This review specifically focuses on its role as a feed supplement and its associated impact on growth performance and innate immune system, as well as its capacity to act as a substitute for oral antibiotics.

Analysis of the Impact of Isoquinoline Alkaloids, Derived from Macleaya cordata Extract, on the Development and Innate Immune Response in Swine and Poultry

PubMed Central

Martínez, Yordan; Rodríguez, Román; Más, Dairon; Peng, Hanhui; Valdivié Navarro, Manuel

2016-01-01

Medicinal extract has been chronicled extensively in traditional Chinese medicine. Isoquinoline alkaloids, extract of Macleaya cordata (Willd.) R. Br., have been used as feed additive in both swine and poultry. Dietary supplementation with isoquinoline alkaloids increases feed intake and weight gain. In addition, recent researches have demonstrated that isoquinoline alkaloids can regulate metabolic processes, innate immune system, and digestive functioning in animals. This review summarizes the latest scientific researches on isoquinoline alkaloids which are extracted from Macleaya cordata (Willd.) R. Br. This review specifically focuses on its role as a feed supplement and its associated impact on growth performance and innate immune system, as well as its capacity to act as a substitute for oral antibiotics. PMID:28042566

Purification, cloning, functional expression and characterization of perakine reductase: the first example from the AKR enzyme family, extending the alkaloidal network of the plant Rauvolfia.

PubMed

Sun, Lianli; Ruppert, Martin; Sheludko, Yuri; Warzecha, Heribert; Zhao, Yu; Stöckigt, Joachim

2008-07-01

Perakine reductase (PR) catalyzes an NADPH-dependent step in a side-branch of the 10-step biosynthetic pathway of the alkaloid ajmaline. The enzyme was cloned by a "reverse-genetic" approach from cell suspension cultures of the plant Rauvolfia serpentina (Apocynaceae) and functionally expressed in Escherichia coli as the N-terminal His(6)-tagged protein. PR displays a broad substrate acceptance, converting 16 out of 28 tested compounds with reducible carbonyl function which belong to three substrate groups: benzaldehyde, cinnamic aldehyde derivatives and monoterpenoid indole alkaloids. The enzyme has an extraordinary selectivity in the group of alkaloids. Sequence alignments define PR as a new member of the aldo-keto reductase (AKR) super family, exhibiting the conserved catalytic tetrad Asp52, Tyr57, Lys84, His126. Site-directed mutagenesis of each of these functional residues to an alanine residue results in >97.8% loss of enzyme activity, in compounds of each substrate group. PR represents the first example of the large AKR-family which is involved in the biosynthesis of plant monoterpenoid indole alkaloids. In addition to a new esterase, PR significantly extends the Rauvolfia alkaloid network to the novel group of peraksine alkaloids.

Identification and simultaneous quantification of five alkaloids in Piper longum L. by HPLC-ESI-MS(n) and UFLC-ESI-MS/MS and their application to Piper nigrum L.

PubMed

Liu, Hao-Long; Luo, Rong; Chen, Xiao-Qing; Ba, Yin-Ying; Zheng, Li; Guo, Wei-Wei; Wu, Xia

2015-06-15

A simple, effective and suitable UFLC-ESI-MS/MS method was firstly developed to simultaneously determine five characteristic constituents (piperine, piperlonguminine, Δα,β-dihydropiperlonguminine, pellitorine and piperanine) of Piper longum L. The total alkaloids of P. longum L. was prepared. The alkaloid contents of Piper nigrum L. and P. longum L. were compared. The analysis was carried out in multiple reaction monitoring scan mode. The method showed a good specificity, linearity (R(2)>0.995), stability (RSD<2.53%), repeatability (RSD<2.58%), and recovery (90.0-103.5%). The limits of detection and limits of quantification of five alkaloids were in the range of 0.02-0.03 and 0.05-0.10 ng/mL, respectively. The intra- and inter-day precision was less than 9.30% and 9.55%, respectively. The validation results confirmed that the method could simultaneously determine the target alkaloids in the sample. Furthermore, the identities of the alkaloids were verified by HPLC-ESI-MS/MS. Compared with P. nigrum, P. longum had lower piperine content but was enriched in the other four alkaloids. Copyright © 2015 Elsevier Ltd. All rights reserved.

Chemical UPLC-ESI-MS/MS profiling of aconitum alkaloids and their metabolites in rat plasma and urine after oral administration of Aconitum carmichaelii Debx. Root extract.

PubMed

Zhang, Mingjie; Wang, Manman; Liang, Jiajia; Wen, Yongqing; Xiong, Zhili

2018-02-01

In this paper, an ultra high performance liquid chromatography tandem mass spectrometric (UPLC-ESI-MS/MS) method in positive ion mode was established to systematically identify and to compare the major aconitum alkaloids and their metabolites in rat plasma and urine after oral administration of Fuzi extract. A total twenty-nine components including twenty-five C19-diterpenoid alkaloids and four C20-diterpenoid alkaloids were identified in Fuzi extract. Thirteen of the parent components and five metabolites were detected in rat plasma and sixteen parent compounds and six metabolites in urine. These parent components found in rat plasma and urine were mainly C19-diterpenoid alkaloids. All of the metabolites in vivo were demethylated metabolites (phase I metabolites), which suggested that demethylation was the major metabolic pathway of aconitum alkaloids in vivo. A comparison of the parent components in rat plasma and urine revealed that 3-deoxyacontine was found in plasma but not in urine, while kalacolidine, senbusine and 16-β-hydroxycardiopetaline existed in urine but not in plasma, which indicated that most alkaloids components were disposed and excreted in prototype form. This research provides some important information for further metabolic investigations of Fuzi in vivo. Copyright © 2017 John Wiley & Sons, Ltd.

Permeability of ergot alkaloids across the blood-brain barrier in vitro and influence on the barrier integrity

PubMed Central

Mulac, Dennis; Hüwel, Sabine; Galla, Hans-Joachim; Humpf, Hans-Ulrich

2012-01-01

Scope Ergot alkaloids are secondary metabolites of Claviceps spp. and they have been in the focus of research for many years. Experiments focusing on ergotamine as a former migraine drug referring to the ability to reach the brain revealed controversial results. The question to which extent ergot alkaloids are able to cross the blood-brain barrier is still not answered. Methods and results In order to answer this question we have studied the ability of ergot alkaloids to penetrate the blood-brain barrier in a well established in vitro model system using primary porcine brain endothelial cells. It could clearly be demonstrated that ergot alkaloids are able to cross the blood-brain barrier in high quantities in only a few hours. We could further identify an active transport for ergometrine as a substrate for the BCRP/ABCG2 transporter. Investigations concerning barrier integrity properties have identified ergocristinine as a potent substance to accumulate in these cells ultimately leading to a weakened barrier function. Conclusion For the first time we could show that the so far as biologically inactive described 8-(S) isomers of ergot alkaloids seem to have an influence on barrier integrity underlining the necessity for a risk assessment of ergot alkaloids in food and feed. PMID:22147614

Nicotinic plant poisoning.

PubMed

Schep, Leo J; Slaughter, Robin J; Beasley, D Michael G

2009-09-01

A wide range of plants contain nicotinic and nicotinic-like alkaloids. Of this diverse group, those that have been reported to cause human poisoning appear to have similar mechanisms of toxicity and presenting patients therefore have comparable toxidromes. This review describes the taxonomy and principal alkaloids of plants that contain nicotinic and nicotinic-like alkaloids, with particular focus on those that are toxic to humans. The toxicokinetics and mechanisms of toxicity of these alkaloids are reviewed and the clinical features and management of poisoning due to these plants are described. This review was compiled by systematically searching OVID MEDLINE and ISI Web of Science. This identified 9,456 papers, excluding duplicates, all of which were screened. Reviewed plants and their principal alkaloids. Plants containing nicotine and nicotine-like alkaloids that have been reported to be poisonous to humans include Conium maculatum, Nicotiana glauca and Nicotiana tabacum, Laburnum anagyroides, and Caulophyllum thalictroides. They contain the toxic alkaloids nicotine, anabasine, cytisine, n-methylcytisine, coniine, n-methylconiine, and gamma-coniceine. These alkaloids act agonistically at nicotinic-type acetylcholine (cholinergic) receptors (nAChRs). The nicotinic-type acetylcholine receptor can vary both in its subunit composition and in its distribution within the body (the central and autonomic nervous systems, the neuromuscular junctions, and the adrenal medulla). Agonistic interaction at these variable sites may explain why the alkaloids have diverse effects depending on the administered dose and duration of exposure. Nicotine and nicotine-like alkaloids are absorbed readily across all routes of exposure and are rapidly and widely distributed, readily traversing the blood-brain barrier and the placenta, and are freely distributed in breast milk. Metabolism occurs predominantly in the liver followed by rapid renal elimination. Following acute exposure, symptoms typically follow a biphasic pattern. The early phase consists of nicotinic cholinergic stimulation resulting in symptoms such as abdominal pain, hypertension, tachycardia, and tremors. The second inhibitory phase is delayed and often heralded by hypotension, bradycardia, and dyspnea, finally leading to coma and respiratory failure. Supportive care is the mainstay of management with primary emphasis on cardiovascular and respiratory support to ensure recovery. Exposure to plants containing nicotine and nicotine-like alkaloids can lead to severe poisoning but, with prompt supportive care, patients should make a full recovery.

An Efficient High-performance Liquid Chromatography Combined with Electrospray Ionization Tandem Mass Spectrometry Method to Elaborate the Changes of Components Between the Raw and Processed Radix Aconitum kusnezoffii

PubMed Central

Wang, Beibei; Ji, Jiaojiao; Zhao, Shuang; Dong, Jie; Tan, Peng; Na, Shengsang; Liu, Yonggang

2016-01-01

Background: Crude radix Aconitum kusnezoffii (RAK) has great toxicity. Traditional Chinese medicine practice proved that processing may decrease its toxicity. In our previous study, we had established a new method of RAK processing (Paozhi). However, the mechanism is yet not perfect. Objective: To explore the related mechanism of processing through comparing the chemical contents. Materials and Methods: A new processing method of RAK named stoving (Hong Zhi) was used. In particular, RAK was stored at 110°C for 8 h, and then high performance liquid chromatography combined with electrospray ionization tandem mass spectrometry (HPLC-ESI-MSn) was developed for the detection of the alkaloids of the crude and processed RAK decoction pieces. Results: Thirty components of the crude RAK were discovered, among which, 23 alkaloids were identified. Meanwhile, 23 ingredients were detected in the processed RAK decoction pieces, among which, 20 alkaloids were determined yet. By comparison, eight alkaloids were found in both crude and processed RAK decoction pieces, 15 alkaloids were not found in the crude RAK, however, 10 new constituents yield after processing, which are 10-OH-hypaconine, 10-OH-mesaconine, isomer of bullatine A, 14-benzoyl-10-OH-mesaconine, 14-benzoyl-10-OH-aconine, 14-benzoyl-10-OH-hypaconine, dehydrated aconitine, 14-benzoylaconine, chuanfumine, dehydrated mesaconitine. Conclusion: The present study showed that significant change of alkaloids was detected in RAK before and after processing. Among them, the highly toxic diester alkaloids decreased and the less toxic monoester alkaloids increased. Moreover, the concentration changes significantly. HPLC-ESI-MSn are Efficient to elaborate the mechanism of reduction of toxicity and enhancement efficacy after processing. SUMMARY Stoving is a simple and effective method for the processing of radix Aconitum kusnezoffii.In the positive mode, the characteristic fragmentations of Aconitum alkaloids were obtained.The highly toxic alkaloids have decreased, and the new constituents appeared, which has explained successfully the processing mechanism of radix Aconitum kusnezoffii in chemistry. PMID:27019554

Single cell subtractive transcriptomics for identification of cell-specifically expressed candidate genes of pyrrolizidine alkaloid biosynthesis.

PubMed

Sievert, Christian; Beuerle, Till; Hollmann, Julien; Ober, Dietrich

2015-09-01

Progress has recently been made in the elucidation of pathways of secondary metabolism. However, because of its diversity, genetic information concerning biosynthetic details is still missing for many natural products. This is also the case for the biosynthesis of pyrrolizidine alkaloids. To close this gap, we tested strategies using tissues that express this pathway in comparison to tissues in which this pathway is not expressed. As many pathways of secondary metabolism are known to be induced by jasmonates, the pyrrolizidine alkaloid-producing species Heliotropium indicum, Symphytum officinale, and Cynoglossum officinale of the Boraginales order were treated with methyl jasmonate. An effect on pyrrolizidine alkaloid levels and on transcript levels of homospermidine synthase, the first specific enzyme of pyrrolizidine alkaloid biosynthesis, was not detectable. Therefore, a method was developed by making use of the often observed cell-specific production of secondary compounds. H. indicum produces pyrrolizidine alkaloids exclusively in the shoot. Homospermidine synthase is expressed only in the cells of the lower leaf epidermis and the epidermis of the stem. Suggesting that the whole pathway of pyrrolizidine alkaloid biosynthesis might be localized in these cells, we have isolated single cells of the upper and lower epidermis by laser-capture microdissection. The resulting cDNA preparations have been used in a subtractive transcriptomic approach. Quantitative real-time polymerase chain reaction has shown that the resulting library is significantly enriched for homospermidine-synthase-coding transcripts providing a valuable source for the identification of further genes involved in pyrrolizidine alkaloid biosynthesis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Identification and Quantification of the Main Active Anticancer Alkaloids from the Root of Glaucium flavum

PubMed Central

Bournine, Lamine; Bensalem, Sihem; Wauters, Jean-Noël; Iguer-Ouada, Mokrane; Maiza-Benabdesselam, Fadila; Bedjou, Fatiha; Castronovo, Vincent; Bellahcène, Akeila; Tits, Monique; Frédérich, Michel

2013-01-01

Glaucium flavum is used in Algerian folk medicine to remove warts (benign tumors). Its local appellations are Cheqiq el-asfar and Qarn el-djedyane. We have recently reported the anti-tumoral activity of Glaucium flavum root alkaloid extract against human cancer cells, in vitro and in vivo. The principal identified alkaloid in the extract was protopine. This study aims to determine which component(s) of Glaucium flavum root extract might possess potent antitumor activity on human cancer cells. Quantitative estimation of Glaucium flavum alkaloids was realized by HPLC-DAD. Glaucium flavum effect on human normal and cancer cell viability was determined using WST-1 assay. Quantification of alkaloids in Glaucium flavum revealed that the dried root part contained 0.84% of protopine and 0.07% of bocconoline (w/w), while the dried aerial part contained only 0.08% of protopine, glaucine as the main alkaloid, and no bocconoline. In vitro evaluation of the growth inhibitory activity on breast cancer and normal cells demonstrated that purified protopine did not reproduce the full cytotoxic activity of the alkaloid root extract on cancer cell lines. On the other hand, bocconoline inhibited strongly the viability of cancer cells with an IC50 of 7.8 μM and only a low cytotoxic effect was observed against normal human cells. Our results showed for the first time that protopine is the major root alkaloid of Glaucium flavum. Finally, we are the first to demonstrate a specific anticancer effect of Glaucium flavum root extract against breast cancer cells, which can be attributed, at least in part, to bocconoline. PMID:24317429

Distribution of Aconitum alkaloids in autopsy cases of aconite poisoning.

PubMed

Niitsu, Hisae; Fujita, Yuji; Fujita, Sachiko; Kumagai, Reiko; Takamiya, Masataka; Aoki, Yasuhiro; Dewa, Koji

2013-04-10

Aconite is a well-known toxic-plant containing Aconitum alkaloids such as aconitines, benzoylaconines, and aconins. We describe here the distribution of Aconitum alkaloids detected by liquid chromatography-tandem mass spectrometry (LC/MS/MS) in three autopsy cases of suicide by aconite poisoning. Case 1: a male in his fifties had eaten aconite leaves. The concentrations of jesaconitine in cardiac blood, urine, and kidney were 12.1 ng/ml, 993.0 ng/ml, and 114.2 ng/g, respectively. Case 2: a female in her fifties had eaten aconite root. The aconite root in the stomach included a high level of mesaconitine. The concentrations of mesaconitine in cardiac blood, liver, and kidney were 69.1 ng/ml, 960.9 ng/g, and 776.9 ng/g, respectively. Case 3: a male in his sixties had drunk liquor in which aconite root had been soaked. The concentrations of mesaconitine and aconitine in cardiac blood were 259.5 and 228.5 ng/ml, respectively. The Aconitum alkaloid levels were very high in the liver. The absorption of ethanol and Aconitum alkaloids might have been increased because of his having undergone total gastrectomy. In all three cases, the Aconitum alkaloid levels were high in the liver and kidney and low in the heart and cerebrum. The level in the cerebrum was lower than that in blood. Data on the distribution of the Aconitum alkaloids in the body in cases of aconite poisoning is useful to elucidate various actions of aconite alkaloids. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Effect of ergot alkaloids associated with fescue toxicosis on hepatic cytochrome P450 and antioxidant proteins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Settivari, Raja S.; Evans, Tim J.; Rucker, Ed

Intake of ergot alkaloids found in endophyte-infected tall fescue grass is associated with decreased feed intake and reduction in body weight gain. The liver is one of the target organs of fescue toxicosis with upregulation of genes involved in xenobiotic metabolism and downregulation of genes associated with antioxidant pathways. It was hypothesized that short-term exposure of rats to ergot alkaloids would change hepatic cytochrome P450 (CYP) and antioxidant expression, as well as reduce antioxidant enzyme activity and hepatocellular proliferation rates. Hepatic gene expression of various CYPs, selected nuclear receptors associated with the CYP induction, and antioxidant enzymes were measured usingmore » real-time PCR. Hepatic expression of CYP, antioxidant and proliferating cell nuclear antigen (PCNA) proteins were measured using Western blots. The CYP3A1 protein expression was evaluated using primary rat hepatocellular cultures treated with ergovaline, one of the major ergot alkaloids produced by fescue endophyte, in order to assess the direct role of ergot alkaloids in CYP induction. The enzyme activities of selected antioxidants were assayed spectrophotometrically. While hepatic CYP and nuclear receptor expression were increased in ergot alkaloid-exposed rats, the expression and activity of antioxidant enzymes were reduced. This could potentially lead to increased oxidative stress, which might be responsible for the decrease in hepatocellular proliferation after ergot alkaloid exposure. This study demonstrated that even short-term exposure to ergot alkaloids can potentially induce hepatic oxidative stress which can contribute to the pathogenesis of fescue toxicosis.« less

Identification and quantification of the main active anticancer alkaloids from the root of Glaucium flavum.

PubMed

Bournine, Lamine; Bensalem, Sihem; Wauters, Jean-Noël; Iguer-Ouada, Mokrane; Maiza-Benabdesselam, Fadila; Bedjou, Fatiha; Castronovo, Vincent; Bellahcène, Akeila; Tits, Monique; Frédérich, Michel

2013-12-02

Glaucium flavum is used in Algerian folk medicine to remove warts (benign tumors). Its local appellations are Cheqiq el-asfar and Qarn el-djedyane. We have recently reported the anti-tumoral activity of Glaucium flavum root alkaloid extract against human cancer cells, in vitro and in vivo. The principal identified alkaloid in the extract was protopine. This study aims to determine which component(s) of Glaucium flavum root extract might possess potent antitumor activity on human cancer cells. Quantitative estimation of Glaucium flavum alkaloids was realized by HPLC-DAD. Glaucium flavum effect on human normal and cancer cell viability was determined using WST-1 assay. Quantification of alkaloids in Glaucium flavum revealed that the dried root part contained 0.84% of protopine and 0.07% of bocconoline (w/w), while the dried aerial part contained only 0.08% of protopine, glaucine as the main alkaloid, and no bocconoline. In vitro evaluation of the growth inhibitory activity on breast cancer and normal cells demonstrated that purified protopine did not reproduce the full cytotoxic activity of the alkaloid root extract on cancer cell lines. On the other hand, bocconoline inhibited strongly the viability of cancer cells with an IC50 of 7.8 µM and only a low cytotoxic effect was observed against normal human cells. Our results showed for the first time that protopine is the major root alkaloid of Glaucium flavum. Finally, we are the first to demonstrate a specific anticancer effect of Glaucium flavum root extract against breast cancer cells, which can be attributed, at least in part, to bocconoline.

Chemical comparison of goldenseal (Hydrastis canadensis L.) root powder from three commercial suppliers.

PubMed

Weber, Holly A; Zart, Matthew K; Hodges, Andrew E; Molloy, H Michael; O'Brien, Brandon M; Moody, Leslie A; Clark, Alice P; Harris, Roger K; Overstreet, J Diane; Smith, Cynthia S

2003-12-03

The characterization of herbal materials is a significant challenge to analytical chemists. Goldenseal (Hydrastis canadensis L.), which has been chosen for toxicity evaluation by NIEHS, is among the top 15 herbal supplements currently on the market and contains a complex mixture of indigenous components ranging from carbohydrates and amino acids to isoquinoline alkaloids. One key component of herbal supplement production is botanical authentication, which is also recommended prior to initiation of efficacy or toxicological studies. To evaluate material available to consumers, goldenseal root powder was obtained from three commercial suppliers and a strategy was developed for characterization and comparison that included Soxhlet extraction, HPLC, GC-MS, and LC-MS analyses. HPLC was used to determine the weight percentages of the goldenseal alkaloids berberine, hydrastine, and canadine in the various extract residues. Palmatine, an isoquinoline alkaloid native to Coptis spp. and other common goldenseal adulterants, was also quantitated using HPLC. GC-MS was used to identify non-alkaloid constituents in goldenseal root powder, whereas LC-MS was used to identify alkaloid components. After review of the characterization data, it was determined that alkaloid content was the best biomarker for goldenseal. A 20-min ambient extraction method for the determination of alkaloid content was also developed and used to analyze the commercial material. All three lots of purchased material contained goldenseal alkaloids hydrastinine, berberastine, tetrahydroberberastine, canadaline, berberine, hydrastine, and canadine. Material from a single supplier also contained palmatine, coptisine, and jatrorrhizine, thus indicating that the material was not pure goldenseal. Comparative data for three commercial sources of goldenseal root powder are presented.

In-silico Investigation of Antitrypanosomal Phytochemicals from Nigerian Medicinal Plants

PubMed Central

Setzer, William N.; Ogungbe, Ifedayo V.

2012-01-01

Background Human African trypanosomiasis (HAT), a parasitic protozoal disease, is caused primarily by two subspecies of Trypanosoma brucei. HAT is a re-emerging disease and currently threatens millions of people in sub-Saharan Africa. Many affected people live in remote areas with limited access to health services and, therefore, rely on traditional herbal medicines for treatment. Methods A molecular docking study has been carried out on phytochemical agents that have been previously isolated and characterized from Nigerian medicinal plants, either known to be used ethnopharmacologically to treat parasitic infections or known to have in-vitro antitrypanosomal activity. A total of 386 compounds from 19 species of medicinal plants were investigated using in-silico molecular docking with validated Trypanosoma brucei protein targets that were available from the Protein Data Bank (PDB): Adenosine kinase (TbAK), pteridine reductase 1 (TbPTR1), dihydrofolate reductase (TbDHFR), trypanothione reductase (TbTR), cathepsin B (TbCatB), heat shock protein 90 (TbHSP90), sterol 14α-demethylase (TbCYP51), nucleoside hydrolase (TbNH), triose phosphate isomerase (TbTIM), nucleoside 2-deoxyribosyltransferase (TbNDRT), UDP-galactose 4′ epimerase (TbUDPGE), and ornithine decarboxylase (TbODC). Results This study revealed that triterpenoid and steroid ligands were largely selective for sterol 14α-demethylase; anthraquinones, xanthones, and berberine alkaloids docked strongly to pteridine reductase 1 (TbPTR1); chromenes, pyrazole and pyridine alkaloids preferred docking to triose phosphate isomerase (TbTIM); and numerous indole alkaloids showed notable docking energies with UDP-galactose 4′ epimerase (TbUDPGE). Polyphenolic compounds such as flavonoid gallates or flavonoid glycosides tended to be promiscuous docking agents, giving strong docking energies with most proteins. Conclusions This in-silico molecular docking study has identified potential biomolecular targets of phytochemical components of antitrypanosomal plants and has determined which phytochemical classes and structural manifolds likely target trypanosomal enzymes. The results could provide the framework for synthetic modification of bioactive phytochemicals, de novo synthesis of structural motifs, and lead to further phytochemical investigations. PMID:22848767

Semiquantitative determination of ergot alkaloids in seed, straw, and digesta samples using a competitive enzyme-linked immunosorbent assay.

PubMed

Schnitzius, J M; Hill, N S; Thompson, C S; Craig, A M

2001-05-01

Ergot alkaloids present in endophyte-infected (E+) tall fescue cause fescue toxicosis and other toxic effects in livestock that consume infected plant tissue, leading to significant financial losses in livestock production each year. The predominant method currently in use for quantifying ergot alkaloid content in plant tissue is through high-performance liquid chromatography (HPLC), which quantifies the amount of ergovaline, one of many ergot alkaloids in E+ plant tissue. The enzyme-linked immunosorbent assay (ELISA) method used in this study detects quantities of nonspecific ergot alkaloids and therefore accounts for greater amounts of the total ergot alkaloid content in E+ tissue than does HPLC. The ELISA can also be used to more expediently analyze a larger number of forage samples without sophisticated and costly analytical equipment and therefore could be more desirable in a diagnostic setting. The purpose of this study was to evaluate the between-day and within-run variability of the ELISA and to determine the binding efficiency of 6 ergot alkaloids to the 15F3.E5 antibody used in the competitive ELISA to ascertain its feasibility as a quick analysis tool for ergot alkaloids. Straw samples had an average coefficient of variation (CV) for concentration of 10.2% within runs and 18.4% between runs, and the seed samples had an average CV for concentration of 13.3% within runs and 24.5% between runs. The grass tissue-based lysergic acid standard curve calculated from the ELISA had an average r2 of 0.99, with a CV of 2.1%. Ergocryptine, ergocristine, ergocornine, and ergotamine tartrate did not bind strongly to the 15F3.E5 antibody because of the presence of large side groups on these molecules, which block their binding to the antibody, whereas ergonovine and ergonovine maleate were bound much more efficiently because of their structural similarity to lysergic acid. Clarified rumen fluid was tested as an additional matrix for use in the ergot alkaloid competitive ELISA to determine whether future livestock metabolism experiments on the postingestion fate of ergot alkaloids in ruminants could utilize this assay as a quick screening tool for the presence of nonspecific ergot alkaloids in rumen fluid. HPLC and ELISA procedures were compared for their ability in determining ergot alkaloid toxicity based on the repeatability of the procedures and on the specific compounds they measure. The ratio of ELISA concentration to HPLC concentration (ergovaline) varied from 2.00 to 2.81 in seed samples and from 0.62 to 8.66 in straw samples, showing no consistent pattern between the 2 methods. Based on the lack of data at present for the identity of the toxin causing endophyte toxicosis and the lack of agreement between the ergovaline HPLC and ELISA analyses for ergot alkaloids, each method is equally valid as an indicator of toxicityand is the best means for determining the quantity of the specific toxin(s) they measure.

New pyrrolizidine alkaloids from Heliotropium crassifolium.

PubMed

Farsam, H; Yassa, N; Sarkhail, P; Shafiee, A

2000-05-01

Heliotropium crassifolium Boiss, (Boraginaceae) from a population of Ilam, western region of Iran was studied for pyrrolizidine alklaoids (PAs). Four alkaloids have been identified: europine 1, europine N-oxide 2 and a new pyrrolizidine alkaloids ilamine 3 and its N-oxide 4, respectively. Their structures were elucidated by IR, 1H-NMR and EIMS data.

Anagyrine desensitization of peripheral nicotinic acetylcholine receptors. A potential biomarker of quinolizidine alkaloid teratogenesis in cattle.

USDA-ARS?s Scientific Manuscript database

Anagyrine, a teratogenic quinolizidine alkaloid found in certain Lupinus spp., has been proposed to undergo metabolism by pregnant cattle to a piperidine alkaloid which acts inhibit fetal movement, the putative mechanism behind crooked calf syndrome. The objective of this study was to test the hypot...

27 CFR 21.99 - Brucine alkaloid.

Code of Federal Regulations, 2011 CFR

2011-04-01

..., characteristic of strychnine, will be obtained. (d) Sulfate test. No white precipitate is formed that is not... Brucine alkaloid. (a) Identification test. Add a few drops of concentrated nitric acid to about 10 mg of... tetrahydrate melts at 105 °C. while the anhydrous form melts at 178 °C. (c) Strychnine test. Brucine alkaloid...

27 CFR 21.99 - Brucine alkaloid.

Code of Federal Regulations, 2012 CFR

2012-04-01

..., characteristic of strychnine, will be obtained. (d) Sulfate test. No white precipitate is formed that is not... Brucine alkaloid. (a) Identification test. Add a few drops of concentrated nitric acid to about 10 mg of... tetrahydrate melts at 105 °C. while the anhydrous form melts at 178 °C. (c) Strychnine test. Brucine alkaloid...

27 CFR 21.99 - Brucine alkaloid.

Code of Federal Regulations, 2014 CFR

2014-04-01

..., characteristic of strychnine, will be obtained. (d) Sulfate test. No white precipitate is formed that is not... Brucine alkaloid. (a) Identification test. Add a few drops of concentrated nitric acid to about 10 mg of... tetrahydrate melts at 105 °C. while the anhydrous form melts at 178 °C. (c) Strychnine test. Brucine alkaloid...

27 CFR 21.99 - Brucine alkaloid.

Code of Federal Regulations, 2013 CFR

2013-04-01

..., characteristic of strychnine, will be obtained. (d) Sulfate test. No white precipitate is formed that is not... Brucine alkaloid. (a) Identification test. Add a few drops of concentrated nitric acid to about 10 mg of... tetrahydrate melts at 105 °C. while the anhydrous form melts at 178 °C. (c) Strychnine test. Brucine alkaloid...

27 CFR 21.99 - Brucine alkaloid.

Code of Federal Regulations, 2010 CFR

2010-04-01

..., characteristic of strychnine, will be obtained. (d) Sulfate test. No white precipitate is formed that is not... Brucine alkaloid. (a) Identification test. Add a few drops of concentrated nitric acid to about 10 mg of... tetrahydrate melts at 105 °C. while the anhydrous form melts at 178 °C. (c) Strychnine test. Brucine alkaloid...

A pharmacodynamic comparison of piperidine and pyridine alkaloid actions at fetal muscle-type nicotinic acetylcholine receptors (nAChR)

USDA-ARS?s Scientific Manuscript database

Piperidine and pyridine alkaloids are found in many species of plants including Lobelia spp., Conium spp., Nicotiana spp., and Lupinus spp. Some of these alkaloids cause multiple congenital contracture deformities (MCC) and cleft palates in cattle, pigs, sheep, and goats. The mechanism behind MCC ...

The comparative toxicity of a reduced, crude comfrey (Symphytum officinale) alkaloid extract and the pure, comfrey-derived pyrrolizidine alkaloids, lycopsamine and intermedine in chicks (Gallus gallus domesticus)

USDA-ARS?s Scientific Manuscript database

Comfrey (Symphytum officinale), a commonly used herb, contains dehydropyrrolizidine alkaloids (DHPAs) that, as a group of bioactive metabolites, are potentially hepatotoxic, pneumotoxic, genotoxic and carcinogenic. Consequently, regulatory agencies and international health organizations have recomm...

Pro-toxic 1,2-Dehydropyrrolizidine alkaloid esters, including unprecedented 10-membered macrocyclic diesters, in the medicinally-used Alafia cf. caudata and Amphineurion marginatum (Apocynaceae: Apocynoideae: Nerieae and Apoc

USDA-ARS?s Scientific Manuscript database

The attraction of pyrrolizidine alkaloid-pharmacophagous insects indicated the presence of pro-toxic dehydropyrrolizidine alkaloids in Alafia cf. caudata Stapf (Nerieae: Alafinae) and Amphineurion marginatum (Roxb.) D.J. Middleton (Apocyneae: Amphineuriinae). Subsequently, monoesters of retronecine ...

Protein and alkaloid patterns of the floral nectar in some solanaceous species.

PubMed

Kerchner, András; Darók, Judit; Bacskay, Ivett; Felinger, Attila; Jakab, Gábor; Farkas, Ágnes

2015-09-01

The family Solanaceae includes several melliferous plants, which tend to produce copious amounts of nectar. Floral nectar is a chemically complex aqueous solution, dominated by sugars, but minor components such as amino acids, proteins, flavonoids and alkaloids are present as well. This study aimed at analysing the protein and alkaloid profile of the nectar in seven solanaceous species. Proteins were examined with SDS-PAGE and alkaloids were analyzed with HPLC. The investigation of protein profile revealed significant differences in nectar-protein patterns not only between different plant genera, but also between the three Nicotiana species investigated. SDS-PAGE suggested the presence of several Nectarin proteins with antimicrobial activity in Nicotiana species. The nectar of all tobacco species contained the alkaloid nicotine, N. tabacum having the highest nicotine content. The nectar of Brugmansia suaveolens, Datura stramonium, Hyoscyamus niger and Lycium barbarum contained scopolamine, the highest content of which was measured in B. suaveolens. The alkaloid concentrations in the nectars of most solanaceous species investigated can cause deterrence in honeybees, and the nectar of N. rustica and N. tabacum can be considered toxic for honeybees.

Study on the Alkaloids in Tibetan Medicine Aconitum pendulum Busch by HPLC-MSn Combined with Column Chromatography.

PubMed

Wang, Beibei; Dong, Jie; Ji, Jiaojiao; Yuan, Jiang; Wang, Jiali; Wu, Jiarui; Tan, Peng; Liu, Yonggang

2016-01-01

A rapid, convenient and effective identification method of alkaloids was established and an attempt on isolating and analyzing the alkaloids in Aconitum pendulum Busch was conducted successfully. In this article, four high-content components including deoxyaconitine, benzoylaconine, aconine and neoline were isolated by using column chromatography. HPLC-MS(n)was employed to deduce the regulations of fragmentation of diterpenoid alkaloids which displayed a characteristic behavior of loss of CO(28u), CH3COOH(60u), CH3OH(32u), H2O(18u) and C6H5COOH(122u). Then, according to fragmentation regulation of mass spectrometry, 42 alkaloids were found inA. pendulum Among them, 38 compounds were identified and 29 alkaloids were reported for the first time for this herb. Therefore, this means that HPLC-MS(n)combined with column chromatography could work as an effective and reliable tool for rapid identification of the chemical components of herbal medicine. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Actions of piperidine alkaloid teratogens at fetal nicotinic acetylcholine receptors.

PubMed

Green, Benedict T; Lee, Stephen T; Panter, Kip E; Welch, Kevin D; Cook, Daniel; Pfister, James A; Kem, William R

2010-01-01

Teratogenic alkaloids are found in many species of plants including Conium maculatum L., Nicotiana glauca, Nicotiana tabaccum, and multiple Lupinus spp. Fetal musculoskeletal defects produced by alkaloids from these plants include arthrogyropisis, scoliosis, torticollis, kyposis, lordosis, and cleft palate. A pharmacodynamic comparison of the alkaloids ammodendrine, anabasine, anabaseine, anagyrine, and coniine in SH-SY5Y cells and TE-671 cells was made. These alkaloids and their enantiomers were more effective in depolarizing TE-671 cells which express the human fetal-muscle type nicotinic acetylcholine receptor (nAChR) relative to SH-SY5Y cells which predominately express autonomic nAChRs. The rank order of potency in TE-671 cells was: anabaseine>(+)-anabasine>(-)-anabasine > (+/-)-anabasine>anagyrine>(-)-coniine > (+/-)-coniine>(+)-coniine>(+/-)-ammodendrine>(+)-ammodendrine. The rank order potency in SH-SY5Y cells was: anabaseine>(+)-anabasine>(-)-coniine>(+)-coniine>(+)-ammodendrine>anagyrine>(-)-anabasine>(+/-)-coniine>(+/-)-anabasine>(-)-ammodendrine. The actions of these alkaloids at nAChRs in both cell lines could be distinguished by their maximum effects in depolarizing cell membrane potential. The teratogenic action of these compounds may be related to their ability to activate and subsequently desensitize nAChRs.

Metabolism and Resistance of Fusarium spp. to the Manzamine Alkaloids via a Putative Retro Pictet-Spengler Reaction and Utility of the Rational Design of Antimalarial and Antifungal Agents

PubMed Central

Farr, Lorelei Lucas; Gholipour, Abbas; Wedge, David E.; Hamann, Mark T.

2014-01-01

As a part of our continuing investigation of the manzamine alkaloids we studied the in vitro activity of the β-carboline containing manzamine alkaloids against Fusarium solani, Fusarium oxysporium, and Fusarium proliferatum by employing several bioassay techniques including one-dimensional direct bioautography, dilution, and plate susceptibility, and microtiter broth assays. In addition, we also studied the metabolism of the manzamine alkaloids by Fusarium spp. in order to facilitate the redesign of the compounds to prevent resistance of Fusarium spp. through metabolism. The present research reveals that the manzamine alkaloids are inactive against Fusarium spp. and the fungi transform manzamines via hydrolysis, reduction, and a retro Pictet-Spengler reaction. This is the first report to demonstrate an enzymatically retro Pictet-Spengler reaction. The results of this study reveal the utility of the rational design of metabolically stable antifungal agents from this class and the development of manzamine alkaloids as antimalarial drugs through the utilization of Fusarium’s metabolic products to reconstruct the molecule. PMID:24553735

[Chemoprotective effect of the alkaloid extract of Melocactus bellavistensis against colon cancer induced in rats using 1,2-dimethylhydrazine].

PubMed

Ríos-León, Karla; Fuertes-Ruiton, Cesar; Arroyo, Jorge; Ruiz, Julio

2017-01-01

To determine the toxicity and chemoprotective effect of the alkaloid extract of Melocactus bellavistensis against colon cancer induced in rats using 1,2-dimethylhydrazine (DMH). The alkaloid extract was obtained from the fleshy part of M. bellavistensis, and an acute toxicity test was then carried out on 30 mice of the Balb C57 strain. To assess its chemoprotective effect, colon cancer was induced in 45 Holtzman rats using DMH according to the following experimental design: one control group received 2 mL/kg sodium polysorbate, and four groups received 20 mg/kg DMH plus 0, 1, 5, or 10 mg/kg M. bellavistensis alkaloid extract. With a sample of 5 g of alkaloid extract, an LD50 greater than 1000 mg/mL was determined in the acute toxicity test. Histological indicators revealed that the 5 and 10 mg/kg doses had significant anti-tumor activity with 100% neoplasia inhibition against DMH- induced colon cancer in rats. Under experimental conditions, the alkaloid extract of M. bellavistensis has a chemoprotective effect against DMH-induced colon cancer in rats.

Screening and optimization of some inorganic salts for the production of ergot alkaloids from Penicillium species using surface culture fermentation process.

PubMed

Shahid, Memuna Ghafoor; Nadeem, Muhammad; Baig, Shahjehan; Cheema, Tanzeem Akbar; Atta, Saira; Ghafoor, Gul Zareen

2016-03-01

The present study deals with the production of ergot alkaloids from Penicillium commune and Penicillium citrinum, using surface culture fermentation process. Impact of various inorganic salts was tested on the production of ergot alkaloids during the optimization studies of fermentation medium such as impact of various concentration levels of succinic acid, ammonium chloride, MgSO4, FeSO4, ZnSO4, pH and the effect of various incubation time periods was also determined on the production of ergot alkaloids from Penicillium commune and Penicillium citrinum. Highest yield of ergot alkaloids was obtained when Penicillium commune and Penicillium citrinum that were grown on optimum levels of ingredients such as 2 g succinic acid, 1.5 and 2 g NH4Cl, 1.5 g MgSO4, 1 g FeSO4, 1 and 1.5 g ZnSO4 after 21 days of incubation time period using pH 5 at 25(°)C incubation temperature in the fermentation medium. Ergot alkaloids were determined using Spectrophotometry and Thin Layer Chromatography (TLC) techniques.

[Evaluation of crude drugs by means of colorimeter (I). Study on correlation between color and alkaloids content of coptidis rhizoma].

PubMed

Yoshimitsu, Michiyo; Qu, Xian-You; Luo, Wei-Zao; Qin, Song-Yun

2014-05-01

To examine the correlation between alkaloids content and L*, a* and b* color indices of Rhizoma Coptidis for quality control. A colorimeter was used for the measurement of reflected light from sieved powder samples using the CIE 1976 L* a* b* color system. The content of six alkaloids were determined by HPLC. The correlation between alkaloids content and color indices of Rhizoma Coptidis was analyzed. When the particle size of Rhizoma Coptidis was less than 355 microm and the colorimeter parameters were set as measurement diameter of 3 mm, observation degree of 10, and light source of F2 and F7, the measured color was significantly correlated with total alkaloids content (r = 0.793, P < 0.05). As light source of F11, the measured color was significantly correlated with berberine content (r = 0.867, P < 0.01). The correlation between the color of powdered Coptidis Rhizoma and its alkaloids contents was found in this study. Measurment of the color of Coptidis Rhizoma can be used to assess its quality.

Diversity in aconitine alkaloid profile of Aconitum plants in Hokkaido contrasts with their genetic similarity.

PubMed

Kakiuchi, Nobuko; Atsumi, Toshiyuki; Higuchi, Mari; Kamikawa, Shohei; Miyako, Haruka; Wakita, Yuriko; Ohtsuka, Isao; Hayashi, Shigeki; Hishida, Atsuyuki; Kawahara, Nobuo; Nishizawa, Makoto; Yamagishi, Takashi; Kadota, Yuichi

2015-01-01

Aconite tuber is a representative crude drug for warming the body internally in Japanese Kampo medicine and Chinese traditional medicine. The crude drug is used in major prescriptions for the aged. Varieties of Aconitum plants are distributed throughout the Japanese Islands, especially Hokkaido. With the aim of identifying the medicinal potential of Aconitum plants from Hokkaido, 107 specimens were collected from 36 sites in the summer of 2011 and 2012. Their nuclear DNA region, internal transcribed spacer (ITS), and aconitine alkaloid contents were analyzed. Phylogenic analysis of ITS by maximum parsimony analysis showed that the majority of the specimens were grouped into one cluster (cluster I), separated from the other cluster (cluster II) consisting of alpine specimens. The aconitine alkaloid content of the tuberous roots of 76 specimens showed 2 aspects-specimens from the same collection site showed similar aconitine alkaloid profiles, and cluster I specimens from different habitats showed various alkaloid profiles. Environmental pressure of each habitat is presumed to have caused the morphology and aconitine alkaloid profile of these genetically similar specimens to diversify.

Claviceps nigricans and Claviceps grohii: their alkaloids and phylogenetic placement.

PubMed

Pazoutová, Sylvie; Olsovská, Jana; Sulc, Miroslav; Chudícková, Milada; Flieger, Miroslav

2008-06-01

Claviceps purpurea, C. grohii, C. zizaniae, C. cyperi, and C. nigricans are closely related ergot fungi and form a monophyletic clade inside the genus Claviceps. Analysis of alkaloid content in C. nigricans sclerotia using UPLC detected ergocristine (1), ergosine (2), alpha-ergocryptine (3), and ergocristam (4). Alkaloids 1, 3, and 4 were found in the sclerotia of C. grohii. The content of 4 in the mixture of alkaloids from C. nigricans and C. grohii (over 8% and over 20%, respectively) was unusually high. Submerged shaken cultures of C. nigricans produced no alkaloids, whereas C. grohii culture formed small amounts (15 mg L (-1)) of extracellular clavines and 1. In the previously used HPLC method the ergocristam degradation product could have been obscured by the ergosine peak. Therefore sclerotia of a C. purpurea habitat-specific population G2 with the dominant production of 1 and 2 have been reanalyzed, but no 4 was detected. The phylogeny of the C. purpurea-related species group is discussed with regard to alkaloid-specific nonribosomal peptide synthetase duplication leading to the production of two main ergopeptines instead of a single product.

Ricinoleic acid as a marker for ergot impurities in rye and rye products.

PubMed

Franzmann, Carolin; Wächter, Johannes; Dittmer, Natascha; Humpf, Hans-Ulrich

2010-04-14

Ergot alkaloid and ricinoleic acid contents of 63 ergot sclerotia samples from rye throughout Germany of the harvest years 2006-2009 were determined. Alkaloid contents were analyzed by means of high-performance liquid chromatography with fluorescence detection (HPLC-FLD) and ricinoleic acid contents by means of gas chromatography with flame ionization detection (GC-FID). Ergot alkaloid amounts ranged from 0.01 to 0.2 g/100 g of sclerotia with an average amount of 0.08 g/100 g. Ergotamine and ergocristine were identified as lead alkaloids representing 57% (w/w) of the total alkaloid content. The average ricinoleic acid amount in the ergot sclerotia was 10.3 g/100 g. Because of the low variation of ricinoleic acid content in the ergot sclerotia, a new method for the determination of ricinoleic acid in rye products as a marker for ergot contaminations was developed. This method allows the determination of ergot impurities as low as 0.01% (w/w). Furthermore, 29 rye products (flours, bread mix, bread) were investigated for their ricinoleic acid and ergot alkaloid contents.

Ergot Alkaloids of the Family Clavicipitaceae.

PubMed

Florea, Simona; Panaccione, Daniel G; Schardl, Christopher L

2017-05-01

Ergot alkaloids are highly diverse in structure, exhibit diverse effects on animals, and are produced by diverse fungi in the phylum Ascomycota, including pathogens and mutualistic symbionts of plants. These mycotoxins are best known from the fungal family Clavicipitaceae and are named for the ergot fungi that, through millennia, have contaminated grains and caused mass poisonings, with effects ranging from dry gangrene to convulsions and death. However, they are also useful sources of pharmaceuticals for a variety of medical purposes. More than a half-century of research has brought us extensive knowledge of ergot-alkaloid biosynthetic pathways from common early steps to several taxon-specific branches. Furthermore, a recent flurry of genome sequencing has revealed the genomic processes underlying ergot-alkaloid diversification. In this review, we discuss the evolution of ergot-alkaloid biosynthesis genes and gene clusters, including roles of gene recruitment, duplication and neofunctionalization, as well as gene loss, in diversifying structures of clavines, lysergic acid amides, and complex ergopeptines. Also reviewed are prospects for manipulating ergot-alkaloid profiles to enhance suitability of endophytes for forage grasses.

Ergot Alkaloids of the Family Clavicipitaceae

PubMed Central

Florea, Simona; Panaccione, Daniel G.; Schardl, Christopher L.

2017-01-01

Ergot alkaloids are highly diverse in structure, exhibit diverse effects on animals, and are produced by diverse fungi in the phylum Ascomycota, including pathogens and mutualistic symbionts of plants. These mycotoxins are best known from the fungal family Clavicipitaceae and are named for the ergot fungi that, through millennia, have contaminated grains and caused mass poisonings, with effects ranging from dry gangrene to convulsions and death. However, they are also useful sources of pharmaceuticals for a variety of medical purposes. More than a half-century of research has brought us extensive knowledge of ergot-alkaloid biosynthetic pathways from common early steps to several taxon-specific branches. Furthermore, a recent flurry of genome sequencing has revealed the genomic processes underlying ergot-alkaloid diversification. In this review, we discuss the evolution of ergot-alkaloid biosynthesis genes and gene clusters, including roles of gene recruitment, duplication and neofunctionalization, as well as gene loss, in diversifying structures of clavines, lysergic acid amides, and complex ergopeptines. Also reviewed are prospects for manipulating ergot-alkaloid profiles to enhance suitability of endophytes for forage grasses. PMID:28168931

Bitterness and antibacterial activities of constituents from Evodia rutaecarpa.

PubMed

Liang, Xiaoguang; Li, Bo; Wu, Fei; Li, Tingzhao; Wang, Youjie; Ma, Qiang; Liang, Shuang

2017-03-29

Bitter herbs are important in Traditional Chinese Medicine and the Electronic Tongue (e-Tongue) is an instrument that can be trained to evaluate bitterness of bitter herbs and their constituents. The aim of this research was to evaluate bitterness of limonoids and alkaloids from Evodia rutaecarpa to demonstrate that they are main bitter material basic of E. rutaecarpa. Nine compounds, including limonoids, indoloquinazoline alkaloids and quinolone alkaloids, were isolated, identified and analyzed by the e-Tongue. Additionally, the antibacterial activities of the nine compounds were evaluated against E. coli and S. aureus. All the nine compounds had bitter taste and antibacterial activities to some extent. Among them, limonoids, which were the bitterest compounds, had greater antibacterial activities than alkaloids. And there is a positive correlation between bitter taste and antibacterial activities. It was confirmed in our study that limonoids, indoloquinazoline alkaloids and quinolone alkaloids are main bitter material basic of E. rutaecarpa based on two evaluation methods of e-Tongue and antibacterial experiment. In addition, the e-Tongue technique is a suitable new method to measure bitter degree in herbs.

Geographic distribution of three alkaloid chemotypes of Croton lechleri.

PubMed

Milanowski, Dennis J; Winter, Rudolph E K; Elvin-Lewis, Memory P F; Lewis, Walter H

2002-06-01

Three known alkaloids, isoboldine (2), norisoboldine (1), and magnoflorine (8), have been isolated for the first time from Croton lechleri, a source of the wound healing latex "sangre de grado". An HPLC system was developed, and a large number of latex and leaf samples of C. lechleri from 22 sites in northern Peru and Ecuador were analyzed to gain an understanding of the natural variation in alkaloid content for the species. Up to six alkaloids were found to occur in the leaves including, in addition to those listed above, thaliporphine (3), glaucine (4), and taspine (9), whereas the latex contained only 9. Taspine (9) is the component that has been previously found to be responsible for the wound healing activity of C. lechleri latex, and its mean concentration throughout the range examined was found to be 9% of the latex by dry weight. In addition, three chemotypes are defined based on the alkaloid content of the leaves, and the geographic distribution of these chemotypes is discussed along with a quantitative analysis of the alkaloid content as a function of chemotype.

The biosynthesis of hydroxycinnamoyl quinate esters and their role in the storage of cocaine in Erythroxylum coca.

PubMed

Torre, José Carlos Pardo; Schmidt, Gregor W; Paetz, Christian; Reichelt, Michael; Schneider, Bernd; Gershenzon, Jonathan; D'Auria, John C

2013-07-01

Complexation of alkaloids is an important strategy plants utilize to facilitate storage in vacuoles and avoid autotoxicity. Previous studies have implicated hydroxycinnamoyl quinate esters in the complexation of purine alkaloids in Coffea arabica. The goal of this study was to determine if Erythroxylum coca uses similar complexation agents to store abundant tropane alkaloids, such as cocaine and cinnamoyl cocaine. Metabolite analysis of various E. coca organs established a close correlation between levels of coca alkaloids and those of two hydroxycinnamoyl esters of quinic acid, chlorogenic acid and 4-coumaroyl quinate. The BAHD acyltransferase catalyzing the final step in hydroxycinnamoyl quinate biosynthesis was isolated and characterized, and its gene expression found to correlate with tropane alkaloid accumulation. A physical interaction between chlorogenic acid and cocaine was observed and quantified in vitro using UV and NMR spectroscopic methods yielding similar values to those reported for a caffeine chlorogenate complex in C. arabica. These results suggest that storage of cocaine and other coca alkaloids in large quantities in E. coca involves hydroxycinnamoyl quinate esters as complexation partners. Copyright © 2012 Elsevier Ltd. All rights reserved.

Indolizidine 239Q and Quinolizidine 275I. Major alkaloids in two Argentinian bufonid toads (Melanophryniscus)

PubMed Central

Daly, John W.; Garraffo, H. Martin; Spande, Thomas F.; Yeh, Herman J. C.; Peltzer, Paola M.; Cacivio, Pedro; Baldo, J. Diego; Faivovich, Julián

2008-01-01

Alkaloid profiles in skin of poison frogs/toads (Dendrobatidae, Mantellidae, Bufonidae, and Myobatrachidae) are highly dependent on diet and hence on the nature of habitat. Extracts of the two species of toads (Melanophryniscus klappenbachi and M. cupreuscapularis) from similar habitats in the Corrientes/Chaco Provinces of Argentina have similar profiles of alkaloids, which differ considerably from profiles from other Melanophryniscus species from Brazil, Uruguay and Argentina. Structures of two major alkaloids 239Q (1) and 275I (2) were determined by mass, FTIR, and NMR spectral analysis as 5Z,9Z-3-(1-hydroxybutyl)-5-propylindolizidine and 6Z,10E-4,6-di(pent-4-enyl) quinolizidine, respectively. A third alkaloid, 249F (3), is postulated to be a homopumiliotoxin with an unprecedented conjugated exocyclic diene moiety. PMID:18848574

Effect of alkaloids derived from jellyfish (Aeginura sp.) on the intestinal histopathology and relative percentage survival (RPS) of tiger grouper (Epinephelus fuscoguttatus) infected by Vibrio harveyi

NASA Astrophysics Data System (ADS)

Andayani, S.; Fajar, M.; Rahman, M. F.

2018-04-01

The purposes of this research were to determine the effect of alkaloid jellyfish compounds on intestinal histopathology of tiger grouper and to determine the best doses to the relative percent survival (RPS) of tiger grouper. The method of this research was descriptive with completely randomized design. The treatment of active alkaloid compound on feed was investigated for 28 days. The fish were then challenged with Vibrio harveyi at 105 CFU/cell for 7 days. Alkaloids were added to the feed with the doses (g alkaloid/kg feed) of 0 (control); A = 0.5; B = 0.75; C = 1.0; and D = 1.25. The intestinal histopathology and RPS were observed. The best RPS was found at a treatment of C with the value of 100 %.

Brassicaceae contain nortropane alkaloids.

PubMed

Brock, Andrea; Herzfeld, Tobias; Paschke, Reinhard; Koch, Marcus; Dräger, Birgit

2006-09-01

The report of cochlearine, the 3-hydroxybenzoate ester of tropine found in Cochlearia officinalis, Brassicaceae, initiated a screening for tropane alkaloids in Cochlearia species and for calystegines in further Brassicaceae. All ten Cochlearia species investigated contained cochlearine, tropine, and pseudotropine. Calystegines, nortropane alkaloids deriving from pseudotropine, were also identified in all Cochlearia species and accumulated up to 0.5% dry mass in leaves. Brassicaceae species of all major lineages of the family were analysed for calystegines. Of the 43 species included in the study, 18 accumulated calystegines of various structures. This is the first screening of Brassicaceae for products of the tropane alkaloid pathway, which is known as characteristic for plants of Solanaceae family. The identification of calystegines in all branches of the Brassicaceae family including Aethionema, a species at the basis of the family, suggests tropane alkaloids as secondary compound typical for Brassicaceae.

Determination of tropane alkaloids by heart cutting reversed phase - Strong cation exchange two dimensional liquid chromatography.

PubMed

Long, Zhen; Zhang, Yanhai; Gamache, Paul; Guo, Zhimou; Steiner, Frank; Du, Nana; Liu, Xiaoda; Jin, Yan; Liu, Xingguo; Liu, Lvye

2018-01-01

Current Chinese Pharmacopoeia (ChP) standards apply liquid extraction combined with one dimensional liquid chromatography (1DLC) method for determining alkaloids in herbal medicines. The complex pretreatments lead to a low analytical efficiency and possible component loss. In this study, a heart cutting reversed phase - strong cation exchange two dimensional liquid chromatography (RP - SCX 2DLC) approach was optimized for simultaneously quantifying tropane alkaloids (anisodine, scopolamine and hyoscyamine) in herbal medicines and herbal medicine tablets without further treatment of the filtered extract. The chromatographic conditions were systematically optimized in terms of column type, mobile phase composition and flow rate. To improve peak capacity and obtain symmetric peak shape of alkaloids, a polar group embedded C18 column combined with chaotropic salts was used in the first dimension. To remove the disturbance of non-alkaloids, achieve unique selectivity and acquire symmetric peak shape of alkaloids, an SCX column combined with phosphate buffer was used in the second dimension. Method validation was performed in terms of linearity, precision (0.54-0.82%), recovery (94.1-105.2%), limit of detection (LOD) and limit of quantification (LOQ) of the three analytes varied between 0.067-0.115mgL -1 and 0.195-0.268mgL -1 , respectively. The method demonstrated superiority over 1DLC method in respect of resolution (less alkaloid co-eluted), sample preparation (no pretreatment procedure) and transfer rate (minimum component loss). The optimized RP - SCX 2DLC approach was subsequently applied to quantify target alkaloids in five herbal medicines and herbal medicine tablets from three different manufactures. The results demonstrated that the developed heart cutting RP - SCX 2DLC approach represented a new, strategically significant methodology for the quality evaluation of tropane alkaloid in related herbal medicines that involve complex chemical matrix. Copyright © 2017. Published by Elsevier B.V.

Synthesis of avenanthramides using engineered Escherichia coli.

PubMed

Lee, Su Jin; Sim, Geun Young; Kang, Hyunook; Yeo, Won Seok; Kim, Bong-Gyu; Ahn, Joong-Hoon

2018-03-22

Hydroxycinnamoyl anthranilates, also known as avenanthramides (avns), are a group of phenolic alkaloids with anti-inflammatory, antioxidant, anti-itch, anti-irritant, and antiatherogenic activities. Some avenanthramides (avn A-H and avn K) are conjugates of hydroxycinnamic acids (HC), including p-coumaric acid, caffeic acid, and ferulic acid, and anthranilate derivatives, including anthranilate, 4-hydroxyanthranilate, and 5-hydroxyanthranilate. Avns are primarily found in oat grain, in which they were originally designated as phytoalexins. Knowledge of the avns biosynthesis pathway has now made it possible to synthesize avns through a genetic engineering strategy, which would help to further elucidate their properties and exploit their beneficial biological activities. The aim of the present study was to synthesize natural avns in Escherichia coli to serve as a valuable resource. We synthesized nine avns in E. coli. We first synthesized avn D from glucose in E. coli harboring tyrosine ammonia lyase (TAL), 4-coumarate:coenzyme A ligase (4CL), anthranilate N-hydroxycinnamoyl/benzoyltransferase (HCBT), and anthranilate synthase (trpEG). A trpD deletion mutant was used to increase the amount of anthranilate in E. coli. After optimizing the incubation temperature and cell density, approximately 317.2 mg/L of avn D was synthesized. Avn E and avn F were then synthesized from avn D, using either E. coli harboring HpaBC and SOMT9 or E. coli harboring HapBC alone, respectively. Avn A and avn G were synthesized by feeding 5-hydroxyanthranilate or 4-hydroxyanthranilate to E. coli harboring TAL, 4CL, and HCBT. Avn B, avn C, avn H, and avn K were synthesized from avn A or avn G, using the same approach employed for the synthesis of avn E and avn F from avn D. Using different HCs, nine avns were synthesized, three of which (avn D, avn E, and avn F) were synthesized from glucose in E. coli. These diverse avns provide a strategy to synthesize both natural and unnatural avns, setting a foundation for exploring the biological activities of diverse avns.

Neopetrosiamine A, biologically active bis-piperidine alkaloid from the Caribbean Sea sponge Neopetrosia proxima

PubMed Central

Wei, Xiaomei; Nieves, Karinel; Rodríguez, Abimael D.

2010-01-01

A new tetracyclic bis-piperidine alkaloid, neopetrosiamine A (1), has been extracted from the marine sponge Neopetrosia proxima collected off the west coast of Puerto Rico. The structure of compound 1 was elucidated by analysis of spectroscopic data coupled with careful comparisons of its 1H and 13C NMR data with those of a well-known 3-alkylbispiperidine alkaloid model. The new alkaloid displayed strong in vitro cytotoxic activity against a panel of cancer cell lines as well as in vitro inhibitory activity against the pathogenic microbes Mycobacterium tuberculosis and Plasmodium falciparum. PMID:20727745

In vitro antiplasmodial, antiamoebic, and cytotoxic activities of some monomeric isoquinoline alkaloids.

PubMed

Wright, C W; Marshall, S J; Russell, P F; Anderson, M M; Phillipson, J D; Kirby, G C; Warhurst, D C; Schiff, P L

2000-12-01

Twenty-one alkaloids have been assessed for activities against Plasmodium falciparum (multidrug- resistant strain K1) in vitro; 18 of these are reported for the first time. Two protoberberine alkaloids, dehydrodiscretine and berberine, were found to have antiplasmodial IC(50) values less than 1 M, while seven alkaloids-allocrytopine, columbamine, dehydroocoteine, jatrorrhizine, norcorydine, thalifendine, and ushinsunine-had values between 1 and 10 M. These results are discussed in the context of structure-activity relationships. Compounds were also assessed for antiamoebic and cytotoxic activities, but none was significantly active except for berberine, which was moderately cytotoxic.

Applications of Iridium-Catalyzed Asymmetric Allylic Substitution Reactions in Target-Oriented Synthesis.

PubMed

Qu, Jianping; Helmchen, Günter

2017-10-17

Metal catalyzed allylic substitution is a cornerstone of organometallic and synthetic chemistry. Enantioselective versions have been developed with catalysts derived from transition metals, most notably molybdenum, nickel, ruthenium, rhodium, iridium, palladium, and copper. The palladium- and the iridium-catalyzed versions have turned out to be particularly versatile in organic synthesis because of the very broad scope of the nucleophile and great functional group compatibility. Assets of the iridium-catalyzed reaction are the formation of branched, chiral products from simple monosubstituted allylic substrates, high degrees of regio- and enantioselectivity, and use of modular, readily available chiral ligands. The possibility to use carbon, nitrogen, oxygen, and sulfur compounds as well as fluoride as nucleophiles allows a wide range of chiral building blocks to be prepared. Our Account begins with the presentation of fundamental reaction schemes and chiral ligands. We will focus our discussion on reactions promoted by phosphoramidite ligands, though numerous chiral ligands have been employed. The subsequent section presents a brief overview of reaction mechanism and experimental conditions. Two versions of the iridium-catalyzed allylic substitution have emerged. In type 1 reactions (introduced in 1997), linear allylic esters are commonly used as substrates under basic reaction conditions. In type 2 reactions (introduced in 2007), environmentally friendly branched allylic alcohols can be reacted under acidic conditions; occasionally, derivatives of allylic alcohols have also been applied. A unique feature of the type 2 reactions is that highly electrophilic allylic intermediates can be brought to reaction with weakly activated alkenes. The subsequent text is ordered according to the strategies followed to transform allylic substitution products to desired targets, most of which are natural products or drugs. Syntheses starting with an intermolecular allylic substitution are discussed first. Some fairly complex targets, for example, the potent nitric oxide inhibitor (-)-nyasol and the drug (-)-protrifenbute, have been synthesized via less than five steps from simple starting materials. Most targets discussed are cyclic compounds. Intermolecular allylic substitution with subsequent ring closing metathesis is a powerful strategy for their synthesis. Highlights are stereodivergent syntheses of Δ 9 -tetrahydrocannabinols (THC), wherein iridium- and organocatalysis are combined (dual catalysis). The combination of allylic alkylation with a Diels-Alder reaction was utilized to synthesize the ketide apiosporic acid and the drug fesoterodine (Toviaz). Sequential allylic amination, hydroboration and Suzuki-Miyaura coupling generates enones suitable for conjugate addition reactions; this strategy was employed in syntheses of a variety of alkaloids, for example, the poison frog alkaloid (+)-cis-195A (pumiliotoxin C). Intramolecular substitutions offer interesting possibilities to build up stereochemical complexity via short synthetic routes. For example, in diastereoselective cyclizations of chiral compounds, substrate control can be overruled by catalyst control in order to generate cis- and trans-isomers selectively from a given precursor. This approach was used to prepare a variety of piperidine and pyrrolidine alkaloids. Finally, complex polycyclic structures, including the structurally unusual indolosesquiterpenoid mycoleptodiscin A, have been generated diastereo- and enantioselectively from olefins by polyene cyclizations and from electron-rich arenes, such as indoles, in dearomatization reactions.

Ultraviolet-visible study on acid-base equilibria of aporphine alkaloids with antiplasmodial and antioxidant activities from Alseodaphne corneri and Dehaasia longipedicellata

PubMed Central

Zahari, Azeana; Ablat, Abdulwali; Omer, Noridayu; Nafiah, Mohd Azlan; Sivasothy, Yasodha; Mohamad, Jamaludin; Khan, Mohammad Niyaz; Awang, Khalijah

2016-01-01

The UV-vis spectra of isocorydine 1, norisocorydine 2 and boldine 3 were studied in 2% v/v acetonitrile, at constant ionic strength (0.1 M NaCl, 35 degree Celsius). The pKa values of isocorydine 1 and norisocorydine 2 were 11.75 and 12.07, respectively. Boldine 3 gave a pKa value of 9.16 and 10.44. All of the alkaloids 1–3 were stable at physiological pH; thereby all of them will not ionize, thus permitting the basic nitrogen to be protonated and accumulated within the acidic food vacuole of Plasmodium via pH trapping. Subsequently, acidic food vacuoles that have been neutralized by alkaloids would result in enhancement of the antiplasmodial activity. The alkaloids showed antiplasmodial activity against Plasmodium falciparum and antioxidant activities; DPPH radical scavenging, metal chelating and ferric reducing power. The antioxidant properties of the alkaloids under investigation revealed that in addition to the antiplasmodial activity, the alkaloids can also prevent oxidative damage. It can be prevented by binding free heme and neutralizing the electrons produced during the Plasmodium falciparum mediated haemoglobin destruction in the host. Slightly basic properties of the aforementioned alkaloids, along with their antioxidant activities, are advantageous in improving the suppression of malaria infection that cause less damage to the host. PMID:26898753

Identification, occurrence and activity of quinazoline alkaloids in Peganum harmala.

PubMed

Herraiz, Tomás; Guillén, Hugo; Arán, Vicente J; Salgado, Antonio

2017-05-01

Peganum harmala L. is a medicinal plant from the Mediterranean region and Asia currently used for recreative psychoactive purposes (Ayahuasca analogue), and increasingly involved in toxic cases. Its psychopharmacological and toxicological properties are attributed to quinazoline and β-carboline alkaloids. In this work three major quinazoline alkaloids were isolated from P. harmala extracts and characterized as peganine (vasicine), deoxypeganine (deoxyvasicine) and a novel compound identified by HPLC-DAD-MS and NMR as peganine β-d-glucopyranosyl-(1 → 6)-β-d-glucopyranoside (peganine glycoside). Peganine appeared in flowers and leaves in high levels; high amounts of deoxypeganine and peganine were found in immature and green fruits whereas peganine and peganine glycoside accumulated in high amount in dry seeds reaching up to 1 and 3.9% (w/w), respectively. Roots and stems contained low amount of quinazolines. Seeds extracts containing both quinazoline and β-carboline alkaloids potently inhibited human monoamine oxidase (MAO)-A. However, quinazoline alkaloids did not contribute to MAO inhibition that was due to β-carbolines, suggesting that MAO-related psychoactive or toxic actions do not arise from quinazolines. Quinazoline alkaloids were poor radical scavengers in the ABTS assay whereas seed extracts had good activity. Quinazoline alkaloids are known to exert bronchodilator and abortifacient actions, and could contribute to such effects reported in P. harmala. Copyright © 2017 Elsevier Ltd. All rights reserved.

Binding of DNA-binding alkaloids berberine and palmatine to tRNA and comparison to ethidium: Spectroscopic and molecular modeling studies

NASA Astrophysics Data System (ADS)

Islam, Md. Maidul; Pandya, Prateek; Chowdhury, Sebanti Roy; Kumar, Surat; Kumar, Gopinatha Suresh

2008-11-01

The interaction of two natural protoberberine plant alkaloids berberine and palmatine with tRNA phe was studied using various biophysical techniques and molecular modeling and the data were compared with the binding of the classical DNA intercalator, ethidium. Circular dichroic studies revealed that the tRNA conformation was moderately perturbed on binding of the alkaloids. The cooperative binding of both the alkaloids and ethidium to tRNA was revealed from absorbance and fluorescence studies. Fluorescence quenching studies advanced a conclusion that while berberine and palmatine are partially intercalated, ethidium is fully intercalated on the tRNA molecule. The binding of the alkaloids as well as ethidium stabilized the tRNA melting, and the binding constant evaluated from the averaged optical melting temperature data was in agreement with fluorescence spectral-binding data. Differential scanning calorimetry revealed that the tRNA melting showed three close transitions that were affected on binding of these small molecules. Molecular docking calculations performed showed the preferred regions of binding of these small molecules on the tRNA. Taken together, the results suggest that the binding of the alkaloids berberine and palmatine on the tRNA structure appears to be mostly by partial intercalation while ethidium intercalates fully on the tRNA. These results further advance our knowledge on the molecular aspects on the interaction of these alkaloids to tRNA.

Variation of alkaloid contents and antimicrobial activities of Papaver rhoeas L. growing in Turkey and northern Cyprus.

PubMed

Çoban, İlkcan; Toplan, Gizem Gülsoy; Özbek, Berna; Gürer, Çağlayan Unsal; Sarıyar, Günay

2017-12-01

Papaver rhoeas L. (Papaveraceae) corn poppy, widely distributed in Turkey, is used to make a cough syrup for children, as a tea for disturbed sleep, for pain relief and as a sedative in folk medicine. Samples of P. rhoeas collected from eight different locations in Turkey and three from northern Cyprus were investigated for their alkaloid content and screened for their antimicrobial activities. From the aerial parts of P. rhoeas samples, alkaloids were isolated by column and preparative thin-layer chromatography. The alkaloids were identified by comparing their spectral data (UV, IR and 1 H-NMR) and TLC Rf values with those of authentic samples. The antimicrobial study was carried out by microbroth dilution technique against six strains of bacteria and three strains of fungi. Twelve different alkaloids belonging to proaporphine (mecambrine), aporphine (roemerine), promorphinan (salutaridine), protopine (coulteropine and protopine) and rhoeadine (epiglaucamine, glaucamine, glaudine, isorhoeadine, isorhoeagenine, rhoeadine and rhoeagenine) groups were isolated. The most significant activity was observed with the alkaloid extract of P8 against Staphylococcus aureus with a MIC value of 1.22 μg/mL and against Candida albicans with a MIC value of 2.4 μg/mL. The results indicate that P. rhoeas samples (P8 and P9), which contain roemerine as their major alkaloid, were the most active extracts.

Chemical Diversity and Defence Metabolism: How Plants Cope with Pathogens and Ozone Pollution

PubMed Central

Iriti, Marcello; Faoro, Franco

2009-01-01

Chemical defences represent a main trait of the plant innate immune system. Besides regulating the relationship between plants and their ecosystems, phytochemicals are involved both in resistance against pathogens and in tolerance towards abiotic stresses, such as atmospheric pollution. Plant defence metabolites arise from the main secondary metabolic routes, the phenylpropanoid, the isoprenoid and the alkaloid pathways. In plants, antibiotic compounds can be both preformed (phytoanticipins) and inducible (phytoalexins), the former including saponins, cyanogenic glycosides and glucosinolates. Chronic exposure to tropospheric ozone (O3) stimulates the carbon fluxes from the primary to the secondary metabolic pathways to a great extent, inducing a shift of the available resources in favour of the synthesis of secondary products. In some cases, the plant defence responses against pathogens and environmental pollutants may overlap, leading to the unspecific synthesis of similar molecules, such as phenylpropanoids. Exposure to ozone can also modify the pattern of biogenic volatile organic compounds (BVOC), emitted from plant in response to herbivore feeding, thus altering the tritrophic interaction among plant, phytophagy and their natural enemies. Finally, the synthesis of ethylene and polyamines can be regulated by ozone at level of S-adenosylmethionine (SAM), the biosynthetic precursor of both classes of hormones, which can, therefore, mutually inhibit their own biosynthesis with consequence on plant phenotype. PMID:20111684

Caste specific alkaloid chemistry of Solenopsis maboya and S

Treesearch

J.A. Torres; V.E. Zottig; J.E. Co; T.H. Jones; R.R. Snelling

2001-01-01

Examination of the alkaloids of Solenopsis maboya Snelling and comparison with those previously found in S. Torresi Snelling, reveals a clear example of caste-specific alkaloid production in the queens and workers of each species. The queens of Solenopsis maboya contain a single piperidine while the workers produce a different piperidine along with two indolizidine...

Rauniticine-allo-oxindole B and rauniticinic-allo acid B, new heteroyohimbine-type oxindole alkaloids from the stems of Malaysian Uncaria longiflora var. pteropoda.

PubMed

Salim, Fatimah; Ismail, Nor Hadiani; Awang, Khalijah; Ahmad, Rohaya

2011-08-04

Two new heteroyohimbine-type oxindole alkaloids, rauniticine-allo-oxindole B and rauniticinic-allo acid B, have been successfully isolated from the stems extract of Malaysian Uncaria longiflora var. pteropoda. The structures of the two new alkaloids were determined by spectroscopic analysis.

Case Study: Recovery from ergot alkaloid-induced vasoconstriction for steers conditioned to grazing seedhead suppressed and unsuppressed pastures of toxic endophyte-infected tall fescue

USDA-ARS?s Scientific Manuscript database

Chemical seedhead suppression of toxic endophyte-infected (E+) tall fescue can enhance steer performance and mitigate the adverse effects of ergot alkaloids on cattle physiology; however, it is not known if seedhead suppression can mitigate alkaloid-induced vasoconstriction and improve post-graze pe...