Convolinine,a new alkaloid from <Emphasis Type="Italic">Convolvulus subhirsutus</Emphasis> of Uzbekistan flora

Several alkaloids of known structure and the new base convolinine were isolated from total alkaloids from the aerial part of Convolvulis subhirsutus growing in Uzbekistan. It has been established that convolinine is an N-hydroxyethyl derivative of convolvine and has the structure (±)-3α-(3,4-dimethoxybenzoyl)-N-hydroxyethylnortropane based on spectral data and an x-ray crystal structure.     

Structure d'alcaloïdes indoliques doubles d'un type nouveau

The Structure of bis-indoline alkaloids of a novel type The structure of folicangine 4 , a bis-indoline alkaloid from the leaves of Voacanga africana, is obtained by correlation with voafolidine 3a and isovoafolidine 3b . It requires an ether bridge between the two parts of the molecule, as in subsessiline (amataine 5a ). Subsessiline-lactone, from the leaves of Voacanga thouarsii has structure 5b proved by correlation with 5a . The CD. curves of double-indole alkaloids of vobtusine type are given (Table 3).     

Characterization of tropane and cinnamamide alkaloids from Scopolia tangutica by high‐performance liquid chromatography with quadrupole time‐of‐flight tandem mass spectrometry

Scopolia tangutica is a traditional Chinese medicine used for antispasmodic, anesthesia, analgesia, and sedation. Its medicinal activity is associated to alkaloid constituents, including tropane and cinnamamide types. Low content of alkaloids in plant makes them difficult to be isolated and identified. The present work developed an effective method to quickly characterize alkaloids from Scopolia tangutica by high‐performance liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry. Thirteen reference compounds were studied for their fragmentation pathways, including five tropane alkaloids and eight cinnamamide ones. Alkaloid constituent was analyzed by an optimized high‐performance liquid chromatography method and mass spectrometry analysis to achieve systematic characterization of alkaloids from Scopolia tangutica. As a result, 53 compounds were identified, including 21 tropane alkaloids (eight new ones), 18 caffeoyl ones (ten new ones) and 14 dicaffeoyl ones (seven new ones). It was important to provide rich information in phytochemical study and structure‐guided isolation of important compounds from this plant.     

Shawurensine,a new C<Subscript>19</Subscript>-diterpenoid alkaloid from <Emphasis Type="Italic">Delphinium shawurense</Emphasis>

The new norditerpenoid alkaloid shawurensine in addition to β-sitosterol and the known alkaloids elatin, delbrulin, and methyllycaconitine were isolated from Delphinium shawurense. A structure for shawurensine was proposed based on spectral data. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 248–250, May–June, 2007.     

Macrocyclische Spermidinalkaloide aus Pleurostylia africana LOES. 9. Mitteilung über Celastraceen-Inhaltsstoffe

Macrocyclic Spermidine Alcaloids from Pleurostylia africana LOES . The structure of pleurostyline, a new macrocyclic spermidine alkaloid from Pleurostylia africana (Celastraceae), has been elucidated mainly by ¹H- and ¹³C-NMR.-spectroscopy. Pleurostyline represents a new structure type in which spermidine is incorporated in a 13-membered lactam ring to which an additional cinnamoyl residue is fused to yield a 7-membered ring. The same plant contains also the spermidine alkaloids celacinnine and cellallocinnine of which ¹³C- and high field ¹H-NMR.-measurements have been carried out for the first time. Both alkaloids are interconvertible by UV.-irradiation. In addition the existence of rotational isomerism of one amide group of these alkaloids has been demonstrated by NMR.-spectroscopy.     

Conpropine,a new alkaloid from the aerial part of <Emphasis Type="Italic">Convolvulus subhirsutus</Emphasis> from Uzbekistan

The known alkaloid convolvidine and a new base conpropine, for which the structure N-propylconvolvine was proposed, were isolated from total alkaloids from the aerial part of Convolvulus subhirsutus. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 601–602, November–December, 2008.     

pH‐Zone‐refining counter‐current chromatography for two new lipo‐alkaloids separated from refined alkaline extraction of Kusnezoff monkshood root

An efficient and refined method for the separation of six aconitine‐type alkaloids from the alkaline prepared “Kusnezoff monkshood root” was established. It is the first study that two new lipo‐alkaloids were successfully isolated from refined sample by pH‐zone‐refining counter‐current chromatography rather than synthetic method. It was of interest that a great deal of lipo‐alkaloids was produced in crude extract from the alkalization of “Kusnezoff monkshood root.” A refined sample method was proposed to enrich two types of alkaloids by liquid–liquid extraction, i.e. lipo‐alkaloids and monoester‐diterpenoid alkaloids. The pH‐zone‐refining counter‐current chromatography was performed with an optimized two‐phase solvent system composed of n‐hexane‐ethyl acetate–methanol–water (3:5:4:5, v/v), where upper organic phase was added to 3 mmol/L triethylamine as a retainer and lower aqueous mobile phase was added to 3 mmol/L hydrochloric acid as an eluter. As a result, six aconitum alkaloids, including two lipo‐alkaloids (8‐lino‐14‐benzoylaconine, 8‐pal‐14‐benzoylaconine), three monoester‐diterpenoid alkaloids (14‐benzoylmesaconine, 14‐benzoylaconine, beyzoyldeoxyaconine), and one aconine alkaloid (neoline) were acquired from the plant at the same time. The anti‐inflammatory activities of the two new lipo‐alkaloids were compared to the six alkaloids in vitro, in cyclo‐oxygen‐ase‐2 inhibition assays. The separation mechanism of six alkaloids by pH‐zone‐refining counter‐current chromatography was illustrated.     

Ruspolia hypercrateriformisM.R.: Isolierung und Strukturaufklärung von neuen Pyrrolidin-Alkaloiden. 169. Mitt. über organische Naturstoffe

Ruspolia hypercrateriformis M.R. : Isolation and Structure Elucidation of New Pyrrolidine Alkaloids Three new pyrrolidine alkaloids have been isolated from Ruspolia hypercrateriformis, which belongs to the plant family of Acanthaceae. The structure of the alkaloids ruspolinone ( 1 ), norruspolinone ( 2 ) and norruspoline ( 3 ) (Scheme 1) has been elucidated by means of spectroscopic data of the pure compounds and their derivatives, by chemical transformation fo 2 to 1 by methylation, by trans-formation of 3 and 2 to identical hydrogenation products, and by comparison of degradation products with synthetically prepared model compounds.     

Mass‐spectrometry‐directed analysis and purification of pyrrolizidine alkaloid cis/trans isomers in Gynura japonica

Pyrrolizidine alkaloids are highly hepatotoxic natural chemicals that produce irreversible chronic and acute hepatotoxic effects on human beings. Purification of large amounts of pyrrolizidine alkaloids is necessary for toxicity studies. In this study, an efficient method for targeted analysis and purification of pyrrolizidine alkaloid cis/trans isomers from herbal materials was developed for the first time. Targeted analysis of the hepatotoxic pyrrolizidine alkaloids was performed by liquid chromatography with tandem mass spectrometry (precursor ion scan and daughter ion scan), and the purification of pyrrolizidine alkaloids was achieved with a mass‐directed auto purification system. The extraction and preparative liquid chromatography conditions were optimized. The developed method was applied to analysis of Gynura japonica (Thunb.) Juel., a herbal medicine traditionally used for detumescence and relieving pain but is potentially hepatotoxic as it contains pyrrolizidine alkaloids. Twelve pyrrolizidine alkaloids (six cis/trans isomer pairs) were identified with reference compounds or characterized by liquid chromatography with tandem mass spectrometry, and five individual pyrrolizidine alkaloids, including (E)‐seneciphylline, seneciphylline, integerrimine, senecionine, and seneciphyllinine, were prepared from G. japonica roots with high efficiency. The results of this work provide a new technique for the preparation of large amounts of pyrrolizidine alkaloid reference substances, which will also benefit toxicological studies of pyrrolizidine alkaloids and treatments for pyrrolizidine alkaloid‐induced toxicity.     

Folipidine,a New Type Quinoline Alkaloid from Plants of the <Emphasis Type="Italic">Haplophyllum</Emphasis> Genus

The new quinoline alkaloid folipidine, the structure of which was established by chemical transformations and spectral data (UV, IR, mass, NMR) using APT, 2D ¹H-¹H COSY, NOESY, and ¹H-¹³C HSQC, HMBC, was isolated from two plants of the Haplophyllum genus. Folipidine is the first representative of a new type of quinoline alkaloids that contain a heteroaromatic skeleton of [3,4-b] conjugated pyrrole and quinoline fragments. The total alkaloids of these plants exhibit antitumor activity. Folipidine does not possess such activity.__________Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 49–52, January–February, 2005.     

Rapid screening and identification of lycodine‐type alkaloids in Lycopodiaceae and Huperziaceae plants by ultra‐performance liquid chromatography coupled with quadrupole time‐of‐flight mass spectrometry

Lycodine‐type alkaloids have gained significant interest owing to their unique skeletal characteristics and acetylcholinesterase activity. This study established a rapid and reliable method using ultra‐performance liquid chromatography coupled with electrospray ionization quadrupole time‐of‐flight tandem mass spectrometry (UPLC‐ESI‐Q/TOF‐MS/MS) for comprehensive characterization of lycodine‐type alkaloids for the first time. The lycodine‐type alkaloids were detected successfully from Lycopodiastrum casuarinoides, Huperzia serrata and Phlegmarirus carinatus in seven plants of the Lycopodiaceae and Huperziaceae families, based on the established characteristic MS fragmentation of five known alkaloids. Furthermore, a total of 13 lycodine‐type alkaloids were identified, of which three pairs of isomers were structurally characterized and differentiated. This study further improves mass analysis of lycodine‐type alkaloids and demonstrates the superiority of UPLC with a high‐resolution mass spectrometer for the rapid and sensitive structural elucidation of other trace active compounds. Copyright © 2016 John Wiley & Sons, Ltd.     

Three New Alkaloids,Paxiphyllines C – E,from Daphniphyllum paxianum

Nine Daphniphyllum alkaloids, including three new ones, paxiphyllines C–E ( 1 – 3 , resp.), were isolated from the twigs and the leaves of Daphniphyllum paxianum. Paxiphylline C ( 1 ) represents the first example of Daphniphyllum alkaloids with a carbonyldioxy group. Their structures were elucidated on the basis of spectroscopic data.     

Structural characterization and identification of C19‐ and C20‐diterpenoid alkaloids in roots of Aconitum carmichaeli by rapid‐resolution liquid chromatography coupled with time‐of‐flight mass spectrometry

Aconite alkaloids from the roots of Aconitum carmichaeli (Fuzi, in Chinese) have been investigated by rapid‐resolution liquid chromatography coupled with time‐of‐flight mass spectrometry (TOFMS) in positive mode. With dynamic adjustment of the key role as fragmentor voltage in TOFMS, an efficient transmission of the ions was achieved to obtain the best sensitivity for providing the molecular formula for each analyte, and abundant fragment ions for structural information. Fifteen authentic standards isolated from Fuzi with various structures were first characterized by TOFMS, including diester‐diterpenoid alkaloids (DDAs), monoester‐diterpenoid alkaloids (MDAs), alkylol amine‐diterpenoid alkaloids (ADAs), veatchine‐type alkaloids and atisine‐type alkaloids. Fragmentation rules and key diagnostic fragment ions have been summarized, and possible pathways of fragmentation have been proposed. By accurate mass measurements within 5 ppm error for each ion, 30 C₁₉‐diterpenoid alkaloids including 10 DDAs, 3 MDAs, 9 ADAs and 8 other type alkaloids, and 8 C₂₀‐diterpenoid alkaloids including 4 veatchine‐type alkaloids and 4 atisine‐type alkaloids could be identified in a methanolic extract of Fuzi. Some isomers of aconite alkaloids were also differentiated. Based on the differences between their fragmentation pathways and special fragment ions, each type of aconite alkaloids was differentiated. Copyright © 2009 John Wiley & Sons, Ltd.     

Sensitive determination of pyrrolizidine alkaloids in Tussilago farfara L. by field‐amplified,sample‐stacking,sweeping micellar electrokinetic chromatography

Pyrrolizidine alkaloids are the toxic components in Tussilago farfara L. Due to the lack of standard substances for quantitative analysis and traces of pyrrolizidine alkaloids in total alkaloids, the full quality control of Tussilago farfara L has been limited. In this study, we aimed to solve the difficulty of determination of pyrrolizidine alkaloids and identify more components in the total alkaloids. An on‐line preconcentration method has been applied to improve determining sensitivity of pyrrolizidine alkaloids in Tussilago farfara L. in which included field‐amplified sample stacking and sweeping in micellar electrokinetic capillary chromatography. The main parameters that affected separation and stacking efficiency were investigated in details. Under the optimal conditions, the sensitivity enhancement factors obtained by the developed method for the analytes were from 15‐ to 12‐fold, the limits of detection of senkirkine and senecionine were 2～5 μg/L. Senkirkine and senecionine have been detected in alkaloids ( c ) of Tussilago farfara L, along ferulic acid methyl ester and methyl caffeate. The developed method was also applied to the analysis of acid extraction ( a ) of Tussilago farfara L, and senkirkine could be detected directly. The results indicated that the developed method is feasible for the analysis of pyrrolizidine alkaloids in Tussilago farfara L with good recoveries.     

Norditerpene Alkaloids from <Emphasis Type="Italic">Delphinium cuneatum</Emphasis>

A mixture of two new norditerpene alkaloids consisting of two regioisomers was isolated from the total alkaloids of Delphinium cuneatum roots. Their structures were proposed as 16-demethoxydelavaine (2a and b) on the basis of PMR, ¹³C NMR, IR, and mass spectra. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 467–468, September–October, 2005.     

Preparative separation of isoquinoline alkaloids from Corydalis impatiens using a middle‐pressure chromatogram isolated gel column coupled with two‐dimensional liquid chromatography

We established a two‐dimensional strong cation exchange/reversed‐phase liquid chromatography protocol to isolate and purify isoquinoline alkaloids from Corydalis impatiens. Isoquinoline alkaloids were first enriched from a C. impatiens extract in which liposoluble components were removed using a medium‐pressure chromatographic tower containing middle chromatogram isolated gel. A strong cation exchange column was employed to separate and obtain 30 fractions. We chose fractions 22–29 for reversed‐phase liquid chromatography purification using characteristic isoquinoline alkaloid ultraviolet absorption spectra. Several isoquinoline alkaloid fractions (22–29) were further separated, and those of low resolution were isolated via two‐dimensional liquid chromatography in the orthogonal plane. A total of eight novel isoquinoline alkaloids with characteristic ultraviolet spectra were obtained from C. impatiens. We thus demonstrate the benefits of off‐line two‐dimensional strong cation exchange/reversed‐phase liquid chromatography to isolate isoquinoline alkaloids from C. impatiens.     

Efficient Synthesis of N‐Alkylated 4‐Pyridones by Copper‐Catalyzed Intermolecular Asymmetric Propargylic Amination

Copper‐catalyzed intermolecular asymmetric propargylic amination with 4‐hydroxypyridines has been realized for the first time. In the presence of Cu complex derived from Pybox ligand, the N‐propargylated 4‐pyridones were obtained under mild reaction conditions with up to 99 % yield and 95 % ee. The Pybox ligand bearing a 4‐F‐phenyl substituent plays a key role for the high enantioselectivity. The products can be easily transformed to the core structure of quinolizidine alkaloids.     

Über Juliprosin,ein weiteres Alkaloid aus Prosopis julifloraA.DC. 180. Mitteilung über organische Naturstoffe

Juliprosine, a Further Alkaloid Isolated from Prosopis juliflora A .DC . By catalytic hydrogenation of the second base juliprosine ( 2 ) isolated from Prosopis juliflora (Leguminosae) the hexahydroderivative 5 was formed. The same product was obtained also by catalytic hydrogenation of juliprosopine ( 1 ) of known structure. The absolute configuration of 2 was deduced by comparison of [M]_D values of Prosopis alkaloids of known absolute configuration.     

Karaconitine,a new C<Subscript>19</Subscript>-norditerpenoid alkaloid from <Emphasis Type="Italic">Aconitum karakolicum</Emphasis> roots

The known alkaloids aconitine, benzoylaconine, and songorine and the new C₁₉-norditerpenoid alkaloid karaconitine were isolated from roots of Aconitum karakolicum Rapaics (Ranunculaceae). The structure of karaconitine was established using ESI-mass spectra, 1D (¹H and ¹³C) and 2D NMR (HSQC, HMBC) and DEPT spectral data, and comparison of its ¹³C NMR spectrum with that of aconine.     

Isolation and purification of alkaloids from the fruits of Macleaya cordata by ionic‐liquid‐modified high‐speed counter‐current chromatography

Macleaya cordata (Willd) R. Br. is a medicinal plant. The most important bioactive compounds of M. cordata are alkaloids that have many biological activities including antifungal, anti‐inflammatory, and antitumor. In this study, an ionic‐liquid‐modified high‐speed counter‐current chromatography method was established to obtain alkaloids from the fruits of M. cordata. The conditions of ionic‐liquid‐modified high‐speed counter‐current chromatography, including solvent systems, the content of ionic liquid (1‐butyl‐3‐methylimidazolium tetrafluoroborate [C₄mim][BF₄]), and the posttreatment of the ionic liquid, were investigated. Five alkaloids protopine, allocryptopine, sanguinarine, 8‐O‐demethylchelerythrine, and chelerythrine were separated from the extract of the fruits using a high speed counter‐current chromatography with two‐phase solvent system composed of dichloromethane/methanol/0.3 mol/L hydrochloric acid aqueous solution/[C₄mim][BF₄] (4:2:2:0.015, v/v). Their purities were 96.33, 95.56, 97.94, 96.22, and 97.90%, respectively. The results indicated that a small amount of ionic liquids as modifier of the two‐phase solvent system could shorten the separation time and improve the separation efficiency of the alkaloids from the fruits. The ionic‐liquid‐modified high‐speed counter‐current chromatography would provide a feasible way for highly effective separation of alkaloids from natural products.