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1.
《Analytical letters》2012,45(18):2846-2859
Lotus (nelumbo) is a traditional Chinese medical herb, and alkaloids are responsible for its pharmaceutical activities. Therefore, a rapid, validated method to determine alkaloids in lotus leaves is useful for its quality control. The goal of this work was to develop and validate an analytical method for the identification and quantitation of the bioactive alkaloids of extracts from lotus leaf and classification of lotus germplasm based on alkaloid concentrations. Solid-phase extraction was used prior to high-performance liquid chromatography coupled with photodiode array detection at 272 nm and tandem electrospray ionization triple quadrupole mass spectrometry for analysis. Nuciferine and O-nornuciferine were the dominant compounds in lotus used for seed production and some used for flower production. However, anonaine, roemerine, and N-nornuciferine were abundant only in some lotus flowers. All the lotuses were classified into four groups by principal component analysis of alkaloid content: 10 flower and three seed lotuses characterized by high nuciferine and O-nornuciferine content; 12 flower lotuses with high N-nornuciferine, roemerine, and anonaine content; two flower lotuses with a relatively high content of all five alkaloids; and cultivars with a low alkaloid content and without dominant alkaloids. 相似文献
2.
Tomasz Mroczek Karine Ndjoko-Ioset Agnieszka Mi?tkiewicz-Capa?a 《Analytica chimica acta》2006,566(2):157-166
From the alkalised crude extract of Symphytum cordatum (L.) W.K. roots, pyrrolizidine alkaloids (PAs) were extracted as free tertiary bases and polar N-oxides in a merely one-step liquid-liquid partitioning (LLP) in separation funnel and subsequently pre-fractionated by preparative multiple-development (MD) thin-layer chromatography (TLC) on silica gel plates. In this way three alkaloid fractions of different polarities and retention on silica gel plates were obtained as: the most polar N-oxides of the highest retention, the tertiary bases of medium retention, and diesterified N-oxides of the lowest retention. The former fraction was reduced into free bases by sodium hydrosulfite and purified by LLP on Extrelut-NT3 cartridge. It was further analysed together with the two other fractions by high-performance liquid chromatography (HPLC)-ion-trap mass spectrometry with atmospheric pressure chemical ionization (APCI) interface on XTerra C18 column using a gradient elution. Based on MSn spectra, 18 various alkaloids have been tentatively determined for the first time in this plant as the following types of structure: echimidine-N-oxide (three diasteroisomers), 7-sarracinyl-9-viridiflorylretronecine (two diasteroisomers), echimidine (two diasteroisomers), lycopsamine (two diasteroisomers), dihydroechinatine-N-oxide, dihydroheliospathuline-N-oxide, lycopsamine-N-oxide (three diasteroisomers), 7-acetyllycopsamine-N-oxide, symphytine-N-oxide (two diasteroisomers) and 2″,3″-epoxyechiumine-N-oxide. 相似文献
3.
Simultaneous determination of the content of isoquinoline alkaloids in Dicranostigma leptopodum (Maxim) Fedde and the effective fractionation of the alkaloids by high‐performance liquid chromatography with diode array detection
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Yali Chen Min Li Jianjun Liu Qian Yan Mei Zhong Junxi Liu Duolong Di Jinxia Liu 《Journal of separation science》2015,38(1):9-17
A simple and efficient method was developed for the simultaneous determination of eight isoquinoline alkaloids in methanol extracts of Dicranostigma leptopodum (Maxim) Fedde and the effective fractionation of the alkaloids of D. leptopodum by high‐performance liquid chromatography with diode array detection. The chromatographic conditions were optimized on a SinoChrom ODS‐BP column to obtain a good separation of the four types of alkaloid analytes, including two aporphines (isocorydine, corydine), two protopines (protopine and allocryptopine), a morphine (sinoacutine), and three quaternary protoberberine alkaloids (berberrubine, 5‐hydroxycoptisine, and berberine). The separation of these alkaloids was significantly affected by the composition of the mobile phase, and particularly by its pH value. Acetonitrile (A) and 0.2% phosphoric acid solution adjusted to pH 6.32 with triethylamine (B) were selected as the mobile phase with a gradient elution. With this method, a new quaternary protoberberine alkaloid was isolated and the two structural isomers (isocorydine and corydine) were baseline separated. The appropriate harvest period for D. leptopodum was also recommended based on our analysis. The method for the effective fraction of the alkaloids of D. leptopodum was optimized under this method with regard to the varying significant pharmacological activities of the alkaloids. 相似文献
4.
Sakornrat Thorroad Prateep Worawittayanont Nisachon Khunnawutmanotham Nitirat Chimnoi Apiwan Jumruksa Somsak Ruchirawat Nopporn Thasana 《Tetrahedron》2014
Eleven Lycopodium alkaloids with lycodine-type, lycopodine-type, and fawcettimine-related skeletons were isolated from the whole plants of Huperzia carinata (Desv. Ex. Poir.) Trevis and Huperzia squarrosa (G. Forst) Trevis (Huperziaceae). Among them, 8,15-dihydrohuperzine A (2), lycocarinatine A (3), and lycoposerramine U N-oxide (11) are new compounds. The structures of these new alkaloids were elucidated on the basis of 2D NMR correlations. Some of these isolated alkaloids were assayed for acetylcholinesterase (AChE) inhibitory activity. 相似文献
5.
《Biomedical chromatography : BMC》2018,32(10)
For the rational utilization and the quantitative quality control of the Stephania yunnanensis Lo, an HPLC‐DAD method was developed for the quantitative and simultaneous determination of five alkaloids in rat plasma (stepharine, sinomenine, palmatine, isocorydine and tetrahydropalmatine), which were the main active chemical constituents of this plant and belong to four kinds of isoquinoline‐type alkaloids (protoberberine, morphine, aporphine and protaporphine alkaloids). The contents of five alkaloids ranged from 0.09 to 2.32% (w/w). The method validation was tested for the linearity (r2 > 0.9975), precision (intra‐day RSD < 4.8% and inter‐day RSD < 4.9%), extraction recovery (85.49 ± 2.29% to 99.21 ± 1.48%) and stability (98.5 ± 5.3% to 101.2 ± 3.4%). We developed an HPLC‐DAD method to simultaneously measure these alkaloids in rat plasma after oral administration of the extract of this plant to rats. The results supported the hypothesis that isoquinoline alkaloids were the compounds responsible for the main pharmacological activities for anti‐inflammatory and analgesic. 相似文献
6.
The Chinese medicinal plant-derived antineoplastic alkaloids and their analogs are reviewed with emphasis on those discovered from the authors' laboratory. The active compounds include camptothecin, colchicine, ellipticine, harringtonine, Vinca alkaloids, indirubin, (-)-sophocarpine, lycobetaine, monocrotaline, d-tetrandrine, indicine N-oxide, maytansine, aporphine type alkaloids, palmatine, murrapanine, emarginatine alkaloids, and the alkaloids from Securinega virosa. The compounds are discussed briefly with the recent advances concerning their antitumor activity, structure-activity relationships and mechanisms of action. 相似文献
7.
AbstractA new N-oxide, Pseudolycorine N-oxide (1) was characterised along with eleven known alkaloids homolycorine (2), O-methylmaritidine (3), 8-O-demethylhomolycorine (4), homolycorine N-oxide (5), lycorine (6), narciclasine (7), pseudolycorine (8), ungeremine (9), 8-O-demethylmaritidine (10), zefbetaine (11) and lycorine N-oxide (12), from Narcissus tazetta. Their structures were established on the basis of spectroscopic data analysis. The extract, fractions and isolated compounds were screened for in vitro cytotoxicity against two human cancer cell lines, human cervical cancer (SiHa) and human epidermoid carcinoma (KB) cells. The study demonstrated the cytotoxic potential of extract and its chloroform and n-butanol fractions. Further, the results revealed the bioactive potential of narciclasine, pseudolycorine and homolycorine alkaloids. However, new N-oxide (1) was not active against these cell lines. 相似文献
8.
Pyridine-N-oxide-2-carbaldehyde (4a) was converted to the corresponding imine (5a) by treatment with 2,6-diisopropylaniline. Subsequent reduction with a sodium borohydride gave the corresponding (N-arylaminomethyl)pyridine-N-oxide derivative (6a). A series of analogous compounds was prepared starting from the respective (aldimino)quinoline-N-oxide (4b) or (ketimino)pyridine-N-oxide (10) systems. Deprotonation of the (aminomethyl)pyridine-N-oxides resulted in a series of unexpected reactions, such as coupling, internal redox reactions or fragmentation. Eventually, the N,O-chelate aluminum complexes (22, 23) derived from the (aminoethyl)pyridine-N-oxide ligand systems could be obtained by treatment of the respective iminopyridine-N-oxides with trimethylaluminum. Many products were characterized by X-ray diffraction. 相似文献
9.
New ZnX2 (X = Cl, Br) complexes with sparteine N1-oxide, sparteine epi-N16-oxide, lupanine (2-oxosparteine) N-oxide and α-isosparteine N-oxide were obtained and characterized by spectroscopic and crystallographic methods. Complexation with N1-oxides involves inversion of the configuration at the N16 atom of sparteine, converting its C ring from a boat into a chair form, whereas the structure of sparteine epi-N16-oxide, typified by the trans boat/chair C/D quinolizidine moiety, remains unchanged upon complexation. Coordination of zinc salts in the above compounds is realized solely through the oxygen atom of the N-O group and is accompanied by protonation of the “not-N-oxide” nitrogen atom. At variance lupanine N-oxide forms bis-monodentate complexes with ZnX2 utilizing both the N-oxide and the lactam carbonyl oxygen atoms to bridge the neighboring ZnX2 units, while reaction of α-isosparteine N-oxide with ZnX2 leads to formation of complex salts of the general formula [H(−)α-Sp(N-oxide)][(ZnX3)(H2O)]. 相似文献
10.
《Tetrahedron》2019,75(27):3733-3739
Six new biphenyl quinolizidine lactone alkaloids: 14α-hydroxydecodine (1), 14β-hydroxydecodine (2), 4″-O-demethylheimidine (3), 4″-O-demethyl-9β-hydroxyvertine (4), 4″-O-demethylvertine N-oxide (5), and 4″-O-demethyl-9β-hydroxyvertine N-oxide (6) were isolated from so-called “sinicuichi” (origin: Heimia salicifolia) together with 18 known alkaloids. Their structures were determined by spectroscopic analyses and chemical conversions. 相似文献
11.
Nine alkaloids have been isolated from the woods and the barks of Phoebe formosana Hayata and four of these have been identified with laurolitsine) (IV), roemerine (V), ushinsunine (VI) and oxoushinsunine (liriodenine) (VII). 相似文献
12.
Michalina Oplatowska Christopher T. Elliott Anne-Catherine Huet Mark McCarthy Patrick P. J. Mulder Christoph von Holst Philippe Delahaut Hans P. Van Egmond Katrina Campbell 《Analytical and bioanalytical chemistry》2014,406(3):757-770
Pyrrolizidine alkaloids (PAs) are a group of plant secondary metabolites with carcinogenic and hepatotoxic properties. When PA-producing plants contaminate crops, toxins can be transferred through the food chain and cause illness in humans and animals, most notably hepatic veno-occlusive disease. Honey has been identified as a direct risk of human exposure. The European Food Safety Authority has recently identified four groups of PAs that are of particular importance for food and feed: senecionine-type, lycopsamine-type, heliotrine-type and monocrotaline-type. Liquid or gas chromatography methods are currently used to detect PAs but there are no rapid screening assays available commercially. Therefore, the aim of this study was to develop a rapid multiplex ELISA test for the representatives of three groups of alkaloids (senecionine, lycopsamine and heliotrine types) that would be used as a risk-management tool for the screening of these toxic compounds in food and feed. The method was validated for honey and feed matrices and was demonstrated to have a detection capability less than 25 μg/kg for jacobine, lycopsamine, heliotrine and senecionine. The zinc reduction step introduced to the extraction procedure allows for the additional detection of the presence of N-oxides of PAs. This first multiplex immunoassay for PA detection with N-oxide reduction can be used for the simultaneous screening of 21 samples for >12 PA analytes. Honey samples (n?=?146) from various origins were analysed for PA determination. Six samples were determined to contain measurable PAs >25 μg/kg by ELISA which correlated to >10 μg/kg by LC-MS/MS. 相似文献
13.
I. T. Rakipov M. A. Varfolomeev A. Yu. Kirgizov B. N. Solomonov 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2014,88(12):2023-2028
Enthalpies of dissolution are measured at infinite dilution of nitrogen-containing cyclic (pyrrolidine, piperidine) and aromatic compounds (aniline, N-methylaniline, N,N-dimethylaniline, N-methylimidazole, pyridine, 2-, 3-, 4-methylpyridine, pyrrole, N-methylpyrrole) in chloroform and dichloromethane, and vice versa (T = 298.15 K). The enthalpies of hydrogen bonds in the above systems are calculated. Relationships between resulting thermochemical data and the structure of nitrogen-containing cyclic and aromatic compounds are explored. 相似文献
14.
Sheng Ouyang Lei Wang Qing-Wen ZhangGuo-Cai Wang Ying WangXiao-Jun Huang Xiao-Qi ZhangRen-Wang Jiang Xin-Sheng YaoChun-Tao Che Wen-Cai Ye 《Tetrahedron》2011,67(26):4807-4813
Six new monoterpenoid indole alkaloids along with four known analogues were isolated from the aerial part of Gelsemium elegans. Their structures with absolute configurations were elucidated by NMR, HRESIMS, X-ray diffraction, CD spectra, and molecular modeling calculation. Among them, gelselenidine (1) is a new gelsedine-type alkaloid with a 2,3-epoxybutane unit. Gelseziridine (2) is the first example of monoterpenoid indole alkaloids with an oxaziridine residue. Compounds 6 and 7 are a pair of N4 epimers of humantenine N4-oxide. A plausible biogenetic pathway for compounds 1-4 was also proposed. 相似文献
15.
Metabolic reactions that occur at alkylamino moieties may provide insight into the roles of these moieties when they are parts of drug molecules that act at different receptors. N-dealkylation of N,N-dialkylamino moieties has been associated with retaining, attenuation or loss of pharmacologic activities of metabolites compared to their parent drugs. Further, N-dealkylation has resulted in clinically used drugs, activation of prodrugs, change of receptor selectivity, and providing potential for developing fully-fledged drugs. While both secondary and tertiary alkylamino moieties (open chain aliphatic or heterocyclic) are metabolized by CYP450 isozymes oxidative N-dealkylation, only tertiary alkylamino moieties are subject to metabolic N-oxidation by Flavin-containing monooxygenase (FMO) to give N-oxide products. In this review, two aspects will be examined after surveying the metabolism of representative alkylamino-moieties-containing drugs that act at various receptors (i) the pharmacologic activities and relevant physicochemical properties (basicity and polarity) of the metabolites with respect to their parent drugs and (ii) the role of alkylamino moieties on the molecular docking of drugs in receptors. Such information is illuminative in structure-based drug design considering that fully-fledged metabolite drugs and metabolite prodrugs have been, respectively, developed from N-desalkyl and N-oxide metabolites. 相似文献
16.
Yuanyuan Liu Wenjuan Wang Fenfang Che Yanzhen Lu Aoxin Li Hao Li Jiangang Liu Yun Wei 《Journal of separation science》2020,43(12):2459-2466
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. 相似文献
17.
《Journal of separation science》2018,41(2):571-577
An effective high‐speed countercurrent chromatography method was successfully established by using ionic liquids as the modifier of the two‐phase solvent system. Adding a small amount of ionic liquids significantly shortens the separation time and improves the separation efficiency. The conditions of ionic‐liquid‐modified high‐speed countercurrent chromatography including solvent systems, types and content of added ionic liquids, and ionic liquids posttreatment were investigated. The established method was successfully applied to separate alkaloids from lotus leaves using a two‐phase solvent system composed of petroleum ether/ethyl acetate/methanol/water/[C4mim][BF4] (1:5:1:5:0.15, v/v/v/v/v). Four alkaloids pronuciferine (1.7 mg), N‐nornuciferine (4.3 mg), nuciferine (3.1 mg), and roemerine (2.1 mg) were obtained with the purities of 90.53, 92.25, 99.86, and 98.63%, respectively, from 100 mg crude extract of lotus leaves. The results indicated that the ionic‐liquid‐modified high‐speed countercurrent chromatography method was suitable for alkaloid separation from lotus leaves and would be a promising method for the separation of alkaloids from other natural products. 相似文献
18.
The electronic structures of a series of 4-substituted pyridine N-oxides and 4-nitroquinoline N-oxide are investigated using the simple Pariser-Parr-Pople (PPP), a modified PPP, IEH and MINDO/2 methods. The electronic absorption band maxima and dipole moments are calculated and compared with experimental values. The photoelectron spectra of these compounds are assigned. The nature of the N-oxide group is characterized using the orbital population distributions. The antifungal activity exhibited by some of these compounds is discussed in terms of the nucleophilic frontier electron densities, superdelocalizabilities and electron acceptor properties. The effect of the electron releasing as well as the electron withdrawing substituents on the physico-chemical properties is explained. 相似文献
19.
Sixteen alkaloids have been isolated from the fruits of Kopsia officinalis Tsiang and P. T. Li (Apocynaceae), a plant commonly used in folk medicine for treating tonsillitis and rheumatism. Ten of them were identified as known alkaloids — eburnamenine ( 1 ), kopsanone ( 2 ), 5, 18-dioxokopsan ( 3 ), kopsinilam ( 4 ), kopsinine ( 5 ), pleiocarpine ( 6 ), kopsamine ( 7 ), N-carbomethoxy-12-methoxykopsinaline ( 8 ), N-carbomethoxy-11, 12-dimethoxykopsinaline ( 9 ) and (+)-vincadifformine ( 13 ). The other three have now been proved to be new. They are N-carbomethoxy-11-hydroxy-12-methoxy-kopsinaline ( 10 ), N-carbomethoxy-11-methoxy-12-hydroxykopsinaline ( 11 ) and kopsamine N-oxide ( 12 ). 相似文献
20.
Mousa AlTarabeen Qosay Al-Balas Amgad Albohy Werner Ernst Georg Müller Peter Proksch 《Molecules (Basel, Switzerland)》2023,28(1)
Manzamines are chemically related compounds extracted from the methanolic extract of Acanthostrongylophora ingens species. Seven compounds were identified by our research group and are being characterized. As their biological target is unknown, this work is based on previous screening work performed by Mayer et al., who revealed that manzamine A could be an inhibitor of RSK1 kinase. Within this work, the RSK1 N-terminal kinase domain is exploited as a target for our work and the seven compounds are docked using Autodock Vina software. The results show that one of the most active compounds, Manzamine A N-oxide (5), with an IC50 = 3.1 μM, displayed the highest docking score. In addition, the compounds with docking scores lower than the co-crystalized ligand AMP-PCP (−7.5 and −8.0 kcal/mol) for ircinial E (1) and nakadomarin A (7) were found to be inferior in activity in the biological assay. The docking results successfully managed to predict the activities of four compounds, and their in silico results were in concordance with their biological data. The β-carboline ring showed noticeable receptor binding, which could explain its reported biological activities, while the lipophilic side of the compound was found to fit well inside the hydrophobic active site. 相似文献