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1.
Mukhtar MR Hadi AH Rondeau D Richomme P Litaudon M Mustafa MR Awang K 《Natural product research》2008,22(11):921-926
The phytochemical study of the bark of Malaysian Phoebe scortechinii (Lauraceae) has resulted in the isolation and identification of two new proaporphine alkaloids; (+)-scortechiniine A (1) and (+)-scortechiniine B (2) together with two known proaporphines; (-)-hexahydromecambrine A (3), (-)-norhexahydromecambrine A (4), and one aporphine; norboldine (5). Structural elucidations of these alkaloids were performed using spectroscopic methods especially 1D and 2D (1)H and (13)C NMR. 相似文献
2.
Su JH Dai CF Huang HH Wu YC Sung PJ Hsu CH Sheu JH 《Chemical & pharmaceutical bulletin》2007,55(4):594-597
Two new sesquiterpenoidal natural products chabrolidiones A and B (1 and 2), two C(18) terpenoid-related carboxylic acids, ketochabrolic acid (3) and isoketochabrolic acid (4), and one naphthoquinone derivative chabrolonaphthoquinone C (5), along with two known compounds (+)-aristolone (6) and teuhetenone A (7) were isolated from a Formosan soft coral Nephthea chabrolii. The structures of the new metabolites were determined on the basis of extensive spectroscopic analysis and by comparison of NMR data with those of related metabolites. Metabolite 1 has been synthesized previously, but was isolated for the first time from natural sources. Cytotoxic activity of metabolites 1-3 and 5-7 against a limited panel of cancer cell lines is also described. 相似文献
3.
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
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《Biomedical chromatography : BMC》2018,32(2)
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. 相似文献
4.
Dr. Kevin Antien Dr. Aitor Lacambra Prof. Fernando P. Cossío Dr. Stéphane Massip Dr. Denis Deffieux Prof. Laurent Pouységu Dr. Philippe A. Peixoto Prof. Stéphane Quideau 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(49):11574-11580
The so-called Securinega alkaloids constitute a class of tetracyclic biologically active specialised metabolites isolated principally from subtropical plants belonging to the Phyllanthaceae family. Following a strategy based on alternative hypotheses for their biosynthesis, an easy and time-efficient divergent synthesis enabled access to twelve of those alkaloids featuring (neo)(nor)securinane skeletons. Moreover, this work permitted to reassign the absolute configurations of (+)-virosine B and (−)-episecurinol A. 相似文献
5.
Karl Bernauer 《Helvetica chimica acta》1967,50(6):1583-1588
From an extract of Laurelia novae-zelandiae A. CUNN . the aporphine alkaloids (?)-pukateine (I), (?)-pukateine methyl ether (II), (?)-roemerine (IV), (?)-mecambroline (V), (+)-boldine (VII), (+)-isoboldine (VIII), (+)-laurolitsine (IX), and the proaporphine alkaloid (+)-stepharine (X) were isolated. Compounds II and V were up to now not described as natural alkaloids. These and the alkaloids IV, VII, VIII, IX and X are new for L. novae-zelandiae. 相似文献
6.
Bianco A Bonadies F Cianciolo V Melchioni C Ramunno A Dezzi S Nicoletti M Serafini M Ballero M 《Natural product letters》2002,16(2):77-80
Argylia radiata (L.) D. Don (Bignoniaceae) represents an important source of secondary metabolites, largely unexplored. The paper presents the isolation from the plant root of two new monoterpene alkaloids, 10-acetoxy-actinidine and 4-nor-7,8-dehydro-10-hydroxy-skytanthine, whose structures were elucidated by Mass spectrometry and 1H-NMR data. 相似文献
7.
Three new pavine N-oxide alkaloids, (-)-isocaryachine-N-oxide B, (+)-caryachine-N-oxide, (-)-caryachine-N-oxide, and a new isoquinoline alkaloid, 6,7-methylenedioxy-N-methylisoquinoline together with 11 known alkaloids were isolated and characterized from the stem bark of Cryptocarya chinensis. The structures of the isolated compounds were determined by spectral methods. The stereochemistry of pavine-N-oxide alkaloids is also discussed. 相似文献
8.
Two new compounds, taraxafolide (1) and (+)-taraxafolin-B (2) together with eighteen known compounds, which include one sesquiterpene, thirteen benzenoids, two indole alkaloids, one pyridine derivative and steroid mixtures were isolated and characterized from the fresh roots of Taraxacum formosanum. Structures of new compounds were determined by spectral analysis. (+)-Taraxafolin-B had the bioactive caffeic acid moiety, but its activity was weaker than alpha-tocopherol in DPPH radicals scavenging activity assay. 相似文献
9.
Pérez Colmenares A Alarcón L Rojas LB Mitaine-Offer AC Pouységu L Quideau S Paululat T Usubillaga A Lacaille-Dubois MA 《Natural product communications》2010,5(11):1743-1746
Two new steroidal alkaloids (1-2) have been isolated from the leaves and roots of Solanum hypomalacophyllum Bitter, respectively. Their structures have been elucidated as deacetoxysolaphyllidine-3-O-beta-D-glucopyranoside (1) and 4-keto-5,6-dihydro-(20S)-verazine (2). Furthermore, two known steroidal alkaloids, 20R-verazine and 20S-verazine, and the common secondary metabolites oleanolic acid and beta-sitosterol were isolated from the roots, whereas deacetoxysolaphyllidine was obtained from the leaves. 相似文献
10.
Chen Y Shao C Huang Z Zhang Y Cai X She Z Zhou S Lin Y 《Magnetic resonance in chemistry : MRC》2009,47(1):92-95
The structure elucidations and complete (1)H and (13)C NMR assignments are reported for two new natural products: 3-benzylidene-8,8a-dihydroxy-2-methyl-hexahydro-pyrrolo[1,2-a]pyrazine-1,4-dione(1) and 4-hydroxy-6-(hydroxy-phenyl-methyl)-N-(3-methyl-butyryl)-nicotinamide (2). Both of these secondary metabolites were isolated from the fermentation medium of a Mangrove endophytic fungus. High resolution electron impact mass spectrometry (HREIMS), FT-IR Spectroscopy and NMR experiments including gCOSY, gHMQC, gHMBC and NOE were used for determination of the structures and assignments of the amide alkaloids. 相似文献
11.
[structures: see text] The highly convergent stereocontrolled total synthesis of (-)-vincamajinine (7), (-)-11-methoxy-17-epivincamajine (9), and the oxygen-bridged (+)-dehydrovoachalotine (22) are described. Key steps in the synthesis of 7 and 9 involved the stereospecific enolate-driven palladium-catalyzed cross-coupling reaction, a Tollens reaction, an acid-assisted intramolecular cyclization to form the C(7)-C(17) quaternary center, and two stereospecific reductions. The efficiency of this strategy is illustrated by the completion of the synthesis of 7 and 9 in 16 [from d-(+)-tryptophan methyl ester 17] and 17 (from the Sch?llkopf chiral auxiliary 27) reaction vessels, respectively. This constitutes the first total synthesis of these indole alkaloids and provides the first regiospecific route to 11-methoxy-substituted ajmaline/vincamajine-related alkaloids. The synthesis of 22 required a novel DDQ-mediated cyclization to furnish the C(6)-O(17) bond, executed in stereospecific fashion. Completion of these syntheses illustrates a concise and versatile strategy for the synthesis of vincamajine-related alkaloids, which has also been employed to prepare the related compounds quebrachidine diol (53), vincamajine diol (56), and vincarinol (59). 相似文献
12.
Harpagoside,which is one main iridoid constituent of the dried roots of Scrophularia ningpoensis Hemsl.,was biotransformated by bacteria isolated from human fecal flora and three metabolites were obtained.The structures of the metabolites,including two new alkaloids,named harpagometabolins I(1)and II(2),and a known alkaloid acubinine B(3),were identified by chemi cal methods and the spectroscopic evidences. 相似文献
13.
Reto Stahl Renato Galli Rolf Güller Hans-Jürg Borschberg 《Helvetica chimica acta》1994,77(8):2125-2132
The oxidative transformation of synthetic (+)-aristoteline ((+)- 6 ) into other metabolites which had been isolated from Aristotelia species was investigated. Thus, treatment of (+)- 6 with I2 as the single oxidant furnished the naturally occurring indole alkaloids (+)-makonine ((+)- 9 ),(+)-aristotelinone ((+)- 11 ), or (+)-11, 12-didehydroaristoteline ((+)- 7 ) in good yields, the selectivity of the oxidation process depending on the chosen reaction conditions. 相似文献
14.
Hedda Schrey Prof. Dr. Peter Spiteller 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(34):8035-8042
Fruiting bodies of Laccaria proxima were screened for the presence of new secondary metabolites by means of HPLC-UV and LC-HR-(+)-ESIMS. Thus, two isomeric alkaloids with a highly unusual core structure, E-proxamidine and its Z-isomer, were isolated from Laccaria proxima. The proxamidines consist of an eight-membered heterocyclic ring system with a formamidine unit. The structures were established by 2D NMR spectroscopic methods, HR-(+)-ESIMS, and HR-(+)-ESIMS/MS. The proxamidines are probably biosynthetically derived from tryptophan, dimethylallyl pyrophosphate, and S-adenosylmethionine and the eight-membered ring of the proxamidines is likely to be generated by a rearrangement of the tryptophan sceleton. Metabolic profiling of fruiting bodies of some other Laccaria species revealed that the proxamidines appear in significant amounts only in L. proxima making the compounds suitable as chemotaxonomic markers. E-Proxamidine exhibits herbicidal activity against Lepidium sativum. 相似文献
15.
The first total syntheses of two cernuane-type Lycopodium alkaloids, (-)-cernuine and (+)-cermizine D, were accomplished starting from (+)-citronellal. The syntheses involved organocatalytic alpha-amination to afford oxazolidinone, which is used for diastereoselective allylation, and asymmetric transfer aminoallylation followed by stereoselective construction of an aminal moiety as key steps. 相似文献
16.
Tsuda M Yasuda T Fukushi E Kawabata J Sekiguchi M Fromont J Kobayashi J 《Organic letters》2006,8(19):4235-4238
Diffusion-ordered NMR spectroscopy (DOSY) is a versatile and powerful NMR technique and a noninvasive analytical method for mixture analysis that does not require prior physical separation of the analytes. In our search for new metabolites from natural resources, DOSY was applied for constituent analysis of crude bromopyrrole fractions separated from an Okinawan marine sponge Agelas sp. so that two new bromopyrrole alkaloids, agesamides A (1) and B (2), have been isolated. The structures and relative stereochemistry of 1 and 2 were elucidated from spectroscopic data. 相似文献
17.
Christiane Kan Henri-Philippe Husson Henri Jacquemin Siew-Kwong Kan Mauri Lounasmaa 《Tetrahedron letters》1980,21(1):55-58
The structures of two new alkaloids of the 21-nor (+) pandolane type from the bark of (Miq.) Pull. (Apocynaceae), were determined. 相似文献
18.
A new C(19)-diterpenoid alkaloid, ouvrardiantine (1) and two new C(20)-diterpenoid alkaloids, ouvrardiandines A (2) and B (3) were isolated from the root of Aconitum ouvrardianum HAND.-MAZZ. The structure of the new alkaloids was established on the basis of spectral data (1D- and 2D-NMR, HR-MS). 相似文献
19.
Xiangyu Zhang James C. Anderson 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(50):18208-18213
The total synthesis of representative members of the schizozygine alkaloids, (+)‐vallesamidine and (+)‐14,15‐dehydrostrempeliopine, were completed from a late‐stage divergent intermediate. The synthesis took advantage of efficient nitro‐group reactions with the A/B/C ring skeleton constructed concisely on a gram scale through an asymmetric Michael addition, nitro‐Mannich/lactamisation, Tsuji–Trost allylation, and intramolecular C?N coupling reaction. Other key features of the synthesis are a novel [1,4] hydride transfer/Mannich‐type cyclisation to build ring E and a diastereoselective ring‐closing metathesis reaction to construct ring D. This approach gave access to a late‐stage C14,C15 alkene divergent intermediate that could be simply transformed into (+)‐vallesamidine, (+)‐14,15‐dehydrostrempeliopine, and potentially other schizozygine alkaloids and unnatural derivatives. 相似文献
20.
The 100 MHz p.m.r. data on the new ergot alkaloids agroclavine-I and epoxyagroclavine-I, metabolites of fungus Penicillium kapuscinskii strain UCM F-2156D, are reported. Their C and D rings are shown to exist in an “envelope” form. A cis orientation of the C/D ring junction is confirmed for both alkaloids. 相似文献