共查询到20条相似文献,搜索用时 15 毫秒
1.
Hao-Fei Yu Wan-Yi Huang Cai-Feng Ding Xin Wei Lan-Chun Zhang Xu-Jie Qin Hong-Xia Ma Zi-Feng Yang Ya-Ping Liu Rong-Ping Zhang Xin-Hua Wang Xiao-Dong Luo 《Tetrahedron letters》2018,59(31):2975-2978
Three new cage-like monoterpenoid indole alkaloids, scholarisines T–V (1–3), together with three known analogues 4–6 were isolated from the leaves of Alstonia scholaris. Among them, 2 represents a unique degraded derivative, whereas 3 shares a rare 5,16-seco lactone scaffold. The structures were mainly established by extensive spectroscopic data analyses, and their plausible biosynthesis pathway from picrinine were proposed. Compared with positive control cefotaxime, alkaloid 2 showed remarkable antibacterial activity against Bacillus subtilis with an MIC value of 3.12?μg/mL, whereas 1–3 exhibited significant antibacterial effects on Escherichia coli with an MIC value of 0.78?μg/mL. 相似文献
2.
Ann-Louise Johnson 《Tetrahedron》2006,62(47):10815-10820
The exocyclic analogue of the indole alkaloid isolated from the marine sponge Halichondria melanodocia has been prepared via olefination of a phosphonoester derived from 3-(2-bromoacyl)indole. The formation of an unexpected indolylazepine is also discussed. 相似文献
3.
Ling-Li Liu Ying-Tong Di Xin Fang Dong-Lin Chen Hong-Ping He 《Tetrahedron letters》2010,51(43):5670-5673
Two novel monoterpenoid indole alkaloids, aminocadambines A (1) and B (2), characterized by tetrahydrofuran and 1,2,3,4-tetrahydropyridine rings, were isolated from the leaves of Neolamarckia cadamba. Their structures were elucidated on the basis of spectroscopic and computational methods. The absolute configuration of 1 was established by CD analysis. A plausible biosynthetic pathway for 1 and 2 is proposed. 相似文献
4.
Two novel indole alkaloids having unusual skeletons were isolated from the aerial part of Yunnan Kopsia arborea. Kopsiyunnanine A (1) is a new class of bisindole alkaloid composed of vallesiachotamine (modified Corynanthe-type) and Aspidospermatan-type alkaloids. Kopsiyunnanine B (2) is a new Corynanthe-type oxindole alkaloid rearranged by D ring rotation. 相似文献
5.
Olusegun S. Ajala Andrew M. PiggottFabien Plisson Zeinab KhalilXiao-cong Huang Sunday A. AdesegunHerbert A.B. Coker Robert J. Capon 《Tetrahedron letters》2011,52(52):7125-7127
Chemical investigations into samples of Hunteria umbellata (K. Schum) collected in Osun State, Nigeria, led to the discovery of a new indole alkaloid, ikirydinium A, featuring an unprecedented 3-alkylpyridinium-indole-2-carboxylate scaffold. Ikirydinium A was found to exhibit antimicrobial activity (IC50 0.6 μM) against Bacillus subtilis ATCC 6051. The involvement of a common intermediate in the biosynthesis of ikirydinium A and vinblastine is hypothesized. 相似文献
6.
A hexacyclic indole alkaloid possessing an unprecedented ring system incorporating a diazaspiro center and fused oxadiazepine-tetrahydrofuran rings has been isolated from the Malayan Tabernaemontana corymbosa. The structure was established by analysis of the spectroscopic data and a possible biogenetic pathway from a cleavamine-type precursor is presented. 相似文献
7.
Two new oxindole alkaloids, rankiniridine (1) and humanteniridine (2), having a nitrogen-carbon linkage between a humantenine-type monoterpenoid indole alkaloid and a monoterpene unit with an iridoid skeleton, were isolated from Gelsemium rankinii and Gelsemium elegans, respectively. 相似文献
8.
Naonobu Tanaka Rei Momose Azusa Takahashi-Nakaguchi Tohru Gonoi Jane Fromont Jun'ichi Kobayashi 《Tetrahedron》2014
Six new indole alkaloids, hyrtimomines F–K (1–6), were isolated from Okinawan marine sponges Hyrtios spp. The structures of 1–6 were elucidated on the basis of spectroscopic analysis. Hyrtimomine F (1) is a structurally unique bisindole alkaloid possessing an α-keto-?-caprolactam ring, while hyrtimomine G (2) is a symmetrical bisindole alkaloid. Hyrtimomines H–K (3–6) are indole alkaloids possessing β-carboline skeleton with an imidazolium unit. Antimicrobial activities of hyrtimomines F–K (1–6) were evaluated. 相似文献
9.
Three unusual natural products, viz., alstopirocine, a macroline alkaloid incorporating a substituted pyrrole moiety, pleiomaltinine, an alkaloid-pyrone adduct, and pleiomalicine, an alkaloid-carbamic acid adduct, were isolated from the Malayan Alstonia angustifolia. The alkaloid moiety in alstopirocine was alstomicine while that in pleiomaltinine and pleiomalicine was pleiocarpamine. The structures were determined by spectroscopic methods and in the case of pleiomaltinine, confirmed by X-ray diffraction analysis. Possible biogenetic pathways to these unusual compounds are presented. 相似文献
10.
A novel securinega alkaloid, suffruticosine (1), was isolated from the leaves and barks of Securinegasuffruticosa. The structure of 1, characterized by a fused complex octacyclic system, was elucidated by combined spectroscopic techniques, especially 2D NMR and CD spectral analyses. 相似文献
11.
Zhi-Jun Zhang Jing Yang Juan He Xing-De Wu Li-Dong Shao Yan Li Sheng-Xiong Huang Rong-Tao Li Qin-Shi Zhao 《Tetrahedron letters》2014
Two new monoterpenoid indole alkaloids, vincamajorines A (1) and B (2), were isolated from Vinca major. Their structures were elucidated by means of 1D and 2D NMR, and HREIMS spectroscopic data. The relative and absolute configurations were deduced by comparing the experimental 13C NMR, ECD spectra, and OR data with those theoretically calculated. Vincamajorine A (1) represents a new C20 carbon skeleton arranged compactly in seven rings, and vincamajorine B (2) is an alkaloid with an unprecedented 6/5/7/5/6 pentacyclic ring system. A possible biosynthetic pathway was also proposed for the formation of 1 and 2. 相似文献
12.
Chew-Yan Gan 《Tetrahedron letters》2009,50(9):1059-1230
A tetracyclic ring-opened oxindole alkaloid, possessing an unprecedented ring system incorporating fused piperidine-tetrahydrofuran rings, has been isolated from the Malayan species, Leuconotis griffithii. The structure was established by analysis of the spectroscopic data and a possible biogenetic pathway from an Aspidosperma precursor is presented. 相似文献
13.
Kuan-Hon Lim 《Tetrahedron letters》2006,47(29):5037-5039
A new pentacyclic indole alkaloid of the pericine-type, valparicine, representing the first member of this sub-group, was obtained from a Malayan Kopsia species and the structure was established by spectroscopic analysis. A partial synthesis of valparicine and apparicine from pericine was carried out via the Potier-Polonovski reaction and the biogenetic implications are discussed. 相似文献
14.
Jian-Jun Xia Xu-Yang Li Shao-Zhi Zhang Jie-Qing Liu Wei-Ming Zhang Yu-xin Yan Zhong-Tao Ding Ming-Hua Qiu 《Tetrahedron letters》2014
An unusual 9,11-seco limonoid, toonasecone A (1), had been isolated from the bark of Toona ciliata. The structure was elucidated on the basis of extensive spectroscopic data analysis. This is the first time the 9,11-seco limonoid has been isolated from the Meliaceae family. 相似文献
15.
Xin Wei Jing Yang Hong-Xia Ma Cai-Feng Ding Hao-Fei Yu Yun-Li Zhao Ya-Ping Liu Afsar Khan Yi-Fen Wang Zi-Feng Yang Wan-Yi Huang Xin-Hua Wang Xiao-Dong Luo 《Tetrahedron letters》2018,59(21):2066-2070
Gelselegandines A-C (1–3), three unprecedented gelsedines incorporating additional C9 aromatic unit as side chain, were isolated from Gelsemium elegans. Their structures were elucidated by means of spectroscopic techniques and electronic circular dichroism (ECD) calculation. Additionally, gelselegandines A–C showed moderate antimicrobial activities against four bacterial strains and two fungi. 相似文献
16.
Two new monoterpenoid oxindole alkaloids, gelsevanillidine (1) having an additional vanillin residue on gelsenicine-type alkaloid and gelseoxazolidinine (2) possessing an unusual oxazolidine ring, were isolated from Gelsemium elegans. To confirm their structures, the chemical transformation of a humantenine-type alkaloid into gelsevanillidine (1) and the deacetoxy derivative of gelseoxazolidinine was performed. 相似文献
17.
Zoe E. Wilson 《Tetrahedron》2007,63(25):5379-5385
Racemic syntheses of indole analogues of four phthalide-containing anti-Helicobacter pylori agents CJ-13,015, CJ-13,102, CJ-13,104 and CJ-13,108 are reported via manipulation of a common intermediate. This intermediate was formed by the N-alkylation of 4,6-dimethoxyindole with a long chain bromide followed by further chain extension. Oxidation, acetylation, or Barton-McCombie deoxygenation of the intermediate followed by Wacker oxidation afforded three analogues whilst further reduction of one analogue afforded the final analogue. 相似文献
18.
Noriyuki Kogure 《Tetrahedron letters》2005,46(35):5857-5861
One new yohimbane and five new sarpagine-type indole alkaloids were isolated from the radix of Gelsemium sempervirens Ait. f., and their structures were determined by spectroscopic analysis, chemical conversion or total synthesis. It was found that 2-acyl sarpagine-type alkaloids possessing an Nb-methyl group take a keto-amino structure or a transannular form in solution depending on the solvent. 相似文献
19.
A new indole alkaloid, 7β-hydroxy-7H-mitraciliatine (1) and a new oxindole alkaloid, isospeciofoleine (2) together with nine known alkaloids were isolated from Mitragyna speciosa and characterized by NMR, CD, and MS spectroscopic data analyses. The 1H and 13C NMR spectroscopic data of isospeciofoline (3), isorotundifoline (4), paynantheine (5), and 3-isopaynantheine (6) were also reported for the first time. 相似文献
20.
Gui-Guang Cheng Yun-Li Zhao Yu Zhang Paul-Keilah Lunga Dong-Bao Hu Yan Li Ji Gu Chang-Wei Song Wei-Bang Sun Ya-Ping Liu Xiao-Dong Luo 《Tetrahedron》2014
Nine new indole alkaloids, vinmajines A–I (1–9), and 43 known indole alkaloids were isolated from cultivated Vinca major in Kunming. The new structures were elucidated by extensive spectroscopic and quantum theory analysis. In addition, the results also supported that types of indole alkaloids from V. major might be influenced significantly by the ecological environment. 相似文献