共查询到20条相似文献,搜索用时 15 毫秒
1.
A novel Daphniphyllum alkaloid with an unprecedented tetracyclic ring system consisting of an octahydroindole and a hexahydroazulene rings, daphniglaucin C (1), has been isolated from the leaves of Daphniphyllum glaucescens and the structure and relative stereochemistry were elucidated on the basis of spectroscopic data. Daphniglaucin C (1) inhibited the polymerization of tubulin. 相似文献
2.
Chengjian Tan Yingtong Di Ye Wang Suo Gao Ningchuan Kong Jianxin Zhang Chunshun Li Xiaojiang Hao 《Tetrahedron letters》2008,49(21):3376-3379
Oldhamine A, a novel alkaloid with an unusual cyclopentadienyl anion in the fused-pentacyclic skeleton was isolated from the twigs of Daphniphyllum oldhami. The structure of oldhamine A was elucidated based on the spectroscopic data and the single-crystal X-ray diffraction crystallography. It is the first X-ray diffraction of the Daphniphyllum alkaloids with nitrogen-containing two pentacyclic rings. The inter-conversion between cyclopentadienyl anion and conjugated enolic unit was also conducted. 相似文献
3.
Shizuka Saito 《Tetrahedron letters》2007,48(32):5693-5695
Calyciphylline G (1), a novel Daphniphyllum alkaloid with an unprecedented fused-hexacyclic skeleton containing a 5-azatricyclo[6.2.1.01,5]undecane ring, has been isolated from the stem of Daphniphyllum calycinum (Daphniphyllaceae), and the structure and relative stereochemistry were elucidated on the basis of spectroscopic data. 相似文献
4.
Ning-Chuan Kong Yu Zhang Yang Lu Quan-Yun Sun Ying-Tong Di Xiao-Jiang Hao 《Tetrahedron letters》2009,50(8):957-2106
A new oxa-cage natural product daphniacetal A (1) was isolated from Daphniphyllum macropodum Miq. Its structure and relative configuration were established based on spectroscopic data and the single-crystal X-ray diffraction crystallography. Compound 1 was also synthesized for determination of its absolute configuration and evaluation of antioxidant effects. 相似文献
5.
Five new fused-hexacyclic alkaloids, daphniglaucins D (1), E (2), F (3), G (4), and H (5), and two new yuzurimine-type alkaloids, daphniglaucins J (6) and K (7), have been isolated from the leaves of Daphniphyllum glaucescens, and the structures and relative stereochemistry were elucidated on the basis of spectroscopic data and chemical means. 相似文献
6.
Three new alkaloids, daphcalycinosidines A (1) and B (2) and daphcalycic acid (3) have been isolated from the seeds of Daphniphyllum calycinum. The structures and relative stereochemistries were determined on the basis of spectral studies including 2D NMR, mass spectrometry and chemical transformations. Structures 1 and 2 are characterized by an iridoid glucoside moiety linked to new Daphniphyllum alkaloid moieties. 相似文献
7.
An unusual yuzurine-type alkaloid daphnilongerine (1), with an unprecedented fused pentacyclic skeleton in addition to seven known ones, daphnigracine (2), daphnezomine R, daphnigraciline, yuzurine, longistylumphyllines A, daphnilongeranin C, and calycinine A, was isolated from the fruits of Daphniphyllum longeracemosum. The structure and relative stereochemistry of 1 were determined by spectroscopic analysis. 相似文献
8.
Shizuka Saito 《Tetrahedron letters》2007,48(22):3809-3812
Two new Daphniphyllum alkaloids, calyciphyllines E (1) and F (2), have been isolated from the leaves of Daphniphyllum calycinum (Daphniphyllaceae), and the structures and relative stereochemistry were elucidated on the basis of spectroscopic data. 相似文献
9.
Six new Daphniphyllum alkaloids, calyciphyllines H-M (1-6), were isolated from the leaves and stems of Daphniphyllum calycinum (Daphniphyllaceae). The structures and relative stereochemistry of 1-6 were elucidated on the basis of spectroscopic data, and the absolute stereochemistry of 3 was assigned by PGME method. 相似文献
10.
Zha-Jun Zhan 《Tetrahedron》2005,61(46):11038-11045
Six new Daphniphyllum alkaloids, namely caldaphnidines A-F (1-6), together with eight known ones, deoxycalyciphylline B, deoxyisocalyciphylline B, bukittiggine, calycicine A, methyl homosecodaphniphyllate, daphnilactone B, and daphnezomines L-M, were isolated from the leaves and the seeds of Daphniphyllum calycinum. The structure of 1 was determined by a single-crystal X-ray diffraction study, and the structures of 2-6 were established by spectral methods, especially two-dimensional NMR techniques (1H-1H COSY, HMQC, HMBC, and NOESY). 相似文献
11.
Yusuke Hirasawa Yuri Kato Chin Piow Wong Nahoko Uchiyama Yukihiro Goda A. Hamid A. Hadi Hapipah Mohd Ali Hiroshi Morita 《Tetrahedron letters》2014
A novel C16N2-type Lycopodium alkaloid consisting of a quinolizidine with a 6-dimethylaminohexyl side chain, hupermine A (1), was isolated from the club moss of Huperzia phlegmaria, and the structure and relative stereochemistry were elucidated on the basis of spectroscopic data. 相似文献
12.
Mariana G. Vallejo Maria Gabriela OrtegaJosé L. Cabrera Alicia Mariel Agnese 《Tetrahedron letters》2013
The present study describes the isolation and identification of N-demethyl-sauroxine, a novel Lycopodium alkaloid obtained from Huperzia saururus (Lam.) Trevis. (Lycopodiaceae). Its structure and relative stereochemistry were elucidated on the basis of its spectral data and chemical correlations. Additionally, acetylcholinesterase inhibitory activity was evaluated (IC50 = 209.6 ± 1.1 μM). The structure of the already identified alkaloid sauroxine was also re-validated through two dimensional NMR data. 相似文献
13.
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
14.
Michelle S. LiberioDhanya Sooraj Elizabeth D. WilliamsYunjiang Feng Rohan A. Davis 《Tetrahedron letters》2011,52(50):6729-6731
Chemical investigation of the CH2Cl2/MeOH extract from the Australian ascidian Leptoclinideskingi led to the isolation of a new brominated indole alkaloid, kingamide A (1). The planar structure of kingamide A was elucidated following the interpretation of 1D/2D NMR and MS data, and the absolute configuration was determined using Marfey’s method. This is the first report of a natural product from L. kingi. 相似文献
15.
Yumiko NagasawaHikaru Kato Henki Rotinsulu Remy E.P. MangindaanNicole J. de Voogd Sachiko Tsukamoto 《Tetrahedron letters》2011,52(41):5342-5344
Spironaamidine (1), a unique spiroquinone-containing alkaloid, was isolated from the marine sponge, Leucetta microraphis, along with two known imidazole alkaloids, naamidine H (2) and (9E)-clathridine 9-N-(2-sulfoethyl)imine (3). Spironaamidine (1) showed antimicrobial activity against Bacillus cereus. 相似文献
16.
A novel ergosterol conjunction-type alkaloid, hericirine (1), was isolated from the dried fruiting bodies of Hericium erinaceum. The overall framework of 1 was isolated, and combined with hericerin and ergosterol. Its structure was elucidated based on spectroscopic analysis using 1D and 2D NMR, IR and HRESIMS techniques. We found that hericirine significantly inhibited protein expression of iNOS and COX-2 and reduced NO, PGE2, TNF-α, IL-6 and IL-1β production in RAW264.7 cells exposed to LPS. 相似文献
17.
Cochinchistemonine (1), an alkaloid with a novel skeleton, was isolated from the roots of Stemona cochinchinensis collected from northern Vietnam. Its structure was established on the basis of one- and two-dimensional NMR and other spectroscopic studies. The relative configuration was confirmed by single crystal X-ray diffraction experiment. 相似文献
18.
Xiao-Lan Hu Xi-Qing Bian Xin Wu Jian-Yong Li Hui-Ming Hua Yue-Hu Pei Ai-Hong Han Jiao Bai 《Tetrahedron letters》2014
Penioxalamine A (1), a novel prenylated spiro-oxindole alkaloid having a unique seven-membered nitrogen heterocycle system, was isolated from the fungus Penicillium oxalicum TW01-1. The structure of 1 was elucidated on the basis of the spectral data, single-crystal X-ray diffraction, and CD analysis. Compound 1 showed moderate cytotoxicity against HL-60 cell line. The possible biosynthetic pathway of 1 was also proposed. 相似文献
19.
Xian-Wen Yang Lin Feng Jun-Mian Tian Xiao-Hua Liu Juan Su Wei-Dong Zhang 《Tetrahedron letters》2008,49(19):3042-3044
A novel biflavanol with unique six connective hexacyclic rings, abiesanol A (1), was isolated from the aerial parts of Abies georgei together with four known flavanols. The structure of new compound was elucidated mainly by the analysis of 1D and 2D NMR spectroscopic data. In addition, single-crystal X-ray diffraction analysis was adopted to confirm the structure of abiesanol A (1). In biological assay for inhibitory activities against LPS-induced nitric oxide (NO) production in RAW264.7 macrophages, abiesanol A (1) showed potent effects at 50 μg/mL with the inhibition rate of 43.0%. Under the same concentration, abiesanol A (1) did not show any cytotoxicity against RAW264.7 macrophages. 相似文献
20.
Lay-Kien YangRobert P. Glover K. YoganathanJayant P. Sarnaik Archana J. GodboleDoel D. Soejarto Antony D. BussMark S. Butler 《Tetrahedron letters》2003,44(31):5827-5829
A novel naphthylisoquinoline alkaloid, ancisheynine 1, was isolated from the aerial part of Ancistrocladus heyneanus Wallich ex J. Graham (Ancistrocladaceae). Ancisheynine 1 contained a previously undescribed N-2,C-8′-linkage between the isoquinoline and naphthalene units and its structure was established by spectroscopic methods. 相似文献