共查询到20条相似文献,搜索用时 15 毫秒
1.
Mariko Kitajima Satoko Ohara Noriyuki Kogure Dammrong Santiarworn Hiromitsu Takayama 《Tetrahedron》2013
Six new β-carboline-type indole alkaloid glycosides, ophiorrhisides A–F (1–6), were isolated from Ophiorrhiza trichocarpon (Rubiaceae) collected in Thailand. Ophiorrhisides A (1) and B (2) possess a lactam function in the C ring and a unique biose residue in the molecule. Ophiorrhiside F (6) has a highly oxidized C ring with a 1,2-dicarbonyl function at C-5 and C-6 positions as well as a double bond between C-3 and C-14. 相似文献
2.
3.
Kitajima M Hashimoto K Yokoya M Takayama H Aimi N Sakai SI 《Chemical & pharmaceutical bulletin》2000,48(10):1410-1412
A new gluco indole alkaloid, 3,4-dehydro-5-carboxystrictosidine, was obtained from Peruvian U?a de Gato (Cat's Claw, original plant: Uncaria tomentosa) together with two known gluco indole alkaloids. This compound was the first example of isolation of a gluco monoterpenoid indole alkaloid having a 3,4-dihydro-beta-carboline ring system from nature. A characteristic feature of the compound was the quick replacement of the methylene hydrogens on C-14 with deuterium that was observed when it was dissolved in CD3OD. We demonstrated a similar proton-deuterium exchange on a model compound, 1-methyl-3,4-dihydro-gamma-carboline, in CD3OD solution. 相似文献
4.
A new alkaloid from Stemona sessilifolia 总被引:1,自引:0,他引:1
Peng Wang Hai Lin Qin Zhi Hong Li Ai Lin Liu Guan Hua Du Institute of Materia Medica Chinese Academy of Medical Sciences & Peking Union Medical College Beijing China 《中国化学快报》2007,18(2):152-154
A new alkaloid, named sessilistemonamine D, was isolated from the roots of Stemona sessilifolia and the structure and relative configuration were determined on the basis of NMR and MS spectrometric data analysis. 相似文献
5.
Two new indole alkaloids,4-oxo-4,12-dihydroindolo[2,3-a]quinolizine-3-carbaldehyde(1)and 1,6,7-trihydro-indolo-[2,3- a]furan[3,4-g]quinolizine-3,4(13H)-dione(2),were isolated from Nauclea officinalis.Their structures were determined on the basis of 1D and 2D NMR spectral data. 相似文献
6.
A new alkaloid, named 6-(2',3'-dihydroxy-4'-hydroxymethyl-tetrahydro-furan-1'-yl)cyclopentadiene[c]pyrrole-1,3-diol, was isolated from the seeds of Castanea mollissima Blume. The structure was elucidated based on spectroscopic evidence including 2D NMR techniques. 相似文献
7.
Adam Shih-Yuan Lee Yu-Chi Wu Yu-Ting Chang Bo-Cheng Wang 《Research on Chemical Intermediates》2014,40(6):2277-2285
A one-pot Lewis acid-promoted reaction condition of β,γ-unsaturated ketone with indole was developed for the synthesis of 3-substituted indoles with moderate to good yields. A Lewis acid such as AlCl3 was shown to be a promising promoter for in situ isomerization of β,γ-unsaturated ketone to its corresponding α,β-unsaturated ketone, then undergoing Friedel–Crafts Michael addition reaction with indole to afford 3-substituted indole. 相似文献
8.
Zhengxi Hu Jianping Wang Xiaobin Bi Jinwen Zhang Yongbo Xue Yingda Yang Zengwei Luo Guangmin Yao Yonghui Zhang 《Tetrahedron letters》2014
Chemical investigations on the EtOAc extract of the cultures of Colletotrichum capsici afforded a novel indole–pyrazine alkaloid embodying a structurally unique C16N3-type skeleton, colletotrichumine A (1), together with five known steroids (2–6). Their structures were elucidated by spectroscopic analysis and that of 1 was further confirmed by a single-crystal X-ray diffraction method. The plausible biogenetic pathway of 1 was also discussed. 相似文献
9.
A simple route to 7‐formyl‐indole (5) is described in which appropriately functionalized o‐nitrotoluenes (1) are converted to 7‐hydroxymethyl‐indole (4) using the Batcho–Leimgruber process. Condensation of 3‐methyl‐2‐nitrobenzyl alcohol (1a) with N,N‐dimethylformamide dimethyl acetal yields the enamine 2a, which upon catalytic hydrogenation affords 4 in 22% yield. When the hydroxyl function in 1 is protected with pivaloyl or tetrahydropyranyl group, the yields of 4 are increased to 39% and 48%, respectively. Finally, 4 is oxidized with pyridinium chlorochromate (PCC) to afford 5 in 86% yield. 相似文献
10.
《Tetrahedron》2014,70(51):9709-9717
We report herein a method that allows for the formation of a C–N bond between the C–3 carbon of α-lactams and the nitrogen atom of indoles. A general procedure for the coupling of indoles and α-lactams in only 25 min with high yield is reported. The scope of the reaction was extended by the development of a method for the in situ generation of less stable phenyl-substituted α-lactams. The developed method provides an atom-economical method for the formation of substituted α-amino amides that are found in a variety of biologically-active compounds. 相似文献
11.
Pradeep K. Jaiswal Vashundhra Sharma Jaroslav Prikhodko Irina V. Mashevskaya Sandeep Chaudhary 《Tetrahedron letters》2017,58(22):2077-2083
For the first time, an efficient, simple, synthetic green protocol for the one-pot synthesis of functionalized 2-oxo-benzo[1,4]oxazines 24–29 in water under ultrasound irradiation is presented. As compared to conventional methods, the present protocol avoids traditional chromatography and purification steps and furnished the target molecules in excellent yields (upto 98%) with no side products. The methodology was also demonstrated on gram scale synthesis. Moreover, functionalized 2-oxo-quinoxaline analogues 31–33, another class of bio-active heterocyclic scaffolds, were also prepared using this method. For the first time, this protocol was successfully applied in the synthesis of the anticancer indole alkaloid, Cephalandole A 35. 相似文献
12.
N. N. Karpyshev A. G. Tolstikov O. V. Tolstikova O. D. Yakovleva V. S. Shmakov 《Russian Chemical Bulletin》2000,49(3):569-570
The scalemic form of active alkaloid (−)-dipthocarpamine was synthesized by asymmetric oxidation ofN-isopropyl-N′-(methylthiohexyl)urea with hydrogen peroxide in the presence of vanadium(IV) complexes with chiral Shiff's bases.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 564–565, March, 2000. 相似文献
13.
Ashok K. Varma Ashwini Nangia Gautam R. Desiraju Venkatachalam S. Giri Parasuraman Jaisankar 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(1):97-99
3-Acetyl-1,6,7,12b-tetrahydroindolo[2,3-a]quinolizin-2(12H)-one, C17H16N2O2, consists of two symmetry-independent molecules and each forms a layered structure stabilized by N—H⃛O and C—H⃛O hydrogen bonds. In 3-acetyl-6,7-dihydroindolo[2,3-a]quinolizin-4(12H)-one monohydrate, C17H14N2O2·H2O, the structure is stabilized by O—H⃛O, N—H⃛O and C—H⃛O hydrogen bonds, with the ordered water molecule playing a crucial role in the self-assembly. Contribution from the weak interactions to the strong hydrogen-bonded network is a common feature in both structures. 相似文献
14.
Koichiro Koyama Yusuke Hirasawa Alfarius E. Nugroho Toshio Kaneda Teh Chin Hoe Kit-Lam Chan Hiroshi Morita 《Tetrahedron》2012,68(5):1502-1506
Three novel indole alkaloids, alsmaphorazines C (1)–E (3), were isolated from the leaves of Alstonia pneumatophora (Apocynaceae) and their structures were determined on the basis of the 2D NMR and MS spectral analyses. The absolute configurations of 1 and 3 were elucidated by applying a modified Mosher’s method and CD spectral analysis. These alkaloids possessed novel ring skeletons containing an octahydropyrrolo[2,3-b]pyrrole unit. 相似文献
15.
Tetsuro Fujita 《中国化学快报》2007,18(2):175-177
A new highly conjugated alkaloid of veratramine type, 225,25S,5α-veratramine-7(8),12(14)-diene-3β,13β,23β-triol-6-one (1), was isolated from the bulbs of Fritillaria hupehensis Hsiao et K.C. Hsia. Its structure was determined on the basis of spectroscopic evidences. 相似文献
16.
Ren-Wang Jiang Shuang-Cheng Ma Paul P. H. But Hui Dong Thomas C. W. Mak 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(2):170-171
In the title compound, 3,20-dihydroxycevan-6-one, C27H43NO3, all the six-membered rings have normal chair conformations except ring D, which exists in a twist-chair conformation. The five-membered ring C adopts an envelope conformation. An O—H⃛O hydrogen bond connects the molecules into spirals, which run along the b-axis direction. 相似文献
17.
van den Broek SA Lemmers JG van Delft FL Rutjes FP 《Organic & biomolecular chemistry》2012,10(5):945-951
A novel approach to a formal total synthesis of the monoterpenoid indole alkaloid (±)-tangutorine has been developed starting from an α,β-unsaturated cyclic dehydroamino ester. Synthesis of the rather unusual trans-substituted 2,3-indoloquinolizidine substructure was accomplished via Cu(II)-mediated conjugate addition and organozinc/copper coupling as the key steps, thereby setting the stage for ring-closing metathesis to produce the quinolone substructure. Finally, Bischler-Napieralski cyclization gave rise to the pentacyclic system of (±)-tangutorine thereby realizing a formal synthesis in an overall yield of 5.2% in eight consecutive steps. 相似文献
18.
M. S. Yunusov E. M. Tsyrlina E. D. Khairitdinova L. V. Spirikhin A. Yu. Kovalevsky M. Yu. Antipin 《Russian Chemical Bulletin》2000,49(9):1629-1633
A new alkaloid, anhydrolycaconitine (C36H46N2O9), was isolated from roots ofAconitum septentrionale K. Based on the results of1H and13C NMR and IR spectroscopy and mass spectrometry of the alkaloid and the product of its alkaline hydrolysis and on the data
of X-ray diffraction analysis of the hydrolysis product, the structure of 1α, 6β, 14α, 16β-tetramethoxy-7-oxo-18-succinylanthranoyloxy-17-(7→8)abeo-aconane was assigned to anhydrolycaconitine.
Published inIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1640–1644, September, 2000. 相似文献
19.
Mariana G. Vallejo Marcos E. Corzo María Gabriela Ortega 《Natural product research》2020,34(9):1270-1275
Abstract12α-hydroxy-N-demethyl-sauroxine (1), another new Lycopodium alkaloid from the Lycodane group, was isolated from Phlegmariurus saururus (Lam.) B. Øllg. (Lycopodiaceae). Elucidation of the chemical structure and relative stereochemistry were stated by spectroscopic data and chemical correlation. In addition, the inhibitory activity on acetylcholinesterase for 1 was determined as well as for N-methyllycodine (2), a derivative with the same nucleus, previously identified in P. saururus (IC50 = 33.8?±?0.8?μM and 547.5?±?0.5?μM, respectively) and N-demethylsauroxine (3) whose inhibition in the actual conditions was better than the previously informed. 相似文献
20.
A. Karimov M. F. Faskhutdinov N. D. Abdullaev M. G. Levkovich E. G. Mil'grom Ya V. Rashkes R. Shakirov 《Chemistry of Natural Compounds》1993,29(6):774-777
Berberine, palmatine, jatrorrhizine, oxyacanthine, berbamine, reticuline, obaberine, isocorydine, thalicmidine, and the new base berberal (I) have been isolated from leaves and young shoots ofBerberis heterobotrys Wolf. The structure of berberal has been established by a study of its1H and13C NMR spectra and measurement of intramolecular NOEs, and also by mass-spectrometric analysis. 相似文献