Showing papers on "Indole alkaloid published in 2008"
TL;DR: The first total synthesis of (+/-)-psychotrimine, a novel trimeric indole alkaloid isolated from Psychotria rostrata, was achieved.
95 citations
TL;DR: Two new isomeric alkaloids were isolated from the CHCl3 extract of the leaves of Uncaria rhynchophylla and exhibited inhibitory activity on lipopolysaccharide (LPS)-induced NO release in primary cultured rat cortical microglia.
Abstract: Two new isomeric alkaloids, 18,19-dehydrocorynoxinic acid B (1) and 18,19-dehydrocorynoxinic acid (2), were isolated from the CHCl3 extract of the leaves of Uncaria rhynchophylla, together with four known rhynchophylline-type alkaloids, corynoxeine (3), isocorynoxeine (4), rhynchophylline (5), and isorhynchophylline (6), and an indole alkaloid glucoside, vincoside lactam (7). The structures of compounds 1 and 2 were elucidated by spectroscopic methods including UV, IR, HREIMS, 1D and 2D NMR, and CD experiments. The activity assay showed that compounds 3-6, with a C-16 carboxylic ester group, and 7 exhibited inhibitory activity on lipopolysaccharide (LPS)-induced NO release in primary cultured rat cortical microglia (IC 50: 13.7-19.0 microM). However, only weak inhibitory activity was observed for compounds 1 and 2, with a C-16 carboxylic acid group (IC 50: >100 microM).
81 citations
TL;DR: Compound 1 is a new monoterpenoid indole alkaloid of Yunnan local medicinal plants Alstonia scholaris, and is reported to be the first of its kind in the world.
39 citations
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TL;DR: Examples of indole alkaloid N-oxides from simple indole bases to complex dimeric alkaloids are given and their toxicity, metabolism and role in the plant considered.
Abstract: 1. Naturally occurring alkaloid N-oxides are reviewed.2. Examples of indole alkaloid N-oxides from simple indole bases to complex dimeric alkaloids are given.3. Pyrrolizidine alkaloid N-oxides are listed and their toxicity, metabolism and role in the plant considered.4. A brief account of quinolizidine, piperidine and miscellaneous alkaloid N-oxides, together with nicotine N-oxide and N-oxides from micro-organisms, is given.
31 citations
TL;DR: In this paper, four gelsedine-type oxindole alkaloids (1, 2, 3 and 4) were isolated from the leaves and branches of Gelsemium elegans.
31 citations
TL;DR: Two new oxindole alkaloids, rankiniridine (1 ) and humanteniridine(2 ), having a nitrogen-carbon linkage between a humantene-type monoterpenoid indole alkaloid and a monoterpene unit with an iridoid skeleton, were isolated from Gelsemium rankinii and Gelsemia elegans, respectively as mentioned in this paper.
18 citations
TL;DR: The results demonstrate the high potential of the methodology for the synthesis of new pyrroloimidazoindole derivatives, which displayed moderate microM cytotoxicities in human cancer cell lines and at 10 microg/mL inhibited more than 50% EGFR or HIF-1alpha.
16 citations
TL;DR: A new indole alkaloid, 11,12‐dimethoxyhenningsamine, was isolated from the roots of Strychnos cathayensis, together with 19 known compounds and exhibited potent inhibition on superoxide‐anion generation and elastase release by human neutrophils in response to fMet‐Leu‐Phe/cytochalasin B.
Abstract: A new indole alkaloid, 11,12-dimethoxyhenningsamine (1), was isolated from the roots of Strychnos cathayensis, together with 19 known compounds. The structure of this new compound was determined through spectroscopic and mass-spectrometric analyses. Among the isolated compounds, 11-methoxyhenningsamine (3) and aesculetin dimethyl ether (4) exhibited potent inhibition (IC50<5.5 μg/ml) on superoxide-anion generation and elastase release by human neutrophils in response to fMet-Leu-Phe/cytochalasin B.
16 citations
TL;DR: The concise asymmetric total synthesis of evodiamine, an indole alkaloid in Evodia Fructus, was achieved by employing Noyori's ruthenium(II)-catalyzed asymmetric transfer hydrogenation as discussed by the authors.
Abstract: The concise asymmetric total synthesis of evodiamine, an indole alkaloid in Evodia Fructus, was achieved by employing Noyori's ruthenium(II)-catalyzed asymmetric transfer hydrogenation.
15 citations
TL;DR: A new alkaloid, kopreasin A, was isolated from the leaves of Kopsia arborea together with ten known indole alkaloids, and the structure was elucidated by NMR spectral analysis using 2D techniques.
Abstract: A new alkaloid, kopreasin A (1) was isolated from the leaves of Kopsia arborea (Apocynaceae) together with ten known indole alkaloids (2 - 11), and the structure was elucidated by NMR spectral analysis using 2D techniques. These indole alkaloids showed a moderate vasorelaxant activity on isolated rat aorta ring.
11 citations
TL;DR: In this paper, two new methyl chanofruticosinate-type indole alkaloids, flavisiamines E (1) and F (2), and an aspidofractinine-type INDO alkaloid, fruticosiamine A (3), were isolated from Kopsia flavida and K. fruticosa, respectively and their structures were elucidated by NMR spectral analysis using 2D techniques.
Abstract: Two new methyl chanofruticosinate-type indole alkaloids, flavisiamines E (1) and F (2), and an aspidofractinine-type indole alkaloid, fruticosiamine A (3), have been isolated from Kopsia flavida and K. fruticosa, respectively and their structures were elucidated by NMR spectral analysis using 2D techniques.
TL;DR: In this article, four new methyl chanofruticosinate-type alkaloids, flavisiamines A (1) ∼ D (4) have been isolated from Kopsia flavida (Apocynaceae) and their structures were elucidated by NMR spectral analysis using 2D techniques.
Abstract: Four new methyl chanofruticosinate-type alkaloids, flavisiamines A (1) ∼ D (4) have been isolated from Kopsia flavida (Apocynaceae) and their structures were elucidated by NMR spectral analysis using 2D techniques.
TL;DR: Results of a phytochemical study showed that the bark of all these plants contains β-carboline alkaloids and that the first four of them can be promising sources of β- carbohydrate alkaloid for the creation of drugs.
Abstract: We have studied the qualitative and quantitative composition of β-carboline indole alkaloids that have been isolated for the first time from bark of Hippophae rhamnoides L., Elaeagnus angustifolia L., E. orientalis L., E. umbellata Thunb., E. multiflora Thunb., and E. argentea Pursh. occurring in Russia. Results of a phytochemical study showed that the bark of all these plants contains β-carboline alkaloids and that the first four of them can be promising sources of β-carboline alkaloids for the creation of drugs.
TL;DR: Study on chemical constituents from the leaves of Kopsia singapurensis yielded a new indole alkaloid, singaporentine A, together with two known alkaloids, kopsifoline A and kopsininic acid.
Abstract: Study on chemical constituents from the leaves of Kopsia singapurensis (Apocynaceae) yielded a new indole alkaloid, singaporentine A (1) together with two known alkaloids, kopsifoline A (2) and kopsininic acid (3). The structure of 1 was elucidated by combination of various spectroscopic methods such as MS, UV, IR, 1D and 2D NMR. Singaporentine A exhibited cytotoxic activity against P388 murine leukemia cells.
TL;DR: Two new oxindole alkaloids, rankiniridine (1 ) and humanteniridine(2 ), having a nitrogen-carbon linkage between a humantene-type monoterpenoid indole alkaloid and a monoterpene unit with an iridoid skeleton, were isolated from Gelsemium rankinii and Gelsemia elegans, respectively as discussed by the authors.
Abstract: 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.
01 Jan 2008
TL;DR: Singaporentine A (1) as discussed by the authors is a new indole alkaloid from the leaves of Kopsia singapurensis (Apocynaceae) which has shown cytotoxic activity against P388 murine leukemia cells.
Abstract: – Study on chemical constituents from the leaves of Kopsia singapurensis (Apocynaceae) yielded a new indole alkaloid, singaporentine A ( 1 ) together with two known alkaloids, kopsifoline A ( 2 ) and kopsininic acid ( 3 ). The structure of 1 was elucidated by combination of various spectroscopic methods such as MS, UV, IR, 1D and 2D NMR. Singaporentine A exhibited cytotoxic activity against P388 murine leukemia cells. INTRODUCTION The genus Kopsia (Apocynaceae) comprises of 30 species which is native to China, India and Southeast Asia. 1-7 This genus is known to produce a large number of biologically active indole alkaloids possessing interesting skeletons. 1-7 Various medicinal uses have been reported; the roots of K. larutensis King & Gamble, K. macrophylla Hook f., K. singapurensis Ridl. and K. pauciflora Hook f. are used to treat poulticing ulcerated noses in tertiary syphilis 8 while K. officinalis Tsiang & Li is used in Chinese traditional medicine for rheumatoid arthritis, dropsy and tonsillitis.
TL;DR: The first total synthesis of (±)-psychotrimine, a novel trimeric indole alkaloid isolated from Psychotria rostrata, was achieved in this paper. But this synthesis was performed with a single tryptamine unit.
Abstract: The first total synthesis of (±)-psychotrimine, a novel trimeric indole alkaloid isolated from Psychotria rostrata, was achieved. In the total synthesis, the copper-mediated intramolecular and intermolecular aminations of halobenzenes, which respectively contributed to the construction of a pyrrolidinoindoline core and the installation of a third tryptamine unit, were used as key steps.
TL;DR: In this paper, four gelsedine-type oxindole alkaloids (1, 2, 3 and 4) were isolated from the leaves and branches of Gelsemium elegans.
Abstract: Four new gelsedine-type oxindole alkaloids (1–4) were isolated from the leaves and branches of Gelsemium elegans, together with 10 known alkaloids. The structures of the new alkaloids were determined by spectroscopic analyses and partial synthesis from known compounds. Gelsecrotonidine (1), 14-hydroxygelsecrotonidine (2), and 11-methoxygelsecrotonidine (3) possess an additional C2 unit with an acetic acid residue compared to gelsenicine-related monoterpenoid indole alkaloids. 14-Hydroxygelsedilam (4) is an 18,19-nor-type monoterpenoid indole alkaloid.