First Total Synthesis of the 2,7‐Naphthyridine Alkaloids Lophocladine A and B

Lotter, Matthias; Schilling, Johannes; Reimann, Eberhard; Bracher, Franz

doi:10.1002/ardp.200600134

Cited by 13 publications

(11 citation statements)

References 16 publications

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“…Moreover, the analyses of lophocladine B 52 effects on cellular microtubes and actin filaments in A-10 cells (used as vascular smooth muscle cells model) showed that this metabolite acts as microtubules inhibitor with no loss of actin filament [ 153 ]. In the same year Lotter et al reported that lophocladine B 52 is also able to inhibit human leukemia cells (HL-60) (IC 50 = 1 µM) [ 155 ].…”

Section: Secondary Metabolites From Seaweeds With In Vitro Cytotoxmentioning

confidence: 99%

“…The well-known potential of the antitubulin compounds as effective anticancer agents, for example taxol and vincristine, spread the interest of the scientific community in the synthesis of lophocladine B 52 or derivatives, seeking new and more potent antitumor agents and/or structure activity relationship studies [ 155 , 156 , 157 , 158 ]. To date, only two of the synthesized compounds (simplified isoquinolines isoquinoline-triazole derivatives) exhibit better cytotoxicity (IC 50 = 10.14 and 12.76 µM) than lophocladine B 52 against hepatic cancer (HepG2) and cervical cancer (HeLa) cell lines (IC 50 = 89.5 and >100 µM) [ 158 ].…”

Section: Secondary Metabolites From Seaweeds With In Vitro Cytotoxmentioning

confidence: 99%

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Seaweed Secondary Metabolites In Vitro and In Vivo Anticancer Activity

2018

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Isolation, finding or discovery of novel anticancer agents is very important for cancer treatment, and seaweeds are one of the largest producers of chemically active metabolites with valuable cytotoxic properties, and therefore can be used as new chemotherapeutic agents or source of inspiration to develop new ones. Identification of the more potent and selective anticancer components isolated from brown, green and red seaweeds, as well as studies of their mode of action is very attractive and constitute a small but relevant progress for pharmacological applications. Several researchers have carried out in vitro and in vivo studies in various cell lines and have disclosed the active metabolites among the terpenoids, including carotenoids, polyphenols and alkaloids that can be found in seaweeds. In this review the type of metabolites and their cytotoxic or antiproliferative effects will be discussed additionally their mode of action, structure-activity relationship and selectivity will also be revealed. The diterpene dictyolactone, the sterol cholest-5-en-3β,7α-diol and the halogenated monoterpene halomon are among the reported compounds, the ones that present sub-micromolar cytotoxicity. Additionally, one dimeric sesquiterpene of the cyclolaurane-type, three bromophenols and one halogenated monoterpene should be emphasized because they exhibit half maximal inhibitory concentration (IC50) values between 1–5 µM against several cell lines.

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Section: Secondary Metabolites From Seaweeds With In Vitro Cytotoxmentioning

confidence: 99%

Section: Secondary Metabolites From Seaweeds With In Vitro Cytotoxmentioning

confidence: 99%

Seaweed Secondary Metabolites In Vitro and In Vivo Anticancer Activity

2018

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“…The annulation of the bromopyridine ring (ring E of the pyridoacridines) was accomplished in a two‐step protocol. In analogy to our total syntheses of the alkaloids perlolidine 21 and lophocladine A 29, heating of 9 with dimethylformamide diethylacetal converted the acidic methyl group at C‐4 to an enamine, which was directly cyclized to the benzo[c][2,7]naphthyridin‐4‐one 10 upon heating with conc. sulfuric acid/acetic acid.…”

Section: Resultsmentioning

confidence: 99%

A Novel Approach to the Pyridoacridine Ring System: Synthesis of the Topoisomerase Inhibitor 13‐Deazaascididemin

Raeder

Bracher

2012

Archiv der Pharmazie

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A novel approach to the pyridoacridine ring system of the ascididemin-type marine alkaloids is presented. This approach allows for the introduction of the ring A of the alkaloids by using a simple aromatic aldehyde building block. The viability of this approach is demonstrated with the synthesis of AK37, a bioactive deaza analogue of the alkaloid ascididemin. Starting from 3-cyano-4-methylquinoline, a sequence of regioselective homolytic benzoylation, annulation of a bromopyridine ring, and radical cyclization leads to the pentacyclic ring system.

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“…Alkaloids containing the 2,7‐naphthyridine scaffold have been isolated from different kinds of living organisms. Many of these natural alkaloids show anticancer , antiviral , antifungal , and antimalarial activity. Recently, researchers have tried to obtain new 2,7‐naphthyridine derivatives, also by the synthetic route.…”

Section: Introductionmentioning

confidence: 99%

“…IR spectra were performed on a Specord M80 spectrometer (Zeiss/Analytic Jena, Germany) using KBr pellets. 1 H NMR spectra were recorded in DMSO-d6 with a Bruker Avance ARX-300 MHz spectrometer (Bruker Analytic, Karlsruhe, Germany) with tetramethylsilane as the internal standard. The new products were analyzed using a Perkin Elmer 2400 analyzer (Waltham, MA, USA).…”

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confidence: 99%

Synthesis andIn vitroAntitumor Screening of Novel 2,7-Naphthyridine-3-carboxylic Acid Derivatives

Wójcicka

Wagner

Dryś

et al. 2013

J. Heterocyclic Chem.

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New derivatives of 2,7‐naphthyridine‐3‐carboxylic acid were synthesized. We report the hydrolysis, chlorination, alkylation, and amination of the 2,7‐naphthyridine esters 1, 2. A series of Schiff's bases 8a, 8b, 8c, 8d, 8e, 8f, 8g, 8h, 8i, 8j, 9a, 9b, 9b', 9c, 9d, 9e were produced by treating the obtained hydrazides 6 and 7 with aromatic aldehydes. The anticancer activities of the obtained derivatives were examined. Eighteen of the 24 newly synthesized compounds were qualified by the National Cancer Institute NCI (Bethesda, MD, USA) for in vitro screening against 60 different human tumor cell lines. The most active compound 8i was evaluated against a 60‐cell panel at five concentration levels and proved to be most sensitive towards central nervous system cancer (SF‐539), with GI50 = 0.70 µmol, total growth inhibition = 5.41 µmol, and LC50 = 53.7 µmol.

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First Total Synthesis of the 2,7‐Naphthyridine Alkaloids Lophocladine A and B

Abstract: The one-pot reaction of 4-benzylpyridine-3-carbonitrile with Bredereck's reagent and subsequent treatment with either glacial acetic acid and sulfuric acid or ammonium acetate provided the new bioactive naphthyridine alkaloids lophocladine A and B, respectively.

Cited by 13 publications

References 16 publications

Seaweed Secondary Metabolites In Vitro and In Vivo Anticancer Activity

Seaweed Secondary Metabolites In Vitro and In Vivo Anticancer Activity

A Novel Approach to the Pyridoacridine Ring System: Synthesis of the Topoisomerase Inhibitor 13‐Deazaascididemin

Synthesis andIn vitroAntitumor Screening of Novel 2,7-Naphthyridine-3-carboxylic Acid Derivatives

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