Polycyclic Aromatic Alkaloids Research Articles

A GC-MS Protocol for the Identification of Polycyclic Aromatic Alkaloids from Annonaceae.

The Annonaceae are an old family of flowering plants belonging to the order Magnoliales, distributed mainly in tropical regions. Numerous Annonaceae species find ethnobotanical use for curing a broad range of diseases, among them cancer and infections by diverse pathogens. Hence, bioactive natural products from Annonaceae have received considerable interest in drug development. Beyond cytotoxic acetogenins, unique aporphine-derived polycyclic aromatic alkaloids are characteristic constituents of Annonaceae. Among them are unique tri- and tetracyclic aromatic alkaloids like azafluorenones, diazafluoranthenes, azaanthracenes, and azaoxoaporphines. The complex substitution pattern of these alkaloids represents a major challenge in structure elucidation of isolated natural products. Based on a broad spectrum of alkaloids available from our previous work, we present a GC-MS protocol for the identification of over 20 polycyclic aromatic alkaloids from Annonaceae. This collection of data will contribute to the future identification of the metabolite patterns of extracts from Annonaceae as an important source of novel bioactive secondary metabolites.

New Perspectives in the Chemistry of Marine Pyridoacridine Alkaloids.

Secondary metabolites from marine organisms are a rich source of novel leads for drug development. Among these natural products, polycyclic aromatic alkaloids of the pyridoacridine type have attracted the highest attention as lead compounds for the development of novel anti-cancer and anti-infective drugs. Numerous sophisticated total syntheses of pyridoacridine alkaloids have been worked out, and many of them have also been extended to the synthesis of libraries of analogues of the alkaloids. This review summarizes the progress in the chemistry of pyridoacridine alkaloids that was made in the last one-and-a-half decades.

ChemInform Abstract: Polycyclic Aromatic Alkaloids. Part 6. A Regioselective Synthesis of Azafluorenone Alkaloids.

ChemInform Abstract: Polycyclic Aromatic Alkaloids. Part 6. A Regioselective Synthesis of Azafluorenone Alkaloids.

ChemInform Abstract: Two New Polycyclic Aromatic Alkaloids from the Okinawan Marine Sponge Biemna sp.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Mechanism of ascididemin-induced cytotoxicity.

Some marine animals are rich sources of unique polycyclic aromatic alkaloids that are cytotoxic against tumor cell lines and effective in mouse tumor xenograft models. Ascididemin is a pyridoacridine alkaloid originally derived from a Didemnum sp. tunicate. It has potent cytotoxicity against tumor cells in vitro and in vivo. Preclinical screening at NCI revealed the antineoplastic activities of ascididemin and a synthetic analogue 48. Ascididemin has been reported to inhibit topoisomerase II and induce topoisomerase II-mediated DNA cleavage. This study, however, focuses on the unique ability of ascididemin and two synthetic analogues (48 and 109) to cleave DNA in the absence of topoisomerase I or II. An in vitro assay revealed their concentration-dependent ability to cleave DNA and identified dithiothreitol as the sole requirement for maximal activity. On the basis of shared structural features of the three analogues, a double N-bay region and iminoquinone heterocyclic ring, two possible mechanisms of action were hypothesized: (1) generation of reactive oxygen species facilitated by metal binding to the common phenanthroline bay region, and (2) production of reactive oxygen species by direct reduction of the iminoquinone moiety. Experimental results supported direct iminoquinone reduction and ROS generation as the mechanism of ascididemin cytotoxicity. Antioxidants protected against DNA cleavage in vitro and protected cultured Chinese hamster ovary cells from toxicity. Additionally, it was shown that cells deficient in the ability to repair reactive oxygen species damage to their DNA were more susceptible to ascididemin and analogues than repair competent cells. Ascididemin-treated cells were also shown to induce oxygen-stress related proteins, further implicating the production of reactive oxygen species as the mechanism of cytotoxicity for these molecules.

ChemInform Abstract: Polycyclic Aromatic Alkaloids. Part 10. Annonaceous Alkaloids with Antifungal Activity.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform Abstract: Polycyclic Aromatic Alkaloids. Part 8. The Structure of Neocalliactine Acetate ‐ Proof by Total Synthesis.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Two new polycyclic aromatic alkaloids from the Okinawan marine sponge Biemna sp.

Two new polycyclic aromatic alkaloids, biemnadin ( 1) and 8,9-dihydro-11-hydroxyascididemin ( 2), have been isolated from the Okinawan marine sponge Biemna sp. The X-ray diffraction analysis of 1 has established its octacyclic structure and the structure of 2 elucidated on the basis of extensive spectroscopic and chemical studies.

Polycyclic Aromatic Alkaloids, 8. The Structure of Neocalliactine Acetate — Proof by Total Synthesis

AbstractThe pentacyclic compound 1 is prepared in six steps by starting from 5,8‐quinolinedione (7). Its spectral data are in accordance with those of neocalliactine acetate, a derivative or the marine alkaloid calliactine. This represents the first definite confirmation of the structure of neocalliactine acetate.

ChemInform Abstract: Biologically Active Compounds from Marine Organisms

In our search for cytotoxic compounds from marine animals we have isolated representatives from various classes of nitrogen-containing compounds, most of which show cytotoxic activity. Structure elucidation of these compounds is discussed. Included among the isolates are new acylated spermidines, polycyclic aromatic alkaloids related to amphimedine and 2-bromoleptoclinidinone, and a representative of a novel sulfur containing 3,5,8-isoquinolinetrione.

Polycyclische Aromatische Alkaloide, V. Synthese von 2‐Bromleptoclinidinon

Polycyclic Aromatic Alkaloids, V. – Synthesis of 2‐Bromoleptoclinidinone4‐Bromo‐2‐nitroacetophenone (6) is selectively reduced to the amine 7 by Fe in aqueous acetic acid. Oxidative amination of quinolinequinone 8 with 7 gives 9. Acid‐catalyzed cyclization of 9, followed by anellation of a pyridine ring, gives the cytotoxic pentacyclic alkaloid 2‐bromoleptoclinidinone (3).

ChemInform Abstract: Polycyclic Aromatic Alkaloids. Part 3. Synthesis of Perlolidine.

ChemInformVolume 21, Issue 2 Natural Products ChemInform Abstract: Polycyclic Aromatic Alkaloids. Part 3. Synthesis of Perlolidine. F. BRACHER, F. BRACHER Inst. Pharm. Chem., Philipps-Univ., D-3550 Marburg/LahnSearch for more papers by this author F. BRACHER, F. BRACHER Inst. Pharm. Chem., Philipps-Univ., D-3550 Marburg/LahnSearch for more papers by this author First published: January 9, 1990 https://doi.org/10.1002/chin.199002318Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume21, Issue2January 9, 1990 RelatedInformation

Biologically active compounds from marine organisms

Abstract

ChemInform Abstract: Polycyclic Aromatic Alkaloids. Part 2. Synthesis of Onychine and Eupolauridine.

AbstractThe benzoylacetic ester (II) reacts with crotonaldehyde (I) in the presence of hydroxylamine hydrochloride (III) to give the phenylpyridinecarboxylate (IV).

ChemInform Abstract: Polycyclic Aromatic Alkaloids. Part 1. Synthesis of Cleistopholine and Sampangine.

AbstractCleistopholine (III), an alkaloid from Cleistopholis patens, is prepared in a one‐pot synthesis as shown thus proving that dimethylhydrazones of type (II) can be used as azadienes.

Polycyclische aromatische Alkaloide, I. Synthese von Cleistopholin und Sampangin

Polycyclic Aromatic Alkaloids, I. ‐ Synthesis of Cleistopholine and SampangineCleistopholine (4) is prepared in a one‐pot synthesis by Diels‐Alder cycloaddition of 1 to 2, followed by thermal elimination of dimethylamine. Reaction of 4 with tripiperidinomethane or dimethylformamide diethyl acetal yields the enamines 5a/5b, which, without further purification, give sampangine (6) on heating with ammonium chloride in glacial acetic acid.